import 'package:flutter_riverpod/flutter_riverpod.dart';

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

import '../../../../shared/models/audit_log_model.dart';
import '../../../../shared/models/export_file_result.dart';
import '../../data/repositories/audit_repository_impl.dart';
import '../../domain/usecases/audit_usecases.dart';

class AuditLogsListState {
  const AuditLogsListState({
    this.items = const [],
    this.filters = const AuditLogFilterOptions(),
    this.query = const AuditLogListQuery(),
    this.total = 0,
    this.totalPages = 1,
    this.filtersRequired = true,
    this.isRefreshing = false,
    this.isExporting = false,
    this.actionError,
    this.actionSuccess,
  });

  final List<AuditLogEntryModel> items;
  final AuditLogFilterOptions filters;
  final AuditLogListQuery query;
  final int total;
  final int totalPages;
  final bool filtersRequired;
  final bool isRefreshing;
  final bool isExporting;
  final String? actionError;
  final String? actionSuccess;

  AuditLogsListState copyWith({
    List<AuditLogEntryModel>? items,
    AuditLogFilterOptions? filters,
    AuditLogListQuery? query,
    int? total,
    int? totalPages,
    bool? filtersRequired,
    bool? isRefreshing,
    bool? isExporting,
    String? actionError,
    String? actionSuccess,
    bool clearMessages = false,
  }) {
    return AuditLogsListState(
      items: items ?? this.items,
      filters: filters ?? this.filters,
      query: query ?? this.query,
      total: total ?? this.total,
      totalPages: totalPages ?? this.totalPages,
      filtersRequired: filtersRequired ?? this.filtersRequired,
      isRefreshing: isRefreshing ?? this.isRefreshing,
      isExporting: isExporting ?? this.isExporting,
      actionError: clearMessages ? null : actionError ?? this.actionError,
      actionSuccess: clearMessages ? null : actionSuccess ?? this.actionSuccess,
    );
  }
}

final getAuditFiltersUseCaseProvider = Provider((ref) {
  return GetAuditFiltersUseCase(ref.watch(auditRepositoryProvider));
});

final getAuditLogsUseCaseProvider = Provider((ref) {
  return GetAuditLogsUseCase(ref.watch(auditRepositoryProvider));
});

final getAuditLogByIdUseCaseProvider = Provider((ref) {
  return GetAuditLogByIdUseCase(ref.watch(auditRepositoryProvider));
});

final exportAuditLogsUseCaseProvider = Provider((ref) {
  return ExportAuditLogsUseCase(ref.watch(auditRepositoryProvider));
});

final auditLogsListProvider =
    AsyncNotifierProvider<AuditLogsListNotifier, AuditLogsListState>(
  AuditLogsListNotifier.new,
);

class AuditLogsListNotifier extends AsyncNotifier<AuditLogsListState> {
  final _columnSearch = ColumnSearchPaging();

  @override
  Future<AuditLogsListState> build() async {
    ref.keepAlive();
    return _loadAll(const AuditLogListQuery(limit: 20));
  }

  Future<AuditLogsListState> _loadAll(AuditLogListQuery query) async {
    final filtersResult = await ref.read(getAuditFiltersUseCaseProvider)();
    final listResult = await ref.read(getAuditLogsUseCaseProvider)(query);

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

    final page = listResult.data!;
    return AuditLogsListState(
      items: page.items,
      filters: filtersResult.data ?? const AuditLogFilterOptions(),
      query: query,
      total: page.total,
      totalPages: page.totalPages,
      filtersRequired: page.filtersRequired || !query.hasActiveFilter,
    );
  }

  Future<void> refresh() async {
    final current = state.valueOrNull ?? const AuditLogsListState();
    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(AuditLogListQuery query) async {
    final previous = state.valueOrNull;
    if (previous == null) {
      state = const AsyncLoading();
    } else {
      state = AsyncData(previous.copyWith(query: query, clearMessages: true));
    }
    try {
      final filters = previous?.filters ?? const AuditLogFilterOptions();
      final listResult = await ref.read(getAuditLogsUseCaseProvider)(query);
      if (listResult.failure != null) throw listResult.failure!;
      final page = listResult.data!;
      state = AsyncData(
        AuditLogsListState(
          items: page.items,
          filters: filters,
          query: query,
          total: page.total,
          totalPages: page.totalPages,
          filtersRequired: page.filtersRequired || !query.hasActiveFilter,
        ),
      );
    } 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 setTableName(String? tableName) {
    final current = state.valueOrNull;
    if (current == null) return;
    applyQuery(current.query.copyWith(tableName: tableName, page: 1));
  }

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

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

  void setDateRange(DateTime? dateFrom, DateTime? dateTo) {
    final current = state.valueOrNull;
    if (current == null) return;
    applyQuery(
      current.query.copyWith(dateFrom: dateFrom, dateTo: dateTo, page: 1),
    );
  }

  Future<void> resetFilters() async {
    final current = state.valueOrNull;
    if (current == null) return;
    await applyQuery(AuditLogListQuery(limit: current.query.limit));
  }

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

    if (!current.query.hasActiveFilter) {
      state = AsyncData(
        current.copyWith(
          actionError: 'Apply at least one filter before exporting.',
        ),
      );
      return null;
    }

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

    final result = await ref.read(exportAuditLogsUseCaseProvider)(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;
  }
}

final auditLogDetailProvider = AsyncNotifierProvider.family<
    AuditLogDetailNotifier, AuditLogDetailModel, String>(
  AuditLogDetailNotifier.new,
);

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