REFACTOR Moving around some code.

This places the parser in its own submodule so that we can be ready
for the next two or three phases of textual analysis.  Right now we
only scan for deliberate references, but the plan is to also scan
for explicit but incidental references, and then to go futher and
go the full tf-idf on the source.

.gitignore

@@ -0,0 +1,6 @@
+/target
+Cargo.lock
+*#
+.#*
+*~
+

Cargo.toml

@@ -0,0 +1,2 @@
+[workspace]
+members = ["server/*"]

server/Pipfile

@@ -0,0 +1,11 @@
+[[source]]
+url = "https://pypi.python.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+
+[dev-packages]
+
+[requires]
+python_version = "2.7"

server/nm-store/clippy.toml

@@ -0,0 +1 @@
+cognitive-complexity-threshold = 9

server/nm-store/docs/TODO.md

@@ -0,0 +1,5 @@
+[ ] Add RelationshipKind to Notes passed out
+[ ] Add KastenKind to Backreferences passed out
+[ ] Provide the array of note references (the 'cycle' manager) to make
+    mapping from Vec->Tree easier.
+	

server/nm-store/docs/content.md

@@ -0,0 +1 @@
+Content analysis 

server/nm-store/docs/thinking.md

@@ -0,0 +1,10 @@
+The thing of it is, we have two kinds of notes:
+
+1. This layer of the system will handle broken/missing position issues.
+2. The client layer of the system will ensure that a parent is provided.
+3. The notes retrieved via the CTE have information and parenting and
+   location.
+4. Notes put *into* the system have parent and location provided
+   separately.
+5. Clients do not specify the ids of notes put into the system.
+6. Retrieval by slug must test for is-a-box. 

server/nm-store/experiments/base.sql

@@ -7,34 +7,15 @@ DROP TABLE IF EXISTS favorites;
 CREATE TABLE notes (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
     uuid TEXT NOT NULL UNIQUE,
-    content TEXT NULL,
     notetype TEXT,
-	creation_date DATETIME NOT NULL,
-	updated_date DATETIME NOT NULL,
-	lastview_date DATETIME NOT NULL,
-	deleted_date DATETIME NULL
-);
-
-CREATE INDEX notes_uuids ON notes (uuid);
+)
 
 CREATE TABLE pages (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
-    title text NOT NULL UNIQUE,
     slug text NOT NULL UNIQUE,
     note_id INTEGER,
-	creation_date DATETIME NOT NULL,
-	updated_date DATETIME NOT NULL,
-	lastview_date DATETIME NOT NULL,
-	deleted_date DATETIME NULL,
     FOREIGN KEY (note_id) REFERENCES notes (id) ON DELETE NO ACTION ON UPDATE NO ACTION
-);
-
-CREATE INDEX pages_slugs ON pages (slug);
-
-CREATE TABLE favorites (
-    id INTEGER PRIMARY KEY AUTOINCREMENT,
-    position INTEGER NOT NULL
-);
+)
 
 CREATE TABLE note_relationships (
     note_id INTEGER NOT NULL,
@@ -51,3 +32,5 @@ CREATE TABLE page_relationships (
 	FOREIGN KEY (note_id) references notes (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
 	FOREIGN KEY (page_id) references pages (id) ON DELETE NO ACTION ON UPDATE NO ACTION
 );
+
+	

server/nm-store/experiments/demo_select_references.sql

@@ -0,0 +1,101 @@
+DROP TABLE IF EXISTS notes;
+DROP TABLE IF EXISTS note_relationships;
+DROP TABLE IF EXISTS pages;
+DROP TABLE IF EXISTS page_relationships;
+DROP TABLE IF EXISTS favorites;
+
+CREATE TABLE notes (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    uuid TEXT NOT NULL UNIQUE,
+    notetype TEXT
+);
+
+CREATE TABLE pages (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    slug text NOT NULL UNIQUE,
+    note_id INTEGER,
+    FOREIGN KEY (note_id) REFERENCES notes (id) ON DELETE NO ACTION ON UPDATE NO ACTION
+);
+
+CREATE TABLE note_relationships (
+    note_id INTEGER NOT NULL,
+    parent_id INTEGER NOT NULL,
+    position INTEGER NOT NULL,
+    nature TEXT NOT NULL,
+    FOREIGN KEY (note_id) REFERENCES notes (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+    FOREIGN KEY (parent_id) REFERENCES notes (id) ON DELETE NO ACTION ON UPDATE NO ACTION
+);
+
+CREATE TABLE page_relationships (
+    note_id INTEGER NOT NULL,
+	page_id INTEGER NOT NULL,
+	FOREIGN KEY (note_id) references notes (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+	FOREIGN KEY (page_id) references pages (id) ON DELETE NO ACTION ON UPDATE NO ACTION
+);
+
+INSERT INTO notes (id, uuid, notetype) VALUES
+	   (1, "U1", "root"),
+	   (2, "U2", "note"),
+	   (3, "U3", "note"),
+	   (4, "U4", "note"),
+	   (5, "U5", "note"),
+	   (6, "U6", "note"),
+	   (7, "U7", "note"),
+	   (8, "U8", "note");
+
+INSERT INTO note_relationships (note_id, parent_id, position, nature) VALUES
+	   (2, 1, 1, "note"),
+	   (3, 1, 2, "note"),
+	   (4, 3, 1, "note"),
+	   (5, 3, 2, "note"),
+	   (6, 5, 1, "note"),
+	   (7, 4, 1, "note"),
+	   (8, 7, 1, "note");
+
+
+SELECT id, uuid, parent_id, parent_uuid, notetype
+FROM (
+  WITH RECURSIVE parents (
+    id, uuid, parent_id, parent_uuid, notetype, cycle
+  )
+
+  AS (
+    SELECT notes.id, notes.uuid,
+	       note_parents.id,
+		   note_parents.uuid,
+		   notes.notetype,
+		   ','||notes.id||','
+      FROM notes
+	    INNER JOIN note_relationships
+		  ON notes.id = note_relationships.note_id
+		  AND notes.notetype = 'note'
+		INNER JOIN notes as note_parents
+		  ON note_parents.id = note_relationships.parent_id
+        WHERE notes.id = 4
+    
+    UNION
+	SELECT DISTINCT notes.id,
+		   notes.uuid,
+	       next_parent.id,
+		   next_parent.uuid,
+		   notes.notetype,
+           parents.cycle||notes.id||','
+      FROM notes
+      INNER JOIN parents
+	    ON parents.parent_id = notes.id
+	  LEFT JOIN note_relationships
+	    ON note_relationships.note_id = notes.id
+	  LEFT JOIN notes as next_parent
+	    ON next_parent.id = note_relationships.parent_id
+      WHERE parents.cycle NOT LIKE '%,'||notes.id||',%'
+  )
+
+  SELECT * FROM parents);
+
+-- Possible outcomes epending on the 'WHERE notes.id' clause in the root SELECT (first value is passed in):
+-- 8, 7, 4, 3, 1
+-- 6, 5, 3, 1
+-- 2, 1
+-- 4, 3, 1
+-- 1 should result in no return (root notes aren't returned by themselves; they exist only so that
+-- valid note reversals can find their parent page objects.

server/nm-store/experiments/demo_select_tree.sql

@@ -0,0 +1,88 @@
+DROP TABLE IF EXISTS notes;
+DROP TABLE IF EXISTS note_relationships;
+DROP TABLE IF EXISTS pages;
+DROP TABLE IF EXISTS page_relationships;
+DROP TABLE IF EXISTS favorites;
+
+CREATE TABLE notes (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    uuid TEXT NOT NULL UNIQUE,
+    notetype TEXT
+);
+
+CREATE TABLE pages (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    slug text NOT NULL UNIQUE,
+    note_id INTEGER,
+    FOREIGN KEY (note_id) REFERENCES notes (id) ON DELETE NO ACTION ON UPDATE NO ACTION
+);
+
+CREATE TABLE note_relationships (
+    note_id INTEGER NOT NULL,
+    parent_id INTEGER NOT NULL,
+    position INTEGER NOT NULL,
+    nature TEXT NOT NULL,
+    FOREIGN KEY (note_id) REFERENCES notes (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+    FOREIGN KEY (parent_id) REFERENCES notes (id) ON DELETE NO ACTION ON UPDATE NO ACTION
+);
+
+CREATE TABLE page_relationships (
+    note_id INTEGER NOT NULL,
+	page_id INTEGER NOT NULL,
+	FOREIGN KEY (note_id) references notes (id) ON DELETE NO ACTION ON UPDATE NO ACTION,
+	FOREIGN KEY (page_id) references pages (id) ON DELETE NO ACTION ON UPDATE NO ACTION
+);
+
+INSERT INTO notes (id, uuid, notetype) VALUES
+	   (1, "U1", "root"),
+	   (2, "U2", "note"),
+	   (3, "U3", "note"),
+	   (4, "U4", "note"),
+	   (5, "U5", "note"),
+	   (6, "U6", "note"),
+	   (7, "U7", "note"),
+	   (8, "U8", "note");
+
+INSERT INTO note_relationships (note_id, parent_id, position, nature) VALUES
+	   (2, 1, 1, "note"),
+	   (3, 1, 2, "note"),
+	   (4, 3, 1, "note"),
+	   (5, 3, 2, "note"),
+	   (6, 5, 1, "note"),
+	   (7, 4, 1, "note"),
+	   (8, 7, 1, "note");
+
+SELECT id, uuid, parent_id, parent_uuid, position, notetype
+FROM (
+  WITH RECURSIVE notetree (
+    id, uuid, parent_id, parent_uuid, position, notetype, cycle
+  )
+
+  AS (
+    SELECT notes.id, notes.uuid, 
+           notes.id AS parent_id, 
+           notes.uuid AS parent_uuid, 
+           0, notes.notetype, ','||notes.id||','
+      FROM notes
+      WHERE notes.id = 1 AND notes.notetype = "root"
+    
+    UNION
+	SELECT notes.id, notes.uuid, 
+           notetree.id AS parent_id, 
+           notetree.uuid AS parent_uuid,
+		   note_relationships.position,
+		   notes.notetype,
+		   notetree.cycle||notes.id||','
+      FROM notes
+	    INNER JOIN note_relationships
+		  ON notes.id = note_relationships.note_id
+		INNER JOIN notetree
+		  ON note_relationships.parent_id = notetree.id
+        WHERE notetree.cycle NOT LIKE '%,'||notes.id||',%'
+		ORDER BY note_relationships.position
+	)
+
+	SELECT * from notetree);
+		 
+	
+  

server/nm-store/src/errors.rs

@@ -8,6 +8,9 @@ pub enum NoteStoreError {
     #[error("Invalid Note Structure")]
     InvalidNoteStructure(String),
 
+    /// The requested kasten or note was not found.  As much as
+    /// possible, this should be preferred to a
+    /// sqlx::Error::RowNotFound.
     #[error("Not found")]
     NotFound,
 

server/nm-store/src/lib.rs

@@ -1,10 +1,11 @@
 mod errors;
-mod reference_parser;
+mod parser;
 mod store;
 mod structs;
 
 pub use crate::errors::NoteStoreError;
 pub use crate::store::NoteStore;
+pub use crate::structs::{Note, NoteKind, NoteRelationship, PageRelationship};
 
 #[cfg(test)]
 mod tests {
@@ -21,14 +22,14 @@ mod tests {
         storagepool
     }
 
-    // Request for the page by slug.
-    // If the page exists, return it.  If the page doesn't, return NotFound
-
+    // Request for the page by slug.  If the page exists, return it.
+    // If the page doesn't, return NotFound
+    //
     #[tokio::test(threaded_scheduler)]
     async fn fetching_unfound_page_by_slug_works() {
         let storagepool = fresh_inmemory_database().await;
-        let unfoundpage = storagepool.get_page_by_slug("nonexistent-page").await;
-        assert!(unfoundpage.is_err());
+        let foundpage = storagepool.get_page_by_slug("nonexistent-page").await;
+        assert!(foundpage.is_err());
     }
 
     // Request for the page by title.  If the page exists, return it.
@@ -43,23 +44,22 @@ mod tests {
         let newpageresult = storagepool.get_page_by_title(&title).await;
 
         assert!(newpageresult.is_ok(), "{:?}", newpageresult);
-        let (newpage, newnotes) = newpageresult.unwrap();
+        let (newpages, _) = newpageresult.unwrap();
 
-        assert_eq!(newpage.title, title, "{:?}", newpage.title);
-        assert_eq!(newpage.slug, "nonexistent-page");
-
-        assert_eq!(newnotes.len(), 1);
-        assert_eq!(newnotes[0].notetype, "root");
-        assert_eq!(newpage.note_id, newnotes[0].id);
+        assert_eq!(newpages.len(), 1);
+        let newpage = newpages.iter().next().unwrap();
 
+        assert_eq!(newpage.content, title, "{:?}", newpage.content);
+        assert_eq!(newpage.id, "nonexistent-page");
+        assert_eq!(newpage.kind, NoteKind::Page);
         assert!((newpage.creation_date - now).num_minutes() < 1);
         assert!((newpage.updated_date - now).num_minutes() < 1);
         assert!((newpage.lastview_date - now).num_minutes() < 1);
         assert!(newpage.deleted_date.is_none());
     }
 
-    fn make_new_note(content: &str) -> row_structs::NewNote {
-        row_structs::NewNoteBuilder::default()
+    fn make_new_note(content: &str) -> structs::NewNote {
+        structs::NewNoteBuilder::default()
             .content(content.to_string())
             .build()
             .unwrap()
@@ -70,38 +70,46 @@ mod tests {
         let title = "Nonexistent Page";
         let storagepool = fresh_inmemory_database().await;
         let newpageresult = storagepool.get_page_by_title(&title).await;
-        let (_newpage, newnotes) = newpageresult.unwrap();
 
