<?php
/**
 * Export Invoices as Professional Excel (.xlsx) with Formulas
 * GET /v1/invoices/export-excel
 * 
 * Generates a real .xlsx file with:
 * - Invoice header info + line items
 * - Excel formulas for subtotals, tax, discount, net
 * - SUM row at the bottom
 * - Professional formatting (colors, borders, Arabic RTL)
 */

use App\Core\Database;
use App\Core\Encryption;
use App\Middleware\AuthMiddleware;
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
use PhpOffice\PhpSpreadsheet\Style\Alignment;
use PhpOffice\PhpSpreadsheet\Style\Border;
use PhpOffice\PhpSpreadsheet\Style\Fill;
use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
use PhpOffice\PhpSpreadsheet\Style\Color;

// Enable error reporting for debugging
ini_set('display_errors', '1');
error_reporting(E_ALL);

// Autoload PhpSpreadsheet
require_once ROOT_PATH . '/vendor/autoload.php';

try {

// Auth: Support both Bearer header and ?token= query param (for download links)
$token = $_GET['token'] ?? null;
if (!$token) {
    $headers = getallheaders();
    $authHeader = $headers['Authorization'] ?? $headers['authorization'] ?? '';
    if (preg_match('/Bearer\s(\S+)/', $authHeader, $matches)) {
        $token = $matches[1];
    }
}
if (!$token) json_error('غير مصرح: لا يوجد رمز دخول', 401);

$decoded = \App\Core\JWT::decode($token, env('JWT_SECRET', ''));
if (!$decoded) json_error('غير مصرح: رمز دخول غير صالح', 401);

$db = Database::getInstance();

$tenantId = $decoded['tenant_id'];
$role = $decoded['role'];
$companyId = $_GET['company_id'] ?? null;
$dateFrom = $_GET['date_from'] ?? null;
$dateTo = $_GET['date_to'] ?? null;
$status = $_GET['status'] ?? null;
$invoiceId = $_GET['invoice_id'] ?? null; // Single invoice export

// Build query with filters
$where = [];
$params = [];

if ($role !== 'super_admin') {
    $where[] = 'i.tenant_id = ?';
    $params[] = $tenantId;
}

if ($invoiceId) {
    $where[] = 'i.id = ?';
    $params[] = $invoiceId;
}

if ($companyId) {
    $where[] = 'i.company_id = ?';
    $params[] = $companyId;
}

if ($dateFrom) {
    $where[] = 'i.invoice_date >= ?';
    $params[] = $dateFrom;
}

if ($dateTo) {
    $where[] = 'i.invoice_date <= ?';
    $params[] = $dateTo;
}

if ($status) {
    $where[] = 'i.status = ?';
    $params[] = $status;
}

$whereClause = $where ? 'WHERE ' . implode(' AND ', $where) : '';

$stmt = $db->prepare("
    SELECT i.*, c.name as company_name_raw
    FROM invoices i
    JOIN companies c ON i.company_id = c.id
    $whereClause
    ORDER BY i.invoice_date DESC
    LIMIT 5000
");
$stmt->execute($params);
$invoices = $stmt->fetchAll();

if (empty($invoices)) {
    json_error('لا توجد فواتير لتصديرها', 404);
}

// Decrypt helper
$dec = function($val) {
    if (empty($val)) return '';
    $result = Encryption::decrypt((string)$val);
    return ($result !== false && $result !== null) ? $result : (string)$val;
};

// ══════════════════════════════════════════
// BUILD SPREADSHEET
// ══════════════════════════════════════════

$spreadsheet = new Spreadsheet();
$spreadsheet->getProperties()
    ->setCreator('مُصادَق - Musadaq')
    ->setTitle('تقرير الفواتير')
    ->setDescription('تقرير فواتير المشتريات - تم إنشاؤه تلقائياً من منصة مُصادَق');

// === COLORS ===
$headerBg = '1C1550';       // Deep violet
$headerFont = 'FFFFFF';     // White
$subHeaderBg = 'EDE9FE';    // Light violet
$subHeaderFont = '5B21B6';  // Violet
$totalBg = 'D1FAE5';        // Light green
$totalFont = '065F46';      // Dark green
$borderColor = 'E2E1F0';    // Light border
$altRowBg = 'F8F7FD';       // Alternating row

