import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../../../core/utils/column_search_paging.dart';
import '../../../../core/utils/table_search.dart';

import '../../../../shared/models/export_file_result.dart';
import '../../../../shared/models/user_management_models.dart';
import '../../data/repositories/user_repository_impl.dart';
import '../../domain/usecases/user_usecases.dart';

class UsersListState {
  const UsersListState({
    this.users = const [],
    this.summary,
    this.filters,
    this.query = const UserListQuery(),
    this.total = 0,
    this.totalPages = 1,
    this.isRefreshing = false,
    this.isExporting = false,
    this.actionError,
    this.actionSuccess,
  });

  final List<ManagedUserModel> users;
  final UserSummaryModel? summary;
  final UserFiltersModel? filters;
  final UserListQuery query;
  final int total;
  final int totalPages;
  final bool isRefreshing;
  final bool isExporting;
  final String? actionError;
  final String? actionSuccess;

  UsersListState copyWith({
    List<ManagedUserModel>? users,
    UserSummaryModel? summary,
    UserFiltersModel? filters,
    UserListQuery? query,
    int? total,
    int? totalPages,
    bool? isRefreshing,
    bool? isExporting,
    String? actionError,
    String? actionSuccess,
    bool clearMessages = false,
  }) {
    return UsersListState(
      users: users ?? this.users,
      summary: summary ?? this.summary,
      filters: filters ?? this.filters,
      query: query ?? this.query,
      total: total ?? this.total,
      totalPages: totalPages ?? this.totalPages,
      isRefreshing: isRefreshing ?? this.isRefreshing,
      isExporting: isExporting ?? this.isExporting,
      actionError: clearMessages ? null : actionError ?? this.actionError,
      actionSuccess: clearMessages ? null : actionSuccess ?? this.actionSuccess,
    );
  }
}

final getUsersUseCaseProvider = Provider((ref) {
  return GetUsersUseCase(ref.watch(userRepositoryProvider));
});

final getUserSummaryUseCaseProvider = Provider((ref) {
  return GetUserSummaryUseCase(ref.watch(userRepositoryProvider));
});

final getUserFiltersUseCaseProvider = Provider((ref) {
  return GetUserFiltersUseCase(ref.watch(userRepositoryProvider));
});

final createUserUseCaseProvider = Provider((ref) {
  return CreateUserUseCase(ref.watch(userRepositoryProvider));
});

final updateUserUseCaseProvider = Provider((ref) {
  return UpdateUserUseCase(ref.watch(userRepositoryProvider));
});

final deleteUserUseCaseProvider = Provider((ref) {
  return DeleteUserUseCase(ref.watch(userRepositoryProvider));
});

final updateProfileUseCaseProvider = Provider((ref) {
  return UpdateProfileUseCase(ref.watch(userRepositoryProvider));
});

final getUserByIdUseCaseProvider = Provider((ref) {
  return GetUserByIdUseCase(ref.watch(userRepositoryProvider));
});

final exportUsersUseCaseProvider = Provider((ref) {
  return ExportUsersUseCase(ref.watch(userRepositoryProvider));
});

final usersListProvider =
    AsyncNotifierProvider<UsersListNotifier, UsersListState>(UsersListNotifier.new);

class UsersListNotifier extends AsyncNotifier<UsersListState> {
  final _columnSearch = ColumnSearchPaging(defaultLimit: 10);

  @override
  Future<UsersListState> build() async {
    ref.keepAlive();
    return _loadAll(const UserListQuery(limit: 10));
  }

  Future<UsersListState> _loadAll(UserListQuery query) async {
    final summaryResult = await ref.read(getUserSummaryUseCaseProvider)();
    final filtersResult = await ref.read(getUserFiltersUseCaseProvider)();
    final usersResult = await ref.read(getUsersUseCaseProvider)(query);

    if (usersResult.failure != null) throw usersResult.failure!;

    final page = usersResult.data!;
    return UsersListState(
      users: page.items,
      summary: summaryResult.data,
      filters: filtersResult.data,
      query: query,
      total: page.total,
      totalPages: page.totalPages,
    );
  }

  Future<void> refresh() async {
    final current = state.valueOrNull ?? const UsersListState();
    state = AsyncData(current.copyWith(isRefreshing: true, clearMessages: true));
    try {
      state = AsyncData(await _loadAll(current.query));
    } catch (e, st) {
      state = AsyncError(e, st);
    }
  }

  Future<void> applyQuery(UserListQuery query) async {
    final previous = state.valueOrNull;
    if (previous == null) {
      state = const AsyncLoading();
    }
    try {
      state = AsyncData(await _loadAll(query));
    } catch (e, st) {
      state = AsyncError(e, st);
    }
  }

  void setSearch(String search) {
    final current = state.valueOrNull;
    if (current == null) return;
    applyQuery(current.query.copyWith(search: TableSearch.normalize(search), page: 1));
  }

