import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import '../../core/theme/app_theme.dart';
import '../../models/inventory.dart';
import '../../providers/inventory_provider.dart';
import '../../widgets/data_table_card.dart';
import '../../widgets/multi_select_dropdown.dart' show ColDef, ColumnToggleButton, FilterableColumnHeader;
import '../../providers/connectivity_provider.dart';
import '../../core/utils/export_util.dart';

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

  @override
  ConsumerState<BatchTrackingScreen> createState() =>
      _BatchTrackingScreenState();
}

class _BatchTrackingScreenState extends ConsumerState<BatchTrackingScreen> {
  int _page = 1;
  int _pageSize = 20;
  int _total = 0;
  late Future<List<ProductTrackingRecord>> _future;
  List<ProductTrackingRecord> _records = [];

  Set<String> _filterStatus = {};
  Set<String> _filterWarehouse = {};
  Set<String> _filterSupplier = {};
  Set<String> _hiddenCols = {};

  static const _colDefs = [
    ColDef('product', '商品', required: true),
    ColDef('spec', '规格', minWidth: 1100),
    ColDef('batch', '批次号', minWidth: 1000),
    ColDef('order_no', '入库单号', minWidth: 900),
    ColDef('supplier', '供应商', minWidth: 1100),
    ColDef('warehouse', '仓库'),
    ColDef('date', '入库日期', minWidth: 1000),
    ColDef('qty', '数量'),
    ColDef('price', '单价', minWidth: 900),
    ColDef('status', '状态'),
    ColDef('buyer', '买家/时间'),
  ];

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

  void _fetch() {
    _future = ref
        .read(inventoryRepositoryProvider)
        .listProducts(page: _page, pageSize: _pageSize)
        .then((r) {
      _total = r.total;
      _records = r.data;
      return r.data;
    });
  }

  void _refetch() => setState(() => _fetch());

  List<ProductTrackingRecord> _applyFilters(
      List<ProductTrackingRecord> all) {
    return all.where((r) {
      if (_filterStatus.isNotEmpty) {
        final label = r.isSoldOut ? '已卖出' : '在售';
        if (!_filterStatus.contains(label)) return false;
      }
      if (_filterWarehouse.isNotEmpty) {
        if (!_filterWarehouse.contains(r.warehouseName ?? '')) return false;
      }
      if (_filterSupplier.isNotEmpty) {
        if (!_filterSupplier.contains(r.supplierName ?? '')) return false;
      }
      return true;
    }).toList();
  }

  @override
  Widget build(BuildContext context) {
    // 网络恢复时自动刷新
    ref.listen(networkRecoveryCountProvider, (_, __) => _refetch());

    return FutureBuilder<List<ProductTrackingRecord>>(
      future: _future,
      builder: (context, snap) {
        if (snap.connectionState == ConnectionState.waiting) {
          return const Center(child: CircularProgressIndicator());
        }
        if (snap.hasError) {
          // 有缓存数据时展示缓存，顶部加提示条
          if (_records.isNotEmpty) {
            return Column(
              children: [
                _OfflineBanner(onRetry: _refetch),
                Expanded(child: _buildTable(_applyFilters(_records))),
              ],
            );
          }
          return Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                const Icon(Icons.cloud_off, size: 40, color: AppTheme.textSecondary),
                const SizedBox(height: 12),
                const Text('暂无数据，网络不可用', style: TextStyle(color: AppTheme.textSecondary)),
                const SizedBox(height: 12),
                ElevatedButton(onPressed: _refetch, child: const Text('重试')),
              ],
            ),
          );
        }
        final filtered = _applyFilters(_records);
        return _buildTable(filtered);
      },
    );
  }

  Widget _buildTable(List<ProductTrackingRecord> records) {
    // Derive filter options from all loaded records
    final warehouseOptions = _records
        .map((r) => r.warehouseName ?? '')
        .where((s) => s.isNotEmpty)
        .toSet()
        .toList()
      ..sort();
    final supplierOptions = _records
        .map((r) => r.supplierName ?? '')
        .where((s) => s.isNotEmpty)
        .toSet()
        .toList()
      ..sort();

