Mostly documentation changes, but I do want to emphasize that by the

time we hit this layer, the distinction between an API note and a
REST note have been made.

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/docs/TODO.md

@@ -1,2 +1,4 @@
 [ ] Add RelationshipKind to Notes passed out
 [ ] Add KastenKind to Backreferences passed out
+[ ] Provide the array of notes references (the 'cycle' manager) to make
+    mapping from Vec->Tree easier.

server/nm-store/src/errors.rs

@@ -9,6 +9,9 @@ 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/sql/initialize_database.sql

@@ -50,3 +50,9 @@ CREATE TABLE note_kasten_relationships (
 	CHECK (note_id <> kasten_id)
 );
 
+-- A fabulous constraint. This index prevents us from saying that
+-- if a note points to a kasten, the kasten may not point to a
+-- note.  Now, it's absolutely required that a kasten_id point to
+-- a KastenType note; the content should be a title only.
+CREATE UNIQUE INDEX note_kasten_unique_idx 
+  ON note_kasten_relationships (MIN(note_id, kasten_id), MAX(note_id, kasten_id));

server/nm-store/src/store.rs

@@ -137,14 +137,13 @@ impl NoteStore {
         Ok((vec![Note::from(zettlekasten)], vec![]))
     }
 
-    pub async fn add_note(&self, note: &NewNote) -> NoteResult<String> {
-        self.insert_note(
+    pub async fn add_note(&self, note: &NewNote, parent_id: &str, location: Option<i64>) -> NoteResult<String> {
+        let new_id = self.insert_note(
             note,
             &ParentId(parent_id.to_string()),
             location,
-            RelationshipKind::Direct,
-        )
-        .await
+            RelationshipKind::Direct).await?;
+		Ok(new_id)
     }
 
     /// Move a note from one location to another.
@@ -208,7 +207,9 @@ impl NoteStore {
         let note_id = NoteId(note_id.to_string());
         let parent_id = ParentId(note_parent_id.to_string());
 
+		if *parent_id != *note_id {
 			let _ = delete_note_to_note_relationship(&mut tx, &parent_id, &note_id);
+		}
         // 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 {

server/nm-store/src/store_private.rs

@@ -18,12 +18,6 @@ type SqlResult<T> = sqlx::Result<T>;
 // coherent and easily readable, and hides away the gnarliness of some
 // of the SQL queries.
 
-// Important!!!  Note_relationships are usually (parent_note -> note),
-// but Note to Kasten relationships are always (note-as-parent ->
-// kasten_note), so when looking for "all the notes referring to this
-// kasten", you use the kasten's id as the TARGET note_id, and the
-// note referring to the kasten in the parent_id.
-
 lazy_static! {
     static ref SELECT_KASTEN_BY_TITLE_SQL: String = str::replace(
         include_str!("sql/select_notes_by_parameter.sql"),
@@ -65,6 +59,15 @@ where
 // |_|\___|\__\__|_||_| |_|\_\__,_/__/\__\___|_||_|
 //
 
+// Select the requested kasten via its id.  This is fairly rare;
+// kastens should usually be picked up via their title, but if you're
+// navigating to an instance, this is how you specify the kasten 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
+// kasten.
 pub(crate) async fn select_kasten_by_slug<'a, E>(executor: E, slug: &NoteId) -> SqlResult<Vec<Note>>
 where
     E: Executor<'a, Database = Sqlite>,
@@ -76,6 +79,9 @@ where
     Ok(r.into_iter().map(|z| Note::from(z)).collect())
 }
 
+// Fetch the kasten 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_kasten_by_title<'a, E>(executor: E, title: &str) -> SqlResult<Vec<Note>>
 where
     E: Executor<'a, Database = Sqlite>,
@@ -87,6 +93,10 @@ where
     Ok(r.into_iter().map(|z| Note::from(z)).collect())
 }
 
+// Fetch all backreferences to a kasten.  The return value is an array
+// of arrays, and inside each array is a list from a root kasten to
+// the note that references the give kasten.  Clients may choose how
+// they want to display that collection.
 pub(crate) async fn select_backreferences_for_kasten<'a, E>(executor: E, kasten_id: &NoteId) -> SqlResult<Vec<Note>>
 where
     E: Executor<'a, Database = Sqlite>,
@@ -104,6 +114,7 @@ where
 // |___|_||_/__/\___|_|  \__|  \___/|_||_\___| |_|\_\___/\__\___|
 //
 
