import 'package:flutter/material.dart';
import 'package:tdesign_flutter/tdesign_flutter.dart';
import '../../core/i18n/app_localizations.dart';
import '../../core/theme/app_colors_extension.dart';

/// 通用日期区间选择器。
///
/// 关闭态为单个胶囊 chip（日历图标 + 日期区间文本），
/// 点击弹出 TDSlidePopupRoute，内含快捷日期 chip、
/// 起始/截止 TDDatePicker、已选区间展示、取消/确定按钮。
class DateRangePicker extends StatefulWidget {
  final TextEditingController startCtrl;
  final TextEditingController endCtrl;
  final VoidCallback? onChanged;

  const DateRangePicker({
    super.key,
    required this.startCtrl,
    required this.endCtrl,
    this.onChanged,
  });

  @override
  State<DateRangePicker> createState() => _DateRangePickerState();
}

class _DateRangePickerState extends State<DateRangePicker> {
  late DateTime _tempStart;
  late DateTime _tempEnd;

  @override
  void initState() {
    super.initState();
    _initTemp();
  }

  void _initTemp() {
    final now = DateTime.now();
    _tempStart =
        DateTime.tryParse(widget.startCtrl.text) ??
        DateTime(now.year, now.month, 1);
    _tempEnd =
        DateTime.tryParse(widget.endCtrl.text) ??
        DateTime(now.year, now.month + 1, 0);
  }

  String get _displayText =>
      '${widget.startCtrl.text} ~ ${widget.endCtrl.text}';

  DateTime _today() => DateTime.now();

  DateTime _dateOnly(DateTime d) => DateTime(d.year, d.month, d.day);

  // ---- 弹窗 ----

  void _openPicker() {
    _initTemp();

    final l10n = AppLocalizations.of(context);
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    final now = DateTime.now();

    Navigator.of(context).push(
      TDSlidePopupRoute(
        builder: (ctx) => _PickerContent(
          l10n: l10n,
          colors: colors,
          now: now,
          tempStart: _tempStart,
          tempEnd: _tempEnd,
          onStartChanged: (d) => _tempStart = d,
          onEndChanged: (d) => _tempEnd = d,
          onQuick: (key) {
            switch (key) {
              case 'today':
                final t = _dateOnly(_today());
                return (start: t, end: t);
              case 'thisWeek':
                final t = _dateOnly(_today());
                final wd = t.weekday;
                final s = t.subtract(Duration(days: wd - 1));
                return (start: s, end: s.add(const Duration(days: 6)));
              case 'last7Days':
                final t = _dateOnly(_today());
                return (start: t.subtract(const Duration(days: 6)), end: t);
              case 'thisMonth':
                final t = _dateOnly(_today());
                return (
                  start: DateTime(t.year, t.month, 1),
                  end: DateTime(t.year, t.month + 1, 0),
                );
              case 'lastMonth':
                final t = _dateOnly(_today());
                return (
                  start: DateTime(t.year, t.month - 1, 1),
                  end: DateTime(t.year, t.month, 0),
                );
              case 'last30Days':
                final t = _dateOnly(_today());
                return (start: t.subtract(const Duration(days: 29)), end: t);
              case 'thisQuarter':
                final t = _dateOnly(_today());
                final q = (t.month - 1) ~/ 3;
                return (
                  start: DateTime(t.year, q * 3 + 1, 1),
                  end: DateTime(t.year, q * 3 + 4, 0),
                );
              case 'thisYear':
                final t = _dateOnly(_today());
                return (
                  start: DateTime(t.year, 1, 1),
                  end: DateTime(t.year, 12, 31),
                );
              default:
                return (start: _tempStart, end: _tempEnd);
            }
          },
          onConfirm: () {
            widget.startCtrl.text = _fmt(_tempStart);
            widget.endCtrl.text = _fmt(_tempEnd);
            widget.onChanged?.call();
            Navigator.of(ctx).pop();
          },
          onCancel: () => Navigator.of(ctx).pop(),
        ),
      ),
    );
  }