-        let root = &newnotes[0];
+        assert!(newpageresult.is_ok(), "{:?}", newpageresult);
+        let (newpages, _) = newpageresult.unwrap();
+        assert_eq!(newpages.len(), 1);
+        let root = &newpages[0];
+
+        // root <- 1 <- 3
+        //      <- 2 <- 4
 
         let note1 = make_new_note("1");
-        let note1_uuid = storagepool.insert_nested_note(&note1, &root.uuid, 0).await;
-        assert!(note1_uuid.is_ok(), "{:?}", note1_uuid);
-        let note1_uuid = note1_uuid.unwrap();
+        let note1_id = storagepool.add_note(&note1, &root.id, Some(0)).await;
+        assert!(note1_id.is_ok(), "{:?}", note1_id);
+        let note1_id = note1_id.unwrap();
 
         let note2 = make_new_note("2");
-        let note2_uuid = storagepool.insert_nested_note(&note2, &root.uuid, 0).await;
-        assert!(note2_uuid.is_ok(), "{:?}", note2_uuid);
-        let note2_uuid = note2_uuid.unwrap();
+        let note2_id = storagepool.add_note(&note2, &root.id, Some(0)).await;
+        assert!(note2_id.is_ok(), "{:?}", note2_id);
+        let note2_id = note2_id.unwrap();
 
         let note3 = make_new_note("3");
-        let note3_uuid = storagepool.insert_nested_note(&note3, &note1_uuid, 0).await;
-        assert!(note3_uuid.is_ok(), "{:?}", note3_uuid);
-        let note3_uuid = note3_uuid.unwrap();
+        let note3_id = storagepool.add_note(&note3, &note1_id, Some(0)).await;
+        assert!(note3_id.is_ok(), "{:?}", note3_id);
+        let _note3_id = note3_id.unwrap();
 
         let note4 = make_new_note("4");
-        let note4_uuid = storagepool.insert_nested_note(&note4, &note2_uuid, 0).await;
-        assert!(note4_uuid.is_ok(), "{:?}", note4_uuid);
-        let note4_uuid = note4_uuid.unwrap();
+        let note4_id = storagepool.add_note(&note4, &note2_id, Some(0)).await;
+        assert!(note4_id.is_ok(), "{:?}", note4_id);
+        let _note4_id = note4_id.unwrap();
 
         let newpageresult = storagepool.get_page_by_title(&title).await;
-        let (newpage, newnotes) = newpageresult.unwrap();
+        assert!(newpageresult.is_ok(), "{:?}", newpageresult);
+        let (newpages, _) = newpageresult.unwrap();
 
-        assert_eq!(newpage.title, title, "{:?}", newpage.title);
-        assert_eq!(newpage.slug, "nonexistent-page");
+        assert_eq!(newpages.len(), 5);
+        let newroot = newpages.iter().next().unwrap();
 
-        assert_eq!(newnotes.len(), 5);
-        assert_eq!(newnotes[0].notetype, "root");
-        assert_eq!(newpage.note_id, newnotes[0].id);
+        assert_eq!(newroot.content, title, "{:?}", newroot.content);
+        assert_eq!(newroot.id, "nonexistent-page");
+
+        assert_eq!(newpages[1].parent_id, Some(newroot.id.clone()));
+        assert_eq!(newpages[2].parent_id, Some(newpages[1].id.clone()));
     }
 }

server/nm-store/src/parser/mod.rs

@@ -0,0 +1,59 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+//! # Storage layer for Notesmachine
+//!
+//! This library implements the core functionality of Notesmachine and
+//! describes that functionality to a storage layer.  There's a bit of
+//! intermingling in here which can't be helped, although it may make
+//! sense in the future to separate the decomposition of the note
+//! content into a higher layer.
+//!
+//! Notesmachine storage notes consist of two items: Note and Kasten.
+//! This distinction is somewhat arbitrary, as structurally these two
+//! items are stored in the same table.
+//!
+//! - Boxes have titles (and date metadata)
+//! - Notes have content and a type (and date metadata)
+//! - Notes are stored in boxes
+//!   - Notes are positioned with respect to other notes.
+//!   - There are two positions:
+//!     - Siblings, creating lists
+//!     - Children, creating trees like this one
+//! - Notes may have references (pointers) to other boxes
+//! - Notes may be moved around
+//! - Notes may be deleted
+//! - Boxes may be deleted
+//! - When a box is renamed, every reference to that box is auto-edited to
+//!   reflect the change. If a box is renamed to match an existing box, the
+//!   notes in both boxes are merged.
+//!   
+//! Note-to-note relationships form trees, and are kept in a SQL database of
+//! (`parent_id`, `child_id`, `position`, `relationship_type`). The
+//! `position` is a monotonic index on the parent (that is, every pair
+//! (`parent_id`, `position`) must be unique).  The `relationship_type` is
+//! an enum and can specify that the relationship is *original*,
+//! *embedding*, or *referencing*.  An embedded or referenced note may be
+//! read/write or read-only with respect to the original, but there is only
+//! one original note at any time.
+//!
+//! Note-to-box relationships form a graph, and are kept in the SQL database
+//! as a collection of *edges* from the note to the box (and naturally
+//! vice-versa).
+//!
+//! - Decision: When an original note is deleted, do all references and
+//!   embeddings also get deleted, or is the oldest one elevated to be a new
+//!   "original"?  Or is that something the user may choose?
+//!
+//! - Decision: Should the merging issue be handled at this layer, or would
+//!   it make sense to move this to a higher layer, and only provide the
+//!   hooks for it here?
+//!
+
+mod references;
+use references::{build_page_titles, find_links};
+
+pub(crate) fn build_references(content: &str) -> Vec<String> {
+    build_page_titles(&find_links(content))
+}

server/nm-store/src/parser/references.rs

@@ -4,7 +4,7 @@ use lazy_static::lazy_static;
 use regex::bytes::Regex as BytesRegex;
 use regex::Regex;
 
-pub struct Finder(pub Vec<String>);
+struct Finder(pub Vec<String>);
 
 impl Finder {
     pub fn new() -> Self {
@@ -24,9 +24,7 @@ impl Finder {
     }
 }
 
-/// Given a content block, return a list of all the page references found
-/// within the block.  The references may need further massaging.
-pub(crate) fn find_links(document: &str) -> Vec<String> {
+pub(super) fn find_links(document: &str) -> Vec<String> {
     let arena = Arena::new();
     let mut finder = Finder::new();
     let root = parse_document(&arena, document, &ComrakOptions::default());
@@ -40,7 +38,9 @@ pub(crate) fn find_links(document: &str) -> Vec<String> {
             NodeValue::Text(ref text) => Some(
                 RE_REFERENCES
                     .captures_iter(text)
-                    .map(|t| String::from_utf8_lossy(&t.get(1).unwrap().as_bytes()).to_string())
+                    .filter_map(|t| t.get(1))
+                    .map(|t| String::from_utf8_lossy(t.as_bytes()).to_string())
+                    .filter(|s| !s.is_empty())
                     .collect(),
             ),
             _ => None,
@@ -50,41 +50,60 @@ pub(crate) fn find_links(document: &str) -> Vec<String> {
     finder.0
 }
 
+// This function is for the camel and snake case handers.
 fn recase(title: &str) -> String {
     lazy_static! {
+        // Take every word that has a pattern of a capital letter
+        // followed by a lower case, and put a space between the
+        // capital and anything that preceeds it.
+
+        // TODO: Make Unicode aware.
         static ref RE_PASS1: Regex = Regex::new(r"(?P<s>.)(?P<n>[A-Z][a-z]+)").unwrap();
+
+        // Take every instance of a lower case letter or number,
+        // followed by a capital letter, and put a space between them.
+
+        // TODO: Make Unicode aware. [[:lower:]] is an ASCII-ism.
         static ref RE_PASS2: Regex = Regex::new(r"(?P<s>[[:lower:]]|\d)(?P<n>[[:upper:]])").unwrap();
-        static ref RE_PASS4: Regex = Regex::new(r"(?P<s>[a-z])(?P<n>\d)").unwrap();
+
+        // Take every instance of a word suffixed by a number and put
+        // a space between them.
+
+        // TODO: Make Unicode aware. [[:lower:]] is an ASCII-ism.
+        static ref RE_PASS4: Regex = Regex::new(r"(?P<s>[[:lower:]])(?P<n>\d)").unwrap();
+
+        // Take every instance of the one-or-more-of the symbols listed, and
+        // replace them with a space.  This function is Unicode-irrelevant,
+        // although there is a list of symbols in the backreference parser
+        // that may disagree.
+
+        // TODO: Examime backreference parser and determine if this is
+        // sufficient.
         static ref RE_PASS3: Regex = Regex::new(r"(:|_|-| )+").unwrap();
     }
 
     // This should panic if misused, so... :-)
     let pass = title.to_string();
     let pass = pass.strip_prefix("#").unwrap();
-
     let pass = RE_PASS1.replace_all(&pass, "$s $n");
     let pass = RE_PASS4.replace_all(&pass, "$s $n");
     let pass = RE_PASS2.replace_all(&pass, "$s $n");
     RE_PASS3.replace_all(&pass, " ").trim().to_string()
 }
 
-fn build_page_titles(references: &[String]) -> Vec<String> {
+pub(super) fn build_page_titles(references: &[String]) -> Vec<String> {
     references
         .iter()
-        .map(|s| match s.chars().next() {
-            Some('#') => recase(s),
-            Some('[') => s.strip_prefix("[[").unwrap().strip_suffix("]]").unwrap().to_string(),
-            Some(_) => s.clone(),
-            _ => "".to_string(),
+        .filter_map(|s| match s.chars().next() {
+            Some('#') => Some(recase(s)),
+            Some('[') => Some(s.strip_prefix("[[").unwrap().strip_suffix("]]").unwrap().to_string()),
+            Some(_) => Some(s.clone()),
+            _ => None,
         })
-        .filter(|s| s.is_empty())
+        .filter(|s| !s.is_empty())
         .collect()
 }
 
-pub(crate) fn build_references(content: &str) -> Vec<String> {
-    build_page_titles(&find_links(content))
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

server/nm-store/src/sql/insert_one_note.sql

@@ -1,8 +0,0 @@
-INSERT INTO notes (
-	   uuid,
-	   content,
-	   notetype,
-	   creation_date,
-	   updated_date,
-	   lastview_date)
-VALUES (?, ?, ?, ?, ?, ?);

server/nm-store/src/sql/insert_one_page.sql

@@ -1,8 +0,0 @@
-INSERT INTO pages (
-	   slug,
-	   title,
-	   note_id,
-	   creation_date,
-	   updated_date,
-	   lastview_date)
-VALUES (?, ?, ?, ?, ?, ?);

server/nm-store/src/sql/select_note_collection_from_root.sql

@@ -1,86 +0,0 @@
--- This is undoubtedly one of the more complex bits of code I've
--- written recently, and I do wish there had been macros because
--- there's a lot of hand-written, copy-pasted code here around the
--- basic content of a note; it would have been nice to be able to DRY
--- that out.
-
--- This expression creates a table, 'notetree', that contains all of
--- the notes nested under a page.  Each entry in the table includes
--- the note's parent's internal and external ids so that applications
--- can build an actual tree out of a vec of these things.
-
--- TODO: Extensive testing to validate that the nodes are delivered
--- *in nesting order* to the client.
-
-SELECT
-  id,
-  uuid,
-  parent_id,
-  parent_uuid,
-  content,
-  position,
-  notetype,
-  creation_date,
-  updated_date,
-  lastview_date,
-  deleted_date
-
-FROM (
-
-  WITH RECURSIVE notetree(
-    id,
-    uuid,
-    parent_id,
-    parent_uuid,
-    content,
-    position,
-    notetype,
-    creation_date,
-    updated_date,
-    lastview_date,
-    deleted_date,
-    cycle) AS
-
--- ROOT expression    
-     (SELECT
-       notes.id,
-       notes.uuid,
-       notes.id AS parent_id,
-       notes.uuid AS parent_uuid,
-       notes.content,
-       0,  -- Root notes are always in position 0
-       notes.notetype,
-       notes.creation_date,
-       notes.updated_date,
-       notes.lastview_date,
-       notes.deleted_date,
-	   ','||notes.id||','  -- Cycle monitor
-     FROM notes
-	 WHERE notes.id = ? AND notes.notetype = "root"
-
--- RECURSIVE expression
-     UNION SELECT
-	   notes.id,
-	   notes.uuid,
-	   notetree.id AS parent_id,
-	   notetree.uuid AS parent_uuid,
-	   notes.content,
-	   note_relationships.position,
-	   notes.notetype,
-	   notes.creation_date,
-	   notes.updated_date,
-	   notes.lastview_date,
-	   notes.deleted_date,
-	   notetree.cycle||notes.id||','
-	 FROM notes
-	   INNER JOIN note_relationships ON notes.id = note_relationships.note_id
-	   -- For a given ID in the level of notetree in *this* recursion,
-	   -- we want each note's branches one level down.
-	   INNER JOIN notetree ON note_relationships.parent_id = notetree.id
-	   -- And we want to make sure there are no cycles.  There shouldn't
-	   -- be; we're supposed to prevent those.  But you never know.
-	   WHERE
-         notetree.cycle NOT LIKE '%,'||notes.id||',%'
-	   ORDER BY note_relationships.position)
-  SELECT * from notetree);
-

server/nm-store/src/sql/select_one_note.sql

@@ -1 +0,0 @@
-SELECT id, uuid, content, notetype, creation_date, updated_date, lastview_date, deleted_date FROM notes WHERE uuid=?;

server/nm-store/src/sql/select_one_page.sql

@@ -1 +0,0 @@
-SELECT id, title, slug, note_id, creation_date, updated_date, lastview_date, deleted_date FROM pages WHERE slug=?;

server/nm-store/src/sql/update_one_note.sql

@@ -1,3 +0,0 @@
-UPDATE notes
-  SET content = ?, updated_date = ?, lastview_date = ?
-  WHERE uuid = ?;