// ══════════════════════════════════════════
// 1. SUMMARY SHEET (First Sheet)
// ══════════════════════════════════════════

$summarySheet = $spreadsheet->getActiveSheet();
$summarySheet->setTitle('الملخص الإجمالي');
$summarySheet->setRightToLeft(true);

// --- SUMMARY HEADER ---
$summarySheet->mergeCells("A1:J1");
$summarySheet->setCellValue("A1", 'مُـصَـادَق — ملخص الفواتير الإجمالي');
$summarySheet->getStyle("A1")->applyFromArray([
    'font' => ['bold' => true, 'size' => 16, 'color' => ['argb' => 'FF' . $headerFont]],
    'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['argb' => 'FF' . $headerBg]],
    'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER, 'vertical' => Alignment::VERTICAL_CENTER],
]);
$summarySheet->getRowDimension(1)->setRowHeight(40);

// Summary Meta Info
$companyNameFilter = 'جميع الشركات';
if ($companyId) {
    $cStmt = $db->prepare("SELECT name FROM companies WHERE id = ?");
    $cStmt->execute([$companyId]);
    $cName = $cStmt->fetchColumn();
    if ($cName) $companyNameFilter = $dec($cName);
}

$summarySheet->setCellValue("A3", 'الشركة:');
$summarySheet->setCellValue("B3", $companyNameFilter);
$summarySheet->setCellValue("D3", 'الفترة:');
$summarySheet->setCellValue("E3", ($dateFrom ?? '—') . ' إلى ' . ($dateTo ?? '—'));
$summarySheet->setCellValue("G3", 'عدد الفواتير:');
$summarySheet->setCellValue("H3", count($invoices));

$summarySheet->getStyle("A3:H3")->getFont()->setBold(true);

// --- SUMMARY TABLE HEADERS ---
$row = 5;
$summaryHeaders = ['#', 'رقم الفاتورة', 'المورّد', 'وصف البند', 'الكمية', 'سعر الوحدة', 'المجموع الجزئي', 'نسبة الضريبة', 'قيمة الضريبة', 'الصافي'];
$sumCols = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J'];

foreach ($summaryHeaders as $i => $h) {
    $summarySheet->setCellValue($sumCols[$i] . $row, $h);
}

$summarySheet->getStyle("A{$row}:J{$row}")->applyFromArray([
    'font' => ['bold' => true, 'color' => ['argb' => 'FF' . $headerFont]],
    'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['argb' => 'FF' . $headerBg]],
    'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER],
]);

// Summary column widths
$summarySheet->getColumnDimension('B')->setWidth(18);
$summarySheet->getColumnDimension('C')->setWidth(25);
$summarySheet->getColumnDimension('D')->setWidth(35);
$summarySheet->getColumnDimension('G')->setWidth(14);
$summarySheet->getColumnDimension('I')->setWidth(14);
$summarySheet->getColumnDimension('J')->setWidth(16);

$row++;
$summaryStartRow = $row;
$globalLineCount = 0;

// ══════════════════════════════════════════
// 2. INDIVIDUAL INVOICE SHEETS + POPULATE SUMMARY
// ══════════════════════════════════════════

foreach ($invoices as $invIdx => $inv) {
    // Fetch line items for this invoice
    $stmtLines = $db->prepare("SELECT * FROM invoice_lines WHERE invoice_id = ? ORDER BY line_number ASC");
    $stmtLines->execute([$inv['id']]);
    $lines = $stmtLines->fetchAll();

    // --- Add to Summary Sheet ---
    if (!empty($lines)) {
        foreach ($lines as $line) {
            $globalLineCount++;
            $summarySheet->setCellValue("A{$row}", $globalLineCount);
            $summarySheet->setCellValue("B{$row}", $inv['invoice_number'] ?? '-');
            $summarySheet->setCellValue("C{$row}", $dec($inv['supplier_name']));
            $summarySheet->setCellValue("D{$row}", $line['description'] ?? 'بدون وصف');
            $summarySheet->setCellValue("E{$row}", (float)$line['quantity']);
            $summarySheet->setCellValue("F{$row}", (float)$line['unit_price']);
            $summarySheet->setCellValue("G{$row}", "=E{$row}*F{$row}");
            $summarySheet->setCellValue("H{$row}", (float)$line['tax_rate']);
            $summarySheet->setCellValue("I{$row}", "=G{$row}*H{$row}");
            $summarySheet->setCellValue("J{$row}", "=G{$row}+I{$row}");
            