  Future<void> ensureColumnSearchDataset() async {
    final current = state.valueOrNull;
    if (current == null) return;
    final limit = _columnSearch.beginFullDataset(
      currentLimit: current.query.limit,
      total: current.total,
    );
    if (limit == null) return;
    await applyQuery(
      current.query.copyWith(search: null, page: 1, limit: limit),
    );
  }

  void clearColumnSearchDataset() {
    final current = state.valueOrNull;
    if (current == null) return;
    final limit = _columnSearch.endFullDataset();
    if (limit == null) return;
    applyQuery(current.query.copyWith(search: null, page: 1, limit: limit));
  }

  void setPage(int page) {
    final current = state.valueOrNull;
    if (current == null) return;
    applyQuery(current.query.copyWith(page: page));
  }

  void setPageSize(int limit) {
    final current = state.valueOrNull;
    if (current == null) return;
    applyQuery(current.query.copyWith(limit: limit, page: 1));
  }

  void setSort(String sortBy, String sortOrder) {
    final current = state.valueOrNull;
    if (current == null) return;
    applyQuery(current.query.copyWith(sortBy: sortBy, sortOrder: sortOrder, page: 1));
  }

  void setStatusFilter(String? status) {
    final current = state.valueOrNull;
    if (current == null) return;
    applyQuery(current.query.copyWith(status: status, page: 1));
  }

  void setRoleFilter(int? roleId) {
    final current = state.valueOrNull;
    if (current == null) return;
    applyQuery(current.query.copyWith(roleId: roleId, page: 1));
  }

  void setDepartmentFilter(int? departmentId) {
    final current = state.valueOrNull;
    if (current == null) return;
    applyQuery(current.query.copyWith(departmentId: departmentId, page: 1));
  }

  Future<void> resetFilters() async {
    final current = state.valueOrNull;
    if (current == null) return;

    final clearedQuery = UserListQuery(limit: current.query.limit);
    final query = current.query;
    final hasActiveFilters = (query.search?.isNotEmpty ?? false) ||
        query.roleId != null ||
        query.departmentId != null ||
        query.status != null;

    if (!hasActiveFilters &&
        query.page == clearedQuery.page &&
        query.limit == clearedQuery.limit) {
      return;
    }

    await applyQuery(clearedQuery);
  }

  Future<ExportFileResult?> exportUsers() async {
    final current = state.valueOrNull;
    if (current == null) return null;

    state = AsyncData(current.copyWith(isExporting: true, clearMessages: true));

    final result = await ref.read(exportUsersUseCaseProvider)(current.query);
    final latest = state.valueOrNull ?? current;

    if (result.failure != null) {
      state = AsyncData(
        latest.copyWith(
          isExporting: false,
          actionError: result.failure!.message,
        ),
      );
      return null;
    }

    state = AsyncData(latest.copyWith(isExporting: false));
    return result.data;
  }

  Future<bool> deactivateUser(String id) async {
    final result = await ref.read(deleteUserUseCaseProvider)(id);
    if (result.failure != null) {
      final current = state.valueOrNull;
      if (current != null) {
        state = AsyncData(
          current.copyWith(actionError: result.failure!.message),
        );
      }
      return false;
    }
    await refresh();
    return true;
  }

  Future<bool> toggleUserStatus(ManagedUserModel user) async {
    final updateUseCase = ref.read(updateUserUseCaseProvider);
    final activating = user.status != 'active';
    final result = await updateUseCase(
      user.id,
      UpdateUserRequest(
        status: activating ? 'active' : 'inactive',
        isActive: activating,
      ),
    );
    if (result.failure != null) {
      final current = state.valueOrNull;
      if (current != null) {
        state = AsyncData(
          current.copyWith(actionError: result.failure!.message),
        );
      }
      return false;
    }
    await refresh();
    return true;
  }
}

final userDetailProvider = AsyncNotifierProvider.family<UserDetailNotifier, ManagedUserModel, String>(
  UserDetailNotifier.new,
);

class UserDetailNotifier extends FamilyAsyncNotifier<ManagedUserModel, String> {
  @override
  Future<ManagedUserModel> build(String arg) async {
    final useCase = ref.read(getUserByIdUseCaseProvider);
    final result = await useCase(arg);
    if (result.failure != null) throw result.failure!;
    return result.data!;
  }

  Future<bool> deactivate() async {
    final deleteUseCase = ref.read(deleteUserUseCaseProvider);
    final result = await deleteUseCase(arg);
    if (result.failure != null) return false;
    ref.invalidateSelf();
    await future;
    return true;
  }
}

final userFormProvider = AsyncNotifierProvider.family<UserFormNotifier, ManagedUserModel?, String?>(
  UserFormNotifier.new,
);

class UserFormNotifier extends FamilyAsyncNotifier<ManagedUserModel?, String?> {
  @override
  Future<ManagedUserModel?> build(String? arg) async {
    if (arg == null) return null;
    final useCase = ref.read(getUserByIdUseCaseProvider);
    final result = await useCase(arg);
    if (result.failure != null) throw result.failure!;
    return result.data;
  }

  Future<ManagedUserModel?> submitCreate(CreateUserRequest request) async {
    final useCase = ref.read(createUserUseCaseProvider);
    final result = await useCase(request);
    if (result.failure != null) throw result.failure!;
    ref.invalidate(usersListProvider);
    return result.data;
  }

  Future<ManagedUserModel?> submitUpdate(String id, UpdateUserRequest request) async {
    final useCase = ref.read(updateUserUseCaseProvider);
    final result = await useCase(id, request);
    if (result.failure != null) throw result.failure!;
    ref.invalidate(usersListProvider);
    ref.invalidate(userDetailProvider(id));
    return result.data;
  }
}