/// <reference path="../pb_data/types.d.ts" />
// M21 — technicianAssignments optimistic concurrency lock.
//
// Rejects updates to technicianAssignments when the client-sent
// `__expectedUpdated` doesn't match the current `updated` value.
// Clients opt in by including `__expectedUpdated`; if absent the
// check is skipped (backward-compatible).

migrate(
  (app) => {
    app.onRecordUpdateRequest((e) => {
      if (e.collection.name !== 'technicianAssignments') return;

      const body = e.httpContext.request().body;
      const expected = body.get('__expectedUpdated');
      if (!expected) return; // opt-in

      // Fetch the original record from the DB to get the current updated value.
      let original;
      try {
        original = e.dao.findRecordById(e.collection, e.record.id);
      } catch {
        return; // record not found — let the normal error handling cover this
      }

      const originalUpdated = String(original.get('updated') || '');
      if (originalUpdated !== String(expected)) {
        throw new ApiError(409, 'Record was modified by another user');
      }

      // Remove the meta field so it doesn't persist to the database.
      body.remove('__expectedUpdated');
      console.log('[M21] optimistic lock passed for', e.record.id);
    });
    console.log('[M21] optimistic lock hook installed');
  },
  (app) => {
    console.log('[M21] rollback requested — remove this migration file and restart PocketBase');
  },
);