v3: add backlinks between dumps (via either dump url or dump target url mentioned through dump description and dump comments)

api/db/migrate.ts

@@ -1,6 +1,7 @@
 import type { DatabaseSync } from "node:sqlite";
 import { up as up0001CommentLikes } from "./migrations/0001_comment_likes.ts";
 import { up as up0002DumpThumbnail } from "./migrations/0002_dump_thumbnail.ts";
+import { up as up0003DumpBacklinks } from "./migrations/0003_dump_backlinks.ts";
 
 interface Migration {
   name: string;
@@ -13,6 +14,7 @@ interface Migration {
 const MIGRATIONS: Migration[] = [
   { name: "0001_comment_likes", up: up0001CommentLikes },
   { name: "0002_dump_thumbnail", up: up0002DumpThumbnail },
+  { name: "0003_dump_backlinks", up: up0003DumpBacklinks },
 ];
 
 export function runMigrations(db: DatabaseSync): void {

api/db/migrations/0003_dump_backlinks.ts

@@ -0,0 +1,26 @@
+import type { DatabaseSync } from "node:sqlite";
+
+// Idempotent: safe to run against a fresh db (already created from schema.sql
+// with these) or an existing one that predates them.
+export function up(db: DatabaseSync): void {
+  db.exec(`CREATE TABLE IF NOT EXISTS dump_backlinks (
+    source_type  TEXT NOT NULL,
+    source_id    TEXT NOT NULL,
+    from_dump_id TEXT NOT NULL,
+    to_dump_id   TEXT NOT NULL,
+    created_at   TEXT NOT NULL,
+    PRIMARY KEY (source_type, source_id, to_dump_id),
+    FOREIGN KEY (from_dump_id) REFERENCES dumps(id) ON DELETE CASCADE,
+    FOREIGN KEY (to_dump_id)   REFERENCES dumps(id) ON DELETE CASCADE
+  );`);
+
+  db.exec(
+    `CREATE INDEX IF NOT EXISTS idx_dump_backlinks_to ON dump_backlinks(to_dump_id);`,
+  );
+  db.exec(
+    `CREATE INDEX IF NOT EXISTS idx_dump_backlinks_from ON dump_backlinks(from_dump_id);`,
+  );
+  db.exec(
+    `CREATE INDEX IF NOT EXISTS idx_dumps_url ON dumps(url);`,
+  );
+}

api/db/schema.sql

@@ -87,13 +87,27 @@ CREATE TABLE comment_likes (
   FOREIGN KEY (user_id)    REFERENCES users(id)    ON DELETE CASCADE
 );
 
+CREATE TABLE dump_backlinks (
+  source_type  TEXT NOT NULL,
+  source_id    TEXT NOT NULL,
+  from_dump_id TEXT NOT NULL,
+  to_dump_id   TEXT NOT NULL,
+  created_at   TEXT NOT NULL,
+  PRIMARY KEY (source_type, source_id, to_dump_id),
+  FOREIGN KEY (from_dump_id) REFERENCES dumps(id) ON DELETE CASCADE,
+  FOREIGN KEY (to_dump_id)   REFERENCES dumps(id) ON DELETE CASCADE
+);
+
 CREATE INDEX idx_dumps_user           ON dumps(user_id);
+CREATE INDEX idx_dumps_url            ON dumps(url);
 CREATE INDEX idx_votes_user           ON votes(user_id);
 CREATE INDEX idx_playlists_user       ON playlists(user_id);
 CREATE INDEX idx_playlist_dumps_order ON playlist_dumps(playlist_id, position);
 CREATE INDEX idx_playlist_dumps_dump  ON playlist_dumps(dump_id);
 CREATE INDEX idx_comments_dump        ON comments(dump_id, created_at);
 CREATE INDEX idx_comment_likes_user   ON comment_likes(user_id);
+CREATE INDEX idx_dump_backlinks_to    ON dump_backlinks(to_dump_id);
+CREATE INDEX idx_dump_backlinks_from  ON dump_backlinks(from_dump_id);
 
 CREATE TABLE follows (
   id                   TEXT    PRIMARY KEY,