import '../../core/exceptions.dart';
import '../api/projects_api.dart';
import '../local/database.dart';
import '../models/project.dart';

/// Projects repository with read-through caching (Phase 1+2) and offline-write
/// queueing (Phase 3). See `notes_repository.dart` for the full pattern.
///
/// `getAll`'s sort/order/status query parameters are server-side filters; the
/// cache stores the unfiltered list as last seen. Offline fallback returns
/// the full cache regardless of the requested filters — close enough for a
/// "view what you had" experience while disconnected.
class ProjectsRepository {
  final ProjectsApi _api;
  final FabledDatabase _db;

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

  Future<List<Project>> getAll({
    String? status,
    String sort = 'updated_at',
    String order = 'desc',
  }) async {
    try {
      final projects =
          await _api.getAll(status: status, sort: sort, order: order);
      // Only refresh the cache on the unfiltered default fetch — otherwise a
      // status=archived call would clobber the active-projects cache.
      if (status == null) {
        await _db.replaceAllProjects(projects);
      } else {
        for (final p in projects) {
          await _db.upsertProject(p);
        }
      }
      return projects;
    } on NetworkException {
      final cached = await _db.getAllProjects();
      if (cached.isEmpty) rethrow;
      if (status != null) {
        return cached.where((p) => p.status == status).toList();
      }
      return cached;
    }
  }

  Future<Project> getOne(int id) async {
    try {
      final project = await _api.getOne(id);
      await _db.upsertProject(project);
      return project;
    } on NetworkException {
      final cached = await _db.getProject(id);
      if (cached == null) rethrow;
      return cached;
    }
  }

  Future<Project> create({
    required String title,
    String? description,
    String? goal,
    String? color,
    String status = 'active',
  }) async {
    try {
      final project = await _api.create(
        title: title,
        description: description,
        goal: goal,
        color: color,
        status: status,
      );
      await _db.upsertProject(project);
      return project;
    } on NetworkException {
      final tempId = await _db.nextTempId();
      final now = DateTime.now();
      final optimistic = Project(
        id: tempId,
        title: title,
        description: description,
        goal: goal,
        status: status,
        color: color,
        createdAt: now,
        updatedAt: now,
      );
      await _db.upsertProject(optimistic);
      await _db.enqueuePending(
        domain: kSyncDomainProjects,
        verb: kWriteVerbCreate,
        tempId: tempId,
        payload: {
          'title': title,
          'description': description,
          'goal': goal,
          'color': color,
          'status': status,
        },
      );
      return optimistic;
    }
  }

  Future<Project> update(int id, Map<String, dynamic> fields) async {
    try {
      final updated = await _api.update(id, fields);
      await _db.upsertProject(updated);
      return updated;
    } on NetworkException {
      final cached = await _db.getProject(id);
      if (cached == null) rethrow;
      final optimistic = _applyProjectFields(cached, fields);
      await _db.upsertProject(optimistic);
      if (id < 0) {
        final queued = await _db.findQueuedCreate(kSyncDomainProjects, id);
        if (queued != null) {
          await _db.updatePendingPayload(queued.id, fields);
          return optimistic;
        }
      }
      await _db.enqueuePending(
        domain: kSyncDomainProjects,
        verb: kWriteVerbUpdate,
        targetId: id,
        payload: fields,
        baselineUpdatedAt: cached.updatedAt,
      );
      return optimistic;
    }
  }

  Future<void> delete(int id) async {
    try {
      await _api.delete(id);
      await _db.deleteProject(id);
    } on NetworkException {
      if (id < 0) {
        final queued = await _db.findQueuedCreate(kSyncDomainProjects, id);
        if (queued != null) await _db.deletePending(queued.id);
        await _db.deleteProject(id);
        return;
      }
      await _db.deleteProject(id);
      await _db.enqueuePending(
        domain: kSyncDomainProjects,
        verb: kWriteVerbDelete,
        targetId: id,
      );
    }
  }
}

Project _applyProjectFields(Project p, Map<String, dynamic> f) {
  return Project(
    id: p.id,
    title: f['title'] as String? ?? p.title,
    description:
        f.containsKey('description') ? f['description'] as String? : p.description,
    goal: f.containsKey('goal') ? f['goal'] as String? : p.goal,
    status: f['status'] as String? ?? p.status,
    color: f.containsKey('color') ? f['color'] as String? : p.color,
    autoSummary: p.autoSummary,
    createdAt: p.createdAt,
    updatedAt: p.updatedAt,
  );
}