import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:lucide_icons_flutter/lucide_icons.dart';
import 'package:intl/intl.dart';
import 'package:screenshot/screenshot.dart';
import 'package:path_provider/path_provider.dart';
import 'package:share_plus/share_plus.dart';
import 'package:pdf/pdf.dart';
import 'package:pdf/widgets.dart' as pw;
import 'package:printing/printing.dart';
import '../../inventory/providers/products_provider.dart';
import '../../inventory/providers/product_categories_provider.dart';
import '../../inventory/providers/uoms_provider.dart';
import '../../inventory/domain/product.dart';
import '../domain/invoice.dart';
import '../providers/invoices_provider.dart';
import '../providers/customers_provider.dart';
import '../../business/providers/business_provider.dart';
import '../../transactions/presentation/widgets/attachment_gallery_screen.dart';
import '../../../core/network/dio_client.dart';
import 'widgets/receive_payment_sheet.dart';
import 'invoice_builder_screen.dart';

bool _isCommodityProduct({
  ProductCategory? category,
  Product? product,
  InvoiceItem? invoiceItem,
  String? commodityCode,
  String? huid,
}) {
  final h = huid ?? invoiceItem?.huid;
  if (h != null && h.trim().isNotEmpty) return true;

  final code = commodityCode ??
      category?.commodityCode ??
      invoiceItem?.commodityCode;
  if (code != null && code.trim().isNotEmpty && code.trim().toUpperCase() != 'NONE') {
    return true;
  }

  return false;
}

String _resolveProductUnit({
  required Product? product,
  required ProductCategory? category,
  required List<UnitOfMeasure> uoms,
  bool isCommodity = false,
}) {
  if (isCommodity) {
    return (category != null && category.baseUnit.isNotEmpty) ? category.baseUnit : 'g';
  }
  if (product?.uomId != null) {
    final uom = uoms.where((u) => u.id == product!.uomId).firstOrNull;
    if (uom != null && uom.abbreviation != null && uom.abbreviation!.isNotEmpty) return uom.abbreviation!;
    if (uom != null && uom.name.isNotEmpty) return uom.name;
  }
  if (category != null && category.baseUnit.isNotEmpty) {
    return category.baseUnit;
  }
  return 'pcs';
}

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)}';
}

class InvoiceDetailsScreen extends ConsumerStatefulWidget {
  final Invoice invoice;

  const InvoiceDetailsScreen({super.key, required this.invoice});

  @override
  ConsumerState<InvoiceDetailsScreen> createState() => _InvoiceDetailsScreenState();
}

class _InvoiceDetailsScreenState extends ConsumerState<InvoiceDetailsScreen> {
  final ScreenshotController _screenshotController = ScreenshotController();

  void _showReceivePaymentSheet(BuildContext context, WidgetRef ref, Invoice latestInvoice) async {
    final result = await showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      backgroundColor: Colors.transparent,
      builder: (context) => ReceivePaymentSheet(invoice: latestInvoice),
    );
    if (result == true) {
      ref.read(invoicesProvider.notifier).refresh();
    }
  }

  void _editInvoice(Invoice invoice) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (_) => InvoiceBuilderScreen(existingInvoice: invoice),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final invoicesState = ref.watch(invoicesProvider);
    final latestInvoice = invoicesState.value?.firstWhere(
      (i) => i.id == widget.invoice.id,
      orElse: () => widget.invoice,
    ) ?? widget.invoice;

    final customersState = ref.watch(customersProvider);
    final customer = customersState.value?.where((c) => c.id == latestInvoice.customerId).firstOrNull;

    final businessState = ref.watch(businessProfileProvider);
    final business = businessState.value;

    final products = ref.watch(productsProvider).value ?? [];
    final categories = ref.watch(productCategoriesProvider).value ?? [];

    final isDark = Theme.of(context).brightness == Brightness.dark;
    final formatCurrency = NumberFormat.currency(symbol: '₹');
    final formatDate = DateFormat('dd MMM yyyy');

    double remaining = latestInvoice.totalAmount - latestInvoice.amountPaid;

    return Scaffold(
      backgroundColor: isDark ? const Color(0xFF0F172A) : Colors.grey[50],
      appBar: AppBar(
        title: Text(
          'Invoice #${latestInvoice.invoiceNumber}',
          style: const TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
        ),
        centerTitle: true,
        actions: [
          IconButton(
            icon: const Icon(LucideIcons.edit3, size: 20),
            tooltip: 'Edit Invoice',
            onPressed: () => _editInvoice(latestInvoice),
          ),
          IconButton(
            icon: const Icon(LucideIcons.share2, size: 20),
            tooltip: 'Share Invoice',
            onPressed: () => _showShareOptions(context, latestInvoice.invoiceNumber),
          ),
        ],
      ),
      body: SingleChildScrollView(
        child: Screenshot(
          controller: _screenshotController,
          child: Container(
            color: isDark ? const Color(0xFF0F172A) : Colors.grey[50],
            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 20),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                // Top Header Card: Business info
                Container(
                  padding: const EdgeInsets.all(16),
                  decoration: BoxDecoration(
                    color: isDark ? const Color(0xFF1E293B) : Colors.white,
                    borderRadius: BorderRadius.circular(16),
                    border: Border.all(color: isDark ? Colors.white12 : Colors.grey.shade200),
                  ),
                  child: Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      Expanded(
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text(
                              business?.businessName ?? 'KIFI JEWELLERS',
                              style: const TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
                            ),
                            if (business?.address != null)
                              Text(business!.address!, style: TextStyle(fontSize: 12, color: Colors.grey.shade600)),
                            if (business?.gstin != null)
                              Text('GSTIN: ${business!.gstin}', style: const TextStyle(fontSize: 12, fontWeight: FontWeight.w600, color: Colors.blue)),
                          ],
                        ),
                      ),
                      Container(
                        padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
                        decoration: BoxDecoration(
                          color: _getStatusColor(_getEffectiveStatus(latestInvoice)).withValues(alpha: 0.15),
                          borderRadius: BorderRadius.circular(8),
                        ),
                        child: Text(
                          _getEffectiveStatus(latestInvoice),
                          style: TextStyle(
                            fontSize: 12,
                            fontWeight: FontWeight.bold,
                            color: _getStatusColor(_getEffectiveStatus(latestInvoice)),
                          ),
                        ),
                      ),
                    ],
                  ),
                ),
                const SizedBox(height: 12),