server/nm-store/src/store.rs

@@ -1,702 +0,0 @@
-use crate::errors::NoteStoreError;
-use crate::reference_parser::build_references;
-use crate::structs::{
-    JustId, JustSlugs, NewNote, NewNoteBuilder, NewPage, NewPageBuilder, NoteRelationship, PageTitles, RawNote,
-    RawPage, RowCount,
-};
-use lazy_static::lazy_static;
-use regex::Regex;
-use shrinkwraprs::Shrinkwrap;
-use slug::slugify;
-use sqlx::{
-    sqlite::{Sqlite, SqlitePool, SqliteRow},
-    Done, Executor, Row,
-};
-use std::collections::HashMap;
-use std::collections::HashSet;
-use std::sync::Arc;
-
-#[derive(Shrinkwrap, Copy, Clone)]
-struct PageId(i64);
-
-#[derive(Shrinkwrap, Copy, Clone)]
-struct NoteId(i64);
-
-#[derive(Shrinkwrap, Copy, Clone)]
-struct ParentId(i64);
-
-/// A handle to our Sqlite database.
-#[derive(Clone, Debug)]
-pub struct NoteStore(Arc<SqlitePool>);
-
-type NoteResult<T> = core::result::Result<T, NoteStoreError>;
-type SqlResult<T> = sqlx::Result<T>;
-
-impl NoteStore {
-    pub async fn new(url: &str) -> NoteResult<Self> {
-        let pool = SqlitePool::connect(url).await?;
-        Ok(NoteStore(Arc::new(pool)))
-    }
-
-    // Erase all the data in the database and restore it
-    // to its original empty form.  Do not use unless you
-    // really, really want that to happen.
-    pub async fn reset_database(&self) -> NoteResult<()> {
-        reset_database(&*self.0).await.map_err(NoteStoreError::DBError)
-    }
-
-    /// Fetch page by slug
-    ///
-    /// Supports the use case of the user navigating to a known place
-    /// via a bookmark or other URL.  Since the title isn't clear from
-    /// the slug, the slug is insufficient to generate a new page, so
-    /// this use case says that in the event of a failure to find the
-    /// requested page, return a basic NotFound.
-    pub async fn get_page_by_slug(&self, slug: &str) -> NoteResult<(RawPage, Vec<RawNote>)> {
-        //		let select_note_collection_for_root = include_str!("sql/select_note_collection_for_root.sql");
-        let mut tx = self.0.begin().await?;
-        let page = select_page_by_slug(&mut tx, slug).await?;
-        let note_id = page.note_id;
-        let notes = select_note_collection_from_root(&mut tx, note_id).await?;
-        tx.commit().await?;
-        Ok((page, notes))
-    }
-
-    /// Fetch page by title
-    ///
-    /// Supports the use case of the user navigating to a page via
-    /// the page's formal title.  Since the title is the key reference
-    /// of the system, if no page with that title is found, a page with
-    /// that title is generated automatically.
-    pub async fn get_page_by_title(&self, title: &str) -> NoteResult<(RawPage, Vec<RawNote>)> {
-        let mut tx = self.0.begin().await?;
-        let (page, notes) = match select_page_by_title(&mut tx, title).await {
-            Ok(page) => {
-                let note_id = page.note_id;
-                (page, select_note_collection_from_root(&mut tx, note_id).await?)
-            }
-            Err(sqlx::Error::RowNotFound) => {
-                let page = {
-                    let new_root_note = create_unique_root_note();
-                    let new_root_note_id = insert_one_new_note(&mut tx, &new_root_note).await?;
-                    let new_page_slug = generate_slug(&mut tx, title).await?;
-                    let new_page = create_new_page_for(&title, &new_page_slug, new_root_note_id);
-                    let _ = insert_one_new_page(&mut tx, &new_page).await?;
-                    select_page_by_title(&mut tx, &title).await?
-                };
-                let note_id = page.note_id;
-                (page, select_note_collection_from_root(&mut tx, note_id).await?)
-            }
-            Err(e) => return Err(NoteStoreError::DBError(e)),
-        };
-        tx.commit().await?;
-        Ok((page, notes))
-    }
-
-    // TODO: Make sure the position is sane.
-    /// Insert a note as the child of an existing note, at a set position.
-    pub async fn insert_nested_note(
-        &self,
-        note: &NewNote,
-        parent_note_uuid: &str,
-        position: i64,
-    ) -> NoteResult<String> {
-        let mut new_note = note.clone();
-        new_note.uuid = friendly_id::create();
-        let references = build_references(&note.content);
-        let mut tx = self.0.begin().await?;
-
-        // Start by building the note and putting it into its relationship.
-        let parent_id: ParentId = select_note_id_for_uuid(&mut tx, parent_note_uuid).await?;
-        let parent_max_position = assert_max_child_position_for_note(&mut tx, parent_id).await?;
-        let position = if position > parent_max_position {
-            parent_max_position + 1
-        } else {
-            position
-        };
-        let new_note_id = insert_one_new_note(&mut tx, &new_note).await?;
-        let _ = make_room_for_new_note(&mut tx, parent_id, position).await?;
-        let _ = insert_note_to_note_relationship(&mut tx, parent_id, new_note_id, position, "note").await?;
-
-        // From the references, make lists of pages that exist, and pages
-        // that do not.
-        let found_references = find_all_page_references_for(&mut tx, &references).await?;
-        let new_references = diff_references(&references, &found_references);
-        let mut known_reference_ids: Vec<PageId> = Vec::new();
-
-        // Create the pages that don't exist
-        for one_reference in new_references.iter() {
-            let new_root_note = create_unique_root_note();
-            let new_root_note_id = insert_one_new_note(&mut tx, &new_root_note).await?;
-            let new_page_slug = generate_slug(&mut tx, &one_reference).await?;
-            let new_page = create_new_page_for(&one_reference, &new_page_slug, new_root_note_id);
-            known_reference_ids.push(insert_one_new_page(&mut tx, &new_page).await?)
-        }
-
-        // And associate the note with all the pages.
-        known_reference_ids.append(&mut found_references.iter().map(|r| PageId(r.id)).collect());
-        let _ = insert_note_to_page_relationships(&mut tx, new_note_id, &known_reference_ids).await?;
-
-        tx.commit().await?;
-        Ok(new_note.uuid)
-    }
-
-    // This doesn't do anything with the references, as those are
-    // dependent entirely on the *content*, and not the *position*, of
-    // the note and the referenced page.
-    //
-    // TODO: Ensure the position is sane.
-    /// Move a note from one location to another.
-    pub async fn move_note(
-        &self,
-        note_uuid: &str,
-        old_parent_uuid: &str,
-        new_parent_uuid: &str,
-        new_position: i64,
-    ) -> NoteResult<()> {
-        let all_uuids = vec![note_uuid, old_parent_uuid, new_parent_uuid];
-        let mut tx = self.0.begin().await?;
-
-        // This is one of the few cases where we we're getting IDs for
-        // notes, but the nature of the ID isn't known at this time.
-        // This has to be handled manually, in the next paragraph
-        // below.
-        let found_id_vec = bulk_select_ids_for_note_uuids(&mut tx, &all_uuids).await?;
-        let found_ids: HashMap<String, i64> = found_id_vec.into_iter().collect();
-        if found_ids.len() != 3 {
-            return Err(NoteStoreError::NotFound);
-        }
-
-        let old_parent_id = ParentId(*found_ids.get(old_parent_uuid).unwrap());
-        let new_parent_id = ParentId(*found_ids.get(new_parent_uuid).unwrap());
-        let note_id = NoteId(*found_ids.get(note_uuid).unwrap());
-
-        let old_note = get_note_to_note_relationship(&mut tx, old_parent_id, note_id).await?;
-        let old_note_position = old_note.position;
-        let old_note_nature = &old_note.nature;
-
-        let _ = delete_note_to_note_relationship(&mut tx, old_parent_id, note_id).await?;
-        let _ = close_hole_for_deleted_note(&mut tx, old_parent_id, old_note_position).await?;
-        let parent_max_position = assert_max_child_position_for_note(&mut tx, new_parent_id).await?;
-        let new_position = if new_position > parent_max_position {
-            parent_max_position + 1
-        } else {
-            new_position
-        };
-        let _ = make_room_for_new_note(&mut tx, new_parent_id, new_position).await?;
-        let _ =
-            insert_note_to_note_relationship(&mut tx, new_parent_id, note_id, new_position, old_note_nature).await?;
-        tx.commit().await?;
-        Ok(())
-    }
-
-    /// Embed or reference a note from a different location.
-    pub async fn reference_or_embed_note(
-        &self,
-        note_uuid: &str,
-        new_parent_uuid: &str,
-        new_position: i64,
-        new_nature: &str,
-    ) -> NoteResult<()> {
-        let mut tx = self.0.begin().await?;
-        let existing_note_id: NoteId = NoteId(select_note_id_for_uuid(&mut tx, note_uuid).await?.0);
-        let new_parent_id: ParentId = select_note_id_for_uuid(&mut tx, new_parent_uuid).await?;
-        let _ = make_room_for_new_note(&mut tx, new_parent_id, new_position).await?;
-        let _ = insert_note_to_note_relationship(&mut tx, new_parent_id, existing_note_id, new_position, new_nature)
-            .await?;
-        tx.commit().await?;
-        Ok(())
-    }
-
-    /// Delete a note
-    pub async fn delete_note(&self, note_uuid: &str, note_parent_uuid: &str) -> NoteResult<()> {
-        let mut tx = self.0.begin().await?;
-        let condemned_note_id: NoteId = NoteId(select_note_id_for_uuid(&mut tx, note_uuid).await?.0);
-        let note_parent_id: ParentId = select_note_id_for_uuid(&mut tx, note_parent_uuid).await?;
-        let _ = delete_note_to_note_relationship(&mut tx, note_parent_id, condemned_note_id);
-        if count_existing_note_relationships(&mut tx, condemned_note_id).await? == 0 {
-            let _ = delete_note_to_page_relationships(&mut tx, condemned_note_id).await?;
-            let _ = delete_note(&mut tx, condemned_note_id).await?;
-        }
-        tx.commit().await?;
-        Ok(())
-    }
-
-    /// Update a note's content
-    pub async fn update_note_content(&self, note_uuid: &str, content: &str) -> NoteResult<()> {
-        let references = build_references(&content);
-
-        let mut tx = self.0.begin().await?;
-
-        let note_id: NoteId = NoteId(select_note_id_for_uuid(&mut tx, note_uuid).await?.0);
-        let _ = update_note_content(&mut tx, note_id, &content).await?;
-
-        let found_references = find_all_page_references_for(&mut tx, &references).await?;
-        let new_references = diff_references(&references, &found_references);
-        let mut known_reference_ids: Vec<PageId> = Vec::new();
-
-        // Create the pages that don't exist
-        for one_reference in new_references.iter() {
-            let new_root_note = create_unique_root_note();
-            let new_root_note_id = insert_one_new_note(&mut tx, &new_root_note).await?;
-            let new_page_slug = generate_slug(&mut tx, &one_reference).await?;
-            let new_page = create_new_page_for(&one_reference, &new_page_slug, new_root_note_id);
-            known_reference_ids.push(insert_one_new_page(&mut tx, &new_page).await?)
-        }
-
-        // And associate the note with all the pages.
-        known_reference_ids.append(&mut found_references.iter().map(|r| PageId(r.id)).collect());
-        let _ = insert_note_to_page_relationships(&mut tx, note_id, &known_reference_ids).await?;
-
-        tx.commit().await?;
-        Ok(())
-    }
-}
-//  ___     _          _
-// | _ \_ _(_)_ ____ _| |_ ___
-// |  _/ '_| \ V / _` |  _/ -_)
-// |_| |_| |_|\_/\__,_|\__\___|
-//
-
-// I'm putting a lot of faith in Rust's ability to inline stuff.  I'm
-// sure this is okay.  But really, this lets the API be clean and
-// coherent and easily readable, and hides away the gnarliness of some
-// of the SQL queries.
-
-async fn reset_database<'a, E>(executor: E) -> SqlResult<()>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let initialize_sql = include_str!("sql/initialize_database.sql");
-    sqlx::query(initialize_sql).execute(executor).await.map(|_| ())
-}
-
-async fn select_page_by_slug<'a, E>(executor: E, slug: &str) -> SqlResult<RawPage>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let select_one_page_by_slug_sql = concat!(
-        "SELECT id, title, slug, note_id, creation_date, updated_date, ",
-        "lastview_date, deleted_date FROM pages WHERE slug=?;"
-    );
-    Ok(sqlx::query_as(&select_one_page_by_slug_sql)
-        .bind(&slug)
-        .fetch_one(executor)
-        .await?)
-}
-
-async fn select_page_by_title<'a, E>(executor: E, title: &str) -> SqlResult<RawPage>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let select_one_page_by_title_sql = concat!(
