import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:tdesign_flutter/tdesign_flutter.dart';

import '../../core/i18n/app_localizations.dart';
import '../../core/navigation/host_app_channel.dart';
import '../../core/storage/draft_storage.dart';
import '../../core/theme/app_colors.dart';
import '../../core/theme/app_colors_extension.dart';
import '../../shared/widgets/action_bar.dart';
import '../../shared/widgets/app_skeletons.dart';
import '../../shared/widgets/form_field_row.dart';
import '../../shared/widgets/form_section.dart';
import '../../shared/widgets/loading_dialog.dart';
import '../../shared/widgets/nav_bar_config.dart';
import '../../shared/widgets/searchable_picker_sheet.dart';
import 'vehicle_api.dart';

class VehicleCreatePage extends ConsumerStatefulWidget {
  const VehicleCreatePage({super.key});

  @override
  ConsumerState<VehicleCreatePage> createState() => _VehicleCreatePageState();
}

class _VehicleCreatePageState extends ConsumerState<VehicleCreatePage> {
  static const _draftKey = 'vehicle_apply';

  // ── 基本信息 ──
  String _purpose = '';
  final _reasonController = TextEditingController();
  final _reasonFocus = FocusNode();
  String _origin = '';
  String _destinAdr = '';
  DateTime? _startTime;
  DateTime? _endTime;

  // ── 车辆信息 ──
  String _licensePlate = '';
  String _vehicleType = '';
  String _brand = '';
  int _seats = 0;

  // ── 驾驶员 ──
  String _driverName = '';

  // ── 同行信息 ──
  int _passengerCount = 1;
  String _passengerName = '';

  // ── 参考数据 ──
  List<DepartmentItem> _departments = [];
  bool _firstBuild = true;
  bool _refDataLoading = true;
  String _selectedDeptId = '';
  String _selectedDeptName = '';

  final _scrollCtrl = ScrollController();

  // Mock 车牌
  static const _mockLicensePlates = ['粤B12345', '京A88888', '京B66666', '京C12345', '京D99999'];

  // Mock 车辆类型
  static const _mockVehicleTypes = ['sedan', 'suv', 'mpv', 'van'];

  @override
  void initState() {
    super.initState();
    SystemChrome.setSystemUIOverlayStyle(
      const SystemUiOverlayStyle(statusBarColor: Colors.transparent, statusBarIconBrightness: Brightness.dark),
    );
    _reasonFocus.addListener(() => _ensureVisible(_reasonFocus));
    _departments = [];
    _refDataLoading = true;
    _refDataFuture = null;
    _loadRefData();
    WidgetsBinding.instance.addPostFrameCallback((_) => _checkDataReady());
  }

  void _checkDataReady() {
    if (!_refDataLoading && mounted) {
      setState(() => _firstBuild = false);
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (mounted) setState(() {});
      });
    } else if (mounted) {
      WidgetsBinding.instance.addPostFrameCallback((_) => _checkDataReady());
    }
  }

  Future<void>? _refDataFuture;

  Future<void> _loadRefData({bool showLoading = false}) async {
    if (_refDataFuture != null) return _refDataFuture!;
    final completer = Completer<void>();
    _refDataFuture = completer.future;
    if (showLoading) {
      LoadingDialog.show(context, text: AppLocalizations.of(context).get('dataLoading'));
    }
    try {
      final api = ref.read(vehicleApiProvider);
      final results = await Future.wait([api.getDepartments()]);
      if (!mounted) return;
      setState(() {
        _departments = results[0];
        _refDataLoading = false;
        _autoSelectDept();
      });
      completer.complete();
    } catch (_) {
      if (!mounted) { completer.complete(); return; }
      setState(() => _refDataLoading = false);
      completer.complete();
    } finally {
      if (showLoading && mounted) LoadingDialog.hide(context);
      _refDataFuture = null;
    }
  }