                // Invoice metadata & Customer details
                Row(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    // Invoice metadata
                    Expanded(
                      flex: 2,
                      child: Container(
                        padding: const EdgeInsets.all(14),
                        decoration: BoxDecoration(
                          color: isDark ? const Color(0xFF1E293B) : Colors.white,
                          borderRadius: BorderRadius.circular(14),
                          border: Border.all(color: isDark ? Colors.white12 : Colors.grey.shade200),
                        ),
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            const Text('INVOICE NO', style: TextStyle(fontSize: 10, fontWeight: FontWeight.bold, color: Colors.grey)),
                            const SizedBox(height: 2),
                            Text(latestInvoice.invoiceNumber, style: const TextStyle(fontSize: 13, fontWeight: FontWeight.bold, color: Colors.blue)),
                            if (latestInvoice.salesChannel != null && latestInvoice.salesChannel!.isNotEmpty) ...[
                              const SizedBox(height: 6),
                              Container(
                                padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                                decoration: BoxDecoration(
                                  color: Colors.blue.withValues(alpha: 0.12),
                                  borderRadius: BorderRadius.circular(4),
                                  border: Border.all(color: Colors.blue.withValues(alpha: 0.25)),
                                ),
                                child: Row(
                                  mainAxisSize: MainAxisSize.min,
                                  children: [
                                    const Icon(LucideIcons.shoppingBag, size: 10, color: Colors.blue),
                                    const SizedBox(width: 4),
                                    Text(
                                      latestInvoice.salesChannel!,
                                      style: const TextStyle(fontSize: 10, fontWeight: FontWeight.bold, color: Colors.blue),
                                    ),
                                  ],
                                ),
                              ),
                            ],
                            if (latestInvoice.marketplaceOrderId != null && latestInvoice.marketplaceOrderId!.isNotEmpty) ...[
                              const SizedBox(height: 4),
                              Text(
                                'Ref: ${latestInvoice.marketplaceOrderId}',
                                style: TextStyle(fontSize: 10, fontWeight: FontWeight.w600, color: Colors.grey.shade700),
                              ),
                            ],
                            const SizedBox(height: 10),
                            const Text('INVOICE DATE', style: TextStyle(fontSize: 10, fontWeight: FontWeight.bold, color: Colors.grey)),
                            const SizedBox(height: 2),
                            Text(formatDate.format(latestInvoice.issueDate), style: const TextStyle(fontSize: 13, fontWeight: FontWeight.w600)),
                            if (latestInvoice.placeOfSupply != null && latestInvoice.placeOfSupply!.isNotEmpty) ...[
                              const SizedBox(height: 8),
                              const Text('PLACE OF SUPPLY', style: TextStyle(fontSize: 10, fontWeight: FontWeight.bold, color: Colors.grey)),
                              const SizedBox(height: 2),
                              Text(latestInvoice.placeOfSupply!, style: const TextStyle(fontSize: 12, fontWeight: FontWeight.w600)),
                            ],
                          ],
                        ),
                      ),
                    ),
                    const SizedBox(width: 12),
                    // Customer Details
                    Expanded(
                      flex: 3,
                      child: Container(
                        padding: const EdgeInsets.all(14),
                        decoration: BoxDecoration(
                          color: isDark ? const Color(0xFF1E293B) : Colors.white,
                          borderRadius: BorderRadius.circular(14),
                          border: Border.all(color: isDark ? Colors.white12 : Colors.grey.shade200),
                        ),
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            const Text('BILL TO', style: TextStyle(fontSize: 10, fontWeight: FontWeight.bold, color: Colors.grey)),
                            const SizedBox(height: 4),
                            if (customer != null) ...[
                              Text(customer.name, style: const TextStyle(fontSize: 14, fontWeight: FontWeight.bold)),
                              if (customer.phone != null)
                                Text('Ph: ${customer.phone}', style: TextStyle(fontSize: 12, color: Colors.grey.shade600)),
                              if (customer.gstin != null)
                                Text('GSTIN: ${customer.gstin}', style: const TextStyle(fontSize: 11, fontWeight: FontWeight.bold, color: Colors.blue)),
                            ] else ...[
                              const Text('Walk-in Customer', style: TextStyle(fontSize: 13, fontStyle: FontStyle.italic, color: Colors.grey)),
                            ],
                          ],
                        ),
                      ),
                    ),
                  ],
                ),
                const SizedBox(height: 20),

                // Itemized Details Header
                const Text('Itemized Particulars', style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold)),
                const SizedBox(height: 10),

                // Item Cards
                ...(latestInvoice.items).map((item) {
                  final product = products.where((p) => p.id == item.productId).firstOrNull;
                  final category = categories.where((c) => c.name == item.categoryName || c.id == product?.categoryId).firstOrNull;
                  final uoms = ref.watch(uomsProvider).value ?? [];

                  final isItemCommodity = _isCommodityProduct(
                    category: category,
                    product: product,
                    invoiceItem: item,
                  );

                  final qtyOrWeight = item.weight != null && item.weight! > 0 ? item.weight! : (item.quantity > 0 ? item.quantity : 1.0);
                  final baseAmount = qtyOrWeight * item.unitPrice;
                  final unit = _resolveProductUnit(product: product, category: category, uoms: uoms, isCommodity: isItemCommodity);

                  double makingChargeAmt = 0.0;
                  if (isItemCommodity) {
                    if (item.makingChargesType == 'PERCENTAGE') {
                      makingChargeAmt = baseAmount * (item.makingCharge / 100.0);
                    } else if (item.makingChargesType == 'PER_PIECE') {
                      makingChargeAmt = item.makingCharge;
                    } else {
                      makingChargeAmt = qtyOrWeight * item.makingCharge;
                    }
                  }

                  final taxableAmount = baseAmount + makingChargeAmt + item.otherCharges - item.discount;
                  final taxAmount = (taxableAmount * item.taxRate) / 100.0;

