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 '../../inventory/providers/products_provider.dart';
import '../../inventory/providers/product_categories_provider.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';

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(latestInvoice.status).withValues(alpha: 0.15),
                          borderRadius: BorderRadius.circular(8),
                        ),
                        child: Text(
                          latestInvoice.status,
                          style: TextStyle(
                            fontSize: 12,
                            fontWeight: FontWeight.bold,
                            color: _getStatusColor(latestInvoice.status),
                          ),
                        ),
                      ),
                    ],
                  ),
                ),
                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)),
                            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)),
                          ],
                        ),
                      ),
                    ),
                    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.id == product?.categoryId).firstOrNull;
                  final weight = item.weight ?? item.quantity;
                  final metalAmount = weight * item.unitPrice;

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

                  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 ?? 'Jewellery 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 (item.huid != null)
                                        _buildDetailBadge('HUID: ${item.huid}', Colors.purple),
                                      if (item.hsnCode != null)
                                        _buildDetailBadge('HSN: ${item.hsnCode}', Colors.grey),
                                    ],
                                  ),
                                ],
                              ),
                            ),
                            Text(
                              formatCurrency.format(item.total),
                              style: const TextStyle(fontSize: 16, fontWeight: FontWeight.bold, color: Colors.green),
                            ),
                          ],
                        ),
                        const Divider(height: 18),
                        Row(
                          mainAxisAlignment: MainAxisAlignment.spaceBetween,
                          children: [
                            Text(
                              'Metal (${weight.toStringAsFixed(3)}g @ ₹${item.unitPrice.toStringAsFixed(2)}/g):',
                              style: TextStyle(fontSize: 12, color: Colors.grey.shade600),
                            ),
                            Text(formatCurrency.format(metalAmount), style: const TextStyle(fontWeight: FontWeight.w600, fontSize: 12)),
                          ],
                        ),
                        const SizedBox(height: 4),
                        Row(
                          mainAxisAlignment: MainAxisAlignment.spaceBetween,
                          children: [
                            Text(
                              'Making Charges (${item.makingChargesType == 'PERCENTAGE' ? '${item.makingCharge}%' : (item.makingChargesType == 'PER_PIECE' ? '₹${item.makingCharge}/pc' : '₹${item.makingCharge}/g')}):',
                              style: TextStyle(fontSize: 12, color: Colors.grey.shade600),
                            ),
                            Text(formatCurrency.format(makingChargeAmt), style: const TextStyle(fontWeight: FontWeight.w600, fontSize: 12, color: Colors.indigo)),
                          ],
                        ),
                        if (item.taxRate > 0) ...[
                          const SizedBox(height: 4),
                          Row(
                            mainAxisAlignment: MainAxisAlignment.spaceBetween,
                            children: [
                              Text('GST (${item.taxRate.toStringAsFixed(1)}%):', style: TextStyle(fontSize: 11, color: Colors.grey.shade500)),
                              Text(
                                '+ ${formatCurrency.format(((metalAmount + makingChargeAmt) * (item.taxRate / 100.0)))}',
                                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)),
        ],
      ),
    );
  }

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

      final pdf = pw.Document();

      pdf.addPage(
        pw.MultiPage(
          pageFormat: PdfPageFormat.a4,
          margin: const pw.EdgeInsets.all(28),
          build: (pw.Context context) {
            return [
              // Header with Business Details & TAX INVOICE title
              pw.Row(
                mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                crossAxisAlignment: pw.CrossAxisAlignment.start,
                children: [
                  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)
                        pw.Text(business!.address!, style: const pw.TextStyle(fontSize: 10)),
                      if (business?.contactNumber != null)
                        pw.Text('Phone: ${business!.contactNumber}', style: const pw.TextStyle(fontSize: 10)),
                      if (business?.gstin != null)
                        pw.Text('GSTIN: ${business!.gstin}', style: pw.TextStyle(fontSize: 10, fontWeight: pw.FontWeight.bold, color: PdfColors.blue800)),
                    ],
                  ),
                  pw.Column(
                    crossAxisAlignment: pw.CrossAxisAlignment.end,
                    children: [
                      pw.Text(
                        'TAX INVOICE',
                        style: pw.TextStyle(fontSize: 24, fontWeight: pw.FontWeight.bold, color: PdfColors.blue900),
                      ),
                      pw.SizedBox(height: 4),
                      pw.Text('Invoice #: ${latestInvoice.invoiceNumber}', style: pw.TextStyle(fontSize: 12, fontWeight: pw.FontWeight.bold)),
                      pw.Text('Date: ${formatDate.format(latestInvoice.issueDate)}', style: const pw.TextStyle(fontSize: 10)),
                      if (latestInvoice.dueDate != null)
                        pw.Text('Due Date: ${formatDate.format(latestInvoice.dueDate!)}', style: const pw.TextStyle(fontSize: 10)),
                    ],
                  ),
                ],
              ),
              pw.SizedBox(height: 20),

