Expose sync reset API

2026-05-08 19:10:04 -04:00
parent e9f8b1eb43
commit ed44db3034
9 changed files with 597 additions and 1 deletions
@@ -0,0 +1,280 @@
+import type { AuthContext } from "./auth.js";
+import type { ElyD1PreparedStatement, Env } from "./bindings.js";
+import { StorageObjectError, deleteKnownObject } from "./storage.js";
+
+const RESET_CONFIRMATION = "delete-cloud-sync-data";
+const IDEMPOTENCY_KEY_PATTERN = /^[a-zA-Z0-9._:-]{16,128}$/;
+const SYNC_RESET_EVENT_QUERY = `
+  SELECT actor_device_id, outcome, created_at
+  FROM audit_events
+  WHERE user_id = ? AND event_id = ? AND event_type = 'sync.reset'
+`;
+const SYNC_RESET_COUNTS_QUERY = `
+  SELECT
+    (SELECT COUNT(*) FROM sync_objects WHERE user_id = ?) AS objects,
+    (SELECT COUNT(*) FROM sync_change_log WHERE user_id = ?) AS changes,
+    (SELECT COUNT(*) FROM sync_snapshots WHERE user_id = ?) AS snapshots,
+    (SELECT COUNT(*) FROM sync_tombstones WHERE user_id = ?) AS tombstones
+`;
+const SYNC_RESET_R2_KEYS_QUERY = `
+  SELECT payload_r2_key AS r2_key
+  FROM sync_objects
+  WHERE user_id = ? AND payload_r2_key IS NOT NULL
+  UNION
+  SELECT r2_key
+  FROM sync_snapshots
+  WHERE user_id = ?
+  ORDER BY r2_key ASC
+`;
+const SYNC_RESET_AUDIT_INSERT_QUERY = `
+  INSERT INTO audit_events (
+    event_id,
+    user_id,
+    actor_device_id,
+    event_type,
+    subject_type,
+    subject_id,
+    outcome,
+    metadata_hash,
+    created_at
+  ) VALUES (?, ?, ?, 'sync.reset', 'sync', ?, 'success', NULL, ?)
+  ON CONFLICT(event_id) DO NOTHING
+`;
+const SYNC_OBJECTS_DELETE_QUERY = "DELETE FROM sync_objects WHERE user_id = ?";
+const SYNC_CHANGE_LOG_DELETE_QUERY = "DELETE FROM sync_change_log WHERE user_id = ?";
+const SYNC_SNAPSHOTS_DELETE_QUERY = "DELETE FROM sync_snapshots WHERE user_id = ?";
+const SYNC_TOMBSTONES_DELETE_QUERY = "DELETE FROM sync_tombstones WHERE user_id = ?";
+
+export interface SyncResetDocument {
+  version: 1;
+  user_id: string;
+  device_id: string;
+  idempotency_key: string;
+  reset_at: number;
+  deleted: SyncResetDeletedDocument;
+}
+
+export interface SyncResetDeletedDocument {
+  objects: number;
+  changes: number;
+  snapshots: number;
+  tombstones: number;
+  r2_objects: number;
+}
+
+interface SyncResetRequest {
+  idempotencyKey: string;
+}
+
+interface SyncResetEventRow {
+  actor_device_id: unknown;
+  outcome: unknown;
+  created_at: unknown;
+}
+
+interface SyncResetCountsRow {
+  objects: unknown;
+  changes: unknown;
+  snapshots: unknown;
+  tombstones: unknown;
+}
+
+interface SyncResetR2KeyRow {
+  r2_key: unknown;
+}
+
+type RequestBody = Record<string, unknown>;
+
+export class SyncResetRequestError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = "SyncResetRequestError";
+  }
+}
+
+export class SyncResetPersistenceError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = "SyncResetPersistenceError";
+  }
+}
+
+export async function syncResetDocument(
+  request: Request,
+  env: Env,
+  context: AuthContext,
+  nowSeconds = Math.floor(Date.now() / 1000),
+): Promise<SyncResetDocument> {
+  const deviceId = currentDeviceId(context);
+  const reset = await syncResetRequest(request);
+  const eventId = syncResetEventId(context.userId, reset.idempotencyKey);
+  const existingEvent = await env.ELY_DB.prepare(SYNC_RESET_EVENT_QUERY)
+    .bind(context.userId, eventId)
+    .first<SyncResetEventRow>();
+  if (existingEvent !== null) {
+    return existingResetDocument(context, deviceId, reset, existingEvent);
+  }
+
+  const counts = await syncResetCounts(env, context.userId);
+  const r2Keys = await syncResetR2Keys(env, context.userId);
+  for (const key of r2Keys) {
+    await deleteResetObject(env, key);
+  }
+  await env.ELY_DB.batch(syncResetStatements(env, context.userId, deviceId, eventId, nowSeconds));
+
+  return {
+    version: 1,
+    user_id: context.userId,
+    device_id: deviceId,
+    idempotency_key: reset.idempotencyKey,
+    reset_at: nowSeconds,
+    deleted: { ...counts, r2_objects: r2Keys.length },
+  };
+}
+
+function existingResetDocument(
+  context: AuthContext,
+  deviceId: string,
+  reset: SyncResetRequest,
+  row: SyncResetEventRow,
+): SyncResetDocument {
+  if (row.actor_device_id !== deviceId || row.outcome !== "success") {