                  return Container(
                    margin: const EdgeInsets.only(bottom: 12),
                    padding: const EdgeInsets.all(16),
                    decoration: BoxDecoration(
                      color: isDark ? const Color(0xFF1E293B) : Colors.white,
                      borderRadius: BorderRadius.circular(16),
                      border: Border.all(color: isDark ? Colors.white12 : Colors.grey.shade200),
                    ),
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Row(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            if (item.photoUrl != null && item.photoUrl!.isNotEmpty)
                              Container(
                                width: 44,
                                height: 44,
                                margin: const EdgeInsets.only(right: 12),
                                decoration: BoxDecoration(
                                  borderRadius: BorderRadius.circular(8),
                                  image: DecorationImage(
                                    image: NetworkImage(_resolveImageUrl(item.photoUrl!)),
                                    fit: BoxFit.cover,
                                  ),
                                ),
                              ),
                            Expanded(
                              child: Column(
                                crossAxisAlignment: CrossAxisAlignment.start,
                                children: [
                                  Text(
                                    item.productName ?? product?.name ?? item.description ?? 'Item',
                                    style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 15),
                                  ),
                                  const SizedBox(height: 4),
                                  Wrap(
                                    spacing: 6,
                                    runSpacing: 4,
                                    children: [
                                      if (item.categoryName != null || category?.name != null)
                                        _buildDetailBadge(item.categoryName ?? category!.name, const Color(0xFFD4AF37)),
                                      if (item.sku != null || product?.sku != null)
                                        _buildDetailBadge('SKU: ${item.sku ?? product!.sku}', Colors.blue),
                                      if (isItemCommodity && item.huid != null && item.huid!.isNotEmpty)
                                        _buildDetailBadge('HUID: ${item.huid}', Colors.purple),
                                      if (item.hsnCode != null && item.hsnCode!.isNotEmpty)
                                        _buildDetailBadge('HSN: ${item.hsnCode}', Colors.grey),
                                      if (!isItemCommodity)
                                        _buildDetailBadge('Unit: $unit', Colors.teal),
                                    ],
                                  ),
                                ],
                              ),
                            ),
                            Text(
                              formatCurrency.format(item.total),
                              style: const TextStyle(fontSize: 16, fontWeight: FontWeight.bold, color: Colors.green),
                            ),
                          ],
                        ),
                        const Divider(height: 18),
                        if (isItemCommodity) ...[
                          Row(
                            mainAxisAlignment: MainAxisAlignment.spaceBetween,
                            children: [
                              Text(
                                'Metal (${qtyOrWeight.toStringAsFixed(3)}$unit @ ₹${item.unitPrice.toStringAsFixed(2)}/$unit):',
                                style: TextStyle(fontSize: 12, color: Colors.grey.shade600),
                              ),
                              Text(formatCurrency.format(baseAmount), style: const TextStyle(fontWeight: FontWeight.w600, fontSize: 12)),
                            ],
                          ),
                          if (makingChargeAmt > 0) ...[
                            const SizedBox(height: 4),
                            Row(
                              mainAxisAlignment: MainAxisAlignment.spaceBetween,
                              children: [
                                Text(
                                  'Making Charges (${item.makingChargesType == 'PERCENTAGE' ? '${item.makingCharge}%' : (item.makingChargesType == 'PER_PIECE' ? '₹${item.makingCharge}/pc' : '₹${item.makingCharge}/g')}):',
                                  style: TextStyle(fontSize: 12, color: Colors.grey.shade600),
                                ),
                                Text(formatCurrency.format(makingChargeAmt), style: const TextStyle(fontWeight: FontWeight.w600, fontSize: 12, color: Colors.indigo)),
                              ],
                            ),
                          ],
                        ] else ...[
                          Row(
                            mainAxisAlignment: MainAxisAlignment.spaceBetween,
                            children: [
                              Text(
                                'Rate: ₹${item.unitPrice.toStringAsFixed(2)} / $unit  •  Qty: ${qtyOrWeight.toStringAsFixed(qtyOrWeight.truncateToDouble() == qtyOrWeight ? 0 : 2)} $unit',
                                style: TextStyle(fontSize: 12, color: Colors.grey.shade600, fontWeight: FontWeight.w500),
                              ),
                              Text(formatCurrency.format(baseAmount), style: const TextStyle(fontWeight: FontWeight.w600, fontSize: 12)),
                            ],
                          ),
                        ],
                        if (item.discount > 0) ...[
                          const SizedBox(height: 4),
                          Row(
                            mainAxisAlignment: MainAxisAlignment.spaceBetween,
                            children: [
                              const Text('Discount:', style: TextStyle(fontSize: 11, color: Colors.red)),
                              Text('- ${formatCurrency.format(item.discount)}', style: const TextStyle(fontSize: 11, fontWeight: FontWeight.bold, color: Colors.red)),
                            ],
                          ),
                        ],
                        if (item.taxRate > 0) ...[
                          const SizedBox(height: 4),
                          Row(
                            mainAxisAlignment: MainAxisAlignment.spaceBetween,
                            children: [
                              Text('GST (${item.taxRate.toStringAsFixed(1)}%):', style: TextStyle(fontSize: 11, color: Colors.grey.shade500)),
                              Text(
                                '+ ${formatCurrency.format(taxAmount)}',
                                style: TextStyle(fontSize: 11, color: Colors.grey.shade600),
                              ),
                            ],
                          ),
                        ],
                      ],
                    ),
                  );
                }),

                const SizedBox(height: 12),

                // Grand Totals Summary
                Container(
                  padding: const EdgeInsets.all(18),
                  decoration: BoxDecoration(
                    color: isDark ? const Color(0xFF1E293B) : Colors.white,
                    borderRadius: BorderRadius.circular(16),
                    border: Border.all(color: isDark ? Colors.white12 : Colors.grey.shade200),
                  ),
                  child: Column(
                    children: [
                      _buildSummaryRow('Subtotal', formatCurrency.format(latestInvoice.subtotal)),
                      if (latestInvoice.cgstTotal > 0 && latestInvoice.sgstTotal > 0) ...[
                        _buildSummaryRow('CGST', formatCurrency.format(latestInvoice.cgstTotal)),
                        _buildSummaryRow('SGST', formatCurrency.format(latestInvoice.sgstTotal)),
                      ] else if (latestInvoice.igstTotal > 0) ...[
                        _buildSummaryRow('IGST', formatCurrency.format(latestInvoice.igstTotal)),
                      ] else if (latestInvoice.taxTotal > 0) ...[
                        _buildSummaryRow('Tax', formatCurrency.format(latestInvoice.taxTotal)),
                      ],
                      if (latestInvoice.discountTotal > 0)
                        _buildSummaryRow('Discount', '-${formatCurrency.format(latestInvoice.discountTotal)}', color: Colors.green),
                      const Divider(height: 20),
                      _buildSummaryRow('Grand Total', formatCurrency.format(latestInvoice.totalAmount), isBold: true, fontSize: 18),
                      const SizedBox(height: 10),
                      Container(
                        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 10),
                        decoration: BoxDecoration(
                          color: isDark ? Colors.black26 : Colors.grey.shade100,
                          borderRadius: BorderRadius.circular(10),
                        ),
                        child: Column(
                          children: [
                            _buildSummaryRow('Amount Received', formatCurrency.format(latestInvoice.amountPaid), color: Colors.green, isBold: true),
                            const SizedBox(height: 6),
                            _buildSummaryRow('Balance Due', formatCurrency.format(remaining), color: remaining > 0 ? Colors.red : Colors.green, isBold: true, fontSize: 15),
                          ],
                        ),
                      ),
                    ],
                  ),
                ),
                const SizedBox(height: 20),

                // Attached Invoice Bill if available
                if (latestInvoice.invoiceUrl != null && latestInvoice.invoiceUrl!.isNotEmpty) ...[
                  const Text('Attached Document', style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold)),
                  const SizedBox(height: 8),
                  ListTile(
                    tileColor: isDark ? const Color(0xFF1E293B) : Colors.white,
                    shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                    leading: const Icon(LucideIcons.image, color: Colors.blue),
                    title: const Text('View Attached Sales Slip'),
                    subtitle: const Text('Tap to open photo gallery', style: TextStyle(fontSize: 12, color: Colors.blue)),
                    onTap: () {
                      Navigator.push(
                        context,
                        MaterialPageRoute(
                          builder: (_) => AttachmentGalleryScreen(
                            images: [NetworkImage(_resolveImageUrl(latestInvoice.invoiceUrl!))],
                            initialIndex: 0,
                          ),
                        ),
                      );
                    },
                  ),
                  const SizedBox(height: 20),
                ],