  String _fmt(DateTime d) =>
      '${d.year}-${d.month.toString().padLeft(2, '0')}-${d.day.toString().padLeft(2, '0')}';

  // ---- 关闭态 chip ----

  @override
  Widget build(BuildContext context) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    final tdTheme = TDTheme.of(context);
    final text = _displayText;

    return GestureDetector(
      onTap: _openPicker,
      child: Container(
        height: 40,
        padding: const EdgeInsets.symmetric(horizontal: 12),
        decoration: BoxDecoration(
          color: colors.bgSecondaryContainer,
          borderRadius: BorderRadius.circular(20),
          border: Border.all(color: tdTheme.componentStrokeColor),
        ),
        child: Row(
          children: [
            Icon(Icons.calendar_today, size: 16, color: colors.textSecondary),
            const SizedBox(width: 12),
            Expanded(
              child: Text(
                text,
                textAlign: TextAlign.center,
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
                style: TextStyle(fontSize: 14, color: colors.textPrimary),
              ),
            ),
            const SizedBox(width: 4),
            Icon(Icons.chevron_right, size: 16, color: colors.textSecondary),
          ],
        ),
      ),
    );
  }
}

/// 弹窗内容（StatefulWidget，自行管理临时状态）
class _PickerContent extends StatefulWidget {
  final AppLocalizations l10n;
  final AppColorsExtension colors;
  final DateTime now;
  final DateTime tempStart;
  final DateTime tempEnd;
  final void Function(DateTime d) onStartChanged;
  final void Function(DateTime d) onEndChanged;
  final ({DateTime start, DateTime end}) Function(String key) onQuick;
  final VoidCallback onConfirm;
  final VoidCallback onCancel;

  const _PickerContent({
    required this.l10n,
    required this.colors,
    required this.now,
    required this.tempStart,
    required this.tempEnd,
    required this.onStartChanged,
    required this.onEndChanged,
    required this.onQuick,
    required this.onConfirm,
    required this.onCancel,
  });

  @override
  State<_PickerContent> createState() => _PickerContentState();
}

class _PickerContentState extends State<_PickerContent> {
  late DateTime _start;
  late DateTime _end;

  @override
  void initState() {
    super.initState();
    _start = widget.tempStart;
    _end = widget.tempEnd;
  }

  String _fmt(DateTime d) =>
      '${d.year}-${d.month.toString().padLeft(2, '0')}-${d.day.toString().padLeft(2, '0')}';

  List<String> get _quickKeys => [
    'today',
    'thisWeek',
    'last7Days',
    'thisMonth',
    'lastMonth',
    'last30Days',
    'thisQuarter',
    'thisYear',
  ];

  String _quickLabel(String key) {
    switch (key) {
      case 'today':
        return widget.l10n.get('today');
      case 'thisWeek':
        return widget.l10n.get('thisWeek');
      case 'last7Days':
        return widget.l10n.get('last7Days');
      case 'thisMonth':
        return widget.l10n.get('thisMonth');
      case 'lastMonth':
        return widget.l10n.get('lastMonth');
      case 'last30Days':
        return widget.l10n.get('last30Days');
      case 'thisQuarter':
        return widget.l10n.get('thisQuarter');
      case 'thisYear':
        return widget.l10n.get('thisYear');
      default:
        return key;
    }
  }

  void _onQuickTap(String key) {
    final r = widget.onQuick(key);
    setState(() {
      _start = r.start;
      _end = r.end;
    });
  }

  List<int> _toList(DateTime d) => [d.year, d.month, d.day];

