import '../../core/exceptions.dart';
import '../api/notes_api.dart';
import '../local/database.dart';
import '../models/note.dart';

/// Notes repository with read-through caching for Tier 2 offline support.
///
/// Reads attempt the network first; on success the response is written to
/// the local Drift cache. On `NetworkException` the read falls back to the
/// cache (rethrowing if the cache is empty so the UI can show its
/// fresh-install empty state). Writes (create / update / delete) hit the
/// server then sync the cache; offline write queueing is Phase 3 work and
/// not yet wired here — write methods will throw on `NetworkException` in
/// the meantime.
///
/// `AuthStatus.offline` is owned by `AuthNotifier.verify()` (a periodic
/// heartbeat). This repository deliberately does not poke that state — its
/// only job is to serve what's cached when the network is unreachable.
class NotesRepository {
  final NotesApi _api;
  final FabledDatabase _db;

  const NotesRepository(this._api, this._db);

  Future<List<Note>> getAll() async {
    try {
      final notes = await _api.getAll();
      await _db.replaceAllNotes(notes);
      return notes;
    } on NetworkException {
      final cached = await _db.getAllNotes();
      if (cached.isEmpty) rethrow;
      return cached;
    }
  }

  Future<Note> getOne(int id) async {
    try {
      final note = await _api.getOne(id);
      await _db.upsertNote(note);
      return note;
    } on NetworkException {
      final cached = await _db.getNote(id);
      if (cached == null) rethrow;
      return cached;
    }
  }

  Future<Note> create(
    String title,
    String body, {
    List<String> tags = const [],
    int? projectId,
    String noteType = 'note',
  }) async {
    final note = await _api.create(
      title,
      body,
      tags: tags,
      projectId: projectId,
      noteType: noteType,
    );
    await _db.upsertNote(note);
    return note;
  }

  Future<Note> update(
    int id,
    String title,
    String body, {
    List<String> tags = const [],
    int? projectId,
    bool clearProject = false,
    String noteType = 'note',
  }) async {
    final updated = await _api.update(
      id,
      title,
      body,
      tags: tags,
      projectId: projectId,
      clearProject: clearProject,
      noteType: noteType,
    );
    await _db.upsertNote(updated);
    return updated;
  }

  Future<void> delete(int id) async {
    await _api.delete(id);
    await _db.deleteNote(id);
  }

  /// Last successful `getAll` sync timestamp. Surfaced by the OfflineBanner
  /// when the network is unreachable so the user knows how stale the
  /// cached notes list is.
  Future<DateTime?> lastSyncedAt() => _db.getLastSync(kSyncDomainNotes);
}