feat: add note collaboration schema, access control, and API routes

Add noteCollaborators and noteUserState tables for sharing notes between
users. Implement access control helpers (canAccessNote, requireNoteAccess,
requireNoteOwnership) and collaborators CRUD service. Create API endpoints
for managing collaborators and searching users.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/lib/server/api-utils.ts

@@ -1,4 +1,7 @@
 import { error } from '@sveltejs/kit';
+import { db } from './db/index.js';
+import { notes, noteCollaborators } from './db/schema.js';
+import { eq, and } from 'drizzle-orm';
 
 type EventWithLocals = {
 	locals: App.Locals;
@@ -14,3 +17,36 @@ export function requireAdmin(event: EventWithLocals) {
 	if (!user || user.role !== 'admin') throw error(403, 'Forbidden');
 	return user;
 }
+
+/**
+ * Check if a user can access a note (as owner or collaborator).
+ */
+export function canAccessNote(noteId: string, userId: number): { canAccess: boolean; isOwner: boolean } {
+	const note = db.select({ userId: notes.userId }).from(notes).where(eq(notes.id, noteId)).get();
+	if (!note) return { canAccess: false, isOwner: false };
+	if (note.userId === userId) return { canAccess: true, isOwner: true };
+
+	const collab = db
+		.select({ userId: noteCollaborators.userId })
+		.from(noteCollaborators)
+		.where(and(eq(noteCollaborators.noteId, noteId), eq(noteCollaborators.userId, userId)))
+		.get();
+	return { canAccess: !!collab, isOwner: false };
+}
+
+/**
+ * Require that a user can access a note. Throws 404 if no access.
+ */
+export function requireNoteAccess(noteId: string, userId: number): { isOwner: boolean } {
+	const { canAccess, isOwner } = canAccessNote(noteId, userId);
+	if (!canAccess) throw error(404, 'Not found');
+	return { isOwner };
+}
+
+/**
+ * Require that a user is the owner of a note. Throws 404 if not owner.
+ */
+export function requireNoteOwnership(noteId: string, userId: number): void {
+	const note = db.select({ userId: notes.userId }).from(notes).where(eq(notes.id, noteId)).get();
+	if (!note || note.userId !== userId) throw error(404, 'Not found');
+}

src/lib/server/collaborators.ts

@@ -0,0 +1,75 @@
+import { db } from './db/index.js';
+import { noteCollaborators, noteUserState, users } from './db/schema.js';
+import { eq, and, inArray } from 'drizzle-orm';
+import type { Collaborator } from '$lib/types/index.js';
+
+/**
+ * Batch fetch collaborators for multiple notes.
+ * Returns a Map of noteId → Collaborator[].
+ */
+export function fetchCollaboratorsForNotes(noteIds: string[]): Map<string, Collaborator[]> {
+	if (noteIds.length === 0) return new Map();
+
+	const rows = db
+		.select({
+			noteId: noteCollaborators.noteId,
+			userId: noteCollaborators.userId,
+			displayName: users.displayName,
+			email: users.email,
+			addedAt: noteCollaborators.addedAt
+		})
+		.from(noteCollaborators)
+		.innerJoin(users, eq(noteCollaborators.userId, users.id))
+		.where(inArray(noteCollaborators.noteId, noteIds))
+		.all();
+
+	const map = new Map<string, Collaborator[]>();
+	for (const row of rows) {
+		const collab: Collaborator = {
+			userId: row.userId,
+			displayName: row.displayName,
+			email: row.email,
+			addedAt: row.addedAt
+		};
+		const existing = map.get(row.noteId);
+		if (existing) {
+			existing.push(collab);
+		} else {
+			map.set(row.noteId, [collab]);
+		}
+	}
+	return map;
+}
+
+/**
+ * Add a collaborator to a note.
+ */
+export function addCollaborator(noteId: string, userId: number, addedBy: number): void {
+	db.insert(noteCollaborators)
+		.values({ noteId, userId, addedBy, addedAt: new Date() })
+		.run();
+}
+
+/**
+ * Remove a collaborator from a note. Also cleans up their per-user state.
+ */
+export function removeCollaborator(noteId: string, userId: number): void {
+	db.delete(noteCollaborators)
+		.where(and(eq(noteCollaborators.noteId, noteId), eq(noteCollaborators.userId, userId)))
+		.run();
+	db.delete(noteUserState)
+		.where(and(eq(noteUserState.noteId, noteId), eq(noteUserState.userId, userId)))
+		.run();
+}
+
+/**
+ * Get all collaborator user IDs for a note.
+ */
+export function getCollaboratorIds(noteId: string): number[] {
+	return db
+		.select({ userId: noteCollaborators.userId })
+		.from(noteCollaborators)
+		.where(eq(noteCollaborators.noteId, noteId))
+		.all()
+		.map((r) => r.userId);
+}

src/lib/server/db/index.ts

@@ -93,6 +93,21 @@ sqlite.exec(`
 		client_id TEXT NOT NULL
 	);
 