                // Bottom Action: Receive Payment if balance due
                if (remaining > 0)
                  ElevatedButton.icon(
                    onPressed: () => _showReceivePaymentSheet(context, ref, latestInvoice),
                    icon: const Icon(LucideIcons.plusCircle, size: 18),
                    label: const Text('Record Payment', style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16)),
                    style: ElevatedButton.styleFrom(
                      padding: const EdgeInsets.symmetric(vertical: 16),
                      backgroundColor: Colors.green,
                      foregroundColor: Colors.white,
                      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                    ),
                  ),
                const SizedBox(height: 30),
              ],
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildDetailBadge(String text, Color color) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
      decoration: BoxDecoration(
        color: color.withValues(alpha: 0.12),
        borderRadius: BorderRadius.circular(4),
        border: Border.all(color: color.withValues(alpha: 0.3), width: 0.5),
      ),
      child: Text(
        text,
        style: TextStyle(fontSize: 10, fontWeight: FontWeight.bold, color: color),
      ),
    );
  }

  Widget _buildSummaryRow(String label, String value, {bool isBold = false, double fontSize = 14, Color? color}) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 3),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Text(label, style: TextStyle(fontSize: fontSize, fontWeight: isBold ? FontWeight.bold : FontWeight.normal)),
          Text(value, style: TextStyle(fontSize: fontSize, fontWeight: isBold ? FontWeight.bold : FontWeight.w600, color: color)),
        ],
      ),
    );
  }

  String _getEffectiveStatus(Invoice invoice) {
    final balanceDue = invoice.totalAmount - invoice.amountPaid;
    if (invoice.status == 'PAID' || balanceDue.abs() < 0.01 || (invoice.totalAmount > 0 && invoice.amountPaid >= invoice.totalAmount - 0.01)) {
      return 'PAID';
    }
    if (invoice.amountPaid > 0.01) {
      return 'PARTIAL';
    }
    return invoice.status.isNotEmpty ? invoice.status : 'DRAFT';
  }

  Color _getStatusColor(String status) {
    switch (status) {
      case 'PAID':
        return Colors.green;
      case 'PARTIAL':
        return Colors.blue;
      case 'FINALIZED':
        return Colors.orange;
      case 'DRAFT':
      default:
        return Colors.grey;
    }
  }

  void _showShareOptions(BuildContext context, String invoiceNumber) {
    showModalBottomSheet(
      context: context,
      shape: const RoundedRectangleBorder(borderRadius: BorderRadius.vertical(top: Radius.circular(20))),
      builder: (ctx) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            const Padding(
              padding: EdgeInsets.all(16),
              child: Text('Share Invoice', style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
            ),
            ListTile(
              leading: const Icon(LucideIcons.image, color: Colors.blue),
              title: const Text('Share as Image'),
              subtitle: const Text('High-resolution receipt preview'),
              onTap: () {
                Navigator.pop(ctx);
                _shareAsImage(invoiceNumber);
              },
            ),
            ListTile(
              leading: const Icon(LucideIcons.fileText, color: Colors.red),
              title: const Text('Share as PDF (Tax Invoice)'),
              subtitle: const Text('Official jewellery tax invoice format'),
              onTap: () {
                Navigator.pop(ctx);
                _shareAsPdf(invoiceNumber);
              },
            ),
            const SizedBox(height: 16),
          ],
        ),
      ),
    );
  }

  Future<void> _shareAsImage(String invoiceNumber) async {
    try {
      final Uint8List? image = await _screenshotController.capture(pixelRatio: 3.0);
      if (image == null) return;

      final directory = await getTemporaryDirectory();
      final imagePath = await File('${directory.path}/Invoice_$invoiceNumber.png').create();
      await imagePath.writeAsBytes(image);

      await Share.shareXFiles([XFile(imagePath.path)], text: 'Invoice $invoiceNumber');
    } catch (e) {
      if (mounted) ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Error sharing image: $e')));
    }
  }

  Future<void> _shareAsPdf(String invoiceNumber) async {
    try {
      final invoicesState = ref.read(invoicesProvider);
      final latestInvoice = invoicesState.value?.firstWhere(
        (i) => i.id == widget.invoice.id,
        orElse: () => widget.invoice,
      ) ?? widget.invoice;

      final customers = ref.read(customersProvider).value ?? [];
      final customer = customers.where((c) => c.id == latestInvoice.customerId).firstOrNull;

      final business = ref.read(businessProfileProvider).value;
      final products = ref.read(productsProvider).value ?? [];
      final categories = ref.read(productCategoriesProvider).value ?? [];
      final uoms = ref.read(uomsProvider).value ?? [];

      final formatCurrency = NumberFormat.currency(symbol: 'Rs. ', decimalDigits: 2);
      final formatDate = DateFormat('dd MMM yyyy');

      final font = await PdfGoogleFonts.robotoRegular();
      final boldFont = await PdfGoogleFonts.robotoBold();

      final businessStateId = business?.stateId;
      final customerStateId = customer?.stateId;
      final isSameState = businessStateId != null && customerStateId != null
          ? (businessStateId == customerStateId)
          : true;

      // Group items by product ID if available, or itemize
      final Map<int, List<InvoiceItem>> groupedItems = {};
      final List<InvoiceItem> ungroupedItems = [];

      for (final item in latestInvoice.items) {
        if (item.productId != null) {
          groupedItems.putIfAbsent(item.productId!, () => []).add(item);
        } else {
          ungroupedItems.add(item);
        }
      }

      final pdf = pw.Document();

