Add page_hierarchy table

apps/server/src/database/migrations/20251223T120000-page-hierarchy.ts

@@ -0,0 +1,200 @@
+import { Kysely, sql } from 'kysely';
+
+export async function up(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .createTable('page_hierarchy')
+    .ifNotExists()
+    .addColumn('ancestor_id', 'uuid', (col) =>
+      col.notNull().references('pages.id').onDelete('cascade'),
+    )
+    .addColumn('descendant_id', 'uuid', (col) =>
+      col.notNull().references('pages.id').onDelete('cascade'),
+    )
+    .addColumn('depth', 'integer', (col) => col.notNull().defaultTo(0))
+    .addPrimaryKeyConstraint('page_hierarchy_pkey', [
+      'ancestor_id',
+      'descendant_id',
+    ])
+    .execute();
+
+  // indexes
+  await db.schema
+    .createIndex('idx_page_hierarchy_descendant')
+    .ifNotExists()
+    .on('page_hierarchy')
+    .column('descendant_id')
+    .execute();
+
+  await db.schema
+    .createIndex('idx_page_hierarchy_ancestor_depth')
+    .ifNotExists()
+    .on('page_hierarchy')
+    .columns(['ancestor_id', 'depth'])
+    .execute();
+
+  await db.schema
+    .createIndex('idx_page_hierarchy_descendant_depth')
+    .ifNotExists()
+    .on('page_hierarchy')
+    .columns(['descendant_id', 'depth'])
+    .execute();
+
+  // rebuild function
+  await sql`
+    CREATE OR REPLACE FUNCTION rebuild_page_hierarchy()
+    RETURNS void
+    LANGUAGE plpgsql
+    AS $$
+    BEGIN
+      TRUNCATE page_hierarchy;
+
+      WITH RECURSIVE page_tree AS (
+        SELECT id AS ancestor_id, id AS descendant_id, 0 AS depth
+        FROM pages WHERE deleted_at IS NULL
+        UNION ALL
+        SELECT pt.ancestor_id, p.id AS descendant_id, pt.depth + 1
+        FROM page_tree pt
+        JOIN pages p ON p.parent_page_id = pt.descendant_id
+        WHERE p.deleted_at IS NULL
+      )
+      INSERT INTO page_hierarchy (ancestor_id, descendant_id, depth)
+      SELECT ancestor_id, descendant_id, depth FROM page_tree;
+    END;
+    $$;
+  `.execute(db);
+
+  // Create insert trigger function
+  await sql`
+    CREATE OR REPLACE FUNCTION page_hierarchy_after_insert()
+    RETURNS TRIGGER
+    LANGUAGE plpgsql
+    AS $$
+    BEGIN
+      IF NEW.deleted_at IS NOT NULL THEN
+        RETURN NEW;
+      END IF;
+
+      IF NEW.parent_page_id IS NULL THEN
+        INSERT INTO page_hierarchy (ancestor_id, descendant_id, depth)
+        VALUES (NEW.id, NEW.id, 0);
+      ELSE
+        INSERT INTO page_hierarchy (ancestor_id, descendant_id, depth)
+        SELECT ancestor_id, NEW.id, depth + 1
+        FROM page_hierarchy
+        WHERE descendant_id = NEW.parent_page_id
+        UNION ALL
+        SELECT NEW.id, NEW.id, 0;
+      END IF;
+
+      RETURN NEW;
+    END;
+    $$;
+  `.execute(db);
+
+  await sql`
+    CREATE OR REPLACE TRIGGER page_hierarchy_after_insert_trigger
+    AFTER INSERT ON pages
+    FOR EACH ROW
+    EXECUTE FUNCTION page_hierarchy_after_insert();
+  `.execute(db);
+
+  // Create update trigger function
+  await sql`
+    CREATE OR REPLACE FUNCTION page_hierarchy_after_update()
+    RETURNS TRIGGER
+    LANGUAGE plpgsql
+    AS $$
+    DECLARE
+      subtree_ids UUID[];
+    BEGIN
+      -- Only process if parent_page_id or deleted_at changed
+      IF OLD.parent_page_id IS NOT DISTINCT FROM NEW.parent_page_id
+         AND OLD.deleted_at IS NOT DISTINCT FROM NEW.deleted_at THEN
+        RETURN NEW;
+      END IF;
+
+      -- Handle soft-delete: remove from closure when deleted_at is set
+      IF OLD.deleted_at IS NULL AND NEW.deleted_at IS NOT NULL THEN
+        SELECT array_agg(descendant_id) INTO subtree_ids
+        FROM page_hierarchy
+        WHERE ancestor_id = NEW.id;
+
+        DELETE FROM page_hierarchy
+        WHERE descendant_id = ANY(subtree_ids);
+
+        RETURN NEW;
+      END IF;
+
+      -- Handle restore: rebuild closure when deleted_at is cleared
+      IF OLD.deleted_at IS NOT NULL AND NEW.deleted_at IS NULL THEN
+        IF NEW.parent_page_id IS NULL THEN
+          INSERT INTO page_hierarchy (ancestor_id, descendant_id, depth)
+          VALUES (NEW.id, NEW.id, 0);
+        ELSE
+          INSERT INTO page_hierarchy (ancestor_id, descendant_id, depth)
+          SELECT ancestor_id, NEW.id, depth + 1
+          FROM page_hierarchy
+          WHERE descendant_id = NEW.parent_page_id
+          UNION ALL
+          SELECT NEW.id, NEW.id, 0;
+        END IF;
+        RETURN NEW;
+      END IF;
+
+      -- Skip if page is soft-deleted
+      IF NEW.deleted_at IS NOT NULL THEN
+        RETURN NEW;
+      END IF;
+
+      -- Move operation: parent changed
+      -- Get all descendants of the moved page (including itself)
+      SELECT array_agg(descendant_id) INTO subtree_ids
+      FROM page_hierarchy
+      WHERE ancestor_id = NEW.id;
+
+      -- Delete old ancestor relationships (keep internal subtree links)
+      DELETE FROM page_hierarchy
+      WHERE descendant_id = ANY(subtree_ids)
+        AND NOT (ancestor_id = ANY(subtree_ids));
+
+      -- Insert new ancestor relationships (if new parent exists)
+      IF NEW.parent_page_id IS NOT NULL THEN
+        INSERT INTO page_hierarchy (ancestor_id, descendant_id, depth)
+        SELECT
+          new_anc.ancestor_id,
+          sub.descendant_id,
+          new_anc.depth + sub.depth + 1
+        FROM page_hierarchy new_anc
+        CROSS JOIN page_hierarchy sub
+        WHERE new_anc.descendant_id = NEW.parent_page_id
+          AND sub.ancestor_id = NEW.id
+          AND sub.descendant_id = ANY(subtree_ids);
+      END IF;
+
+      RETURN NEW;
+    END;
+    $$;
+  `.execute(db);
+
+  await sql`
+    CREATE OR REPLACE TRIGGER page_hierarchy_after_update_trigger
+    AFTER UPDATE ON pages
+    FOR EACH ROW
+    EXECUTE FUNCTION page_hierarchy_after_update();
+  `.execute(db);
+
+  await sql`SELECT rebuild_page_hierarchy()`.execute(db);
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await sql`DROP TRIGGER IF EXISTS page_hierarchy_after_update_trigger ON pages`.execute(
+    db,
+  );
+  await sql`DROP TRIGGER IF EXISTS page_hierarchy_after_insert_trigger ON pages`.execute(
+    db,
+  );
+  await sql`DROP FUNCTION IF EXISTS page_hierarchy_after_update()`.execute(db);
+  await sql`DROP FUNCTION IF EXISTS page_hierarchy_after_insert()`.execute(db);
+  await sql`DROP FUNCTION IF EXISTS rebuild_page_hierarchy()`.execute(db);
+  await db.schema.dropTable('page_hierarchy').ifExists().execute();
+}