  void _autoSelectDept() {
    if (_selectedDeptId.isNotEmpty) return;
    final dep = HostAppChannel.dep;
    if (dep.isEmpty) return;
    final match = _departments.where((d) => d.dep == dep);
    if (match.isNotEmpty) {
      _selectedDeptId = match.first.dep;
      _selectedDeptName = match.first.name;
    }
  }

  void _ensureVisible(FocusNode node) {
    if (!node.hasFocus) return;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (node.hasFocus && _scrollCtrl.hasClients) {
        final ctx = node.context;
        if (ctx != null) {
          Scrollable.ensureVisible(ctx, alignment: 0.3, duration: const Duration(milliseconds: 300));
        }
      }
    });
  }

  @override
  void dispose() {
    _reasonController.dispose();
    _reasonFocus.dispose();
    _scrollCtrl.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context);

    if (_firstBuild) {
      return const SkeletonFormPage();
    }

    Future.microtask(() => ref.read(pageBackProvider.notifier).state = () => _doPop());

    return PopScope(
      canPop: false,
      onPopInvokedWithResult: (didPop, _) {
        if (didPop) return;
        _doPop();
      },
      child: Column(
        children: [
          Expanded(
            child: GestureDetector(
              onTap: () => FocusScope.of(context).unfocus(),
              child: SingleChildScrollView(
                controller: _scrollCtrl,
                padding: const EdgeInsets.all(16),
                child: Column(
                  children: [
                    _buildBasicInfo(l10n),
                    const SizedBox(height: 16),
                    _buildVehicleInfo(l10n),
                    const SizedBox(height: 16),
                    _buildPassengerInfo(l10n),
                    const SizedBox(height: 24),
                    _buildPageFooter(),
                  ],
                ),
              ),
            ),
          ),
          _buildBottomBar(l10n),
        ],
      ),
    );
  }

  // ═══ 基本信息 ═══
  Widget _buildBasicInfo(AppLocalizations l10n) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    return FormSection(
      title: l10n.get('basicInfo'),
      leadingIcon: Icons.info_outline,
      children: [
        FormFieldRow(label: l10n.get('date'), value: _today(), readOnly: true, showArrow: false),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('applyDept'),
          value: _selectedDeptId.isNotEmpty ? '$_selectedDeptId/$_selectedDeptName' : '',
          hint: l10n.get('pleaseSelect'),
          onTap: _refDataLoading ? null : () => _showDeptPicker(),
        ),
        const SizedBox(height: 16),
        _buildPurposeRow(l10n),
        const SizedBox(height: 16),
        _label(l10n.get('vehicleReason'), required: true),
        const SizedBox(height: 8),
        TDTextarea(
          controller: _reasonController,
          focusNode: _reasonFocus,
          hintText: l10n.get('enterVehicleReason'),
          maxLines: 4,
          minLines: 1,
          maxLength: 500,
          indicator: true,
          padding: EdgeInsets.zero,
          bordered: true,
          backgroundColor: colors.bgPage,
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('origin'),
          value: _origin.isNotEmpty ? _origin : null,
          hint: l10n.get('pleaseEnter'),
          onTap: () => _showTextInput(l10n.get('origin'), (v) => setState(() => _origin = v)),
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('destination'),
          value: _destinAdr.isNotEmpty ? _destinAdr : null,
          hint: l10n.get('pleaseEnter'),
          onTap: () => _showTextInput(l10n.get('destination'), (v) => setState(() => _destinAdr = v)),
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('departTime'),
          value: _startTime != null ? _formatDateTime(_startTime!) : null,
          hint: l10n.get('pleaseSelect'),
          onTap: () => _pickDateTime((d) => setState(() => _startTime = d), _startTime),
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('returnTime'),
          value: _endTime != null ? _formatDateTime(_endTime!) : null,
          hint: l10n.get('pleaseSelect'),
          onTap: () => _pickDateTime((d) => setState(() => _endTime = d), _endTime),
        ),
        if (_startTime != null && _endTime != null && !_endTime!.isAfter(_startTime!))
          Padding(
            padding: const EdgeInsets.only(top: 8),
            child: Text(
              l10n.get('returnTimeMustLater'),
              style: TextStyle(fontSize: AppFontSizes.caption, color: colors.danger),
            ),
          ),
      ],
    );
  }