      pdf.addPage(
        pw.MultiPage(
          pageFormat: PdfPageFormat.a4,
          theme: pw.ThemeData.withFont(
            base: font,
            bold: boldFont,
          ),
          margin: const pw.EdgeInsets.all(28),
          build: (pw.Context context) {
            return [
              // 1. Header with Business Details & TAX INVOICE title
              pw.Row(
                mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                crossAxisAlignment: pw.CrossAxisAlignment.start,
                children: [
                  pw.Expanded(
                    child: pw.Column(
                      crossAxisAlignment: pw.CrossAxisAlignment.start,
                      children: [
                        pw.Text(
                          business?.businessName ?? 'KIFI JEWELLERS',
                          style: pw.TextStyle(
                            fontSize: 22,
                            fontWeight: pw.FontWeight.bold,
                            color: PdfColors.blue900,
                          ),
                        ),
                        pw.SizedBox(height: 4),
                        if (business?.address != null && business!.address!.isNotEmpty)
                          pw.Text(
                            business.address!,
                            style: const pw.TextStyle(fontSize: 9, color: PdfColors.grey700),
                          ),
                        if (business?.contactNumber != null && business!.contactNumber!.isNotEmpty)
                          pw.Text(
                            'Phone: ${business.contactNumber}',
                            style: const pw.TextStyle(fontSize: 9, color: PdfColors.grey700),
                          ),
                        if (business?.gstin != null && business!.gstin!.isNotEmpty)
                          pw.Text(
                            'GSTIN: ${business.gstin}',
                            style: pw.TextStyle(
                              fontSize: 9,
                              fontWeight: pw.FontWeight.bold,
                              color: PdfColors.blue800,
                            ),
                          ),
                      ],
                    ),
                  ),
                  pw.Column(
                    crossAxisAlignment: pw.CrossAxisAlignment.end,
                    children: [
                      pw.Text(
                        'TAX INVOICE',
                        style: pw.TextStyle(
                          fontSize: 22,
                          fontWeight: pw.FontWeight.bold,
                          color: PdfColors.blue900,
                        ),
                      ),
                      pw.SizedBox(height: 6),
                      pw.Container(
                        padding: const pw.EdgeInsets.symmetric(horizontal: 8, vertical: 3),
                        decoration: pw.BoxDecoration(
                          color: _getEffectiveStatus(latestInvoice) == 'PAID'
                              ? PdfColors.green100
                              : (_getEffectiveStatus(latestInvoice) == 'PARTIAL' ? PdfColors.orange100 : PdfColors.grey200),
                          borderRadius: const pw.BorderRadius.all(pw.Radius.circular(4)),
                          border: pw.Border.all(
                            color: _getEffectiveStatus(latestInvoice) == 'PAID'
                                ? PdfColors.green700
                                : (_getEffectiveStatus(latestInvoice) == 'PARTIAL' ? PdfColors.orange700 : PdfColors.grey500),
                            width: 0.5,
                          ),
                        ),
                        child: pw.Text(
                          _getEffectiveStatus(latestInvoice),
                          style: pw.TextStyle(
                            fontSize: 9,
                            fontWeight: pw.FontWeight.bold,
                            color: _getEffectiveStatus(latestInvoice) == 'PAID'
                                ? PdfColors.green900
                                : (_getEffectiveStatus(latestInvoice) == 'PARTIAL' ? PdfColors.orange900 : PdfColors.grey800),
                          ),
                        ),
                      ),
                      pw.SizedBox(height: 6),
                      pw.Text(
                        'Invoice #: ${latestInvoice.invoiceNumber}',
                        style: pw.TextStyle(fontSize: 11, fontWeight: pw.FontWeight.bold),
                      ),
                      pw.Text(
                        'Date: ${formatDate.format(latestInvoice.issueDate)}',
                        style: const pw.TextStyle(fontSize: 9, color: PdfColors.grey700),
                      ),
                      if (latestInvoice.dueDate != null)
                        pw.Text(
                          'Due Date: ${formatDate.format(latestInvoice.dueDate!)}',
                          style: const pw.TextStyle(fontSize: 9, color: PdfColors.grey700),
                        ),
                    ],
                  ),
                ],
              ),
              pw.SizedBox(height: 18),

              // 2. Bill To Box (Customer Details)
              pw.Container(
                padding: const pw.EdgeInsets.all(10),
                decoration: pw.BoxDecoration(
                  color: PdfColors.grey100,
                  border: pw.Border.all(color: PdfColors.grey400, width: 0.5),
                  borderRadius: const pw.BorderRadius.all(pw.Radius.circular(6)),
                ),
                child: pw.Row(
                  crossAxisAlignment: pw.CrossAxisAlignment.start,
                  children: [
                    pw.Expanded(
                      child: pw.Column(
                        crossAxisAlignment: pw.CrossAxisAlignment.start,
                        children: [
                          pw.Text(
                            'BILL TO (CUSTOMER):',
                            style: pw.TextStyle(
                              fontSize: 8.5,
                              fontWeight: pw.FontWeight.bold,
                              color: PdfColors.grey700,
                            ),
                          ),
                          pw.SizedBox(height: 2),
                          pw.Text(
                            customer?.name ?? 'Walk-in Customer',
                            style: pw.TextStyle(
                              fontSize: 12,
                              fontWeight: pw.FontWeight.bold,
                            ),
                          ),
                          if (customer?.phone != null && customer!.phone!.isNotEmpty)
                            pw.Text('Phone: ${customer.phone}', style: const pw.TextStyle(fontSize: 9)),
                          if (customer?.address != null && customer!.address!.isNotEmpty)
                            pw.Text('Address: ${customer.address}', style: const pw.TextStyle(fontSize: 9)),
                          if (customer?.gstin != null && customer!.gstin!.isNotEmpty)
                            pw.Text(
                              'GSTIN: ${customer.gstin}',
                              style: pw.TextStyle(fontSize: 9, fontWeight: pw.FontWeight.bold),
                            ),
                        ],
                      ),
                    ),
                  ],
                ),
              ),
              pw.SizedBox(height: 16),

              // 3. Product Groups with Full Details (Category, Purity, HSN, HUID, Weight, Making Charges, GST Breakup)
              ...groupedItems.entries.map((entry) {
                final productId = entry.key;
                final group = entry.value;
                final product = products.where((p) => p.id == productId).firstOrNull;
                final category = categories.where((c) => c.id == product?.categoryId).firstOrNull;

                final productName = product?.name ?? group.first.productName ?? 'Item $productId';
                final categoryName = category?.name ?? group.first.categoryName ?? 'General Category';
                final skuStr = product?.sku ?? group.first.sku;
                final purityStr = product?.purityFactor != null
                    ? '${(product!.purityFactor! * 100).toStringAsFixed(1)}%'
                    : (category?.purityFactor != null ? '${(category!.purityFactor! * 100).toStringAsFixed(1)}%' : '0.916');
                final hsnStr = product?.hsnCode ?? group.first.hsnCode ?? category?.defaultHsn ?? '-';

                double groupSubtotal = 0;
                double groupMaking = 0;
                double groupTax = 0;

                for (final item in group) {
                  final weight = item.weight ?? item.quantity;
                  final metalAmt = weight * item.unitPrice;
                  double makingAmt = 0.0;
                  if (item.makingChargesType == 'PERCENTAGE') {
                    makingAmt = metalAmt * (item.makingCharge / 100.0);
                  } else if (item.makingChargesType == 'PER_PIECE') {
                    makingAmt = item.makingCharge;
                  } else {
                    makingAmt = weight * item.makingCharge;
                  }
                  groupSubtotal += metalAmt;
                  groupMaking += makingAmt;
                  groupTax += (item.cgst + item.sgst + item.igst);
                }

                final groupTotal = group.fold(0.0, (sum, i) => sum + i.total);
                final gstRate = group.first.taxRate > 0 ? group.first.taxRate : (product?.gstRate ?? (category?.defaultGst ?? 0.0));

                final isGroupCommodity = group.any((item) => _isCommodityProduct(
                  category: category,
                  product: product,
                  invoiceItem: item,
                ));

