import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:kifi_app/features/inventory/domain/inventory_item.dart';
import 'package:kifi_app/features/inventory/domain/product.dart';
import 'package:kifi_app/features/inventory/providers/products_provider.dart';
import 'package:kifi_app/features/inventory/providers/product_categories_provider.dart';
import 'package:kifi_app/features/inventory/providers/commodity_rates_provider.dart';
import 'package:kifi_app/core/network/dio_client.dart';
import 'package:intl/intl.dart';
import 'package:lucide_icons_flutter/lucide_icons.dart';
import 'package:kifi_app/features/vendor/presentation/purchase_order_details_screen.dart';
import 'package:kifi_app/features/vendor/providers/purchase_orders_provider.dart';
import 'package:kifi_app/core/utils/purity_utils.dart';
import '../../transactions/presentation/widgets/attachment_gallery_screen.dart';

class StockLedgerTab extends ConsumerStatefulWidget {
  final Product product;

  const StockLedgerTab({super.key, required this.product});

  @override
  ConsumerState<StockLedgerTab> createState() => _StockLedgerTabState();
}

class _StockLedgerTabState extends ConsumerState<StockLedgerTab> {
  List<InventoryItem>? _items;
  bool _isLoading = true;
  String _selectedFilter = 'IN_STOCK'; // 'IN_STOCK', 'SOLD', 'ALL'

  String _resolveImageUrl(String path) {
    if (path.startsWith('http://') || path.startsWith('https://')) {
      return path;
    }
    final base = DioClient().dio.options.baseUrl;
    final cleanPath = path.startsWith('/') ? path.substring(1) : path;
    if (cleanPath.startsWith('api/kifi-v2/upload/view') || cleanPath.startsWith('upload/view')) {
      return '$base/${cleanPath.replaceFirst('api/kifi-v2/', '')}';
    }
    return '$base/upload/view?path=${Uri.encodeComponent(cleanPath)}';
  }

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

  Future<void> _fetchLedger() async {
    try {
      final items = await ref
          .read(productsProvider.notifier)
          .fetchInventoryItems(widget.product.id!);
      if (mounted) {
        setState(() {
          _items = items;
          _isLoading = false;
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _isLoading = false;
        });
        ScaffoldMessenger.of(
          context,
        ).showSnackBar(SnackBar(content: Text(e.toString())));
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    if (_isLoading) {
      return const Center(child: CircularProgressIndicator());
    }

    if (_items == null || _items!.isEmpty) {
      return const Center(child: Text("No stock records found."));
    }

    final inStockItems = _items!.where((i) => i.status != 'SOLD').toList();
    final soldItems = _items!.where((i) => i.status == 'SOLD').toList();

    List<InventoryItem> displayItems;
    if (_selectedFilter == 'IN_STOCK') {
      displayItems = inStockItems;
    } else if (_selectedFilter == 'SOLD') {
      displayItems = soldItems;
    } else {
      displayItems = _items!;
    }

    final categoriesState = ref.watch(productCategoriesProvider);
    final commodityRatesState = ref.watch(commodityRatesProvider);
    
    final category = categoriesState.value?.where(
      (c) => c.id == widget.product.categoryId,
    ).firstOrNull;

    final String unit = category?.baseUnit ?? 'g';
    final double purityFactor = resolvePurity(categoryPurity: category?.purityFactor, productPurity: widget.product.purityFactor);
    
    double commodityRate = 0.0;
    if (category?.commodityCode != null && commodityRatesState.value != null) {
      final match = commodityRatesState.value!.where(
        (r) => r.commodityCode.toUpperCase() == category!.commodityCode!.toUpperCase()
      ).firstOrNull;
      if (match != null) {
        commodityRate = match.rate;
      }
    }
    
    final double currentRate = commodityRate > 0 ? (commodityRate * purityFactor) : (category?.dailyRate ?? 0.0);

    return Column(
      children: [
        // Filter Chips
        Padding(
          padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 8.0),
          child: Row(
            children: [
              _buildFilterChip('In Stock (${inStockItems.length})', 'IN_STOCK'),
              const SizedBox(width: 8),
              _buildFilterChip('Sold (${soldItems.length})', 'SOLD'),
              const SizedBox(width: 8),
              _buildFilterChip('All (${_items!.length})', 'ALL'),
            ],
          ),
        ),
        Expanded(
          child: displayItems.isEmpty
              ? Center(
                  child: Text(
                    _selectedFilter == 'IN_STOCK'
                        ? 'No active stock available.'
                        : (_selectedFilter == 'SOLD' ? 'No sold items yet.' : 'No stock records.'),
                    style: const TextStyle(color: Colors.grey),
                  ),
                )
              : RefreshIndicator(
                  onRefresh: _fetchLedger,
                  child: ListView.builder(
                    padding: const EdgeInsets.all(16.0),
                    itemCount: displayItems.length,
                    itemBuilder: (context, index) {
                      final item = displayItems[index];
                      final isSold = item.status == 'SOLD';
                      final purchaseOrdersState = ref.watch(purchaseOrdersProvider);
                      final purchaseOrders = purchaseOrdersState.value ?? [];