+    throw new SyncResetRequestError("sync_reset_replay_mismatch");
+  }
+  return {
+    version: 1,
+    user_id: context.userId,
+    device_id: deviceId,
+    idempotency_key: reset.idempotencyKey,
+    reset_at: integer(row.created_at, "created_at"),
+    deleted: emptyDeletedDocument(),
+  };
+}
+
+async function syncResetCounts(
+  env: Env,
+  userId: string,
+): Promise<Omit<SyncResetDeletedDocument, "r2_objects">> {
+  const row = await env.ELY_DB.prepare(SYNC_RESET_COUNTS_QUERY)
+    .bind(userId, userId, userId, userId)
+    .first<SyncResetCountsRow>();
+  if (row === null) {
+    throw new SyncResetPersistenceError("sync_reset_counts_missing");
+  }
+  return {
+    objects: integer(row.objects, "objects"),
+    changes: integer(row.changes, "changes"),
+    snapshots: integer(row.snapshots, "snapshots"),
+    tombstones: integer(row.tombstones, "tombstones"),
+  };
+}
+
+async function syncResetR2Keys(env: Env, userId: string): Promise<string[]> {
+  const result = await env.ELY_DB.prepare(SYNC_RESET_R2_KEYS_QUERY)
+    .bind(userId, userId)
+    .all<SyncResetR2KeyRow>();
+  return result.results.map(r2Key);
+}
+
+function syncResetStatements(
+  env: Env,
+  userId: string,
+  deviceId: string,
+  eventId: string,
+  nowSeconds: number,
+): ElyD1PreparedStatement[] {
+  return [
+    env.ELY_DB.prepare(SYNC_CHANGE_LOG_DELETE_QUERY).bind(userId),
+    env.ELY_DB.prepare(SYNC_TOMBSTONES_DELETE_QUERY).bind(userId),
+    env.ELY_DB.prepare(SYNC_SNAPSHOTS_DELETE_QUERY).bind(userId),
+    env.ELY_DB.prepare(SYNC_OBJECTS_DELETE_QUERY).bind(userId),
+    env.ELY_DB.prepare(SYNC_RESET_AUDIT_INSERT_QUERY).bind(
+      eventId,
+      userId,
+      deviceId,
+      userId,
+      nowSeconds,
+    ),
+  ];
+}
+
+async function deleteResetObject(env: Env, key: string): Promise<void> {
+  try {
+    await deleteKnownObject(env.ELY_STORAGE, key);
+  } catch (error) {
+    if (error instanceof StorageObjectError) {
+      throw new SyncResetPersistenceError(error.message);
+    }
+    throw error;
+  }
+}
+
+async function syncResetRequest(request: Request): Promise<SyncResetRequest> {
+  const body = await requestBody(request);
+  assertOnlyFields(body, ["version", "confirmation", "idempotency_key"]);
+  if (body.version !== 1) {
+    throw new SyncResetRequestError("version_invalid");
+  }
+  if (body.confirmation !== RESET_CONFIRMATION) {
+    throw new SyncResetRequestError("confirmation_invalid");
+  }
+  return { idempotencyKey: idempotencyKey(body.idempotency_key) };
+}
+
+async function requestBody(request: Request): Promise<RequestBody> {
+  let value: unknown;
+  try {
+    value = await request.json();
+  } catch {
+    throw new SyncResetRequestError("json_invalid");
+  }
+  if (typeof value !== "object" || value === null || Array.isArray(value)) {
+    throw new SyncResetRequestError("body_invalid");
+  }
+  return value as RequestBody;
+}
+
+function assertOnlyFields(value: RequestBody, fields: string[]): void {
+  const allowed = new Set(fields);
+  for (const field of Object.keys(value)) {
+    if (!allowed.has(field)) {
+      throw new SyncResetRequestError(`unexpected_field:${field}`);
+    }
+  }
+}
+
+function currentDeviceId(context: AuthContext): string {
+  if (context.deviceId === undefined) {
+    throw new SyncResetRequestError("device_context_required");
+  }
+  return context.deviceId;
+}
+
+function idempotencyKey(value: unknown): string {
+  if (typeof value !== "string" || !IDEMPOTENCY_KEY_PATTERN.test(value)) {
+    throw new SyncResetRequestError("idempotency_key_invalid");
+  }
+  return value;
+}
+
+function r2Key(row: SyncResetR2KeyRow): string {
+  if (typeof row.r2_key !== "string") {
+    throw new SyncResetPersistenceError("r2_key_invalid");
+  }
+  return row.r2_key;
+}
+
+function integer(value: unknown, label: string): number {
+  if (typeof value !== "number" || !Number.isSafeInteger(value) || value < 0) {
+    throw new SyncResetPersistenceError(`${label}_invalid`);
+  }
+  return value;
+}
+
+function emptyDeletedDocument(): SyncResetDeletedDocument {
+  return { objects: 0, changes: 0, snapshots: 0, tombstones: 0, r2_objects: 0 };
+}
+
+function syncResetEventId(userId: string, idempotencyKey: string): string {
+  return `sync-reset:${userId}:${idempotencyKey}`;
+}