import 'dart:io';

import 'package:flutter/material.dart';

import '../services/feedback_store.dart';

enum _FeedbackFilter { all, accurate, inaccurate }

/// Browse saved accurate / inaccurate scan feedback.
class FeedbackListScreen extends StatefulWidget {
  const FeedbackListScreen({super.key});

  @override
  State<FeedbackListScreen> createState() => _FeedbackListScreenState();
}

class _FeedbackListScreenState extends State<FeedbackListScreen> {
  List<FeedbackEntry>? _items;
  bool _loading = true;
  _FeedbackFilter _filter = _FeedbackFilter.all;

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

  Future<void> _reload() async {
    setState(() => _loading = true);
    final items = await FeedbackStore.instance.list();
    if (!mounted) return;
    setState(() {
      _items = items;
      _loading = false;
    });
  }

  Future<void> _deleteItem(String id) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('删除反馈'),
        content: const Text('确定要删除这条反馈记录吗？'),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(false),
            child: const Text('取消'),
          ),
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(true),
            child: const Text('删除', style: TextStyle(color: Colors.red)),
          ),
        ],
      ),
    );
    if (confirmed != true) return;
    await FeedbackStore.instance.delete(id);
    await _reload();
  }

  Future<void> _confirmClearAll(BuildContext context) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('清空全部反馈'),
        content: const Text('确定要删除所有反馈记录吗？此操作不可撤销。'),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(false),
            child: const Text('取消'),
          ),
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(true),
            child: const Text('清空全部', style: TextStyle(color: Colors.red)),
          ),
        ],
      ),
    );
    if (confirmed != true) return;
    setState(() => _loading = true);
    await FeedbackStore.instance.clearAll();
    await _reload();
  }

  List<FeedbackEntry> get _filtered {
    final items = _items ?? const <FeedbackEntry>[];
    switch (_filter) {
      case _FeedbackFilter.all:
        return items;
      case _FeedbackFilter.accurate:
        return items.where((e) => e.accurate).toList();
      case _FeedbackFilter.inaccurate:
        return items.where((e) => !e.accurate).toList();
    }
  }

  @override
  Widget build(BuildContext context) {
    final items = _items;
    final total = items?.length ?? 0;
    final accurateCount = items?.where((e) => e.accurate).length ?? 0;
    final inaccurateCount = total - accurateCount;
    final rate = total == 0 ? null : accurateCount / total;

    return Scaffold(
      appBar: AppBar(
        title: const Text('反馈列表'),
        backgroundColor: Colors.transparent,
        actions: [
          if (total > 0)
            IconButton(
              icon: const Icon(Icons.delete_sweep_outlined),
              tooltip: '清空全部',
              onPressed: () => _confirmClearAll(context),
            ),
        ],
      ),
      body: _loading
          ? const Center(child: CircularProgressIndicator())
          : items == null || items.isEmpty
              ? const Center(
                  child: Text(
                    '暂无反馈\n在结果页点「准确」或「不准确」后会出现在这里',
                    textAlign: TextAlign.center,
                    style: TextStyle(color: Colors.white54),
                  ),
                )
              : Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    _AccuracyHeader(
                      total: total,
                      accurateCount: accurateCount,
                      inaccurateCount: inaccurateCount,
                      rate: rate!,
                    ),
                    Padding(
                      padding: const EdgeInsets.fromLTRB(16, 0, 16, 8),
                      child: Wrap(
                        spacing: 8,
                        children: [
                          _FilterChip(
                            label: '全部 ($total)',
                            selected: _filter == _FeedbackFilter.all,
                            onTap: () => setState(
                              () => _filter = _FeedbackFilter.all,
                            ),
                          ),
                          _FilterChip(
                            label: '准确 ($accurateCount)',
                            selected: _filter == _FeedbackFilter.accurate,
                            selectedColor: const Color(0xFF22C55E),
                            onTap: () => setState(
                              () => _filter = _FeedbackFilter.accurate,
                            ),
                          ),
                          _FilterChip(
                            label: '不准确 ($inaccurateCount)',
                            selected: _filter == _FeedbackFilter.inaccurate,
                            selectedColor: const Color(0xFFEF4444),
                            onTap: () => setState(
                              () => _filter = _FeedbackFilter.inaccurate,
                            ),
                          ),
                        ],
                      ),
                    ),
                    Expanded(
                      child: RefreshIndicator(
                        onRefresh: _reload,
                        child: _filtered.isEmpty
                            ? ListView(
                                physics: const AlwaysScrollableScrollPhysics(),
                                children: const [
                                  SizedBox(height: 120),
                                  Center(
                                    child: Text(
                                      '当前筛选下暂无记录',
                                      style: TextStyle(color: Colors.white54),
                                    ),
                                  ),
                                ],
                              )
                            : ListView.separated(
                                physics: const AlwaysScrollableScrollPhysics(),
                                padding:
                                    const EdgeInsets.fromLTRB(16, 0, 16, 24),
                                itemCount: _filtered.length,
                                separatorBuilder: (_, __) =>
                                    const SizedBox(height: 12),
                                itemBuilder: (context, index) {
                                  final entry = _filtered[index];
                                  return _FeedbackTile(
                                    entry: entry,
                                    onDelete: () => _deleteItem(entry.id),
                                  );
                                },
                              ),
                      ),
                    ),
                  ],
                ),
    );
  }
}