                final groupUnit = _resolveProductUnit(
                  product: product,
                  category: category,
                  uoms: uoms,
                  isCommodity: isGroupCommodity,
                );

                return pw.Container(
                  margin: const pw.EdgeInsets.only(bottom: 14),
                  decoration: pw.BoxDecoration(
                    border: pw.Border.all(color: PdfColors.grey300, width: 0.5),
                    borderRadius: const pw.BorderRadius.all(pw.Radius.circular(6)),
                  ),
                  child: pw.Column(
                    crossAxisAlignment: pw.CrossAxisAlignment.stretch,
                    children: [
                      // Product Title & Badges
                      pw.Container(
                        padding: const pw.EdgeInsets.symmetric(horizontal: 10, vertical: 8),
                        decoration: const pw.BoxDecoration(
                          color: PdfColors.grey200,
                          borderRadius: pw.BorderRadius.vertical(top: pw.Radius.circular(5.5)),
                        ),
                        child: pw.Row(
                          mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                          crossAxisAlignment: pw.CrossAxisAlignment.center,
                          children: [
                            pw.Expanded(
                              child: pw.Text(
                                productName,
                                style: pw.TextStyle(
                                  fontSize: 11,
                                  fontWeight: pw.FontWeight.bold,
                                  color: PdfColors.black,
                                ),
                              ),
                            ),
                            pw.Wrap(
                              spacing: 6,
                              runSpacing: 4,
                              children: [
                                pw.Container(
                                  padding: const pw.EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                                  decoration: pw.BoxDecoration(
                                    color: PdfColors.orange50,
                                    border: pw.Border.all(color: PdfColors.orange400, width: 0.5),
                                    borderRadius: const pw.BorderRadius.all(pw.Radius.circular(3)),
                                  ),
                                  child: pw.Text(
                                    categoryName,
                                    style: pw.TextStyle(
                                      fontSize: 7.5,
                                      fontWeight: pw.FontWeight.bold,
                                      color: PdfColors.deepOrange900,
                                    ),
                                  ),
                                ),
                                if (skuStr != null && skuStr.isNotEmpty)
                                  pw.Container(
                                    padding: const pw.EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                                    decoration: pw.BoxDecoration(
                                      color: PdfColors.grey100,
                                      border: pw.Border.all(color: PdfColors.grey500, width: 0.5),
                                      borderRadius: const pw.BorderRadius.all(pw.Radius.circular(3)),
                                    ),
                                    child: pw.Text(
                                      'SKU: $skuStr',
                                      style: const pw.TextStyle(fontSize: 7.5, color: PdfColors.grey800),
                                    ),
                                  ),
                                if (isGroupCommodity)
                                  pw.Container(
                                    padding: const pw.EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                                    decoration: pw.BoxDecoration(
                                      color: PdfColors.amber50,
                                      border: pw.Border.all(color: PdfColors.amber600, width: 0.5),
                                      borderRadius: const pw.BorderRadius.all(pw.Radius.circular(3)),
                                    ),
                                    child: pw.Text(
                                      'Purity: $purityStr',
                                      style: pw.TextStyle(
                                        fontSize: 7.5,
                                        fontWeight: pw.FontWeight.bold,
                                        color: PdfColors.brown800,
                                      ),
                                    ),
                                  ),
                                if (!isGroupCommodity)
                                  pw.Container(
                                    padding: const pw.EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                                    decoration: pw.BoxDecoration(
                                      color: PdfColors.teal50,
                                      border: pw.Border.all(color: PdfColors.teal400, width: 0.5),
                                      borderRadius: const pw.BorderRadius.all(pw.Radius.circular(3)),
                                    ),
                                    child: pw.Text(
                                      'Unit: $groupUnit',
                                      style: pw.TextStyle(
                                        fontSize: 7.5,
                                        fontWeight: pw.FontWeight.bold,
                                        color: PdfColors.teal900,
                                      ),
                                    ),
                                  ),
                                if (hsnStr != '-')
                                  pw.Container(
                                    padding: const pw.EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                                    decoration: pw.BoxDecoration(
                                      color: PdfColors.purple50,
                                      border: pw.Border.all(color: PdfColors.purple400, width: 0.5),
                                      borderRadius: const pw.BorderRadius.all(pw.Radius.circular(3)),
                                    ),
                                    child: pw.Text(
                                      'HSN: $hsnStr',
                                      style: pw.TextStyle(
                                        fontSize: 7.5,
                                        fontWeight: pw.FontWeight.bold,
                                        color: PdfColors.purple900,
                                      ),
                                    ),
                                  ),
                              ],
                            ),
                          ],
                        ),
                      ),

                      // Items Table for this Product
                      pw.TableHelper.fromTextArray(
                        context: context,
                        border: const pw.TableBorder(
                          bottom: pw.BorderSide(color: PdfColors.grey300, width: 0.5),
                          horizontalInside: pw.BorderSide(color: PdfColors.grey200, width: 0.5),
                        ),
                        headerStyle: pw.TextStyle(
                          fontWeight: pw.FontWeight.bold,
                          color: PdfColors.white,
                          fontSize: 8,
                        ),
                        headerDecoration: const pw.BoxDecoration(color: PdfColors.blue900),
                        cellStyle: const pw.TextStyle(fontSize: 8),
                        cellAlignments: {
                          0: pw.Alignment.centerLeft,
                          1: pw.Alignment.centerRight,
                          2: pw.Alignment.centerRight,
                          3: pw.Alignment.centerRight,
                          4: pw.Alignment.centerRight,
                          5: pw.Alignment.centerRight,
                        },
                        headers: isGroupCommodity
                            ? [
                                'Item / HUID',
                                'Weight / Qty',
                                'Rate',
                                'Making Chg',
                                'Other Chg',
                                'Total Amt',
                              ]
                            : [
                                'Item / SKU',
                                'Qty',
                                'Unit Price',
                                'Discount',
                                'GST %',
                                'Total Amt',
                              ],
                        data: isGroupCommodity
                            ? group.map((item) {
                                String particular = '';
                                if (item.huid != null && item.huid!.isNotEmpty) {
                                  particular = 'HUID: ${item.huid}';
                                } else if (item.sku != null && item.sku!.isNotEmpty) {
                                  particular = 'SKU: ${item.sku}';
                                } else {
                                  particular = 'Standard Item';
                                }

                                final weight = item.weight ?? item.quantity;
                                final weightQty = item.weight != null && item.weight! > 0
                                    ? '${item.weight!.toStringAsFixed(item.weight!.truncateToDouble() == item.weight ? 0 : 3)} $groupUnit'
                                    : '${item.quantity.toStringAsFixed(item.quantity.truncateToDouble() == item.quantity ? 0 : 0)} pcs';

                                final rateUnit = item.weight != null && item.weight! > 0 ? '/ $groupUnit' : '/ pc';