    // Build visible columns (respect manual hide + responsive auto-hide)
    final screenWidth = MediaQuery.of(context).size.width;
    final visibleCols = _colDefs
        .where((c) =>
            !_hiddenCols.contains(c.key) &&
            (c.minWidth == null || screenWidth >= c.minWidth!))
        .toList();

    final columns = visibleCols.map((c) {
      final label = switch (c.key) {
        'status' => FilterableColumnHeader(
            text: c.label,
            options: const ['在售', '已卖出'],
            selected: _filterStatus,
            onChanged: (v) => setState(() => _filterStatus = v),
          ),
        'warehouse' => FilterableColumnHeader(
            text: c.label,
            options: warehouseOptions,
            selected: _filterWarehouse,
            onChanged: (v) => setState(() => _filterWarehouse = v),
          ),
        'supplier' => FilterableColumnHeader(
            text: c.label,
            options: supplierOptions,
            selected: _filterSupplier,
            onChanged: (v) => setState(() => _filterSupplier = v),
          ),
        _ => Text(c.label),
      };
      return DataColumn(
          label: label,
          numeric: c.key == 'qty' || c.key == 'price');
    }).toList();

    final rows = records.isEmpty
        ? [
            DataRow(
              cells: List.generate(
                visibleCols.length,
                (i) => i == 1
                    ? const DataCell(Text('暂无记录',
                        style: TextStyle(color: AppTheme.textSecondary)))
                    : const DataCell(SizedBox()),
              ),
            ),
          ]
        : records
            .map((r) => DataRow(
                  cells: visibleCols
                      .map((c) => _buildCell(c.key, r))
                      .toList(),
                ))
            .toList();

    return DataTableCard(
      totalCount: _total,
      page: _page,
      pageSize: _pageSize,
      onPageChanged: (p) => setState(() {
        _page = p;
        _fetch();
      }),
      onPageSizeChanged: (s) => setState(() {
        _pageSize = s;
        _page = 1;
        _fetch();
      }),
      toolbar: Row(
        children: [
          const Text('已审核入库商品（含库存与销售状态）',
              style: TextStyle(fontSize: 13, color: AppTheme.textSecondary)),
          const Spacer(),
          OutlinedButton.icon(
            onPressed: () => exportExcel(
              filename: '商品管理',
              headers: ['商品名称', '商品编码', '规格', '批次号', '入库单号', '供应商', '仓库', '入库日期', '数量', '单价', '状态', '买家'],
              rows: records.map((r) => [
                r.productName ?? '',
                r.productCode ?? '',
                r.productSpec ?? '',
                r.batchNo ?? '',
                r.orderNo ?? '',
                r.supplierName ?? '',
                r.warehouseName ?? '',
                r.orderDate?.substring(0, 10) ?? '',
                r.quantity.toInt(),
                r.unitPrice,
                r.isSoldOut ? '已卖出' : '在售',
                r.buyerName ?? '',
              ]).toList(),
            ),
            icon: const Icon(Icons.download, size: 16),
            label: const Text('导出'),
          ),
          const SizedBox(width: 4),
          IconButton(
            icon: const Icon(Icons.refresh, size: 18),
            onPressed: () => setState(() {
              _page = 1;
              _fetch();
            }),
            tooltip: '刷新',
          ),
          const SizedBox(width: 4),
          ColumnToggleButton(
            columns: _colDefs,
            hidden: _hiddenCols,
            onChanged: (v) => setState(() => _hiddenCols = v),
          ),
        ],
      ),
      columns: columns,
      rows: rows,
    );
  }