  Widget _buildPurposeRow(AppLocalizations l10n) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    final purposes = ['reception', 'business', 'official', 'other'];
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        _label(l10n.get('vehiclePurpose'), required: true),
        const SizedBox(height: 8),
        Wrap(
          spacing: 12,
          runSpacing: 8,
          children: purposes.map((key) {
            final sel = _purpose == key;
            return GestureDetector(
              behavior: HitTestBehavior.opaque,
              onTap: () => setState(() => _purpose = key),
              child: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  Container(
                    width: 18,
                    height: 18,
                    decoration: BoxDecoration(
                      shape: BoxShape.circle,
                      border: Border.all(color: sel ? colors.primary : colors.textPlaceholder, width: 2),
                    ),
                    child: sel
                        ? Center(child: Container(width: 8, height: 8, decoration: BoxDecoration(shape: BoxShape.circle, color: colors.primary)))
                        : null,
                  ),
                  const SizedBox(width: 5),
                  Text(_purposeLabel(key, l10n), style: TextStyle(fontSize: AppFontSizes.subtitle, color: sel ? colors.primary : colors.textPrimary)),
                ],
              ),
            );
          }).toList(),
        ),
      ],
    );
  }

  // ═══ 车辆信息 ═══
  Widget _buildVehicleInfo(AppLocalizations l10n) {
    return FormSection(
      title: l10n.get('vehicleInfo'),
      leadingIcon: Icons.directions_car_outlined,
      children: [
        FormFieldRow(
          label: l10n.get('licensePlate'),
          value: _licensePlate.isNotEmpty ? _licensePlate : null,
          hint: l10n.get('pleaseSelect'),
          onTap: () => _showLicensePlatePicker(),
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('vehicleType'),
          value: _vehicleType.isNotEmpty ? _vehicleTypeLabel(_vehicleType, l10n) : null,
          hint: l10n.get('pleaseSelect'),
          onTap: () => _showVehicleTypePicker(l10n),
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('brand'),
          value: _brand.isNotEmpty ? _brand : null,
          hint: l10n.get('pleaseEnter'),
          onTap: () => _showTextInput(l10n.get('brand'), (v) => setState(() => _brand = v), initialText: _brand),
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('seats'),
          value: _seats > 0 ? '$_seats' : null,
          hint: l10n.get('pleaseEnter'),
          onTap: () => _showNumberInput(l10n.get('seats'), (v) => setState(() => _seats = v), _seats),
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('driverName'),
          value: _driverName.isNotEmpty ? _driverName : null,
          hint: l10n.get('pleaseSelect'),
          onTap: () => _showDriverPicker(),
        ),
      ],
    );
  }

  // ═══ 同行信息 ═══
  Widget _buildPassengerInfo(AppLocalizations l10n) {
    return FormSection(
      title: l10n.get('companionInfo'),
      leadingIcon: Icons.people_outline,
      children: [
        FormFieldRow(
          label: l10n.get('passengerCount'),
          value: '$_passengerCount',
          onTap: () => _showNumberInput(l10n.get('passengerCount'), (v) => setState(() => _passengerCount = v < 1 ? 1 : v), _passengerCount),
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('passengerName'),
          value: _passengerName.isNotEmpty ? _passengerName : null,
          hint: l10n.get('pleaseEnter'),
          onTap: () => _showTextInput(l10n.get('passengerName'), (v) => setState(() => _passengerName = v), initialText: _passengerName),
        ),
      ],
    );
  }