-        "SELECT id, title, slug, note_id, creation_date, updated_date, ",
-        "lastview_date, deleted_date FROM pages WHERE title=?;"
-    );
-    Ok(sqlx::query_as(&select_one_page_by_title_sql)
-        .bind(&title)
-        .fetch_one(executor)
-        .await?)
-}
-
-async fn select_note_id_for_uuid<'a, E>(executor: E, uuid: &str) -> SqlResult<ParentId>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let select_note_id_for_uuid_sql = "SELECT id FROM notes WHERE uuid = ?";
-    let id: JustId = sqlx::query_as(&select_note_id_for_uuid_sql)
-        .bind(&uuid)
-        .fetch_one(executor)
-        .await?;
-    Ok(ParentId(id.id))
-}
-
-async fn make_room_for_new_note<'a, E>(executor: E, parent_id: ParentId, position: i64) -> SqlResult<()>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let make_room_for_new_note_sql = concat!(
-        "UPDATE note_relationships ",
-        "SET position = position + 1 ",
-        "WHERE position >= ? and parent_id = ?;"
-    );
-
-    sqlx::query(make_room_for_new_note_sql)
-        .bind(&position)
-        .bind(&*parent_id)
-        .execute(executor)
-        .await
-        .map(|_| ())
-}
-
-async fn insert_note_to_note_relationship<'a, E>(
-    executor: E,
-    parent_id: ParentId,
-    note_id: NoteId,
-    position: i64,
-    nature: &str,
-) -> SqlResult<()>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let insert_note_to_note_relationship_sql = concat!(
-        "INSERT INTO note_relationships (parent_id, note_id, position, nature) ",
-        "values (?, ?, ?, ?)"
-    );
-
-    sqlx::query(insert_note_to_note_relationship_sql)
-        .bind(&*parent_id)
-        .bind(&*note_id)
-        .bind(&position)
-        .bind(&nature)
-        .execute(executor)
-        .await
-        .map(|_| ())
-}
-
-async fn select_note_collection_from_root<'a, E>(executor: E, root: i64) -> SqlResult<Vec<RawNote>>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let select_note_collection_from_root_sql = include_str!("sql/select_note_collection_from_root.sql");
-    Ok(sqlx::query_as(&select_note_collection_from_root_sql)
-        .bind(&root)
-        .fetch_all(executor)
-        .await?)
-}
-
-async fn insert_one_new_note<'a, E>(executor: E, note: &NewNote) -> SqlResult<NoteId>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let insert_one_note_sql = concat!(
-        "INSERT INTO notes ( ",
-        "	   uuid, ",
-        "	   content, ",
-        "	   notetype, ",
-        "	   creation_date, ",
-        "	   updated_date, ",
-        "	   lastview_date) ",
-        "VALUES (?, ?, ?, ?, ?, ?);"
-    );
-
-    Ok(NoteId(
-        sqlx::query(insert_one_note_sql)
-            .bind(&note.uuid)
-            .bind(&note.content)
-            .bind(&note.notetype)
-            .bind(&note.creation_date)
-            .bind(&note.updated_date)
-            .bind(&note.lastview_date)
-            .execute(executor)
-            .await?
-            .last_insert_rowid(),
-    ))
-}
-
-// Given a possible slug, find the slug with the highest
-// uniquification number, and return that number, if any.
-fn find_maximal_slug(slugs: &[JustSlugs]) -> Option<u32> {
-    lazy_static! {
-        static ref RE_CAP_NUM: Regex = Regex::new(r"-(\d+)$").unwrap();
-    }
-
-    if slugs.is_empty() {
-        return None;
-    }
-
-    let mut slug_counters: Vec<u32> = slugs
-        .iter()
-        .filter_map(|slug| RE_CAP_NUM.captures(&slug.slug))
-        .map(|cap| cap.get(1).unwrap().as_str().parse::<u32>().unwrap())
-        .collect();
-    slug_counters.sort_unstable();
-    slug_counters.pop()
-}
-
-// Given an initial string and an existing collection of slugs,
-// generate a new slug that does not conflict with the current
-// collection.
-async fn generate_slug<'a, E>(executor: E, title: &str) -> SqlResult<String>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    lazy_static! {
-        static ref RE_STRIP_NUM: Regex = Regex::new(r"-\d+$").unwrap();
-    }
-
-    let initial_slug = slugify(title);
-    let sample_slug = RE_STRIP_NUM.replace_all(&initial_slug, "");
-    let slug_finder_sql = "SELECT slug FROM pages WHERE slug LIKE '?%';";
-    let similar_slugs: Vec<JustSlugs> = sqlx::query_as(&slug_finder_sql)
-        .bind(&*sample_slug)
-        .fetch_all(executor)
-        .await?;
-    let maximal_slug = find_maximal_slug(&similar_slugs);
-    match maximal_slug {
-        None => Ok(initial_slug),
-        Some(max_slug) => Ok(format!("{}-{}", initial_slug, max_slug + 1)),
-    }
-}
-
-async fn insert_one_new_page<'a, E>(executor: E, page: &NewPage) -> SqlResult<PageId>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let insert_one_page_sql = concat!(
-        "INSERT INTO pages ( ",
-        "	   slug, ",
-        "	   title, ",
-        "	   note_id, ",
-        "	   creation_date, ",
-        "	   updated_date, ",
-        "	   lastview_date) ",
-        "VALUES (?, ?, ?, ?, ?, ?);"
-    );
-
-    Ok(PageId(
-        sqlx::query(insert_one_page_sql)
-            .bind(&page.slug)
-            .bind(&page.title)
-            .bind(&page.note_id)
-            .bind(&page.creation_date)
-            .bind(&page.updated_date)
-            .bind(&page.lastview_date)
-            .execute(executor)
-            .await?
-            .last_insert_rowid(),
-    ))
-}
-
-async fn insert_note_to_page_relationships<'a, E>(
-    executor: E,
-    note_id: NoteId,
-    references: &[PageId],
-) -> SqlResult<()>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let insert_note_page_references_sql = "INSERT INTO page_relationships (note_id, page_id) VALUES ".to_string()
-        + &["(?, ?)"].repeat(references.len()).join(", ")
-        + &";".to_string();
-
-    let mut request = sqlx::query(&insert_note_page_references_sql);
-    for reference in references {
-        request = request.bind(*note_id).bind(**reference);
-    }
-
-    request.execute(executor).await.map(|_| ())
-}
-
-// For a given collection of uuids, retrieve the internal ID used by
-// the database.
-async fn bulk_select_ids_for_note_uuids<'a, E>(executor: E, ids: &[&str]) -> SqlResult<Vec<(String, i64)>>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let bulk_select_ids_for_note_uuids_sql = "SELECT uuid, id FROM notes WHERE uuid IN (".to_string()
-        + &["?"].repeat(ids.len()).join(",")
-        + &");".to_string();
-
-    let mut request = sqlx::query(&bulk_select_ids_for_note_uuids_sql);
-    for id in ids.iter() {
-        request = request.bind(id);
-    }
-    Ok(request
-        .try_map(|row: SqliteRow| {
-            let l = row.try_get::<String, _>(0)?;
-            let r = row.try_get::<i64, _>(1)?;
-            Ok((l, r))
-        })
-        .fetch_all(executor)
-        .await?
-        .into_iter()
-        .collect())
-}
-
-// Used by move_note to identify the single note to note relationship
-// by the original parent and child pair.  Used mostly to find the
-// position for recalculation, to create a new gap or close an old
-// one.
-async fn get_note_to_note_relationship<'a, E>(
-    executor: E,
-    parent_id: ParentId,
-    note_id: NoteId,
-) -> SqlResult<NoteRelationship>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let get_note_to_note_relationship_sql = concat!(
-        "SELECT parent_id, note_id, position, nature ",
-        "FROM note_relationships ",
-        "WHERE parent_id = ? and note_id = ? ",
-        "LIMIT 1"
-    );
-    sqlx::query_as(get_note_to_note_relationship_sql)
-        .bind(&*parent_id)
-        .bind(&*note_id)
-        .fetch_one(executor)
-        .await
-}
-
-async fn delete_note_to_note_relationship<'a, E>(executor: E, parent_id: ParentId, note_id: NoteId) -> SqlResult<()>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let delete_note_to_note_relationship_sql = concat!(
-        "DELETE FROM note_relationships ",
-        "WHERE parent_id = ? and note_id = ? "
-    );
-
-    let count = sqlx::query(delete_note_to_note_relationship_sql)
-        .bind(&*parent_id)
-        .bind(&*note_id)
-        .execute(executor)
-        .await?
-        .rows_affected();
-
-    match count {
-        1 => Ok(()),
-        _ => Err(sqlx::Error::RowNotFound),
-    }
-}
-
-async fn delete_note_to_page_relationships<'a, E>(executor: E, note_id: NoteId) -> SqlResult<()>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let delete_note_to_page_relationships_sql = concat!("DELETE FROM page_relationships ", "WHERE note_id = ? ");
-
-    let _ = sqlx::query(delete_note_to_page_relationships_sql)
-        .bind(&*note_id)
-        .execute(executor)
-        .await?;
-    Ok(())
-}
-
-async fn delete_note<'a, E>(executor: E, note_id: NoteId) -> SqlResult<()>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let delete_note_sql = concat!("DELETE FROM notes WHERE note_id = ?");
-
-    let count = sqlx::query(delete_note_sql)
-        .bind(&*note_id)
-        .execute(executor)
-        .await?
-        .rows_affected();
-
-    match count {
-        1 => Ok(()),
-        _ => Err(sqlx::Error::RowNotFound),
-    }
-}
-
-async fn count_existing_note_relationships<'a, E>(executor: E, note_id: NoteId) -> SqlResult<i64>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let count_existing_note_relationships_sql = "SELECT COUNT(*) as count FROM page_relationships WHERE note_id = ?";
-
-    let count: RowCount = sqlx::query_as(count_existing_note_relationships_sql)
-        .bind(&*note_id)
-        .fetch_one(executor)
-        .await?;
-
-    Ok(count.count)
-}
-
-async fn assert_max_child_position_for_note<'a, E>(executor: E, note_id: ParentId) -> SqlResult<i64>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let assert_max_child_position_for_note_sql =
-        "SELECT MAX(position) as count FROM note_relationships WHERE parent_id = ?";
-
-    let count: RowCount = sqlx::query_as(assert_max_child_position_for_note_sql)
-        .bind(&*note_id)
-        .fetch_one(executor)
-        .await?;
-
-    Ok(count.count)
-}
-
-// After removing a note, recalculate the position of all notes under
-// the parent note, such that there order is now completely
-// sequential.
-async fn close_hole_for_deleted_note<'a, E>(executor: E, parent_id: ParentId, position: i64) -> SqlResult<()>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let close_hole_for_deleted_note_sql = concat!(
-        "UPDATE note_relationships ",
-        "SET position = position - 1 ",
-        "WHERE position > ? and parent_id = ?;"
-    );
-
-    sqlx::query(close_hole_for_deleted_note_sql)
-        .bind(&position)
-        .bind(&*parent_id)
-        .execute(executor)
-        .await
-        .map(|_| ())
-}
-
-async fn find_all_page_references_for<'a, E>(executor: E, references: &[String]) -> SqlResult<Vec<PageTitles>>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let find_all_references_for_sql = "SELECT id, title FROM pages WHERE title IN (".to_string()
-        + &["?"].repeat(references.len()).join(",")
-        + &");".to_string();
-
-    let mut request = sqlx::query_as(&find_all_references_for_sql);
-    for id in references.iter() {
-        request = request.bind(id);
-    }
-    request.fetch_all(executor).await
-}
-
-async fn update_note_content<'a, E>(executor: E, note_id: NoteId, content: &str) -> SqlResult<()>
-where
-    E: Executor<'a, Database = Sqlite>,
-{
-    let update_note_content_sql = "UPDATE notes SET content = ? WHERE note_id = ?";
-    let count = sqlx::query(update_note_content_sql)
-        .bind(content)
-        .bind(&*note_id)
-        .execute(executor)
-        .await?
-        .rows_affected();
-
-    match count {
-        1 => Ok(()),
-        _ => Err(sqlx::Error::RowNotFound),
-    }
-}
-
-fn create_unique_root_note() -> NewNote {
-    NewNoteBuilder::default()
-        .uuid(friendly_id::create())
-        .content("".to_string())
-        .notetype("root".to_string())
-        .build()
-        .unwrap()
-}
-
-fn create_new_page_for(title: &str, slug: &str, note_id: NoteId) -> NewPage {
-    NewPageBuilder::default()
-        .slug(slug.to_string())
-        .title(title.to_string())
-        .note_id(*note_id)
-        .build()
-        .unwrap()
-}
-
-// Given the references supplied, and the references found in the datastore,
-// return a list of the references not found in the datastore.
-fn diff_references(references: &[String], found_references: &[PageTitles]) -> Vec<String> {
-    let all: HashSet<String> = references.iter().cloned().collect();
-    let found: HashSet<String> = found_references.iter().map(|r| r.title.clone()).collect();
-    all.difference(&found).cloned().collect()
-}