  DataCell _buildCell(String key, ProductTrackingRecord r) {
    final batchText =
        (r.batchNo != null && r.batchNo!.isNotEmpty) ? r.batchNo! : null;
    switch (key) {
      case 'product':
        return DataCell(
          GestureDetector(
            onTap: () => context.push('/products/${r.productId}'),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Text(r.productName ?? '-',
                    style: const TextStyle(
                        fontSize: 13,
                        fontWeight: FontWeight.w500,
                        color: AppTheme.primary,
                        decoration: TextDecoration.underline,
                        decorationColor: AppTheme.primary)),
                if (r.productCode != null)
                  Text(r.productCode!,
                      style: const TextStyle(
                          fontSize: 11,
                          color: AppTheme.textSecondary,
                          fontFamily: 'monospace')),
              ],
            ),
          ),
        );
      case 'spec':
        return DataCell(Text(r.productSpec ?? '-',
            style: const TextStyle(fontSize: 12)));
      case 'batch':
        return DataCell(batchText != null
            ? Container(
                padding:
                    const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                decoration: BoxDecoration(
                  color: AppTheme.primary.withOpacity(0.08),
                  borderRadius: BorderRadius.circular(3),
                ),
                child: Text(batchText,
                    style: const TextStyle(
                        fontSize: 12,
                        color: AppTheme.primary,
                        fontFamily: 'monospace')),
              )
            : const Text('无批次',
                style: TextStyle(
                    fontSize: 12, color: AppTheme.textSecondary)));
      case 'order_no':
        return DataCell(Text(r.orderNo ?? '-',
            style: const TextStyle(
                fontSize: 11,
                color: AppTheme.primary,
                fontFamily: 'monospace')));
      case 'supplier':
        return DataCell(Text(r.supplierName ?? '-',
            style: const TextStyle(fontSize: 12)));
      case 'warehouse':
        return DataCell(Text(r.warehouseName ?? '-',
            style: const TextStyle(fontSize: 12)));
      case 'date':
        return DataCell(Text(r.orderDate?.substring(0, 10) ?? '-',
            style: const TextStyle(fontSize: 12)));
      case 'qty':
        return DataCell(Text(
            '${r.quantity.toStringAsFixed(0)} ${r.productUnit ?? ''}',
            style: const TextStyle(fontWeight: FontWeight.w500)));
      case 'price':
        return DataCell(Text('¥${r.unitPrice.toStringAsFixed(2)}',
            style: const TextStyle(fontSize: 13)));
      case 'status':
        return DataCell(_StatusBadge(r.isSoldOut));
      case 'buyer':
        return DataCell(r.isSoldOut
            ? Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text(
                    r.buyerName?.isNotEmpty == true ? r.buyerName! : '未知买家',
                    style: const TextStyle(
                        fontSize: 12, fontWeight: FontWeight.w500),
                  ),
                  if (r.soldAt != null)
                    Text(
                        r.soldAt!.length > 10
                            ? r.soldAt!.substring(0, 10)
                            : r.soldAt!,
                        style: const TextStyle(
                            fontSize: 11, color: AppTheme.textSecondary)),
                ],
              )
            : const Text('-',
                style: TextStyle(color: AppTheme.textSecondary)));
      default:
        return const DataCell(SizedBox());
    }
  }
}

class _StatusBadge extends StatelessWidget {
  final bool isSoldOut;
  const _StatusBadge(this.isSoldOut);

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
      decoration: BoxDecoration(
        color: isSoldOut
            ? AppTheme.textSecondary.withOpacity(0.12)
            : AppTheme.success.withOpacity(0.12),
        borderRadius: BorderRadius.circular(3),
      ),
      child: Text(
        isSoldOut ? '已卖出' : '在售',
        style: TextStyle(
          fontSize: 12,
          fontWeight: FontWeight.w600,
          color: isSoldOut ? AppTheme.textSecondary : AppTheme.success,
        ),
      ),
    );
  }
}

class _OfflineBanner extends StatelessWidget {
  final VoidCallback onRetry;
  const _OfflineBanner({required this.onRetry});

  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      color: const Color(0xFFFFF8E1),
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 6),
      child: Row(
        children: [
          const Icon(Icons.cloud_off, size: 14, color: Color(0xFFF57F17)),
          const SizedBox(width: 8),
          const Expanded(
            child: Text('网络不可用，当前显示离线缓存数据',
                style: TextStyle(color: Color(0xFFF57F17), fontSize: 12)),
          ),
          TextButton(
            onPressed: onRetry,
            style: TextButton.styleFrom(
                foregroundColor: const Color(0xFFF57F17),
                padding: const EdgeInsets.symmetric(horizontal: 8)),
            child: const Text('重试', style: TextStyle(fontSize: 12)),
          ),
        ],
      ),
    );
  }
}