              // Bill To Box
              pw.Container(
                padding: const pw.EdgeInsets.all(10),
                decoration: pw.BoxDecoration(
                  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: 9, 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) pw.Text('Phone: ${customer!.phone}', style: const pw.TextStyle(fontSize: 9)),
                          if (customer?.address != null) pw.Text('Address: ${customer!.address}', style: const pw.TextStyle(fontSize: 9)),
                          if (customer?.gstin != null) pw.Text('GSTIN: ${customer!.gstin}', style: pw.TextStyle(fontSize: 9, fontWeight: pw.FontWeight.bold)),
                        ],
                      ),
                    ),
                  ],
                ),
              ),
              pw.SizedBox(height: 16),

              // Table of Items with HUID, SKU, Making Charges, etc.
              pw.TableHelper.fromTextArray(
                context: context,
                border: const pw.TableBorder(
                  bottom: pw.BorderSide(color: PdfColors.grey300, width: 0.5),
                  horizontalInside: pw.BorderSide(color: PdfColors.grey300, width: 0.5),
                ),
                headerStyle: pw.TextStyle(fontWeight: pw.FontWeight.bold, color: PdfColors.white, fontSize: 9),
                headerDecoration: const pw.BoxDecoration(color: PdfColors.blue900),
                cellStyle: const pw.TextStyle(fontSize: 8.5),
                cellAlignments: {
                  0: pw.Alignment.centerLeft,
                  1: pw.Alignment.centerLeft,
                  2: pw.Alignment.centerRight,
                  3: pw.Alignment.centerRight,
                  4: pw.Alignment.centerRight,
                  5: pw.Alignment.centerRight,
                  6: pw.Alignment.centerRight,
                },
                headers: ['Item / Particulars', 'HSN / HUID', 'Weight', 'Rate', 'Making Chg', 'GST', 'Total'],
                data: latestInvoice.items.map((item) {
                  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;
                  }

                  String particulars = item.productName ?? item.description ?? 'Item';
                  if (item.sku != null && item.sku!.isNotEmpty) particulars += '\nSKU: ${item.sku}';
                  if (item.categoryName != null) particulars += ' (${item.categoryName})';

                  String hsnHuid = 'HSN: ${item.hsnCode ?? '-'}';
                  if (item.huid != null && item.huid!.isNotEmpty) hsnHuid += '\nHUID: ${item.huid}';

                  return [
                    particulars,
                    hsnHuid,
                    '${weight.toStringAsFixed(3)} g',
                    formatCurrency.format(item.unitPrice),
                    formatCurrency.format(makingAmt),
                    '${item.taxRate.toStringAsFixed(1)}%',
                    formatCurrency.format(item.total),
                  ];
                }).toList(),
              ),
              pw.SizedBox(height: 16),

