import 'package:flutter/material.dart';
import '../core/responsive/responsive.dart';
import 'package:lpinyin/lpinyin.dart';
import '../models/product.dart';

class SelectProductDialog extends StatefulWidget {
  final List<Product> products;
  final int? selectedId;

  const SelectProductDialog({
    super.key,
    required this.products,
    this.selectedId,
  });

  @override
  State<SelectProductDialog> createState() => _SelectProductDialogState();
}

class _SelectProductDialogState extends State<SelectProductDialog> {
  final _searchCtrl = TextEditingController();
  List<Product> _filtered = [];

  // 缓存每个商品的拼音索引，避免搜索时重复计算
  late final Map<int, _PinyinIndex> _pinyinCache;

  @override
  void initState() {
    super.initState();
    _pinyinCache = {
      for (final p in widget.products) p.id: _PinyinIndex.from(p),
    };
    _filtered = widget.products;
    _searchCtrl.addListener(_onSearch);
  }

  @override
  void dispose() {
    _searchCtrl.dispose();
    super.dispose();
  }

  void _onSearch() {
    final q = _searchCtrl.text.trim().toLowerCase();
    setState(() {
      if (q.isEmpty) {
        _filtered = widget.products;
      } else {
        _filtered = widget.products.where((p) {
          // 原文匹配（名称、规格、编码、条码）
          if (p.name.toLowerCase().contains(q)) return true;
          if (p.spec?.toLowerCase().contains(q) ?? false) return true;
          if (p.code.toLowerCase().contains(q)) return true;
          if (p.barcode?.toLowerCase().contains(q) ?? false) return true;
          // 拼音匹配（全拼 or 首字母）
          final idx = _pinyinCache[p.id]!;
          if (idx.fullPinyin.contains(q)) return true;
          if (idx.initials.contains(q)) return true;
          return false;
        }).toList();
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    // 每行约 56px，窗口默认显示约 6 行，可滚动查看全部
    const listHeight = 56.0 * 6;

    return Dialog(
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
      child: SizedBox(
        width: context.dialogWidth(480),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            // 标题栏
            Padding(
              padding: const EdgeInsets.fromLTRB(20, 16, 8, 0),
              child: Row(
                children: [
                  const Text('选择商品',
                      style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600)),
                  const Spacer(),
                  IconButton(
                    onPressed: () => Navigator.pop(context),
                    icon: const Icon(Icons.close, size: 20),
                    visualDensity: VisualDensity.compact,
                  ),
                ],
              ),
            ),
            // 搜索框
            Padding(
              padding: const EdgeInsets.fromLTRB(16, 8, 16, 8),
              child: TextField(
                controller: _searchCtrl,
                autofocus: true,
                decoration: InputDecoration(
                  hintText: '搜索名称 / 规格 / 编码 / 拼音首字母...',
                  prefixIcon: const Icon(Icons.search, size: 18),
                  suffixIcon: _searchCtrl.text.isNotEmpty
                      ? IconButton(
                          onPressed: _searchCtrl.clear,
                          icon: const Icon(Icons.clear, size: 16),
                          visualDensity: VisualDensity.compact,
                        )
                      : null,
                  isDense: true,
                  contentPadding: const EdgeInsets.symmetric(vertical: 10),
                  border: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(8),
                  ),
                ),
              ),
            ),
            const Divider(height: 1),
            // 商品列表（固定高度，可滚动）
            if (_filtered.isEmpty)
              const SizedBox(
                height: listHeight,
                child: Center(
                  child: Text('无匹配商品', style: TextStyle(color: Colors.grey)),
                ),
              )
            else
              SizedBox(
                height: listHeight,
                child: ListView.separated(
                  itemCount: _filtered.length,
                  separatorBuilder: (_, __) =>
                      const Divider(height: 1, indent: 16, endIndent: 16),
                  itemBuilder: (context, i) {
                    final p = _filtered[i];
                    final isSelected = p.id == widget.selectedId;
                    return ListTile(
                      dense: true,
                      selected: isSelected,
                      selectedTileColor: Colors.blue.shade50,
                      title: Text(
                        p.name,
                        style: const TextStyle(fontSize: 13),
                      ),
                      subtitle: Text(
                        [
                          if (p.spec != null && p.spec!.isNotEmpty) p.spec!,
                          p.unit,
                          if (p.code.isNotEmpty) '编码: ${p.code}',
                        ].join(' · '),
                        style: const TextStyle(fontSize: 12, color: Colors.grey),
                      ),
                      trailing: isSelected
                          ? const Icon(Icons.check, color: Colors.blue, size: 18)
                          : null,
                      onTap: () => Navigator.pop(context, p),
                    );
                  },
                ),
              ),
            const SizedBox(height: 8),
          ],
        ),
      ),
    );
  }
}

/// 每个商品的拼音索引：全拼 + 首字母，在 initState 时一次性计算并缓存
class _PinyinIndex {
  final String fullPinyin; // "longjingcha"
  final String initials;   // "ljc"

  const _PinyinIndex({required this.fullPinyin, required this.initials});

  factory _PinyinIndex.from(Product p) {
    // 拼接名称 + 规格作为拼音转换源
    final text = '${p.name}${p.spec ?? ''}';
    final full = PinyinHelper.getPinyinE(text, separator: '', defPinyin: '')
        .toLowerCase();
    final init = PinyinHelper.getShortPinyin(text).toLowerCase();
    return _PinyinIndex(fullPinyin: full, initials: init);
  }
}