server/nm-store/src/store/api.rs

@@ -0,0 +1,254 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+//! # Storage layer for Notesmachine
+//!
+//! This library implements the core functionality of Notesmachine and
+//! describes that functionality to a storage layer.  There's a bit of
+//! intermingling in here which can't be helped, although it may make
+//! sense in the future to separate the decomposition of the note
+//! content into a higher layer.
+//!
+//! Notesmachine storage notes consist of two items: Note and Page.
+//! This distinction is somewhat arbitrary, as structurally these two
+//! items are stored in the same table.
+//!
+//! - Boxes have titles (and date metadata)
+//! - Notes have content and a type (and date metadata)
+//! - Notes are stored in boxes
+//!   - Notes are positioned with respect to other notes.
+//!   - There are two positions:
+//!     - Siblings, creating lists
+//!     - Children, creating trees like this one
+//! - Notes may have references (pointers) to other boxes
+//! - Notes may be moved around
+//! - Notes may be deleted
+//! - Boxes may be deleted
+//! - When a box is renamed, every reference to that box is auto-edited to
+//!   reflect the change. If a box is renamed to match an existing box, the
+//!   notes in both boxes are merged.
+//!   
+//! Note-to-note relationships form trees, and are kept in a SQL database of
+//! (`parent_id`, `child_id`, `position`, `relationship_type`). The
+//! `position` is a monotonic index on the parent (that is, every pair
+//! (`parent_id`, `position`) must be unique).  The `relationship_type` is
+//! an enum and can specify that the relationship is *original*,
+//! *embedding*, or *referencing*.  An embedded or referenced note may be
+//! read/write or read-only with respect to the original, but there is only
+//! one original note at any time.
+//!
+//! Note-to-box relationships form a graph, and are kept in the SQL database
+//! as a collection of *edges* from the note to the box (and naturally
+//! vice-versa).
+//!
+//! - Decision: When an original note is deleted, do all references and
+//!   embeddings also get deleted, or is the oldest one elevated to be a new
+//!   "original"?  Or is that something the user may choose?
+//!
+//! - Decision: Should the merging issue be handled at this layer, or would
+//!   it make sense to move this to a higher layer, and only provide the
+//!   hooks for it here?
+//!
+#![allow(clippy::len_zero)]
+use crate::errors::NoteStoreError;
+use crate::parser::build_references;
+use crate::store::private::*;
+use crate::structs::*;
+use sqlx::sqlite::SqlitePool;
+use std::sync::Arc;
+
+/// A handle to our Sqlite database.
+#[derive(Clone, Debug)]
+pub struct NoteStore(Arc<SqlitePool>);
+
+pub type NoteResult<T> = core::result::Result<T, NoteStoreError>;
+
+// After wrestling for a while with the fact that 'box' is a reserved
+// word in Rust, I decided to just go with Note (note) and Page
+// (box).
+
+impl NoteStore {
+    /// Initializes a new instance of the note store.  Note that the
+    /// note store holds an Arc internally; this code is (I think)
+    /// safe to Send.
+    pub async fn new(url: &str) -> NoteResult<Self> {
+        let pool = SqlitePool::connect(url).await?;
+        Ok(NoteStore(Arc::new(pool)))
+    }
+    /// Erase all the data in the database and restore it
+    /// to its original empty form.  Do not use unless you
+    /// really, really want that to happen.
+    pub async fn reset_database(&self) -> NoteResult<()> {
+        reset_database(&*self.0).await.map_err(NoteStoreError::DBError)
+    }
+
+    /// Fetch page by slug
+    ///
+    /// Supports the use case of the user navigating to a known place
+    /// via a bookmark or other URL.  Since the title isn't clear from
+    /// the slug, the slug is insufficient to generate a new page, so
+    /// this use case says that in the event of a failure to find the
+    /// requested page, return a basic NotFound.
+    pub async fn get_page_by_slug(&self, slug: &str) -> NoteResult<(Vec<Note>, Vec<Note>)> {
+        let page = select_page_by_slug(&*self.0, slug).await?;
+        if page.is_empty() {
+            return Err(NoteStoreError::NotFound);
+        }
+
+        let note_id = &page[0].id;
+        let backreferences = select_backreferences_for_page(&*self.0, &note_id).await?;
+        Ok((page, backreferences))
+    }
+
+    /// Fetch page by title
+    ///
+    /// The most common use case: the user is navigating by requesting
+    /// a page.  The page either exists or it doesn't.  If it
+    /// doesn't, we go out and make it.  Since we know it doesn't exist,
+    /// we also know no backreferences to it exist, so in that case you
+    /// get back two empty vecs.
+    pub async fn get_page_by_title(&self, title: &str) -> NoteResult<(Vec<Note>, Vec<Note>)> {
+        if title.is_empty() {
+            return Err(NoteStoreError::NotFound);
+        }
+
+        let page = select_page_by_title(&*self.0, title).await?;
+        if page.len() > 0 {
+            let note_id = &page[0].id;
+            let backreferences = select_backreferences_for_page(&*self.0, &note_id).await?;
+            return Ok((page, backreferences));
+        }
+
+        // Sanity check!
+        let references = build_references(&title);
+        if references.len() > 0 {
+            return Err(NoteStoreError::InvalidNoteStructure(
+                "Titles may not contain nested references.".to_string(),
+            ));
+        }
+
+        let mut tx = self.0.begin().await?;
+        let slug = generate_slug(&mut tx, title).await?;
+        let page = create_page(&title, &slug);
+        insert_note(&mut tx, &page).await?;
+        tx.commit().await?;
+
+        Ok((vec![Note::from(page)], vec![]))
+    }
+
+    pub async fn add_note(&self, note: &NewNote, parent_id: &str, location: Option<i64>) -> NoteResult<String> {
+        let kind = RelationshipKind::Direct;
+        let new_id = self.insert_note(note, parent_id, location, kind).await?;
+        Ok(new_id)
+    }
+
+    /// Move a note from one location to another.
+    pub async fn move_note(
+        &self,
+        note_id: &str,
+        old_parent_id: &str,
+        new_parent_id: &str,
+        new_location: i64,
+    ) -> NoteResult<()> {
+        let mut tx = self.0.begin().await?;
+
+        let old_note = select_note_to_note_relationship(&mut tx, &old_parent_id, &note_id).await?;
+        let old_note_location = old_note.location;
+        let old_note_kind = old_note.kind;
+
+        delete_note_to_note_relationship(&mut tx, &old_parent_id, &note_id).await?;
+        close_hole_for_deleted_note_relationship(&mut tx, &old_parent_id, old_note_location).await?;
+        let new_location = determine_max_child_location_for_note(&mut tx, &new_parent_id, Some(new_location)).await?;
+        make_room_for_new_note_relationship(&mut tx, &new_parent_id, new_location).await?;
+        insert_note_to_note_relationship(&mut tx, &new_parent_id, &note_id, new_location, &old_note_kind).await?;
+        tx.commit().await?;
+        Ok(())
+    }
+
+    /// Updates a note's content.  Completely rebuilds the note's
+    /// outgoing edge reference list every time.
+    pub async fn update_note_content(&self, note_id: &str, content: &str) -> NoteResult<()> {
+        let references = build_references(&content);
+        let mut tx = self.0.begin().await?;
+        update_note_content(&mut tx, &note_id, &content).await?;
+        delete_bulk_note_to_page_relationships(&mut tx, &note_id).await?;
+        let known_reference_ids = validate_or_generate_all_found_references(&mut tx, &references).await?;
+        insert_bulk_note_to_page_relationships(&mut tx, &note_id, &known_reference_ids).await?;
+        tx.commit().await?;
+        Ok(())
+    }
+
+    /// Deletes a note.  If the note's relationship drops to zero, all
+    /// references from that note to pages are also deleted.
+    pub async fn delete_note(&self, note_id: &str, note_parent_id: &str) -> NoteResult<()> {
+        let mut tx = self.0.begin().await?;
+
+        let note_id = note_id.to_string();
+        let parent_id = note_parent_id.to_string();
+
+        if parent_id != note_id {
+            delete_note_to_note_relationship(&mut tx, &parent_id, &note_id).await?;
+        }
+        // The big one: if zero parents report having an interest in this note, then it,
+        // *and any sub-relationships*, go away.
+        if count_existing_note_relationships(&mut tx, &note_id).await? == 0 {
+            delete_note_to_page_relationships(&mut tx, &note_id).await?;
+            delete_note(&mut tx, &note_id).await?;
+        }
+        tx.commit().await?;
+        Ok(())
+    }
+}
+
+// The Private stuff
+
+impl NoteStore {
+    // Pretty much the most dangerous function in our system. Has to
+    // have ALL the error checking.
+    async fn insert_note(
+        &self,
+        note: &NewNote,
+        parent_id: &str,
+        location: Option<i64>,
+        kind: RelationshipKind,
+    ) -> NoteResult<String> {
+        if let Some(location) = location {
+            if location < 0 {
+                return Err(NoteStoreError::InvalidNoteStructure(
+                    "Add note: A negative location is not valid.".to_string(),
+                ));
+            }
+        }
+
+        if parent_id.is_empty() {
+            return Err(NoteStoreError::InvalidNoteStructure(
+                "Add note: A parent note ID is required.".to_string(),
+            ));
+        }
+
+        if note.id.is_empty() {
+            return Err(NoteStoreError::InvalidNoteStructure(
+                "Add note: Your note should have an id already".to_string(),
+            ));
+        }
+
+        if note.content.is_empty() {
+            return Err(NoteStoreError::InvalidNoteStructure(
+                "Add note: Empty notes are not supported.".to_string(),
+            ));
+        }
+
+        let references = build_references(&note.content);
+
+        let mut tx = self.0.begin().await?;
+        let location = determine_max_child_location_for_note(&mut tx, parent_id, location).await?;
+        insert_note(&mut tx, &note).await?;
+        make_room_for_new_note_relationship(&mut tx, &parent_id, location).await?;
+        insert_note_to_note_relationship(&mut tx, &parent_id, &note.id, location, &kind).await?;
+        let known_reference_ids = validate_or_generate_all_found_references(&mut tx, &references).await?;
+        insert_bulk_note_to_page_relationships(&mut tx, &note.id, &known_reference_ids).await?;
+        tx.commit().await?;
+        Ok(note.id.to_string())
+    }
+}

server/nm-store/src/store/mod.rs

@@ -0,0 +1,58 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+//! # Storage layer for Notesmachine
+//!
+//! This library implements the core functionality of Notesmachine and
+//! describes that functionality to a storage layer.  There's a bit of
+//! intermingling in here which can't be helped, although it may make
+//! sense in the future to separate the decomposition of the note
+//! content into a higher layer.
+//!
+//! Notesmachine storage notes consist of two items: Note and Kasten.
+//! This distinction is somewhat arbitrary, as structurally these two
+//! items are stored in the same table.
+//!
+//! - Boxes have titles (and date metadata)
+//! - Notes have content and a type (and date metadata)
+//! - Notes are stored in boxes
+//!   - Notes are positioned with respect to other notes.
+//!   - There are two positions:
+//!     - Siblings, creating lists
+//!     - Children, creating trees like this one
+//! - Notes may have references (pointers) to other boxes
+//! - Notes may be moved around
+//! - Notes may be deleted
+//! - Boxes may be deleted
+//! - When a box is renamed, every reference to that box is auto-edited to
+//!   reflect the change. If a box is renamed to match an existing box, the
+//!   notes in both boxes are merged.
+//!   
+//! Note-to-note relationships form trees, and are kept in a SQL database of
+//! (`parent_id`, `child_id`, `position`, `relationship_type`). The
+//! `position` is a monotonic index on the parent (that is, every pair
+//! (`parent_id`, `position`) must be unique).  The `relationship_type` is
+//! an enum and can specify that the relationship is *original*,
+//! *embedding*, or *referencing*.  An embedded or referenced note may be
+//! read/write or read-only with respect to the original, but there is only
+//! one original note at any time.
+//!
+//! Note-to-box relationships form a graph, and are kept in the SQL database
+//! as a collection of *edges* from the note to the box (and naturally
+//! vice-versa).
+//!
+//! - Decision: When an original note is deleted, do all references and
+//!   embeddings also get deleted, or is the oldest one elevated to be a new
+//!   "original"?  Or is that something the user may choose?
+//!
+//! - Decision: Should the merging issue be handled at this layer, or would
+//!   it make sense to move this to a higher layer, and only provide the
+//!   hooks for it here?
+//!
+
+mod api;
+mod private;
+
+pub use crate::store::api::NoteResult;
+pub use crate::store::api::NoteStore;