                                double makingAmt = 0.0;
                                if (item.makingChargesType == 'PERCENTAGE') {
                                  makingAmt = (weight * item.unitPrice) * (item.makingCharge / 100.0);
                                } else if (item.makingChargesType == 'PER_PIECE') {
                                  makingAmt = item.makingCharge;
                                } else {
                                  makingAmt = weight * item.makingCharge;
                                }

                                return [
                                  particular,
                                  weightQty,
                                  '${formatCurrency.format(item.unitPrice)} $rateUnit',
                                  makingAmt > 0 ? formatCurrency.format(makingAmt) : '-',
                                  item.otherCharges > 0 ? formatCurrency.format(item.otherCharges) : '-',
                                  formatCurrency.format(item.total),
                                ];
                              }).toList()
                            : group.map((item) {
                                final qty = item.weight != null && item.weight! > 0 ? item.weight! : (item.quantity > 0 ? item.quantity : 1.0);
                                final qtyStr = '${qty.toStringAsFixed(qty.truncateToDouble() == qty ? 0 : 2)} $groupUnit';
                                return [
                                  item.sku ?? skuStr ?? 'Item',
                                  qtyStr,
                                  formatCurrency.format(item.unitPrice),
                                  item.discount > 0 ? '-${formatCurrency.format(item.discount)}' : '-',
                                  '${item.taxRate.toStringAsFixed(1)}%',
                                  formatCurrency.format(item.total),
                                ];
                              }).toList(),
                      ),

                      // Group Subtotal & GST Calculation Box
                      pw.Container(
                        padding: const pw.EdgeInsets.symmetric(horizontal: 10, vertical: 6),
                        decoration: const pw.BoxDecoration(
                          color: PdfColors.blue50,
                          borderRadius: pw.BorderRadius.vertical(bottom: pw.Radius.circular(5.5)),
                        ),
                        child: pw.Column(
                          crossAxisAlignment: pw.CrossAxisAlignment.stretch,
                          children: [
                            pw.Row(
                              mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                              children: [
                                pw.Text(
                                  isGroupCommodity
                                      ? 'Metal Subtotal: ${formatCurrency.format(groupSubtotal)}  |  Making: ${formatCurrency.format(groupMaking)}'
                                      : 'Items Subtotal: ${formatCurrency.format(groupSubtotal)}',
                                  style: const pw.TextStyle(fontSize: 8, color: PdfColors.grey700),
                                ),
                                pw.Text(
                                  'Taxable: ${formatCurrency.format(groupSubtotal + groupMaking)}',
                                  style: const pw.TextStyle(fontSize: 8),
                                ),
                              ],
                            ),
                            if (gstRate > 0) ...[
                              pw.SizedBox(height: 2),
                              if (isSameState) ...[
                                pw.Row(
                                  mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                                  children: [
                                    pw.Text(
                                      'CGST (${(gstRate / 2).toStringAsFixed(1)}%):',
                                      style: const pw.TextStyle(fontSize: 8, color: PdfColors.grey700),
                                    ),
                                    pw.Text(
                                      '+ ${formatCurrency.format(groupTax / 2)}',
                                      style: const pw.TextStyle(fontSize: 8),
                                    ),
                                  ],
                                ),
                                pw.SizedBox(height: 2),
                                pw.Row(
                                  mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                                  children: [
                                    pw.Text(
                                      'SGST (${(gstRate / 2).toStringAsFixed(1)}%):',
                                      style: const pw.TextStyle(fontSize: 8, color: PdfColors.grey700),
                                    ),
                                    pw.Text(
                                      '+ ${formatCurrency.format(groupTax / 2)}',
                                      style: const pw.TextStyle(fontSize: 8),
                                    ),
                                  ],
                                ),
                              ] else ...[
                                pw.Row(
                                  mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                                  children: [
                                    pw.Text(
                                      'IGST (${gstRate.toStringAsFixed(1)}%):',
                                      style: const pw.TextStyle(fontSize: 8, color: PdfColors.grey700),
                                    ),
                                    pw.Text(
                                      '+ ${formatCurrency.format(groupTax)}',
                                      style: const pw.TextStyle(fontSize: 8),
                                    ),
                                  ],
                                ),
                              ],
                            ],
                            pw.Divider(color: PdfColors.grey300, height: 8),
                            pw.Row(
                              mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                              children: [
                                pw.Text(
                                  'Group Total:',
                                  style: pw.TextStyle(fontSize: 8.5, fontWeight: pw.FontWeight.bold),
                                ),
                                pw.Text(
                                  formatCurrency.format(groupTotal),
                                  style: pw.TextStyle(
                                    fontSize: 8.5,
                                    fontWeight: pw.FontWeight.bold,
                                    color: PdfColors.blue900,
                                  ),
                                ),
                              ],
                            ),
                          ],
                        ),
                      ),
                    ],
                  ),
                );
              }),

              // 3b. Ungrouped Items (if any)
              if (ungroupedItems.isNotEmpty) ...[
                pw.TableHelper.fromTextArray(
                  context: context,
                  border: const pw.TableBorder(
                    bottom: pw.BorderSide(color: PdfColors.grey300, width: 0.5),
                    horizontalInside: pw.BorderSide(color: PdfColors.grey200, width: 0.5),
                  ),
                  headerStyle: pw.TextStyle(fontWeight: pw.FontWeight.bold, color: PdfColors.white, fontSize: 8),
                  headerDecoration: const pw.BoxDecoration(color: PdfColors.blue900),
                  cellStyle: const pw.TextStyle(fontSize: 8),
                  headers: ['Particulars', 'Weight / Qty', 'Rate', 'Making Chg', 'Other Chg', 'Total'],
                  data: ungroupedItems.map((item) {
                    final weightQty = item.weight != null && item.weight! > 0
                        ? '${item.weight!.toStringAsFixed(3)} g'
                        : '${item.quantity.toInt()} pcs';
                    return [
                      item.productName ?? item.description ?? 'Item',
                      weightQty,
                      formatCurrency.format(item.unitPrice),
                      item.makingCharge > 0 ? formatCurrency.format(item.makingCharge) : '-',
                      item.otherCharges > 0 ? formatCurrency.format(item.otherCharges) : '-',
                      formatCurrency.format(item.total),
                    ];
                  }).toList(),
                ),
                pw.SizedBox(height: 12),
              ],

              pw.SizedBox(height: 12),

              // 4. Overall Invoice Summary
              pw.Row(
                crossAxisAlignment: pw.CrossAxisAlignment.start,
                children: [
                  // Left Side: Notes & Declarations
                  pw.Expanded(
                    flex: 3,
                    child: pw.Column(
                      crossAxisAlignment: pw.CrossAxisAlignment.start,
                      children: [
                        if (latestInvoice.notes != null && latestInvoice.notes!.isNotEmpty) ...[
                          pw.Text(
                            'Notes:',
                            style: pw.TextStyle(fontSize: 8.5, fontWeight: pw.FontWeight.bold),
                          ),
                          pw.Text(
                            latestInvoice.notes!,
                            style: const pw.TextStyle(fontSize: 8, color: PdfColors.grey800),
                          ),
                          pw.SizedBox(height: 8),
                        ],
                        pw.Text(
                          'Terms & Conditions:',
                          style: pw.TextStyle(fontSize: 8.5, fontWeight: pw.FontWeight.bold),
                        ),
                        pw.SizedBox(height: 2),
                        pw.Text(
                          '1. Goods once sold are subject to standard hallmarking certification.',
                          style: const pw.TextStyle(fontSize: 7.5, color: PdfColors.grey700),
                        ),
                        pw.Text(
                          '2. Weight & purity tested under industry standard electronic balance.',
                          style: const pw.TextStyle(fontSize: 7.5, color: PdfColors.grey700),
                        ),
                      ],
                    ),
                  ),
                  pw.SizedBox(width: 20),