  // ═══ 底部操作栏 ═══
  Widget _buildBottomBar(AppLocalizations l10n) {
    return ActionBar(
      showLeft: false,
      centerLabel: l10n.get('saveDraft'),
      rightLabel: l10n.get('submit'),
      centerTextOnly: true,
      onCenterTap: () async {
        FocusScope.of(context).unfocus();
        try {
          await _saveDraftToStorage();
          if (mounted) _forcePop();
        } catch (_) {
          if (mounted) TDToast.showFail(l10n.get('saveFailed'), context: context);
        }
      },
      onRightTap: () async {
        final err = _validate(l10n);
        if (err.isNotEmpty) {
          TDToast.showText(err.first, context: context);
          return;
        }
        FocusScope.of(context).unfocus();
        LoadingDialog.show(context, text: l10n.get('submitting'));
        try {
          final data = _buildSubmitData();
          final api = ref.read(vehicleApiProvider);
          await api.submit(data);
          await DraftStorage.delete(_draftKey);
          if (mounted) {
            LoadingDialog.hide(context);
            TDToast.showSuccess(l10n.get('submitSuccess'), context: context);
            GoRouter.of(context).go('/vehicle/list');
          }
        } catch (_) {
          if (mounted) {
            LoadingDialog.hide(context);
            TDToast.showFail(l10n.get('submitFailedRetry'), context: context);
          }
        }
      },
    );
  }

  Map<String, dynamic> _buildSubmitData() {
    return {
      'HeadData': {
        'YC_DD': _today(),
        'SAL_NO': HostAppChannel.usr,
        'DEP': _selectedDeptId,
        'PURPOSE': _purpose,
        'REASON': _reasonController.text.trim(),
        'ORIGIN': _origin,
        'DESTIN_ADR': _destinAdr,
        'PASSENGER_COUNT': _passengerCount,
        'PASSENGER_NAME': _passengerName,
        'LICENSEPLATE': _licensePlate,
        'VEHICLE_TYPE': _vehicleType,
        'BRAND': _brand,
        'SEATS': _seats,
        'DRIVER_NAME': _driverName,
        'START_TIME': _startTime?.toIso8601String(),
        'END_TIME': _endTime?.toIso8601String(),
        'USR': HostAppChannel.usr,
      },
    };
  }

  List<String> _validate(AppLocalizations l10n) {
    final e = <String>[];
    if (_reasonController.text.trim().isEmpty) e.add(l10n.get('enterVehicleReason'));
    if (_purpose.isEmpty) e.add('请选择用车目的');
    if (_licensePlate.isEmpty) e.add('请选择车牌号');
    if (_startTime != null && _endTime != null && !_endTime!.isAfter(_startTime!)) {
      e.add(l10n.get('returnTimeMustLater'));
    }
    return e;
  }

  // ═══ 草稿 ═══
  Future<void> _saveDraftToStorage() async {
    await DraftStorage.save(_draftKey, {
      'purpose': _purpose,
      'reason': _reasonController.text,
      'origin': _origin,
      'destinAdr': _destinAdr,
      'startTime': _startTime?.toIso8601String(),
      'endTime': _endTime?.toIso8601String(),
      'licensePlate': _licensePlate,
      'vehicleType': _vehicleType,
      'brand': _brand,
      'seats': _seats,
      'driverName': _driverName,
      'passengerCount': _passengerCount,
      'passengerName': _passengerName,
      'selectedDeptId': _selectedDeptId,
      'selectedDeptName': _selectedDeptName,
    });
  }

  void _doPop() {
    if (_hasUnsaved()) {
      final l10n = AppLocalizations.of(context);
      _showConfirmDialog(l10n.get('confirmExit'), l10n.get('unsavedContentWarning'), l10n.get('continueEditing'), l10n.get('discardAndExit'), () {
        DraftStorage.delete(_draftKey);
        _forcePop();
      });
    } else {
      _forcePop();
    }
  }