                      double weight = (item.grossWeight != null && item.grossWeight! > 0)
                          ? item.grossWeight!
                          : ((item.netWeight != null && item.netWeight! > 0)
                              ? item.netWeight!
                              : (item.fineWeight ?? 0.0));

                      double purchaseRate = (item.purchaseCost != null && item.purchaseCost! > 0)
                          ? item.purchaseCost!
                          : ((item.metalCost != null && item.metalCost! > 0 && weight > 0)
                              ? (item.metalCost! / weight)
                              : 0.0);

                      // If weight or rate was lost due to earlier db overwrite, recover from purchase order
                      if ((weight == 0.0 || purchaseRate == 0.0) && item.purchaseRef != null) {
                        final po = purchaseOrders.where((p) => p.poNumber == item.purchaseRef).firstOrNull;
                        if (po != null) {
                          final poItem = po.items.where((i) => i.productId == widget.product.id || (item.huid != null && i.huid == item.huid) || (item.sku != null && i.sku == item.sku)).firstOrNull ?? po.items.firstOrNull;
                          if (poItem != null) {
                            if (weight == 0.0) {
                              weight = poItem.weight ?? (poItem.quantity > 0 ? poItem.quantity : 1.0);
                            }
                            if (purchaseRate == 0.0) {
                              purchaseRate = poItem.unitPrice;
                            }
                          }
                        }
                      }

                      // Resolve purchase item thumbnail photo
                      String? itemPhotoUrl = (item.photoUrl != null && item.photoUrl!.isNotEmpty) ? item.photoUrl : null;
                      if (itemPhotoUrl == null && item.purchaseRef != null) {
                        final po = purchaseOrders.where((p) => p.poNumber == item.purchaseRef).firstOrNull;
                        if (po != null) {
                          final poItem = po.items.where((i) =>
                              (item.huid != null && i.huid == item.huid) ||
                              (item.sku != null && i.sku == item.sku) ||
                              i.productId == widget.product.id
                          ).firstOrNull ?? po.items.firstOrNull;
                          if (poItem != null && poItem.photoUrl != null && poItem.photoUrl!.isNotEmpty) {
                            itemPhotoUrl = poItem.photoUrl;
                          }
                        }
                      }

                      String? finalDisplayUrl;
                      bool isProductFallback = false;
                      if (itemPhotoUrl != null) {
                        finalDisplayUrl = _resolveImageUrl(itemPhotoUrl);
                      } else if (widget.product.imageIds.isNotEmpty) {
                        finalDisplayUrl = '${DioClient().dio.options.baseUrl}/inventory/products/${widget.product.id}/images/${widget.product.imageIds.first}/content';
                        isProductFallback = true;
                      }

                      final purchasePrice = weight * purchaseRate;
                      final currentPrice = weight * currentRate;
                      final gainLoss = currentPrice - purchasePrice;
                      final isGain = gainLoss >= 0;