+	CREATE TABLE IF NOT EXISTS note_collaborators (
+		note_id TEXT NOT NULL REFERENCES notes(id) ON DELETE CASCADE,
+		user_id INTEGER NOT NULL REFERENCES users(id),
+		added_by INTEGER NOT NULL REFERENCES users(id),
+		added_at INTEGER NOT NULL
+	);
+
+	CREATE TABLE IF NOT EXISTS note_user_state (
+		note_id TEXT NOT NULL REFERENCES notes(id) ON DELETE CASCADE,
+		user_id INTEGER NOT NULL REFERENCES users(id),
+		pinned INTEGER NOT NULL DEFAULT 0,
+		archived INTEGER NOT NULL DEFAULT 0,
+		sort_order INTEGER NOT NULL DEFAULT 0
+	);
+
 	CREATE TABLE IF NOT EXISTS login_attempts (
 		id INTEGER PRIMARY KEY AUTOINCREMENT,
 		ip TEXT NOT NULL,
@@ -168,6 +183,10 @@ sqlite.exec(`
 	CREATE INDEX IF NOT EXISTS sync_log_timestamp_idx ON sync_log(timestamp);
 	CREATE INDEX IF NOT EXISTS login_attempts_ip_timestamp_idx ON login_attempts(ip, timestamp);
 
+	CREATE UNIQUE INDEX IF NOT EXISTS note_collaborators_unique ON note_collaborators(note_id, user_id);
+	CREATE INDEX IF NOT EXISTS note_collaborators_user_id_idx ON note_collaborators(user_id);
+	CREATE UNIQUE INDEX IF NOT EXISTS note_user_state_unique ON note_user_state(note_id, user_id);
+
 	CREATE TABLE IF NOT EXISTS api_keys (
 		id TEXT PRIMARY KEY,
 		user_id INTEGER NOT NULL REFERENCES users(id),

src/lib/server/db/schema.ts

@@ -128,6 +128,42 @@ export const syncLog = sqliteTable(
 	(table) => [index('sync_log_timestamp_idx').on(table.timestamp)]
 );
 
+export const noteCollaborators = sqliteTable(
+	'note_collaborators',
+	{
+		noteId: text('note_id')
+			.references(() => notes.id, { onDelete: 'cascade' })
+			.notNull(),
+		userId: integer('user_id')
+			.references(() => users.id)
+			.notNull(),
+		addedBy: integer('added_by')
+			.references(() => users.id)
+			.notNull(),
+		addedAt: integer('added_at', { mode: 'timestamp' }).notNull()
+	},
+	(table) => [
+		uniqueIndex('note_collaborators_unique').on(table.noteId, table.userId),
+		index('note_collaborators_user_id_idx').on(table.userId)
+	]
+);
+
+export const noteUserState = sqliteTable(
+	'note_user_state',
+	{
+		noteId: text('note_id')
+			.references(() => notes.id, { onDelete: 'cascade' })
+			.notNull(),
+		userId: integer('user_id')
+			.references(() => users.id)
+			.notNull(),
+		pinned: integer('pinned', { mode: 'boolean' }).default(false).notNull(),
+		archived: integer('archived', { mode: 'boolean' }).default(false).notNull(),
+		sortOrder: integer('sort_order').default(0).notNull()
+	},
+	(table) => [uniqueIndex('note_user_state_unique').on(table.noteId, table.userId)]
+);
+
 export const loginAttempts = sqliteTable(
 	'login_attempts',
 	{

src/lib/server/db/test-helpers.ts

@@ -68,6 +68,24 @@ export function createTestDb(options?: { seedUser?: boolean }) {
 		CREATE INDEX note_tags_note_id_idx ON note_tags(note_id);
 		CREATE INDEX note_tags_tag_id_idx ON note_tags(tag_id);
 
+		CREATE TABLE note_collaborators (
+			note_id TEXT NOT NULL REFERENCES notes(id) ON DELETE CASCADE,
+			user_id INTEGER NOT NULL REFERENCES users(id),
+			added_by INTEGER NOT NULL REFERENCES users(id),
+			added_at INTEGER NOT NULL
+		);
+		CREATE UNIQUE INDEX note_collaborators_unique ON note_collaborators(note_id, user_id);
+		CREATE INDEX note_collaborators_user_id_idx ON note_collaborators(user_id);
+
+		CREATE TABLE note_user_state (
+			note_id TEXT NOT NULL REFERENCES notes(id) ON DELETE CASCADE,
+			user_id INTEGER NOT NULL REFERENCES users(id),
+			pinned INTEGER NOT NULL DEFAULT 0,
+			archived INTEGER NOT NULL DEFAULT 0,
+			sort_order INTEGER NOT NULL DEFAULT 0
+		);
+		CREATE UNIQUE INDEX note_user_state_unique ON note_user_state(note_id, user_id);
+
 		CREATE TABLE attachments (
 			id TEXT PRIMARY KEY,
 			user_id INTEGER NOT NULL DEFAULT 0 REFERENCES users(id),