  void _forcePop() {
    FocusManager.instance.primaryFocus?.unfocus();
    final router = GoRouter.of(context);
    if (router.canPop()) { router.pop(); } else { SystemNavigator.pop(); }
  }

  bool _hasUnsaved() =>
      _reasonController.text.isNotEmpty || _purpose.isNotEmpty || _origin.isNotEmpty || _destinAdr.isNotEmpty ||
      _licensePlate.isNotEmpty || _vehicleType.isNotEmpty || _brand.isNotEmpty || _driverName.isNotEmpty ||
      _passengerName.isNotEmpty || _passengerCount != 1;

  void _showConfirmDialog(String title, String content, String leftText, String rightText, VoidCallback onConfirm) {
    FocusScope.of(context).unfocus();
    FocusManager.instance.primaryFocus?.unfocus();
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    showDialog(
      context: context,
      useRootNavigator: true,
      builder: (ctx) => TDAlertDialog(
        title: title,
        content: content,
        buttonStyle: TDDialogButtonStyle.text,
        leftBtn: TDDialogButtonOptions(title: leftText, titleColor: colors.primary, action: () => Navigator.pop(ctx)),
        rightBtn: TDDialogButtonOptions(title: rightText, titleColor: colors.danger, action: () { Navigator.pop(ctx); onConfirm(); }),
      ),
    );
  }

  // ═══ 弹窗方法 ═══
  void _showTextInput(String title, void Function(String) onConfirm, {String initialText = ''}) {
    FocusScope.of(context).unfocus();
    final l10n = AppLocalizations.of(context);
    final c = TextEditingController(text: initialText);
    showGeneralDialog(
      context: context,
      pageBuilder: (ctx, animation, secondaryAnimation) => TDInputDialog(
        textEditingController: c,
        title: title,
        hintText: l10n.get('pleaseEnter'),
        leftBtn: TDDialogButtonOptions(title: l10n.get('cancel'), action: () => Navigator.pop(ctx)),
        rightBtn: TDDialogButtonOptions(title: l10n.get('confirm'), action: () { onConfirm(c.text); Navigator.pop(ctx); }),
      ),
    );
  }

  void _showNumberInput(String title, void Function(int) onSave, int current) {
    FocusScope.of(context).unfocus();
    final l10n = AppLocalizations.of(context);
    final ctrl = TextEditingController(text: '$current');
    showDialog(
      context: context,
      builder: (_) => TDAlertDialog(
        title: title,
        contentWidget: TDInput(controller: ctrl, hintText: '请输入数字', inputType: TextInputType.number),
        leftBtn: TDDialogButtonOptions(title: l10n.get('cancel'), action: () => Navigator.pop(context)),
        rightBtn: TDDialogButtonOptions(
          title: l10n.get('confirm'),
          theme: TDButtonTheme.primary,
          action: () { onSave(int.tryParse(ctrl.text) ?? 1); Navigator.pop(context); },
        ),
      ),
    );
  }

  void _pickDateTime(void Function(DateTime) onPicked, DateTime? initial) {
    FocusScope.of(context).unfocus();
    final l10n = AppLocalizations.of(context);
    final d = initial ?? DateTime.now();
    TDPicker.showDatePicker(
      context,
      title: l10n.get('selectDateTime'),
      useYear: true, useMonth: true, useDay: true, useHour: true, useMinute: true,
      initialDate: [d.year, d.month, d.day, d.hour, d.minute],
      onConfirm: (selected) {
        onPicked(DateTime(selected['year']!, selected['month']!, selected['day']!, selected['hour']!, selected['minute']!));
      },
    );
  }