                      return Card(
                        elevation: 0,
                        margin: const EdgeInsets.only(bottom: 12),
                        shape: RoundedRectangleBorder(
                          borderRadius: BorderRadius.circular(12),
                          side: BorderSide(
                            color: isSold
                                ? Colors.grey.withValues(alpha: 0.2)
                                : Colors.grey.withValues(alpha: 0.3),
                          ),
                        ),
                        color: isSold ? Colors.grey.withValues(alpha: 0.03) : null,
                        child: Padding(
                          padding: const EdgeInsets.all(12.0),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              Row(
                                crossAxisAlignment: CrossAxisAlignment.start,
                                children: [
                                  FutureBuilder<String?>(
                                    future: DioClient().storage.read(key: 'jwt_token'),
                                    builder: (context, snapshot) {
                                      final hasImage = finalDisplayUrl != null;
                                      return GestureDetector(
                                        onTap: hasImage
                                            ? () {
                                                final token = snapshot.data;
                                                final headers = (token != null && isProductFallback)
                                                    ? {'Authorization': 'Bearer $token'}
                                                    : null;
                                                Navigator.push(
                                                  context,
                                                  MaterialPageRoute(
                                                    builder: (_) => AttachmentGalleryScreen(
                                                      images: [
                                                        NetworkImage(
                                                          finalDisplayUrl!,
                                                          headers: headers,
                                                        ),
                                                      ],
                                                      initialIndex: 0,
                                                    ),
                                                  ),
                                                );
                                              }
                                            : null,
                                        child: MouseRegion(
                                          cursor: hasImage ? SystemMouseCursors.click : SystemMouseCursors.basic,
                                          child: Container(
                                            width: 44,
                                            height: 44,
                                            decoration: BoxDecoration(
                                              color: Colors.grey.withValues(alpha: 0.1),
                                              borderRadius: BorderRadius.circular(8),
                                              border: Border.all(
                                                color: Colors.grey.withValues(alpha: 0.2),
                                              ),
                                            ),
                                            child: hasImage
                                                ? Stack(
                                                    children: [
                                                      Positioned.fill(
                                                        child: ClipRRect(
                                                          borderRadius: BorderRadius.circular(7),
                                                          child: Image.network(
                                                            finalDisplayUrl,
                                                            fit: BoxFit.cover,
                                                            headers: (snapshot.hasData && isProductFallback)
                                                                ? {'Authorization': 'Bearer ${snapshot.data}'}
                                                                : null,
                                                            errorBuilder: (context, error, stackTrace) => const Icon(
                                                              LucideIcons.imageOff,
                                                              color: Colors.grey,
                                                              size: 20,
                                                            ),
                                                          ),
                                                        ),
                                                      ),
                                                      Positioned(
                                                        bottom: 2,
                                                        right: 2,
                                                        child: Container(
                                                          padding: const EdgeInsets.all(2),
                                                          decoration: BoxDecoration(
                                                            color: Colors.black.withValues(alpha: 0.5),
                                                            borderRadius: BorderRadius.circular(4),
                                                          ),
                                                          child: const Icon(
                                                            LucideIcons.maximize2,
                                                            size: 8,
                                                            color: Colors.white,
                                                          ),
                                                        ),
                                                      ),
                                                    ],
                                                  )
                                                : const Icon(
                                                    LucideIcons.image,
                                                    color: Colors.grey,
                                                    size: 20,
                                                  ),
                                          ),
                                        ),
                                      );
                                    },
                                  ),
                                  const SizedBox(width: 12),
                                  Expanded(
                                    child: Column(
                                      crossAxisAlignment: CrossAxisAlignment.start,
                                      children: [
                                        Text(
                                          item.createdAt != null
                                              ? DateFormat('dd MMM yyyy').format(item.createdAt!)
                                              : '',
                                          style: TextStyle(color: Colors.grey[600], fontSize: 12),
                                        ),
                                        const SizedBox(height: 4),
                                        if (item.purchaseRef != null)
                                          InkWell(
                                            onTap: () async {
                                              try {
                                                var pos = ref.read(purchaseOrdersProvider).value;
                                                if (pos == null || pos.isEmpty) {
                                                  pos = await ref.read(purchaseOrdersProvider.future);
                                                }
                                                final po = pos!.firstWhere(
                                                  (p) => p.poNumber == item.purchaseRef,
                                                  orElse: () => throw Exception('Purchase invoice not found'),
                                                );
                                                if (mounted) {
                                                  Navigator.push(
                                                    context,
                                                    MaterialPageRoute(
                                                      builder: (context) => PurchaseOrderDetailsScreen(po: po),
                                                    ),
                                                  );
                                                }
                                              } catch (e) {
                                                if (mounted) {
                                                  ScaffoldMessenger.of(context).showSnackBar(
                                                    SnackBar(content: Text('Could not open purchase invoice: $e')),
                                                  );
                                                }