server/nm-store/src/store/private.rs

@@ -0,0 +1,594 @@
+use crate::structs::*;
+use lazy_static::lazy_static;
+use regex::Regex;
+use slug::slugify;
+use sqlx::{sqlite::Sqlite, Acquire, Done, Executor, Transaction};
+use std::cmp;
+use std::collections::HashSet;
+
+type SqlResult<T> = sqlx::Result<T>;
+
+//  ___     _          _
+// | _ \_ _(_)_ ____ _| |_ ___
+// |  _/ '_| \ V / _` |  _/ -_)
+// |_| |_| |_|\_/\__,_|\__\___|
+//
+
+// I'm putting a lot of faith in Rust's ability to inline stuff.  I'm
+// sure this is okay.  But really, this lets the API be clean and
+// coherent and easily readable, and hides away the gnarliness of some
+// of the SQL queries.
+
+lazy_static! {
+    static ref SELECT_PAGE_BY_TITLE_SQL: String = str::replace(
+        include_str!("sql/select_notes_by_parameter.sql"),
+        "QUERYPARAMETER",
+        "notes.content"
+    );
+}
+
+lazy_static! {
+    static ref SELECT_PAGE_BY_ID_SQL: String = str::replace(
+        include_str!("sql/select_notes_by_parameter.sql"),
+        "QUERYPARAMETER",
+        "notes.id"
+    );
+}
+
+lazy_static! {
+    static ref SELECT_NOTES_BACKREFERENCING_PAGE_SQL: &'static str =
+        include_str!("sql/select_notes_backreferencing_page.sql");
+}
+
+//  ___             _
+// | _ \___ ___ ___| |_
+// |   / -_|_-</ -_)  _|
+// |_|_\___/__/\___|\__|
+//
+
+pub(crate) async fn reset_database<'a, E>(executor: E) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let initialize_sql = include_str!("sql/initialize_database.sql");
+    sqlx::query(initialize_sql).execute(executor).await.map(|_| ())
+}
+
+//  ___    _      _      _  __        _
+// | __|__| |_ __| |_   | |/ /__ _ __| |_ ___ _ _
+// | _/ -_)  _/ _| ' \  | ' </ _` (_-<  _/ -_) ' \
+// |_|\___|\__\__|_||_| |_|\_\__,_/__/\__\___|_||_|
+//
+
+// The next three functions are essentially the same, although the internal
+// SQL operations are quite different between the first two and the last.
+async fn select_object_by_query<'a, E>(executor: E, query: &str, field: &str) -> SqlResult<Vec<Note>>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let r: Vec<RowNote> = sqlx::query_as(query).bind(field).fetch_all(executor).await?;
+    Ok(r.into_iter().map(Note::from).collect())
+}
+
+// Select the requested page via its id.  This is fairly rare;
+// pages should usually be picked up via their title, but if you're
+// navigating to an instance, this is how you specify the page in a
+// URL.  The return value is an array of Note objects; it is the
+// responsibility of client code to restructure these into a tree-like
+// object.
+//
+// Recommended: Clients should update the URL whenever changing
+// page.
+pub(crate) async fn select_page_by_slug<'a, E>(executor: E, slug: &str) -> SqlResult<Vec<Note>>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    select_object_by_query(executor, &SELECT_PAGE_BY_ID_SQL, &slug).await
+}
+
+// Fetch the page by title.  The return value is an array of Note
+// objects; it is the responsibility of client code to restructure
+// these into a tree-like object.
+pub(crate) async fn select_page_by_title<'a, E>(executor: E, title: &str) -> SqlResult<Vec<Note>>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    select_object_by_query(executor, &SELECT_PAGE_BY_TITLE_SQL, &title).await
+}
+
+// Fetch all backreferences to a page.  The return value is an array
+// of arrays, and inside each array is a list from a root page to
+// the note that references the give page.  Clients may choose how
+// they want to display that collection.
+pub(crate) async fn select_backreferences_for_page<'a, E>(executor: E, page_id: &str) -> SqlResult<Vec<Note>>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    select_object_by_query(executor, &SELECT_NOTES_BACKREFERENCING_PAGE_SQL, &page_id).await
+}
+
+//  ___                  _      ___             _  _     _
+// |_ _|_ _  ___ ___ _ _| |_   / _ \ _ _  ___  | \| |___| |_ ___
+//  | || ' \(_-</ -_) '_|  _| | (_) | ' \/ -_) | .` / _ \  _/ -_)
+// |___|_||_/__/\___|_|  \__|  \___/|_||_\___| |_|\_\___/\__\___|
+//
+
+// Inserts a single note into the notes table.  That is all.
+pub(crate) async fn insert_note<'a, E>(executor: E, note: &NewNote) -> SqlResult<String>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let insert_one_note_sql = concat!(
+        "INSERT INTO notes (id, content, kind, ",
+        "                   creation_date, updated_date, lastview_date) ",
+        "VALUES (?, ?, ?, ?, ?, ?);"
+    );
+
+    sqlx::query(insert_one_note_sql)
+        .bind(&note.id)
+        .bind(&note.content)
+        .bind(note.kind.to_string())
+        .bind(&note.creation_date)
+        .bind(&note.updated_date)
+        .bind(&note.lastview_date)
+        .execute(executor)
+        .await?;
+    Ok(note.id.clone())
+}
+
+// Inserts a single note into the notes table.  That is all.
+pub(crate) async fn insert_bulk_notes<'a, E>(executor: E, notes: &[NewNote]) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    if notes.is_empty() {
+        return Ok(());
+    }
+
+    let insert_pattern = "VALUES (?, ?, ?, ?, ?, ?)".to_string();
+    let insert_bulk_notes_sql = "INSERT INTO notes (id, content, kind, creation_date, updated_date, lastview_date) "
+        .to_string()
+        + &[insert_pattern.as_str()].repeat(notes.len()).join(", ")
+        + &";".to_string();
+
+    let mut request = sqlx::query(&insert_bulk_notes_sql);
+    for note in notes {
+        request = request
+            .bind(&note.id)
+            .bind(&note.content)
+            .bind(note.kind.to_string())
+            .bind(&note.creation_date)
+            .bind(&note.updated_date)
+            .bind(&note.lastview_date);
+    }
+    request.execute(executor).await.map(|_| ())
+}
+
+//  ___      _ _    _   _  __        _
+// | _ )_  _(_) |__| | | |/ /__ _ __| |_ ___ _ _
+// | _ \ || | | / _` | | ' </ _` (_-<  _/ -_) ' \
+// |___/\_,_|_|_\__,_| |_|\_\__,_/__/\__\___|_||_|
+//
+
+// Given a possible slug, find the slug with the highest
+// uniquification number, and return that number, if any.
+pub(crate) fn find_maximal_slug_number(slugs: &[JustId]) -> Option<u32> {
+    lazy_static! {
+        static ref RE_CAP_NUM: Regex = Regex::new(r"-(\d+)$").unwrap();
+    }
+
+    if slugs.is_empty() {
+        return None;
+    }
+
+    let mut slug_counters: Vec<u32> = slugs
+        .iter()
+        .filter_map(|slug| RE_CAP_NUM.captures(&slug.id))
+        .map(|cap| cap.get(1).unwrap().as_str().parse::<u32>().unwrap())
+        .collect();
+    slug_counters.sort_unstable();
+    slug_counters.pop()
+}
+
+// Given an initial string and an existing collection of slugs,
+// generate a new slug that does not conflict with the current
+// collection.  Right now we're using the slugify operation, which...
+// isn't all that.
+pub(crate) async fn generate_slug<'a, E>(executor: E, title: &str) -> SqlResult<String>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    lazy_static! {
+        static ref RE_STRIP_NUM: Regex = Regex::new(r"-\d+$").unwrap();
+        static ref SLUG_FINDER_SQL: String = format!(
+            "SELECT id FROM notes WHERE kind = '{}' AND id LIKE '?%';",
+            NoteKind::Page.to_string()
+        );
+    }
+
+    let initial_slug = slugify(title);
+    let sample_slug = RE_STRIP_NUM.replace_all(&initial_slug, "");
+    let similar_slugs: Vec<JustId> = sqlx::query_as(&SLUG_FINDER_SQL)
+        .bind(&*sample_slug)
+        .fetch_all(executor)
+        .await?;
+    let maximal_slug_number = find_maximal_slug_number(&similar_slugs);
+    Ok(match maximal_slug_number {
+        None => initial_slug,
+        Some(slug_number) => format!("{}-{}", initial_slug, slug_number + 1),
+    })
+}
+
+// A helper function: given a title and a slug, create a PageType
+// note.
+pub(crate) fn create_page(title: &str, slug: &str) -> NewNote {
+    NewNoteBuilder::default()
+        .id(slug.to_string())
+        .content(title.to_string())
+        .kind(NoteKind::Page)
+        .build()
+        .unwrap()
+}
+
+//  _   _          _      _          ___             _  _     _
+// | | | |_ __  __| |__ _| |_ ___   / _ \ _ _  ___  | \| |___| |_ ___
+// | |_| | '_ \/ _` / _` |  _/ -_) | (_) | ' \/ -_) | .` / _ \  _/ -_)
+//  \___/| .__/\__,_\__,_|\__\___|  \___/|_||_\___| |_|\_\___/\__\___|
+//       |_|
+
+pub(crate) async fn update_note_content<'a, E>(executor: E, note_id: &str, content: &str) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let update_note_content_sql = "UPDATE notes SET content = ? WHERE note_id = ?";
+    let count = sqlx::query(update_note_content_sql)
+        .bind(content)
+        .bind(note_id)
+        .execute(executor)
+        .await?
+        .rows_affected();
+
+    match count {
+        1 => Ok(()),
+        _ => Err(sqlx::Error::RowNotFound),
+    }
+}
+
+//  ___    _      _       ___             _  _     _         ___     _      _   _             _    _
+// | __|__| |_ __| |_    / _ \ _ _  ___  | \| |___| |_ ___  | _ \___| |__ _| |_(_)___ _ _  __| |_ (_)_ __
+// | _/ -_)  _/ _| ' \  | (_) | ' \/ -_) | .` / _ \  _/ -_) |   / -_) / _` |  _| / _ \ ' \(_-< ' \| | '_ \
+// |_|\___|\__\__|_||_|  \___/|_||_\___| |_|\_\___/\__\___| |_|_\___|_\__,_|\__|_\___/_||_/__/_||_|_| .__/
+//                                                                                                  |_|
+
+pub(crate) async fn select_note_to_note_relationship<'a, E>(
+    executor: E,
+    parent_id: &str,
+    note_id: &str,
+) -> SqlResult<NoteRelationship>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let get_note_to_note_relationship_sql = concat!(
+        "SELECT parent_id, note_id, location, kind ",
+        "FROM note_relationships ",
+        "WHERE parent_id = ? and note_id = ? ",
+        "LIMIT 1"
+    );
+    let s: NoteRelationshipRow = sqlx::query_as(get_note_to_note_relationship_sql)
+        .bind(parent_id)
+        .bind(note_id)
+        .fetch_one(executor)
+        .await?;
+    Ok(NoteRelationship::from(s))
+}
+
+//  _  _     _         _         _  _     _         ___     _      _   _             _    _
+// | \| |___| |_ ___  | |_ ___  | \| |___| |_ ___  | _ \___| |__ _| |_(_)___ _ _  __| |_ (_)_ __ ___
+// | .` / _ \  _/ -_) |  _/ _ \ | .` / _ \  _/ -_) |   / -_) / _` |  _| / _ \ ' \(_-< ' \| | '_ (_-<
+// |_|\_\___/\__\___|  \__\___/ |_|\_\___/\__\___| |_|_\___|_\__,_|\__|_\___/_||_/__/_||_|_| .__/__/
+//                                                                                         |_|
+
+pub(crate) async fn insert_note_to_note_relationship<'a, E>(
+    executor: E,
+    parent_id: &str,
+    note_id: &str,
+    location: i64,
+    kind: &RelationshipKind,
+) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let insert_note_to_note_relationship_sql = concat!(
+        "INSERT INTO note_relationships (parent_id, note_id, location, kind) ",
+        "values (?, ?, ?, ?)"
+    );
+
+    sqlx::query(insert_note_to_note_relationship_sql)
+        .bind(parent_id)
+        .bind(note_id)
+        .bind(&location)
+        .bind(kind.to_string())
+        .execute(executor)
+        .await?;
+    Ok(())
+}
+
+pub(crate) async fn make_room_for_new_note_relationship<'a, E>(
+    executor: E,
+    parent_id: &str,
+    location: i64,
+) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let make_room_for_new_note_sql = concat!(
+        "UPDATE note_relationships ",
+        "SET location = location + 1 ",
+        "WHERE location >= ? and parent_id = ?;"
+    );
+
+    sqlx::query(make_room_for_new_note_sql)
+        .bind(&location)
+        .bind(parent_id)
+        .execute(executor)
+        .await?;
+    Ok(())
+}
+
+pub(crate) async fn determine_max_child_location_for_note<'a, E>(
+    executor: E,
+    note_id: &str,
+    comp_loc: Option<i64>,
+) -> SqlResult<i64>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let row_count = assert_max_child_location_for_note(executor, note_id).await? + 1;
+    Ok(match comp_loc {
+        Some(location) => cmp::min(row_count, location),
+        None => row_count,
+    })
+}
+
+pub(crate) async fn assert_max_child_location_for_note<'a, E>(executor: E, note_id: &str) -> SqlResult<i64>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let assert_max_child_location_for_note_sql =
+        "SELECT MAX(location) AS count FROM note_relationships WHERE parent_id = ?;";
+
+    let count: RowCount = sqlx::query_as(assert_max_child_location_for_note_sql)
+        .bind(note_id)
+        .fetch_one(executor)
+        .await?;
+
+    Ok(count.count)
+}
+
+//  _  _     _         _         _  __        _              ___     _      _   _             _    _
+// | \| |___| |_ ___  | |_ ___  | |/ /__ _ __| |_ ___ _ _   | _ \___| |__ _| |_(_)___ _ _  __| |_ (_)_ __ ___
+// | .` / _ \  _/ -_) |  _/ _ \ | ' </ _` (_-<  _/ -_) ' \  |   / -_) / _` |  _| / _ \ ' \(_-< ' \| | '_ (_-<
+// |_|\_\___/\__\___|  \__\___/ |_|\_\__,_/__/\__\___|_||_| |_|_\___|_\__,_|\__|_\___/_||_/__/_||_|_| .__/__/
+//                                                                                                  |_|
+
+pub(crate) async fn insert_bulk_note_to_page_relationships<'a, E>(
+    executor: E,
+    note_id: &str,
+    references: &[String],
+) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    if references.is_empty() {
+        return Ok(());
+    }
+
+    let insert_pattern = format!("(?, ?, '{}')", PageRelationshipKind::Page.to_string());
+    let insert_note_page_references_sql = "INSERT INTO note_page_relationships (note_id, page_id, kind) VALUES "
+        .to_string()
+        + &[insert_pattern.as_str()].repeat(references.len()).join(", ")
+        + &";".to_string();
+
+    let mut request = sqlx::query(&insert_note_page_references_sql);
+    for reference in references {
+        request = request.bind(note_id).bind(reference);
+    }
+
+    request.execute(executor).await.map(|_| ())
+}
+
+pub(crate) async fn delete_bulk_note_to_page_relationships<'a, E>(executor: E, note_id: &str) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let delete_note_to_page_relationship_sql = "DELETE FROM note_page_relationships WHERE and note_id = ?;";
+    sqlx::query(delete_note_to_page_relationship_sql)
+        .bind(note_id)
+        .execute(executor)
+        .await?;
+    Ok(())
+}
+
+// Given the references supplied, and the references found in the datastore,
+// return a list of the references not found in the datastore.
+pub(crate) fn diff_references(references: &[String], found_references: &[PageTitle]) -> Vec<String> {
+    let all: HashSet<String> = references.iter().cloned().collect();
+    let found: HashSet<String> = found_references.iter().map(|r| r.content.clone()).collect();
+    all.difference(&found).cloned().collect()
+}
+
+//   ___         _           _     _         _  __        _              ___     _      _   _             _    _
+//  / __|___ _ _| |_ ___ _ _| |_  | |_ ___  | |/ /__ _ __| |_ ___ _ _   | _ \___| |__ _| |_(_)___ _ _  __| |_ (_)_ __ ___
+// | (__/ _ \ ' \  _/ -_) ' \  _| |  _/ _ \ | ' </ _` (_-<  _/ -_) ' \  |   / -_) / _` |  _| / _ \ ' \(_-< ' \| | '_ (_-<
+//  \___\___/_||_\__\___|_||_\__|  \__\___/ |_|\_\__,_/__/\__\___|_||_| |_|_\___|_\__,_|\__|_\___/_||_/__/_||_|_| .__/__/
+//                                                                                                              |_|
+
+// Returns all the (Id, title) pairs found in the database out of a
+// list of titles.  Used by insert_note and update_note_content to
+// find the ids of all the references in a given document.
+pub(crate) async fn find_all_page_from_list_of_references<'a, E>(
+    executor: E,
+    references: &[String],
+) -> SqlResult<Vec<PageTitle>>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    if references.is_empty() {
+        return Ok(vec![]);
+    }
+
+    lazy_static! {
+        static ref SELECT_ALL_REFERENCES_FOR_SQL_BASE: String = format!(
+            "SELECT id, content FROM notes WHERE kind = '{}' AND content IN (",
+            NoteKind::Page.to_string()
+        );
+    }
+
+    let find_all_references_for_sql =
+        SELECT_ALL_REFERENCES_FOR_SQL_BASE.to_string() + &["?"].repeat(references.len()).join(",") + &");".to_string();
+
+    let mut request = sqlx::query_as(&find_all_references_for_sql);
+    for id in references.iter() {
+        request = request.bind(id);
+    }
+    request.fetch_all(executor).await
+}
+
+//  ___      _     _
+// |   \ ___| |___| |_ ___
+// | |) / -_) / -_)  _/ -_)
+// |___/\___|_\___|\__\___|
+//
+
+pub(crate) async fn delete_note_to_note_relationship<'a, E>(
+    executor: E,
+    parent_id: &str,
+    note_id: &str,
+) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let delete_note_to_note_relationship_sql = concat!(
+        "DELETE FROM note_relationships ",
+        "WHERE parent_id = ? and note_id = ? "
+    );
+
+    let count = sqlx::query(delete_note_to_note_relationship_sql)
+        .bind(parent_id)
+        .bind(note_id)
+        .execute(executor)
+        .await?
+        .rows_affected();
+
+    match count {
+        1 => Ok(()),
+        _ => Err(sqlx::Error::RowNotFound),
+    }
+}
+
+pub(crate) async fn delete_note_to_page_relationships<'a, E>(executor: E, note_id: &str) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    lazy_static! {
+        static ref DELETE_NOTE_TO_PAGE_RELATIONSHIPS_SQL: String = format!(
+            "DELETE FROM note_relationships WHERE kind in ('{}', '{}') AND parent_id = ?;",
+            PageRelationshipKind::Page.to_string(),
+            PageRelationshipKind::Unacked.to_string()
+        );
+    }
+
+    sqlx::query(&DELETE_NOTE_TO_PAGE_RELATIONSHIPS_SQL)
+        .bind(note_id)
+        .execute(executor)
+        .await?;
+    Ok(())
+}
+
+pub(crate) async fn delete_note<'a, E>(executor: E, note_id: &str) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let delete_note_sql = "DELETE FROM notes WHERE note_id = ?";
+
+    let count = sqlx::query(delete_note_sql)
+        .bind(note_id)
+        .execute(executor)
+        .await?
+        .rows_affected();
+
+    match count {
+        1 => Ok(()),
+        _ => Err(sqlx::Error::RowNotFound),
+    }
+}
+
+// After removing a note, recalculate the position of all notes under
+// the parent note, such that there order is now completely
+// sequential.
+pub(crate) async fn close_hole_for_deleted_note_relationship<'a, E>(
+    executor: E,
+    parent_id: &str,
+    location: i64,
+) -> SqlResult<()>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let close_hole_for_deleted_note_sql = concat!(
+        "UPDATE note_relationships ",
+        "SET location = location - 1 ",
+        "WHERE location > ? and parent_id = ?;"
+    );
+
+    sqlx::query(close_hole_for_deleted_note_sql)
+        .bind(&location)
+        .bind(parent_id)
+        .execute(executor)
+        .await?;
+    Ok(())
+}
+
+// Given a list of references found in the content, generate the
+// references that do not previously exist, returning all found
+// references.  NOTE: The function signature for this is for a
+// transaction, and uses a nested transaction.
+pub(crate) async fn validate_or_generate_all_found_references(
+    txi: &mut Transaction<'_, Sqlite>,
+    references: &[String],
+) -> SqlResult<Vec<String>> {
+    let mut tx = txi.begin().await?;
+
+    let found_references = find_all_page_from_list_of_references(&mut tx, &references).await?;
+    let new_references = diff_references(&references, &found_references);
+    let mut new_page: Vec<NewNote> = vec![];
+    for one_reference in new_references.iter() {
+        let slug = generate_slug(&mut tx, one_reference).await?;
+        new_page.push(create_page(&one_reference, &slug));
+    }
+    insert_bulk_notes(&mut tx, &new_page).await?;
+
+    let mut all_reference_ids: Vec<String> = found_references.iter().map(|r| r.id.clone()).collect();
+    all_reference_ids.append(&mut new_page.iter().map(|r| r.id.clone()).collect());
+    tx.commit().await?;
+    Ok(all_reference_ids)
+}
+
+//  __  __ _
+// |  \/  (_)___ __
+// | |\/| | (_-</ _|
+// |_|  |_|_/__/\__|
+//
+
+// The dreaded miscellaneous!
+
+pub(crate) async fn count_existing_note_relationships<'a, E>(executor: E, note_id: &str) -> SqlResult<i64>
+where
+    E: Executor<'a, Database = Sqlite>,
+{
+    let count_existing_note_relationships_sql = "SELECT COUNT(*) as count FROM note_relationships WHERE note_id = ?;";
+    let count: RowCount = sqlx::query_as(&count_existing_note_relationships_sql)
+        .bind(note_id)
+        .fetch_one(executor)
+        .await?;
+    Ok(count.count)
+}