+// Inserts a single note into the notes table.  That is all.
 pub(crate) async fn insert_note<'a, E>(executor: E, zettle: &NewNote) -> SqlResult<String>
 where
     E: Executor<'a, Database = Sqlite>,
@@ -154,7 +165,8 @@ pub(crate) fn find_maximal_slug_number(slugs: &[JustId]) -> Option<u32> {
 
 // Given an initial string and an existing collection of slugs,
 // generate a new slug that does not conflict with the current
-// collection.
+// 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>,
@@ -180,6 +192,8 @@ where
     })
 }
 
+// A helper function: given a title and a slug, create a KastenType
+// note.
 pub(crate) fn create_zettlekasten(title: &str, slug: &str) -> NewNote {
     NewNoteBuilder::default()
         .id(slug.to_string())

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

@@ -12,10 +12,10 @@
 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::{NoteStore, NoteStoreError, NewNote};
-use crate::structs::{Page, Note};
-use crate::make_tree::{make_note_tree, make_backreferences};
+use nm_store::{NewNote, NoteStore, NoteStoreError};
 
 #[derive(Debug)]
 pub struct Notesmachine(pub(crate) NoteStore);
@@ -31,7 +31,7 @@ pub fn make_page(foundtree: &Note, backreferences: Vec<Vec<Note>>) -> Page {
         lastview_date: foundtree.lastview_date,
         deleted_date: foundtree.deleted_date,
         notes: foundtree.children,
-		backreferences: backreferences
+        backreferences: backreferences,
     }
 }
 
@@ -43,12 +43,18 @@ impl Notesmachine {
 
     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)))
+        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)))
+        Ok(make_page(
+            &make_note_tree(&rawtree),
+            make_backreferences(&rawbackreferences),
+        ))
     }
 
     // TODO:
@@ -60,8 +66,7 @@ impl Notesmachine {
     pub async fn add_note(&self, note: &NewNote) -> Result<String> {
         let mut note = note.clone();
         if note.parent_id.is_none() {
-			let (parent, _) = self.get_today_page().await?;
-			note.parent_id = parent.id;
+            note.parent_id = self.get_today_page().await?;
         }
         Ok(self.0.add_note(&note))
     }
@@ -74,16 +79,22 @@ impl Notesmachine {
     // 		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)
+    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(note_id, content)
+        self.0.update_note_content(note_id, content).await
     }
 
-	pub async fn delete_note(&self, note_id: &str) -> Result<()> {
-		self.0.delete_note(note_id)
+    pub async fn delete_note(&self, note_id: &str, parent_note_id: &str) -> Result<()> {
+        self.0.delete_note(note_id, parent_note_id).await
     }
 }
 
@@ -97,7 +108,6 @@ impl Notesmachine {
     }
 }
 
-	
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -115,7 +125,7 @@ mod tests {
     #[tokio::test(threaded_scheduler)]
     async fn fetching_unfound_page_by_slug_works() {
         let notesmachine = fresh_inmemory_database().await;
-        let unfoundpage = notesmachine.navigate_via_slug("nonexistent-slug").await;
+        let unfoundpage = notesmachine.get_page_via_slug("nonexistent-slug").await;
         assert!(unfoundpage.is_err());
     }
 
@@ -123,7 +133,7 @@ mod tests {
     async fn fetching_unfound_page_by_title_works() {
         let title = "Nonexistent Page";
         let notesmachine = fresh_inmemory_database().await;
-        let newpageresult = notesmachine.get_box(&title).await;
+        let newpageresult = notesmachine.get_page(&title).await;
         assert!(newpageresult.is_ok(), "{:?}", newpageresult);
 
         let newpage = newpageresult.unwrap();
@@ -134,4 +144,3 @@ mod tests {
         assert_eq!(newpage.root_note.children.len(), 0, "{:?}", newpage.root_note.children);
     }
 }
-

server/nm-trees/src/structs.rs

@@ -1,7 +1,6 @@
 use chrono::{DateTime, Utc};
-use serde::{Deserialize, Serialize};
 
-#[derive(Clone, Serialize, Deserialize, Debug)]
+#[derive(Clone, Debug)]
 pub struct Note {
     pub id: String,
     pub parent_id: Option<String>,
@@ -15,6 +14,7 @@ pub struct Note {
     pub children: Vec<Note>,
 }
 
+#[derive(Clone, Debug)]
 pub struct Page {
     pub slug: String,
     pub title: String,