                                              }
                                            },
                                            child: Text(
                                              'INV: ${item.purchaseRef}',
                                              style: const TextStyle(
                                                color: Colors.blue,
                                                decoration: TextDecoration.underline,
                                                fontWeight: FontWeight.w600,
                                              ),
                                            ),
                                          ),
                                        if (item.huid != null && item.huid!.isNotEmpty)
                                          Padding(
                                            padding: const EdgeInsets.only(top: 4.0),
                                            child: Text('HUID: ${item.huid}', style: const TextStyle(fontWeight: FontWeight.w500)),
                                          ),
                                      ],
                                    ),
                                  ),
                                  Column(
                                    crossAxisAlignment: CrossAxisAlignment.end,
                                    children: [
                                      Container(
                                        padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                                        decoration: BoxDecoration(
                                          color: isSold
                                              ? Colors.grey.withValues(alpha: 0.15)
                                              : Colors.green.withValues(alpha: 0.1),
                                          borderRadius: BorderRadius.circular(4),
                                        ),
                                        child: Text(
                                          isSold ? 'SOLD' : 'IN STOCK',
                                          style: TextStyle(
                                            fontSize: 10,
                                            fontWeight: FontWeight.bold,
                                            color: isSold ? Colors.grey.shade700 : Colors.green,
                                          ),
                                        ),
                                      ),
                                      const SizedBox(height: 4),
                                      Text(
                                        '${weight.toStringAsFixed(3)} $unit',
                                        style: TextStyle(
                                          fontWeight: FontWeight.bold,
                                          fontSize: 14,
                                          color: isSold ? Colors.grey.shade600 : null,
                                        ),
                                      ),
                                      const SizedBox(height: 3),
                                      Container(
                                        padding: const EdgeInsets.symmetric(horizontal: 5, vertical: 1.5),
                                        decoration: BoxDecoration(
                                          color: Colors.amber.withValues(alpha: 0.12),
                                          borderRadius: BorderRadius.circular(4),
                                          border: Border.all(color: Colors.amber.withValues(alpha: 0.3)),
                                        ),
                                        child: Text(
                                          'Purity: ${formatPurity(double.tryParse(item.purity ?? '') ?? purityFactor)}',
                                          style: TextStyle(
                                            fontSize: 10,
                                            fontWeight: FontWeight.bold,
                                            color: Colors.amber.shade900,
                                          ),
                                        ),
                                      ),
                                    ],
                                  ),
                                ],
                              ),
                              const Divider(height: 24),
                              Row(
                                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                                children: [
                                  Column(
                                    crossAxisAlignment: CrossAxisAlignment.start,
                                    children: [
                                      Text('Purchase Rate', style: TextStyle(color: Colors.grey[500], fontSize: 12)),
                                      Text('₹${purchaseRate.toStringAsFixed(2)}/$unit', style: const TextStyle(fontWeight: FontWeight.w600)),
                                    ],
                                  ),
                                  Column(
                                    crossAxisAlignment: CrossAxisAlignment.end,
                                    children: [
                                      Text('Purchase Amt', style: TextStyle(color: Colors.grey[500], fontSize: 12)),
                                      Text('₹${purchasePrice.toStringAsFixed(2)}', style: const TextStyle(fontWeight: FontWeight.w600)),
                                    ],
                                  ),
                                ],
                              ),
                              const SizedBox(height: 12),
                              Row(
                                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                                children: [
                                  Column(
                                    crossAxisAlignment: CrossAxisAlignment.start,
                                    children: [
                                      Text(isSold ? 'Selling Rate' : 'Current Rate', style: TextStyle(color: Colors.grey[500], fontSize: 12)),
                                      Text('₹${currentRate.toStringAsFixed(2)}/$unit', style: const TextStyle(fontWeight: FontWeight.w600)),
                                    ],
                                  ),
                                  Column(
                                    crossAxisAlignment: CrossAxisAlignment.end,
                                    children: [
                                      Text(isSold ? 'Valuation' : 'Current Amt', style: TextStyle(color: Colors.grey[500], fontSize: 12)),
                                      Text('₹${currentPrice.toStringAsFixed(2)}', style: const TextStyle(fontWeight: FontWeight.w600)),
                                    ],
                                  ),
                                ],
                              ),
                              const SizedBox(height: 16),
                              Container(
                                padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
                                decoration: BoxDecoration(
                                  color: isGain ? Colors.green.withValues(alpha: 0.1) : Colors.red.withValues(alpha: 0.1),
                                  borderRadius: BorderRadius.circular(8),
                                ),
                                child: Row(
                                  mainAxisAlignment: MainAxisAlignment.center,
                                  children: [
                                    Icon(
                                      isGain ? LucideIcons.trendingUp : LucideIcons.trendingDown,
                                      color: isGain ? Colors.green : Colors.red,
                                      size: 16,
                                    ),
                                    const SizedBox(width: 8),
                                    Text(
                                      '${isSold ? "Realized " : ""}${isGain ? 'Gain' : 'Loss'}: ₹${gainLoss.abs().toStringAsFixed(2)}',
                                      style: TextStyle(
                                        color: isGain ? Colors.green : Colors.red,
                                        fontWeight: FontWeight.bold,
                                        fontSize: 14,
                                      ),
                                    ),
                                  ],
                                ),
                              ),
                            ],
                          ),
                        ),
                      );
                    },
                  ),
                ),
        ),
      ],
    );
  }

  Widget _buildFilterChip(String label, String value) {
    final isSelected = _selectedFilter == value;
    return InkWell(
      onTap: () => setState(() => _selectedFilter = value),
      borderRadius: BorderRadius.circular(20),
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
        decoration: BoxDecoration(
          color: isSelected ? Colors.blue : Colors.grey.withValues(alpha: 0.1),
          borderRadius: BorderRadius.circular(20),
        ),
        child: Text(
          label,
          style: TextStyle(
            color: isSelected ? Colors.white : Colors.grey.shade700,
            fontSize: 12,
            fontWeight: isSelected ? FontWeight.bold : FontWeight.normal,
          ),
        ),
      ),
    );
  }
}