src/lib/types/index.ts

@@ -14,6 +14,16 @@ export interface Note {
 	version: number;
 	tags?: string[];
 	attachments?: Attachment[];
+	collaborators?: Collaborator[];
+	isOwner?: boolean;
+	isShared?: boolean;
+}
+
+export interface Collaborator {
+	userId: number;
+	displayName: string;
+	email: string;
+	addedAt: Date;
 }
 
 export interface NoteCreate {

src/routes/api/notes/[id]/collaborators/+server.ts

@@ -0,0 +1,72 @@
+import { json, error } from '@sveltejs/kit';
+import type { RequestHandler } from './$types.js';
+import { getUserId, requireNoteAccess, requireNoteOwnership } from '$lib/server/api-utils.js';
+import { addCollaborator, removeCollaborator, fetchCollaboratorsForNotes } from '$lib/server/collaborators.js';
+import { db } from '$lib/server/db/index.js';
+import { users, notes, noteCollaborators } from '$lib/server/db/schema.js';
+import { eq, and } from 'drizzle-orm';
+
+export const GET: RequestHandler = async ({ params, ...event }) => {
+	const userId = getUserId(event);
+	requireNoteAccess(params.id, userId);
+
+	const collaborators = fetchCollaboratorsForNotes([params.id]);
+	return json(collaborators.get(params.id) ?? []);
+};
+
+export const POST: RequestHandler = async ({ params, request, ...event }) => {
+	const userId = getUserId(event);
+	requireNoteOwnership(params.id, userId);
+
+	const body = await request.json();
+	const targetUserId = body.userId;
+	if (!targetUserId || typeof targetUserId !== 'number') {
+		throw error(400, 'userId is required');
+	}
+
+	// Cannot add yourself
+	const note = db.select({ userId: notes.userId }).from(notes).where(eq(notes.id, params.id)).get();
+	if (note && note.userId === targetUserId) {
+		throw error(400, 'Cannot add the owner as a collaborator');
+	}
+
+	// Target user must exist
+	const targetUser = db.select({ id: users.id }).from(users).where(eq(users.id, targetUserId)).get();
+	if (!targetUser) {
+		throw error(404, 'User not found');
+	}
+
+	// Check not already a collaborator
+	const existing = db
+		.select({ userId: noteCollaborators.userId })
+		.from(noteCollaborators)
+		.where(and(eq(noteCollaborators.noteId, params.id), eq(noteCollaborators.userId, targetUserId)))
+		.get();
+	if (existing) {
+		throw error(409, 'User is already a collaborator');
+	}
+
+	addCollaborator(params.id, targetUserId, userId);
+
+	const collaborators = fetchCollaboratorsForNotes([params.id]);
+	return json(collaborators.get(params.id) ?? [], { status: 201 });
+};
+
+export const DELETE: RequestHandler = async ({ params, url, ...event }) => {
+	const userId = getUserId(event);
+	const targetUserId = Number(url.searchParams.get('userId'));
+	if (!targetUserId) {
+		throw error(400, 'userId query parameter is required');
+	}
+
+	const { isOwner } = requireNoteAccess(params.id, userId);
+
+	// Owner can remove anyone. Collaborator can only remove self.
+	if (!isOwner && targetUserId !== userId) {
+		throw error(403, 'Only the owner can remove other collaborators');
+	}
+
+	removeCollaborator(params.id, targetUserId);
+
+	return json({ success: true });
+};

src/routes/api/users/search/+server.ts

@@ -0,0 +1,35 @@
+import { json } from '@sveltejs/kit';
+import type { RequestHandler } from './$types.js';
+import { getUserId } from '$lib/server/api-utils.js';
+import { db } from '$lib/server/db/index.js';
+import { users } from '$lib/server/db/schema.js';
+import { ne } from 'drizzle-orm';
+
+export const GET: RequestHandler = async ({ url, ...event }) => {
+	const userId = getUserId(event);
+	const query = url.searchParams.get('q')?.trim();
+	if (!query || query.length < 1) {
+		return json([]);
+	}
+
+	const pattern = `%${query}%`;
+	const results = db
+		.select({
+			id: users.id,
+			displayName: users.displayName,
+			email: users.email
+		})
+		.from(users)
+		.where(
+			ne(users.id, userId)
+		)
+		.all()
+		.filter(
+			(u) =>
+				u.displayName.toLowerCase().includes(query.toLowerCase()) ||
+				u.email.toLowerCase().includes(query.toLowerCase())
+		)
+		.slice(0, 10);
+
+	return json(results);
+};