  /// 兼容 TDDatePicker.onChange 的 List / Map 两种回调格式
  List<int> _parseSelected(dynamic selected) {
    if (selected is List) {
      return [
        int.parse(selected[0].toString()),
        int.parse(selected[1].toString()),
        int.parse(selected[2].toString()),
      ];
    }
    return [
      int.parse(selected['year'].toString()),
      int.parse(selected['month'].toString()),
      int.parse(selected['day'].toString()),
    ];
  }

  String? get _errorMessage {
    if (_start.isAfter(_end)) {
      return widget.l10n.get('filterDateStartAfterEnd');
    }
    if (_end.difference(_start).inDays > 365) {
      return widget.l10n.get('dateRangeLimit');
    }
    return null;
  }

  @override
  Widget build(BuildContext context) {
    final l10n = widget.l10n;
    final colors = widget.colors;
    final now = widget.now;

    return ConstrainedBox(
      constraints: BoxConstraints(
        maxHeight: MediaQuery.of(context).size.height * 0.9,
      ),
      child: Container(
        decoration: BoxDecoration(
          color: colors.bgPage,
          borderRadius: const BorderRadius.vertical(top: Radius.circular(16)),
        ),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            // 标题栏（拖拽手柄 + 标题 + 关闭按钮）
            _buildHeader(colors, l10n),
            // 内容区域（可滚动，适应不同屏幕高度）
            Flexible(
              child: SingleChildScrollView(
                physics: const ClampingScrollPhysics(),
                padding: const EdgeInsets.fromLTRB(16, 0, 16, 12),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    // 快捷日期
                    Wrap(
                      spacing: 8,
                      runSpacing: 8,
                      children: _quickKeys.map((key) {
                        return GestureDetector(
                          onTap: () => _onQuickTap(key),
                          child: Container(
                            padding: const EdgeInsets.symmetric(
                              horizontal: 10,
                              vertical: 4,
                            ),
                            decoration: BoxDecoration(
                              color: colors.primary.withValues(alpha: 0.1),
                              borderRadius: BorderRadius.circular(6),
                              border: Border.all(
                                color: colors.primary.withValues(alpha: 0.3),
                                width: 0.5,
                              ),
                            ),
                            child: Text(
                              _quickLabel(key),
                              style: TextStyle(
                                fontSize: 13,
                                color: colors.primary,
                              ),
                            ),
                          ),
                        );
                      }).toList(),
                    ),
                    const SizedBox(height: 24),
                    // 起始日期
                    Text(
                      l10n.get('startDateLabel'),
                      style: TextStyle(
                        fontSize: 14,
                        fontWeight: FontWeight.w500,
                        color: colors.textPrimary,
                      ),
                    ),
                    const SizedBox(height: 8),
                    ClipRRect(
                      borderRadius: BorderRadius.circular(12),
                      child: Container(
                        decoration: BoxDecoration(color: colors.bgCard),
                        child: TDDatePicker(
                          key: ValueKey('start_${_fmt(_start)}'),
                          header: false,
                          model: DatePickerModel(
                            useYear: true,
                            useMonth: true,
                            useDay: true,
                            useHour: false,
                            useMinute: false,
                            useSecond: false,
                            useWeekDay: false,
                            dateStart: [2000, 1, 1],
                            dateEnd: [now.year + 1, 12, 31],
                            dateInitial: _toList(_start),
                          ),
                          onChange: (selected) {
                            final vals = _parseSelected(selected);
                            setState(() {
                              _start = DateTime(vals[0], vals[1], vals[2]);
                            });
                          },
                        ),
                      ),
                    ),
                    const SizedBox(height: 24),
                    // 截止日期
                    Text(
                      l10n.get('endDateLabel'),
                      style: TextStyle(
                        fontSize: 14,
                        fontWeight: FontWeight.w500,
                        color: colors.textPrimary,
                      ),
                    ),
                    const SizedBox(height: 8),
                    ClipRRect(
                      borderRadius: BorderRadius.circular(12),
                      child: Container(
                        decoration: BoxDecoration(color: colors.bgCard),
                        child: TDDatePicker(
                          key: ValueKey('end_${_fmt(_end)}'),
                          header: false,
                          model: DatePickerModel(
                            useYear: true,