class _AccuracyHeader extends StatelessWidget {
  const _AccuracyHeader({
    required this.total,
    required this.accurateCount,
    required this.inaccurateCount,
    required this.rate,
  });

  final int total;
  final int accurateCount;
  final int inaccurateCount;
  final double rate;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context).textTheme;
    final pct = (rate * 100).toStringAsFixed(rate == 1 || rate == 0 ? 0 : 1);

    return Container(
      margin: const EdgeInsets.fromLTRB(16, 4, 16, 12),
      padding: const EdgeInsets.all(14),
      decoration: BoxDecoration(
        color: Colors.white10,
        borderRadius: BorderRadius.circular(12),
      ),
      child: Row(
        children: [
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  '准确率',
                  style: theme.labelMedium?.copyWith(color: Colors.white54),
                ),
                const SizedBox(height: 2),
                Text(
                  '$pct%',
                  style: theme.headlineSmall?.copyWith(
                    fontWeight: FontWeight.w700,
                    color: const Color(0xFF22C55E),
                  ),
                ),
              ],
            ),
          ),
          _Stat(label: '总计', value: '$total'),
          const SizedBox(width: 16),
          _Stat(label: '准确', value: '$accurateCount', color: const Color(0xFF22C55E)),
          const SizedBox(width: 16),
          _Stat(
            label: '不准确',
            value: '$inaccurateCount',
            color: const Color(0xFFEF4444),
          ),
        ],
      ),
    );
  }
}

class _Stat extends StatelessWidget {
  const _Stat({
    required this.label,
    required this.value,
    this.color,
  });

  final String label;
  final String value;
  final Color? color;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context).textTheme;
    return Column(
      crossAxisAlignment: CrossAxisAlignment.end,
      children: [
        Text(
          label,
          style: theme.labelSmall?.copyWith(color: Colors.white54),
        ),
        Text(
          value,
          style: theme.titleMedium?.copyWith(
            fontWeight: FontWeight.w600,
            color: color ?? Colors.white,
          ),
        ),
      ],
    );
  }
}

class _FilterChip extends StatelessWidget {
  const _FilterChip({
    required this.label,
    required this.selected,
    required this.onTap,
    this.selectedColor,
  });

  final String label;
  final bool selected;
  final VoidCallback onTap;
  final Color? selectedColor;

  @override
  Widget build(BuildContext context) {
    final color = selectedColor ?? Theme.of(context).colorScheme.primary;
    return FilterChip(
      label: Text(label),
      selected: selected,
      onSelected: (_) => onTap(),
      selectedColor: color.withOpacity(0.25),
      checkmarkColor: color,
      labelStyle: TextStyle(
        color: selected ? color : Colors.white70,
        fontWeight: selected ? FontWeight.w600 : FontWeight.w400,
      ),
      side: BorderSide(color: selected ? color : Colors.white24),
      backgroundColor: Colors.white10,
      showCheckmark: false,
    );
  }
}

class _FeedbackTile extends StatelessWidget {
  const _FeedbackTile({required this.entry, this.onDelete});