server/nm-store/src/store/sql/initialize_database.sql

@@ -0,0 +1,58 @@
+DROP TABLE IF EXISTS notes;
+DROP TABLE IF EXISTS note_relationships;
+DROP TABLE IF EXISTS note_page_relationships;
+DROP TABLE IF EXISTS favorites;
+
+CREATE TABLE notes (
+    id TEXT NOT NULL PRIMARY KEY,
+    content TEXT NOT NULL,
+    kind TEXT NOT NULL,
+	creation_date DATETIME NOT NULL,
+	updated_date DATETIME NOT NULL,
+	lastview_date DATETIME NOT NULL,
+	deleted_date DATETIME NULL
+);
+
+CREATE INDEX note_ids ON notes (id);
+
+CREATE TABLE favorites (
+	id TEXT NOT NULL UNIQUE,
+    location INTEGER NOT NULL,
+    FOREIGN KEY (id) REFERENCES notes (id) ON DELETE CASCADE
+);
+
+-- This table represents the forest of data relating a page to its
+-- collections of notes.  The root is itself "a note," but the content
+-- of that note will always be just the title of the page.
+--
+CREATE TABLE note_relationships (
+    note_id TEXT NOT NULL,
+    parent_id TEXT NOT NULL,
+    location INTEGER NOT NULL,
+    kind TEXT NOT NULL,
+	-- If either note disappears, we want all the edges to disappear as well.
+    FOREIGN KEY (note_id) REFERENCES notes (id) ON DELETE CASCADE,
+    FOREIGN KEY (parent_id) REFERENCES notes (id) ON DELETE CASCADE,
+	UNIQUE (note_id, parent_id),
+	CHECK (note_id <> parent_id)
+);
+
+-- This table represents the graph of data relating notes to pages.
+--
+CREATE TABLE note_page_relationships (
+    note_id TEXT NOT NULL,
+    page_id TEXT NOT NULL,
+    kind TEXT NOT NULL,
+	-- If either note disappears, we want all the edges to disappear as well.
+    FOREIGN KEY (note_id) REFERENCES notes (id) ON DELETE CASCADE,
+    FOREIGN KEY (page_id) REFERENCES notes (id) ON DELETE CASCADE,
+	UNIQUE (note_id, page_id),
+	CHECK (note_id <> page_id)
+);
+
+-- A fabulous constraint. This index prevents us from saying that
+-- if a note points to a page, the page may not point to a
+-- note.  Now, it's absolutely required that a page_id point to
+-- a PageType note; the content should be a title only.
+CREATE UNIQUE INDEX note_page_unique_idx 
+  ON note_page_relationships (MIN(note_id, page_id), MAX(note_id, page_id));

server/nm-store/src/store/sql/select_notes_backreferencing_page.sql

@@ -0,0 +1,72 @@
+SELECT
+  id,
+  parent_id,
+  content,
+  location,
+  kind,
+  creation_date,
+  updated_date,
+  lastview_date,
+  deleted_date
+
+FROM (
+
+  WITH RECURSIVE parents (
+    id,
+    parent_id,
+    content,
+    location,
+    kind,
+    creation_date,
+    updated_date,
+    lastview_date,
+    deleted_date,
+    cycle
+  )
+
+  AS (
+
+    SELECT
+           notes.id,
+           note_parents.id,
+           notes.content,
+		   note_relationships.location,
+           notes.kind,
+           notes.creation_date,
+           notes.updated_date,
+           notes.lastview_date,
+           notes.deleted_date,
+           ','||notes.id||','
+      FROM notes
+        INNER JOIN note_relationships
+          ON notes.id = note_relationships.note_id
+          AND notes.kind = 'note'
+        INNER JOIN notes as note_parents
+          ON note_parents.id = note_relationships.parent_id
+      WHERE notes.id
+	    IN (SELECT note_id
+		      FROM note_page_relationships
+			    WHERE page_id = ?)  -- IMPORTANT: THIS IS THE PARAMETER
+
+    UNION
+	SELECT DISTINCT
+	       notes.id,
+		   next_parent.id,
+      	   notes.content,
+		   note_relationships.location,
+		   notes.kind,
+      	   notes.creation_date,
+      	   notes.updated_date,
+      	   notes.lastview_date,
+      	   notes.deleted_date,
+      	   parents.cycle||notes.id||','
+      FROM notes
+      INNER JOIN parents
+	    ON parents.parent_id = notes.id
+	  LEFT JOIN note_relationships
+	    ON note_relationships.note_id = notes.id
+	  LEFT JOIN notes as next_parent
+	    ON next_parent.id = note_relationships.parent_id
+      WHERE parents.cycle NOT LIKE '%,'||notes.id||',%'
+  )
+  SELECT * from parents);

server/nm-store/src/store/sql/select_notes_by_parameter.sql

@@ -0,0 +1,98 @@
+-- This is undoubtedly one of the more complex bits of code I've
+-- written recently, and I do wish there had been macros because
+-- there's a lot of hand-written, copy-pasted code here around the
+-- basic content of a note; it would have been nice to be able to DRY
+-- that out.
+
+-- This expression creates a table, 'notetree', that contains all of
+-- the notes nested under a page.  Each entry in the table includes
+-- the note's parent's internal and external ids so that applications
+-- can build an actual tree out of a vec of these things.
+
+-- TODO: Extensive testing to validate that the nodes are delivered
+-- *in nesting order* to the client.
+
+-- Search in here for the term QUERYPARAMETER.  That string will be
+-- substituted with the correct parameter (id or title) depending on
+-- the use case, by the level 1 client (the private parts of
+-- store.rs).
+
+SELECT
+  id,
+  parent_id,
+  content,
+  location,
+  kind,
+  creation_date,
+  updated_date,
+  lastview_date,
+  deleted_date
+
+FROM (
+
+  WITH RECURSIVE notestree (
+    id,
+    parent_id,
+    content,
+    location,
+    kind,
+    creation_date,
+    updated_date,
+    lastview_date,
+    deleted_date,
+    cycle
+  )
+
+  AS (
+
+    -- The seed query.  Finds the root node of any tree of notes,
+    -- which by definition has a location of zero and a type of
+    -- 'page'.
+    SELECT
+      notes.id,
+      NULL as parent_id,
+      notes.content,
+      0, -- All boxes are at position zero. They are the root of the tree.
+      notes.kind,
+      notes.creation_date,
+      notes.updated_date,
+      notes.lastview_date,
+      notes.deleted_date,
+      ','||notes.id||','  -- Cycle monitor
+     FROM notes
+     WHERE notes.kind = "box"
+       AND QUERYPARAMETER = ? -- The Query Parameter
+
+    -- RECURSIVE expression
+    --
+    -- Here, for each recursion down the tree, we collect the child
+    -- nodes for a given node, eliding any cycles.
+    --
+    -- TODO: Figure out what to do when a cycle DOES occur.
+
+    UNION SELECT
+      notes.id,
+      notestree.id AS parent_id,
+      notes.content,
+      note_relationships.location,
+      notes.kind,
+      notes.creation_date,
+      notes.updated_date,
+      notes.lastview_date,
+      notes.deleted_date,
+      notestree.cycle||notes.id||','
+        FROM notes
+          INNER JOIN note_relationships 
+            ON notes.id = note_relationships.note_id
+          -- For a given ID in the level of notestree in *this* recursion,
+          -- we want each note's branches one level down.
+          INNER JOIN notestree 
+            ON note_relationships.parent_id = notestree.id
+          -- And we want to make sure there are no cycles.  There shouldn't
+          -- be; we're supposed to prevent those.  But you never know.
+          WHERE notestree.cycle NOT LIKE '%,'||notes.id||',%'
+          ORDER BY note_relationships.location
+    )
+
+  SELECT * from notestree);
+

server/nm-store/src/structs.rs

@@ -1,57 +1,141 @@
 use chrono::{DateTime, Utc};
 use derive_builder::Builder;
-use serde::{Deserialize, Serialize};
 use sqlx::{self, FromRow};
 
-#[derive(Clone, Serialize, Deserialize, Debug, FromRow)]
-pub struct RawPage {
-    pub id: i64,
-    pub slug: String,
-    pub title: String,
-    pub note_id: i64,
-    pub creation_date: DateTime<Utc>,
-    pub updated_date: DateTime<Utc>,
-    pub lastview_date: DateTime<Utc>,
-    pub deleted_date: Option<DateTime<Utc>>,
+// Page is German for "Box," and is used both because this is
+// supposed to be a Page, and because "Box" is a heavily
+// reserved word in Rust. So, for that matter, are "crate" and
+// "cargo," "cell," and so forth.  If I'd wanted to go the Full
+// Noguchi, I guess I could have used "envelope."
+
+// In order to prevent arbitrary enumeration tokens from getting into
+// the database, the private layer takes a very hard line on insisting
+// that everything sent TO the datastore come in the enumerated
+// format, and everything coming OUT of the database be converted back
+// into an enumeration.  These macros instantiate those objects
+// and their conversions to/from strings.
+
+macro_rules! build_conversion_enums {
+    ( $ty:ident, $( $s:literal => $x:ident, )*) => {
+		#[derive(Clone, Debug, PartialEq, Eq)]
+		pub enum $ty {
+			$( $x ), *
+		}
+
+        impl From<String> for $ty {
+            fn from(kind: String) -> Self {
+                match &kind[..] {
+                    $( $s => $ty::$x, )*
+                    _ => panic!("Illegal value in $ty database: {}", kind),
+                }
+            }
+        }
+
+        impl From<$ty> for String {
+            fn from(kind: $ty) -> Self {
+                match kind {
+                    $( $ty::$x => $s ),*
+                }
+                .to_string()
+            }
+        }
+
+        impl $ty {
+            pub fn to_string(&self) -> String {
+                String::from(self.clone())
+            }
+        }
+    };
 }
 
-#[derive(Clone, Serialize, Deserialize, Debug, FromRow)]
-pub struct RawNote {
-    pub id: i64,
-    pub uuid: String,
-    pub parent_id: i64,
-    pub parent_uuid: String,
+// The different kinds of objects we support.
+
+build_conversion_enums!(
+    NoteKind,
+    "box" => Page,
+    "note" => Note,
+    "resource" => Resource,
+);
+
+// The different kinds of relationships we support.  I do not yet
+// know how to ensure that there is a maximum of one (a ->
+// b)::Direct, and that for any (a -> b) there is no (b <- a), that
+// is, nor, for that matter, do I know how to prevent cycles.
+
+build_conversion_enums!(
+    RelationshipKind,
+    "direct" => Direct,
+    "reference" => Reference,
+    "embed" => Embed,
+);
+
+build_conversion_enums!(
+    PageRelationshipKind,
+    "page" => Page,
+    "unacked" => Unacked,
+    "cancelled" => Cancelled,
+);
+
+// A Note is the base construct of our system. It represents a
+// single note and contains information about its parent and location.
+// This is the object *retrieved* from the database.
+
+#[derive(Clone, Debug, FromRow)]
+pub(crate) struct RowNote {
+    pub id: String,
+    pub parent_id: Option<String>,
     pub content: String,
-    pub position: i64,
-    pub notetype: String,
+    pub kind: String,
+    pub location: i64,
     pub creation_date: DateTime<Utc>,
     pub updated_date: DateTime<Utc>,
     pub lastview_date: DateTime<Utc>,
     pub deleted_date: Option<DateTime<Utc>>,
 }
 
-#[derive(Clone, Serialize, Deserialize, Debug, Builder)]
-pub struct NewPage {
-    pub slug: String,
-    pub title: String,
-    pub note_id: i64,
-    #[builder(default = r#"chrono::Utc::now()"#)]
+/// A Note as it's returned from the private layer.  This is
+/// provided to ensure that the NoteKind is an enum, and that we
+/// control the list of possible values stored in the database.
+#[derive(Clone, Debug)]
+pub struct Note {
+    pub id: String,
+    pub parent_id: Option<String>,
+    pub content: String,
+    pub kind: NoteKind,
+    pub location: i64,
     pub creation_date: DateTime<Utc>,
-    #[builder(default = r#"chrono::Utc::now()"#)]
     pub updated_date: DateTime<Utc>,
-    #[builder(default = r#"chrono::Utc::now()"#)]
     pub lastview_date: DateTime<Utc>,
-    #[builder(default = r#"None"#)]
     pub deleted_date: Option<DateTime<Utc>>,
 }
 
-#[derive(Clone, Serialize, Deserialize, Debug, Builder)]
+impl From<RowNote> for Note {
+    fn from(note: RowNote) -> Self {
+        Self {
+            id: note.id,
+            parent_id: note.parent_id,
+            content: note.content,
+            kind: NoteKind::from(note.kind),
+            location: note.location,
+            creation_date: note.creation_date,
+            updated_date: note.updated_date,
+            lastview_date: note.lastview_date,
+            deleted_date: note.deleted_date,
+        }
+    }
+}
+
+/// A new Note object as it's inserted into the system.  It has no
+/// parent or location information; those are data relative to the
+/// parent, and must be provided by the client.  In the case of a
+/// Page, no location or parent is necessary.
+#[derive(Clone, Debug, Builder)]
 pub struct NewNote {
-    #[builder(default = r#""".to_string()"#)]
-    pub uuid: String,
+    #[builder(default = r#"friendly_id::create()"#)]
+    pub id: String,
     pub content: String,
-    #[builder(default = r#""note".to_string()"#)]
-    pub notetype: String,
+    #[builder(default = r#"NoteKind::Note"#)]
+    pub kind: NoteKind,
     #[builder(default = r#"chrono::Utc::now()"#)]
     pub creation_date: DateTime<Utc>,
     #[builder(default = r#"chrono::Utc::now()"#)]
@@ -62,40 +146,92 @@ pub struct NewNote {
     pub deleted_date: Option<DateTime<Utc>>,
 }
 