  Future<void> _showDeptPicker() async {
    FocusManager.instance.primaryFocus?.unfocus();
    final l10n = AppLocalizations.of(context);
    final api = ref.read(vehicleApiProvider);
    final result = await showSearchablePicker<DepartmentItem>(
      context,
      title: '${l10n.get('select')}${l10n.get('applyDept')}',
      searchHint: l10n.get('search'),
      loader: (keyword, page) => api.getDepartments(keyword: keyword, page: page, size: 20),
      labelBuilder: (d) => d.name.isEmpty ? d.dep : '${d.dep} ${d.name}',
    );
    if (result != null && mounted) {
      setState(() { _selectedDeptId = result.dep; _selectedDeptName = result.name; });
    }
  }

  void _showLicensePlatePicker() {
    FocusScope.of(context).unfocus();
    final l10n = AppLocalizations.of(context);
    TDPicker.showMultiPicker(
      context,
      title: l10n.get('selectLicensePlate'),
      data: [_mockLicensePlates],
      onConfirm: (selected) => setState(() => _licensePlate = selected.first),
    );
  }

  void _showVehicleTypePicker(AppLocalizations l10n) {
    FocusScope.of(context).unfocus();
    final labels = _mockVehicleTypes.map((t) => _vehicleTypeLabel(t, l10n)).toList();
    TDPicker.showMultiPicker(
      context,
      title: l10n.get('selectVehicleType'),
      data: [labels],
      onConfirm: (selected) {
        final idx = labels.indexOf(selected.first);
        if (idx >= 0) setState(() => _vehicleType = _mockVehicleTypes[idx]);
      },
    );
  }

  Future<void> _showDriverPicker() async {
    FocusManager.instance.primaryFocus?.unfocus();
    final l10n = AppLocalizations.of(context);
    final api = ref.read(vehicleApiProvider);
    final result = await showSearchablePicker<EmployeeItem>(
      context,
      title: '${l10n.get('select')}${l10n.get('driverName')}',
      searchHint: l10n.get('search'),
      loader: (keyword, page) => api.getEmployees(keyword: keyword, page: page, size: 20),
      labelBuilder: (e) => e.name.isEmpty ? e.salNo : '${e.salNo} ${e.name}',
    );
    if (result != null && mounted) {
      setState(() { _driverName = result.name; });
    }
  }

  // ═══ 工具方法 ═══
  Widget _label(String t, {bool required = false}) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    return Text.rich(
      TextSpan(
        children: [
          TextSpan(text: t, style: TextStyle(fontSize: AppFontSizes.subtitle, color: colors.textSecondary)),
          if (required) TextSpan(text: ' *', style: TextStyle(fontSize: AppFontSizes.subtitle, color: colors.danger)),
        ],
      ),
    );
  }

  Widget _buildPageFooter() {
    final l10n = AppLocalizations.of(context);
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    return Center(
      child: Padding(
        padding: const EdgeInsets.only(bottom: 16),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(Icons.rocket_launch_outlined, size: 16, color: colors.textPlaceholder),
            const SizedBox(width: 6),
            Text(l10n.get('pageFooter'), style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textPlaceholder)),
          ],
        ),
      ),
    );
  }

  String _today() {
    final n = DateTime.now();
    return '${n.year}-${n.month.toString().padLeft(2, '0')}-${n.day.toString().padLeft(2, '0')}';
  }

  String _formatDateTime(DateTime d) {
    return '${d.year}-${d.month.toString().padLeft(2, '0')}-${d.day.toString().padLeft(2, '0')} ${d.hour.toString().padLeft(2, '0')}:${d.minute.toString().padLeft(2, '0')}';
  }

  String _purposeLabel(String key, AppLocalizations l10n) {
    switch (key) {
      case 'reception': return l10n.get('customerReception');
      case 'business': return l10n.get('businessTrip');
      case 'official': return l10n.get('official');
      case 'other': return l10n.get('other');
      default: return key;
    }
  }

  String _vehicleTypeLabel(String key, AppLocalizations l10n) {
    switch (key) {
      case 'sedan': return '轿车';
      case 'suv': return 'SUV';
      case 'mpv': return '商务车';
      case 'van': return '面包车';
      default: return key;
    }
  }
}