  final FeedbackEntry entry;
  final VoidCallback? onDelete;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context).textTheme;
    final accurate = entry.accurate;
    final badgeColor =
        accurate ? const Color(0xFF22C55E) : const Color(0xFFEF4444);
    final badgeLabel = accurate ? '准确' : '不准确';
    final score = entry.matchScore;
    final status = entry.matchConfident == true
        ? 'confident'
        : (entry.matchCardId == null ? '—' : 'low');

    return Container(
      decoration: BoxDecoration(
        color: Colors.white10,
        borderRadius: BorderRadius.circular(12),
      ),
      padding: const EdgeInsets.all(12),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Row(
            children: [
              Container(
                padding:
                    const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
                decoration: BoxDecoration(
                  color: badgeColor.withOpacity(0.2),
                  borderRadius: BorderRadius.circular(6),
                  border: Border.all(color: badgeColor),
                ),
                child: Text(
                  badgeLabel,
                  style: theme.labelMedium?.copyWith(
                    color: badgeColor,
                    fontWeight: FontWeight.w600,
                  ),
                ),
              ),
              const Spacer(),
              if (onDelete != null)
                InkWell(
                  borderRadius: BorderRadius.circular(6),
                  onTap: onDelete,
                  child: const Padding(
                    padding: EdgeInsets.all(4),
                    child: Icon(Icons.delete_outline, size: 18, color: Colors.white38),
                  ),
                ),
              Text(
                _formatTime(entry.createdAt),
                style: theme.labelSmall?.copyWith(color: Colors.white54),
              ),
            ],
          ),
          const SizedBox(height: 10),
          Row(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Expanded(
                child: _LabeledThumb(
                  label: '拍照图',
                  child: _FileImage(path: entry.photoPath),
                ),
              ),
              const SizedBox(width: 8),
              Expanded(
                child: _LabeledThumb(
                  label: '裁剪图',
                  child: _FileImage(path: entry.cropPath),
                ),
              ),
              const SizedBox(width: 8),
              Expanded(
                child: _LabeledThumb(
                  label: '最佳匹配',
                  child: entry.matchAssetPath == null
                      ? const ColoredBox(
                          color: Colors.black26,
                          child: Center(
                            child: Icon(Icons.image_not_supported_outlined),
                          ),
                        )
                      : Image.asset(
                          entry.matchAssetPath!,
                          fit: BoxFit.cover,
                          errorBuilder: (_, __, ___) => const ColoredBox(
                            color: Colors.black26,
                            child: Center(
                              child: Icon(Icons.broken_image_outlined),
                            ),
                          ),
                        ),
                ),
              ),
            ],
          ),
          const SizedBox(height: 8),
          Text(
            entry.matchCardId == null
                ? '无匹配结果'
                : '${entry.matchCardId}  ·  ${score?.toStringAsFixed(2) ?? '—'} ($status)',
            maxLines: 2,
            overflow: TextOverflow.ellipsis,
            style: theme.bodySmall?.copyWith(color: Colors.white70),
          ),
        ],
      ),
    );
  }

  static String _formatTime(DateTime t) {
    final local = t.toLocal();
    String two(int n) => n.toString().padLeft(2, '0');
    return '${local.month}/${local.day} ${two(local.hour)}:${two(local.minute)}';
  }
}

class _LabeledThumb extends StatelessWidget {
  const _LabeledThumb({required this.label, required this.child});

  final String label;
  final Widget child;

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        Text(
          label,
          style: Theme.of(context).textTheme.labelSmall?.copyWith(
                color: Colors.white54,
              ),
        ),
        const SizedBox(height: 4),
        AspectRatio(
          aspectRatio: 0.72,
          child: ClipRRect(
            borderRadius: BorderRadius.circular(8),
            child: child,
          ),
        ),
      ],
    );
  }
}

class _FileImage extends StatelessWidget {
  const _FileImage({required this.path});

  final String path;

  @override
  Widget build(BuildContext context) {
    final file = File(path);
    if (!file.existsSync()) {
      return const ColoredBox(
        color: Colors.black26,
        child: Center(child: Icon(Icons.broken_image_outlined)),
      );
    }
    return Image.file(
      file,
      fit: BoxFit.cover,
      errorBuilder: (_, __, ___) => const ColoredBox(
        color: Colors.black26,
        child: Center(child: Icon(Icons.broken_image_outlined)),
      ),
    );
  }
}