-#[derive(Clone, Serialize, Deserialize, Debug, FromRow)]
-pub(crate) struct JustSlugs {
-    pub slug: String,
+impl From<NewNote> for Note {
+    /// Only used for building new pages, so the decision- making is
+    /// limited to page-level things, like pointing to self and
+    /// having a location of zero.
+    fn from(note: NewNote) -> Self {
+        Self {
+            id: note.id,
+            parent_id: None,
+            content: note.content,
+            kind: note.kind,
+            location: 0,
+            creation_date: note.creation_date,
+            updated_date: note.updated_date,
+            lastview_date: note.lastview_date,
+            deleted_date: note.deleted_date,
+        }
+    }
 }
 
-#[derive(Clone, Serialize, Deserialize, Debug, FromRow)]
-pub(crate) struct JustTitles {
-    title: String,
-}
-
-#[derive(Clone, Serialize, Deserialize, Debug, FromRow)]
+#[derive(Clone, Debug, FromRow)]
 pub(crate) struct JustId {
-    pub id: i64,
+    pub id: String,
 }
 
-#[derive(Clone, Serialize, Deserialize, Debug, FromRow)]
-pub(crate) struct PageTitles {
-    pub id: i64,
-    pub title: String,
+#[derive(Clone, Debug, FromRow)]
+pub(crate) struct PageTitle {
+    pub id: String,
+    pub content: String,
 }
 
-#[derive(Clone, Serialize, Deserialize, Debug, FromRow)]
-pub(crate) struct NoteRelationship {
-    pub parent_id: i64,
-    pub note_id: i64,
-    pub position: i64,
-    pub nature: String,
-}
-
-#[derive(Clone, Serialize, Deserialize, Debug, FromRow)]
+#[derive(Clone, Debug, FromRow)]
 pub(crate) struct RowCount {
     pub count: i64,
 }
 
+#[derive(Clone, Debug, FromRow)]
+pub(crate) struct NoteRelationshipRow {
+    pub parent_id: String,
+    pub note_id: String,
+    pub location: i64,
+    pub kind: String,
+}
+
+#[derive(Clone, Debug)]
+pub struct NoteRelationship {
+    pub parent_id: String,
+    pub note_id: String,
+    pub location: i64,
+    pub kind: RelationshipKind,
+}
+
+impl From<NoteRelationshipRow> for NoteRelationship {
+    fn from(rel: NoteRelationshipRow) -> Self {
+        Self {
+            parent_id: rel.parent_id,
+            note_id: rel.note_id,
+            location: rel.location,
+            kind: RelationshipKind::from(rel.kind),
+        }
+    }
+}
+
+#[derive(Clone, Debug, FromRow)]
+pub(crate) struct PageRelationshipRow {
+    pub note_id: String,
+    pub page_id: String,
+    pub kind: String,
+}
+
+#[derive(Clone, Debug)]
+pub struct PageRelationship {
+    pub note_id: String,
+    pub page_id: String,
+    pub kind: PageRelationshipKind,
+}
+
+impl From<PageRelationshipRow> for PageRelationship {
+    fn from(rel: PageRelationshipRow) -> Self {
+        Self {
+            page_id: rel.page_id,
+            note_id: rel.note_id,
+            kind: PageRelationshipKind::from(rel.kind),
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -103,11 +239,8 @@ mod tests {
     #[test]
     fn can_build_new_note() {
         let now = chrono::Utc::now();
-        let newnote = NewNoteBuilder::default()
-            .uuid("foo".to_string())
-            .content("bar".to_string())
-            .build()
-            .unwrap();
+        let newnote = NewNoteBuilder::default().content("bar".to_string()).build().unwrap();
+        assert!(newnote.id.len() > 4);
         assert!((newnote.creation_date - now).num_minutes() < 1);
         assert!((newnote.updated_date - now).num_minutes() < 1);
         assert!((newnote.lastview_date - now).num_minutes() < 1);

server/nm-trees/.gitignore

@@ -0,0 +1,2 @@
+/target
+Cargo.lock

server/nm-trees/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "nm-trees"
+version = "0.1.0"
+authors = ["Elf M. Sternberg <elf.sternberg@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+nm-store = { path = "../nm-store" }
+thiserror = "1.0.20"
+tokio = { version = "0.2.22", features = ["rt-threaded", "blocking"] }
+serde = { version = "1.0.116", features = ["derive"] }
+serde_json = "1.0.56"
+chrono = { version = "0.4.18", features = ["serde"] }

server/nm-trees/Makefile

@@ -0,0 +1,15 @@
+.PHONY: all
+all: help
+
+.PHONY: help
+help:
+	@M=$$(perl -ne 'm/((\w|-)*):.*##/ && print length($$1)."\n"' Makefile | \
+		sort -nr | head -1) && \
+		perl -ne "m/^((\w|-)*):.*##\s*(.*)/ && print(sprintf(\"%s: %s\t%s\n\", \$$1, \" \"x($$M-length(\$$1)), \$$3))" Makefile
+
+# This is necessary because I'm trying hard not to use
+# any `nightly` features.  But rustfmt is likely to be
+# a `nightly-only` feature for a long time to come, so
+# this is my hack.
+fmt:  ## Format the code, using the most modern version of rustfmt
+	rustup run nightly cargo fmt

server/nm-trees/src/lib.rs

@@ -0,0 +1,146 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+//! # Tree Layer
+//!
+//! This layer provides an interface between the storage layer and
+//! the outside world.  It provides all of the basic logic, including
+//! the premise that a note without a parent is automatically
+//! made a child of the day's notepad.
+
+mod make_tree;
+mod structs;
+
+use crate::make_tree::{make_backreferences, make_note_tree};
+use crate::structs::{Note, Page};
+use chrono::{DateTime, Utc};
+use nm_store::{NewNote, NoteStore, NoteStoreError};
+
+#[derive(Debug)]
+pub struct Notesmachine(pub(crate) NoteStore);
+
+type Result<T> = core::result::Result<T, NoteStoreError>;
+
+pub fn make_page(foundtree: &Note, backreferences: Vec<Vec<Note>>) -> Page {
+    Page {
+        slug: foundtree.id,
+        title: foundtree.content,
+        creation_date: foundtree.creation_date,
+        updated_date: foundtree.updated_date,
+        lastview_date: foundtree.lastview_date,
+        deleted_date: foundtree.deleted_date,
+        notes: foundtree.children,
+        backreferences: backreferences,
+    }
+}
+
+impl Notesmachine {
+    pub async fn new(url: &str) -> Result<Self> {
+        let notestore = NoteStore::new(url).await?;
+        Ok(Notesmachine(notestore))
+    }
+
+    pub async fn get_page_via_slug(&self, slug: &str) -> Result<Page> {
+        let (rawtree, rawbackreferences) = self.0.get_kasten_by_slug(slug).await?;
+        Ok(make_page(
+            &make_note_tree(&rawtree),
+            make_backreferences(&rawbackreferences),
+        ))
+    }
+
+    pub async fn get_page(&self, title: &str) -> Result<Page> {
+        let (rawtree, rawbackreferences) = self.0.get_kasten_by_title(title).await?;
+        Ok(make_page(
+            &make_note_tree(&rawtree),
+            make_backreferences(&rawbackreferences),
+        ))
+    }
+
+    // TODO:
+    // You should be able to:
+    // Add a note that has no parent (gets added to "today")
+    // Add a note that specifies only the page (gets added to page/root)
+    // Add a note that has no location (gets tacked onto the end of the above)
+    // Add a note that specifies the date of creation.
+    pub async fn add_note(&self, note: &NewNote) -> Result<String> {
+        let mut note = note.clone();
+        if note.parent_id.is_none() {
+            note.parent_id = self.get_today_page().await?;
+        }
+        Ok(self.0.add_note(&note))
+    }
+
+    // 	pub async fn reference_note(&self, note_id: &str, new_parent_id: &str, new_location: i64) -> Result<()> {
+    // 		todo!();
+    // 	}
+    //
+    // 	pub async fn embed_note(&self, note_id: &str, new_parent_id: &str, new_location: i64) -> Result<()> {
+    // 		todo!();
+    // 	}
+
+    pub async fn move_note(
+        &self,
+        note_id: &str,
+        old_parent_id: &str,
+        new_parent_id: &str,
+        location: i64,
+    ) -> Result<()> {
+        self.0.move_note(note_id, old_parent_id, new_parent_id, location).await
+    }
+
+    pub async fn update_note(&self, note_id: &str, content: &str) -> Result<()> {
+        self.0.update_note_content(note_id, content).await
+    }
+
+    pub async fn delete_note(&self, note_id: &str, parent_note_id: &str) -> Result<()> {
+        self.0.delete_note(note_id, parent_note_id).await
+    }
+}
+
+// Private stuff
+
+impl Notesmachine {
+    async fn get_today_page(&self) -> Result<String> {
+        let title = chrono::Utc::now().format("%F").to_string();
+        let (rawtree, _) = self.0.get_kasten_by_title(title).await?;
+        Ok(rawtree.id)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tokio;
+
+    async fn fresh_inmemory_database() -> Notesmachine {
+        let notesmachine = Notesmachine::new("sqlite://:memory:").await;
+        assert!(notesmachine.is_ok(), "{:?}", notesmachine);
+        let notesmachine = notesmachine.unwrap();
+        let reset = notesmachine.0.reset_database().await;
+        assert!(reset.is_ok(), "{:?}", reset);
+        notesmachine
+    }
+
+    #[tokio::test(threaded_scheduler)]
+    async fn fetching_unfound_page_by_slug_works() {
+        let notesmachine = fresh_inmemory_database().await;
+        let unfoundpage = notesmachine.get_page_via_slug("nonexistent-slug").await;
+        assert!(unfoundpage.is_err());
+    }
+
+    #[tokio::test(threaded_scheduler)]
+    async fn fetching_unfound_page_by_title_works() {
+        let title = "Nonexistent Page";
+        let notesmachine = fresh_inmemory_database().await;
+        let newpageresult = notesmachine.get_page(&title).await;
+        assert!(newpageresult.is_ok(), "{:?}", newpageresult);
+
+        let newpage = newpageresult.unwrap();
+        assert_eq!(newpage.title, title, "{:?}", newpage.title);
+        assert_eq!(newpage.slug, "nonexistent-page", "{:?}", newpage.slug);
+        assert_eq!(newpage.root_note.content, "", "{:?}", newpage.root_note.content);
+        assert_eq!(newpage.root_note.notetype, "root", "{:?}", newpage.root_note.notetype);
+        assert_eq!(newpage.root_note.children.len(), 0, "{:?}", newpage.root_note.children);
+    }
+}

server/nm-trees/src/make_tree.rs

@@ -0,0 +1,75 @@
+use crate::structs::{Note, Page};
+use nm_store::NoteKind;
+
+fn make_note_tree_from(rawnotes: &[nm_store::Note], root_id: &str) -> Note {
+    let the_note = {
+        let foundroots: Vec<&nm_store::Note> = rawnotes.iter().filter(|note| note.id == root_id).collect();
+        debug_assert!(foundroots.len() == 1);
+        foundroots.iter().next().unwrap().clone()
+    };
+
+    // The special case of the root node must be filtered out here to
+    // prevent the first pass from smashing the stack in an infinite
+    // loop.  The root node is identified by the type 'root' and
+    // having its `id` and `parent_id` be equal.  Numeric comparisons
+    // are faster.
+    let mut children = rawnotes
+        .iter()
+        .filter(|note| note.parent_id.is_some() && note.parent_id.unwrap() == root_id && note.id != the_note.id)
+        .map(|note| make_note_tree_from(rawnotes, &note.id))
+        .collect::<Vec<Note>>();
+    children.sort_unstable_by(|a, b| a.location.cmp(&b.location));
+
+    Note {
+        id: the_note.id,
+        parent_id: the_note.parent_id,
+        content: the_note.content,
+        kind: the_note.kind.to_string(),
+        location: the_note.location,
+        creation_date: the_note.creation_date,
+        updated_date: the_note.updated_date,
+        lastview_date: the_note.updated_date,
+        deleted_date: the_note.deleted_date,
+        children: children,
+    }
+}
+
+pub(crate) fn make_note_tree(rawnotes: &[nm_store::Note]) -> Note {
+    let the_root = {
+        let foundroots: Vec<&nm_store::Note> = rawnotes.iter().filter(|note| note.kind == NoteKind::Kasten).collect();
+        debug_assert!(foundroots.len() == 1);
+        foundroots.iter().next().unwrap().clone()
+    };
+    make_note_tree_from(&rawnotes, &the_root.id)
+}
+
+fn add_child(rawnotes: &[nm_store::Note], acc: &mut Vec<Note>, note_id: &str) -> Vec<Note> {
+    let child = rawnotes
+        .iter()
+        .find(|note| note.parent_id.is_some() && note.parent_id.unwrap() == note_id);
+    if let Some(c) = child {
+        acc.push(Note {
+            id: c.id,
+            parent_id: Some(note_id.to_string()),
+            content: c.content,
+            kind: c.kind.to_string(),
+            location: c.location,
+            creation_date: c.creation_date,
+            updated_date: c.updated_date,
+            lastview_date: c.updated_date,
+            deleted_date: c.deleted_date,
+            children: vec![],
+        });
+        add_child(rawnotes, acc, &c.id)
+    } else {
+        acc.to_vec()
+    }
+}
+
+pub(crate) fn make_backreferences(rawnotes: &[nm_store::Note]) -> Vec<Vec<Note>> {
+    rawnotes
+        .iter()
+        .filter(|note| note.parent_id.is_none() && note.kind == NoteKind::Kasten)
+        .map(|root| add_child(rawnotes, &mut Vec::<Note>::new(), &root.id))
+        .collect()
+}

server/nm-trees/src/structs.rs

@@ -0,0 +1,27 @@
+use chrono::{DateTime, Utc};
+
+#[derive(Clone, Debug)]
+pub struct Note {
+    pub id: String,
+    pub parent_id: Option<String>,
+    pub content: String,
+    pub location: i64,
+    pub kind: String,
+    pub creation_date: DateTime<Utc>,
+    pub updated_date: DateTime<Utc>,
+    pub lastview_date: DateTime<Utc>,
+    pub deleted_date: Option<DateTime<Utc>>,
+    pub children: Vec<Note>,
+}
+
+#[derive(Clone, Debug)]
+pub struct Page {
+    pub slug: String,
+    pub title: String,
+    pub creation_date: DateTime<Utc>,
+    pub updated_date: DateTime<Utc>,
+    pub lastview_date: DateTime<Utc>,
+    pub deleted_date: Option<DateTime<Utc>>,
+    pub notes: Vec<Note>,
+    pub backreferences: Vec<Vec<Note>>,
+}