                  // Right Side: Grand Total & Tax Summary Box
                  pw.Expanded(
                    flex: 2,
                    child: pw.Container(
                      padding: const pw.EdgeInsets.all(10),
                      decoration: pw.BoxDecoration(
                        color: PdfColors.grey100,
                        border: pw.Border.all(color: PdfColors.grey400, width: 0.5),
                        borderRadius: const pw.BorderRadius.all(pw.Radius.circular(6)),
                      ),
                      child: pw.Column(
                        children: [
                          pw.Row(
                            mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                            children: [
                              pw.Text('Metal Subtotal:', style: const pw.TextStyle(fontSize: 8.5)),
                              pw.Text(formatCurrency.format(latestInvoice.subtotal), style: const pw.TextStyle(fontSize: 8.5)),
                            ],
                          ),
                          if (latestInvoice.cgstTotal > 0 || latestInvoice.sgstTotal > 0 || latestInvoice.igstTotal > 0 || latestInvoice.taxTotal > 0) ...[
                            pw.SizedBox(height: 4),
                            if (isSameState) ...[
                              pw.Row(
                                mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                                children: [
                                  pw.Text('CGST Total:', style: const pw.TextStyle(fontSize: 8.5, color: PdfColors.grey700)),
                                  pw.Text('+ ${formatCurrency.format(latestInvoice.cgstTotal > 0 ? latestInvoice.cgstTotal : (latestInvoice.taxTotal / 2))}', style: const pw.TextStyle(fontSize: 8.5)),
                                ],
                              ),
                              pw.SizedBox(height: 2),
                              pw.Row(
                                mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                                children: [
                                  pw.Text('SGST Total:', style: const pw.TextStyle(fontSize: 8.5, color: PdfColors.grey700)),
                                  pw.Text('+ ${formatCurrency.format(latestInvoice.sgstTotal > 0 ? latestInvoice.sgstTotal : (latestInvoice.taxTotal / 2))}', style: const pw.TextStyle(fontSize: 8.5)),
                                ],
                              ),
                            ] else ...[
                              pw.Row(
                                mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                                children: [
                                  pw.Text('IGST Total:', style: const pw.TextStyle(fontSize: 8.5, color: PdfColors.grey700)),
                                  pw.Text('+ ${formatCurrency.format(latestInvoice.igstTotal > 0 ? latestInvoice.igstTotal : latestInvoice.taxTotal)}', style: const pw.TextStyle(fontSize: 8.5)),
                                ],
                              ),
                            ],
                          ],
                          if (latestInvoice.discountTotal > 0) ...[
                            pw.SizedBox(height: 4),
                            pw.Row(
                              mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                              children: [
                                pw.Text('Discount:', style: const pw.TextStyle(fontSize: 8.5, color: PdfColors.green700)),
                                pw.Text('- ${formatCurrency.format(latestInvoice.discountTotal)}', style: const pw.TextStyle(fontSize: 8.5, color: PdfColors.green700)),
                              ],
                            ),
                          ],
                          pw.Divider(color: PdfColors.grey400, height: 10),
                          pw.Row(
                            mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                            children: [
                              pw.Text(
                                'Grand Total:',
                                style: pw.TextStyle(
                                  fontSize: 11,
                                  fontWeight: pw.FontWeight.bold,
                                  color: PdfColors.blue900,
                                ),
                              ),
                              pw.Text(
                                formatCurrency.format(latestInvoice.totalAmount),
                                style: pw.TextStyle(
                                  fontSize: 11,
                                  fontWeight: pw.FontWeight.bold,
                                  color: PdfColors.blue900,
                                ),
                              ),
                            ],
                          ),
                          if (latestInvoice.amountPaid > 0) ...[
                            pw.SizedBox(height: 6),
                            pw.Row(
                              mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                              children: [
                                pw.Text('Amount Received:', style: const pw.TextStyle(fontSize: 8.5, color: PdfColors.green800)),
                                pw.Text(formatCurrency.format(latestInvoice.amountPaid), style: const pw.TextStyle(fontSize: 8.5, color: PdfColors.green800)),
                              ],
                            ),
                            pw.SizedBox(height: 2),
                            pw.Row(
                              mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                              children: [
                                pw.Text(
                                  'Balance Due:',
                                  style: pw.TextStyle(fontSize: 9, fontWeight: pw.FontWeight.bold, color: PdfColors.red800),
                                ),
                                pw.Text(
                                  formatCurrency.format(latestInvoice.totalAmount - latestInvoice.amountPaid),
                                  style: pw.TextStyle(fontSize: 9, fontWeight: pw.FontWeight.bold, color: PdfColors.red800),
                                ),
                              ],
                            ),
                          ],
                        ],
                      ),
                    ),
                  ),
                ],
              ),
              pw.SizedBox(height: 24),

              // 5. Signatures
              pw.Row(
                mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                children: [
                  pw.Column(
                    crossAxisAlignment: pw.CrossAxisAlignment.start,
                    children: [
                      pw.SizedBox(height: 25),
                      pw.Text(
                        'Customer\'s Signature',
                        style: const pw.TextStyle(fontSize: 8, color: PdfColors.grey700),
                      ),
                    ],
                  ),
                  pw.Column(
                    crossAxisAlignment: pw.CrossAxisAlignment.end,
                    children: [
                      pw.SizedBox(height: 25),
                      pw.Text(
                        'For ${business?.businessName ?? "KIFI JEWELLERS"} (Authorized Signatory)',
                        style: const pw.TextStyle(fontSize: 8, color: PdfColors.grey700),
                      ),
                    ],
                  ),
                ],
              ),
            ];
          },
        ),
      );

      final pdfBytes = await pdf.save();

      // Cross-platform PDF sharing / printing
      await Printing.sharePdf(
        bytes: pdfBytes,
        filename: 'TaxInvoice_${invoiceNumber.replaceAll('/', '_')}.pdf',
      );
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Error sharing PDF: $e')),
        );
      }
    }
  }
}