import 'dart:async';

import 'package:aioa_mobile/core/forms/schema/form_schema.dart';
import 'package:aioa_mobile/core/forms/schema/form_validator.dart';
import 'package:aioa_mobile/features/form/data/leave_local_draft_repository.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

final leaveLocalDraftRepositoryProvider = Provider<LeaveLocalDraftRepository>(
  (ref) => LeaveLocalDraftRepository(),
);

final leaveDraftProvider =
    NotifierProvider<LeaveDraftController, DynamicFormState>(
      LeaveDraftController.new,
    );

class LeaveDraftController extends Notifier<DynamicFormState> {
  late final LeaveLocalDraftRepository _repository;

  @override
  DynamicFormState build() {
    _repository = ref.watch(leaveLocalDraftRepositoryProvider);
    unawaited(_restore());
    return const DynamicFormState();
  }

  Future<void> _restore() async {
    final restored = await _repository.load();
    if (restored == null || state.values.isNotEmpty) return;
    state = DynamicFormState(
      values: restored.values,
      restoredAt: restored.savedAt,
    );
  }

  void setValue(String field, Object? value) {
    final values = {...state.values, field: value};
    final errors = {...state.errors}..remove(field);
    state = state.copyWith(
      values: values,
      errors: errors,
      clearRestoredAt: true,
    );
    unawaited(_repository.save(values));
  }

  void applyAiSuggestion() {
    final start = DateTime.now().add(const Duration(days: 1));
    final normalizedStart = DateTime(
      start.year,
      start.month,
      start.day,
      13,
      30,
    );
    final end = normalizedStart.add(const Duration(hours: 4));
    state = DynamicFormState(
      values: {
        'type': 'PERSONAL',
        'startsAt': normalizedStart.toUtc().toIso8601String(),
        'endsAt': end.toUtc().toIso8601String(),
        'reason': '办理个人事务，已提前完成工作交接。',
      },
    );
    unawaited(_repository.save(state.values));
  }

  void applySuggestion(Map<String, Object?> suggestion) {
    final values = {...state.values, ...suggestion};
    state = DynamicFormState(values: values);
    unawaited(_repository.save(values));
  }

  Future<void> clear() async {
    await _repository.clear();
    state = const DynamicFormState();
  }

  bool validate(JsonFormSchema schema) {
    final errors = validateDynamicForm(schema, state.values);
    final startsAt = DateTime.tryParse(
      state.values['startsAt'] as String? ?? '',
    );
    final endsAt = DateTime.tryParse(state.values['endsAt'] as String? ?? '');
    if (startsAt != null && endsAt != null && !endsAt.isAfter(startsAt)) {
      errors['endsAt'] = '结束时间必须晚于开始时间';
    }
    state = state.copyWith(errors: errors);
    return errors.isEmpty;
  }
}