                            useMonth: true,
                            useDay: true,
                            useHour: false,
                            useMinute: false,
                            useSecond: false,
                            useWeekDay: false,
                            dateStart: [2000, 1, 1],
                            dateEnd: [now.year + 1, 12, 31],
                            dateInitial: _toList(_end),
                          ),
                          onChange: (selected) {
                            final vals = _parseSelected(selected);
                            setState(() {
                              _end = DateTime(vals[0], vals[1], vals[2]);
                            });
                          },
                        ),
                      ),
                    ),
                  ],
                ),
              ),
            ),
            // 校验提示 + 底部按钮
            Container(
              decoration: BoxDecoration(
                color: colors.bgCard,
                border: Border(
                  top: BorderSide(color: colors.border, width: 0.5),
                ),
              ),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  AnimatedSize(
                    duration: const Duration(milliseconds: 200),
                    curve: Curves.easeInOut,
                    child: _errorMessage != null
                        ? Padding(
                            padding: const EdgeInsets.fromLTRB(16, 10, 16, 0),
                            child: Row(
                              children: [
                                Icon(
                                  Icons.error_outline,
                                  size: 14,
                                  color: colors.warning,
                                ),
                                const SizedBox(width: 6),
                                Expanded(
                                  child: Text(
                                    _errorMessage!,
                                    style: TextStyle(
                                      fontSize: 12,
                                      color: colors.warning,
                                    ),
                                  ),
                                ),
                              ],
                            ),
                          )
                        : const SizedBox.shrink(),
                  ),
                  Padding(
                    padding: const EdgeInsets.fromLTRB(16, 12, 16, 16),
                    child: Row(
                      children: [
                        Expanded(
                          child: TDButton(
                            text: l10n.get('cancel'),
                            size: TDButtonSize.large,
                            type: TDButtonType.outline,
                            shape: TDButtonShape.rectangle,
                            theme: TDButtonTheme.defaultTheme,
                            onTap: widget.onCancel,
                          ),
                        ),
                        const SizedBox(width: 12),
                        Expanded(
                          child: TDButton(
                            text: l10n.get('confirm'),
                            size: TDButtonSize.large,
                            type: TDButtonType.fill,
                            shape: TDButtonShape.rectangle,
                            theme: _errorMessage != null
                                ? TDButtonTheme.defaultTheme
                                : TDButtonTheme.primary,
                            onTap: _errorMessage != null
                                ? null
                                : () {
                                    widget.onStartChanged(_start);
                                    widget.onEndChanged(_end);
                                    widget.onConfirm();
                                  },
                          ),
                        ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildHeader(AppColorsExtension colors, AppLocalizations l10n) {
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        Center(
          child: Container(
            margin: const EdgeInsets.only(top: 8, bottom: 4),
            width: 36,
            height: 4,
            decoration: BoxDecoration(
              color: colors.border,
              borderRadius: BorderRadius.circular(2),
            ),
          ),
        ),
        Padding(
          padding: const EdgeInsets.fromLTRB(20, 8, 12, 16),
          child: Row(
            children: [
              const SizedBox(width: 24),
              Expanded(
                child: Center(
                  child: Text(
                    l10n.get('datePickerTitle'),
                    style: TextStyle(
                      fontSize: 18,
                      fontWeight: FontWeight.w600,
                      color: colors.textPrimary,
                    ),
                  ),
                ),
              ),
              GestureDetector(
                onTap: widget.onCancel,
                child: Padding(
                  padding: const EdgeInsets.all(4),
                  child: Icon(
                    Icons.close,
                    size: 20,
                    color: colors.textSecondary,
                  ),
                ),
              ),
            ],
          ),
        ),
      ],
    );
  }
}