              // Summary Section
              pw.Row(
                mainAxisAlignment: pw.MainAxisAlignment.end,
                children: [
                  pw.Container(
                    width: 240,
                    child: pw.Column(
                      crossAxisAlignment: pw.CrossAxisAlignment.stretch,
                      children: [
                        pw.Row(
                          mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                          children: [
                            pw.Text('Metal Subtotal:', style: const pw.TextStyle(fontSize: 10)),
                            pw.Text(formatCurrency.format(latestInvoice.subtotal), style: const pw.TextStyle(fontSize: 10)),
                          ],
                        ),
                        if (latestInvoice.cgstTotal > 0 && latestInvoice.sgstTotal > 0) ...[
                          pw.SizedBox(height: 2),
                          pw.Row(
                            mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                            children: [
                              pw.Text('CGST:', style: const pw.TextStyle(fontSize: 9)),
                              pw.Text(formatCurrency.format(latestInvoice.cgstTotal), style: const pw.TextStyle(fontSize: 9)),
                            ],
                          ),
                          pw.Row(
                            mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                            children: [
                              pw.Text('SGST:', style: const pw.TextStyle(fontSize: 9)),
                              pw.Text(formatCurrency.format(latestInvoice.sgstTotal), style: const pw.TextStyle(fontSize: 9)),
                            ],
                          ),
                        ] else if (latestInvoice.igstTotal > 0) ...[
                          pw.SizedBox(height: 2),
                          pw.Row(
                            mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                            children: [
                              pw.Text('IGST:', style: const pw.TextStyle(fontSize: 9)),
                              pw.Text(formatCurrency.format(latestInvoice.igstTotal), style: const pw.TextStyle(fontSize: 9)),
                            ],
                          ),
                        ],
                        if (latestInvoice.discountTotal > 0) ...[
                          pw.SizedBox(height: 2),
                          pw.Row(
                            mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                            children: [
                              pw.Text('Discount:', style: const pw.TextStyle(fontSize: 9, color: PdfColors.green700)),
                              pw.Text('-${formatCurrency.format(latestInvoice.discountTotal)}', style: const pw.TextStyle(fontSize: 9, color: PdfColors.green700)),
                            ],
                          ),
                        ],
                        pw.Divider(color: PdfColors.grey400, height: 10),
                        pw.Row(
                          mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                          children: [
                            pw.Text('Grand Total:', style: pw.TextStyle(fontWeight: pw.FontWeight.bold, fontSize: 13)),
                            pw.Text(formatCurrency.format(latestInvoice.totalAmount), style: pw.TextStyle(fontWeight: pw.FontWeight.bold, fontSize: 13)),
                          ],
                        ),
                        pw.SizedBox(height: 4),
                        pw.Row(
                          mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                          children: [
                            pw.Text('Amount Received:', style: const pw.TextStyle(fontSize: 10, color: PdfColors.green800)),
                            pw.Text(formatCurrency.format(latestInvoice.amountPaid), style: const pw.TextStyle(fontSize: 10, color: PdfColors.green800)),
                          ],
                        ),
                        pw.Row(
                          mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                          children: [
                            pw.Text('Balance Due:', style: pw.TextStyle(fontWeight: pw.FontWeight.bold, fontSize: 11, color: PdfColors.red800)),
                            pw.Text(formatCurrency.format(latestInvoice.totalAmount - latestInvoice.amountPaid), style: pw.TextStyle(fontWeight: pw.FontWeight.bold, fontSize: 11, color: PdfColors.red800)),
                          ],
                        ),
                      ],
                    ),
                  ),
                ],
              ),
              pw.SizedBox(height: 30),

              // Terms & Signatory
              pw.Divider(color: PdfColors.grey300),
              pw.Row(
                mainAxisAlignment: pw.MainAxisAlignment.spaceBetween,
                crossAxisAlignment: pw.CrossAxisAlignment.end,
                children: [
                  pw.Column(
                    crossAxisAlignment: pw.CrossAxisAlignment.start,
                    children: [
                      pw.Text('Terms & Conditions:', style: pw.TextStyle(fontWeight: pw.FontWeight.bold, fontSize: 8)),
                      pw.Text('1. Goods once sold are subject to standard hallmarking certification.', style: const pw.TextStyle(fontSize: 7, color: PdfColors.grey700)),
                      pw.Text('2. Weight & purity tested under industry standard electronic balance.', style: const pw.TextStyle(fontSize: 7, color: PdfColors.grey700)),
                    ],
                  ),
                  pw.Column(
                    crossAxisAlignment: pw.CrossAxisAlignment.center,
                    children: [
                      pw.Text('For ${business?.businessName ?? "KIFI JEWELLERS"}', style: pw.TextStyle(fontWeight: pw.FontWeight.bold, fontSize: 9)),
                      pw.SizedBox(height: 24),
                      pw.Text('Authorized Signatory', style: const pw.TextStyle(fontSize: 8, color: PdfColors.grey700)),
                    ],
                  ),
                ],
              ),
            ];
          },
        ),
      );

      final directory = await getTemporaryDirectory();
      final pdfPath = await File('${directory.path}/TaxInvoice_$invoiceNumber.pdf').create();
      await pdfPath.writeAsBytes(await pdf.save());

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