apps/server/src/database/types/db.d.ts

@@ -197,6 +197,12 @@ export interface GroupUsers {
   userId: string;
 }
 
+export interface PageHierarchy {
+  ancestorId: string;
+  descendantId: string;
+  depth: Generated<number>;
+}
+
 export interface PageHistory {
   content: Json | null;
   coverPhoto: string | null;
@@ -371,6 +377,7 @@ export interface DB {
   fileTasks: FileTasks;
   groups: Groups;
   groupUsers: GroupUsers;
+  pageHierarchy: PageHierarchy;
   pageHistory: PageHistory;
   pages: Pages;
   shares: Shares;

apps/server/src/database/types/db.interface.ts

@@ -9,6 +9,7 @@ import {
   FileTasks,
   Groups,
   GroupUsers,
+  PageHierarchy,
   PageHistory,
   Pages,
   Shares,
@@ -32,6 +33,7 @@ export interface DbInterface {
   fileTasks: FileTasks;
   groups: Groups;
   groupUsers: GroupUsers;
+  pageHierarchy: PageHierarchy;
   pageEmbeddings: PageEmbeddings;
   pageHistory: PageHistory;
   pages: Pages;

apps/server/src/database/types/entity.types.ts

@@ -3,6 +3,7 @@ import {
   Attachments,
   Comments,
   Groups,
+  PageHierarchy as _PageHierarchy,
   Pages,
   Spaces,
   Users,
@@ -131,3 +132,7 @@ export type UpdatableApiKey = Updateable<Omit<ApiKeys, 'id'>>;
 export type PageEmbedding = Selectable<PageEmbeddings>;
 export type InsertablePageEmbedding = Insertable<PageEmbeddings>;
 export type UpdatablePageEmbedding = Updateable<Omit<PageEmbeddings, 'id'>>;
+
+// Page Hierarchy (closure table - composite primary key)
+export type PageHierarchy = Selectable<_PageHierarchy>;
+export type InsertablePageHierarchy = Insertable<_PageHierarchy>;