            if ($globalLineCount % 2 === 0) {
                $summarySheet->getStyle("A{$row}:J{$row}")->getFill()->setFillType(Fill::FILL_SOLID)->getStartColor()->setARGB('FFF8F7FD');
            }
            $row++;
        }
    } else {
        // Fallback if no line items
        $globalLineCount++;
        $summarySheet->setCellValue("A{$row}", $globalLineCount);
        $summarySheet->setCellValue("B{$row}", $inv['invoice_number'] ?? '-');
        $summarySheet->setCellValue("C{$row}", $dec($inv['supplier_name']));
        $summarySheet->setCellValue("D{$row}", 'إجمالي الفاتورة');
        $summarySheet->setCellValue("E{$row}", 1);
        $summarySheet->setCellValue("F{$row}", (float)$inv['subtotal']);
        $summarySheet->setCellValue("G{$row}", "=E{$row}*F{$row}");
        $summarySheet->setCellValue("H{$row}", 0.16);
        $summarySheet->setCellValue("I{$row}", "=G{$row}*H{$row}");
        $summarySheet->setCellValue("J{$row}", "=G{$row}+I{$row}");
        $row++;
    }

    // --- Create Individual Sheet ---
    $sheet = $spreadsheet->createSheet();
    $invoiceNum = $inv['invoice_number'] ?? ('INV-' . ($invIdx + 1));
    $sheetTitle = mb_substr(preg_replace('/[^a-zA-Z0-9\x{0600}-\x{06FF}\s\-]/u', '', $invoiceNum), 0, 31) ?: ('فاتورة ' . ($invIdx + 1));
    $sheet->setTitle($sheetTitle);
    $sheet->setRightToLeft(true);

    // ── Column widths ──
    $sheet->getColumnDimension('A')->setWidth(6);   // #
    $sheet->getColumnDimension('B')->setWidth(38);  // Description
    $sheet->getColumnDimension('C')->setWidth(12);  // Quantity
    $sheet->getColumnDimension('D')->setWidth(14);  // Unit Price
    $sheet->getColumnDimension('E')->setWidth(16);  // Subtotal (formula)
    $sheet->getColumnDimension('F')->setWidth(14);  // Tax Rate
    $sheet->getColumnDimension('G')->setWidth(16);  // Tax Amount (formula)
    $sheet->getColumnDimension('H')->setWidth(14);  // Discount
    $sheet->getColumnDimension('I')->setWidth(18);  // Net Total (formula)

    $invRow = 1;

    // ── INVOICE HEADER ──────────────────────────
    $sheet->mergeCells("A{$invRow}:I{$invRow}");
    $sheet->setCellValue("A{$invRow}", 'مُـصَـادَق — تقرير فاتورة مشتريات');
    $sheet->getStyle("A{$invRow}")->applyFromArray([
        'font' => ['bold' => true, 'size' => 16, 'color' => ['argb' => 'FF' . $headerFont]],
        'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['argb' => 'FF' . $headerBg]],
        'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER, 'vertical' => Alignment::VERTICAL_CENTER],
    ]);
    $sheet->getRowDimension($invRow)->setRowHeight(40);
    $invRow++;

    // Invoice meta data
    $metaData = [
        ['رقم الفاتورة', $inv['invoice_number'] ?? '-', 'اسم المورّد', $dec($inv['supplier_name'])],
        ['تاريخ الفاتورة', $inv['invoice_date'] ?? '-', 'الرقم الضريبي للمورّد', $dec($inv['supplier_tin'])],
        ['الشركة', $dec($inv['company_name_raw'] ?? ''), 'العملة', $inv['currency_code'] ?? 'JOD'],
        ['نوع الفاتورة', ($inv['invoice_type'] === 'cash' ? 'نقدي' : 'آجل'), 'الحالة', match($inv['status']) {
            'extracted' => 'مستخرجة',
            'approved' => 'معتمدة',
            'submitted' => 'مقدمة لجوفتورة',
            'rejected' => 'مرفوضة',
            default => $inv['status']
        }],
    ];

    foreach ($metaData as $meta) {
        $sheet->setCellValue("A{$invRow}", $meta[0]);
        $sheet->mergeCells("B{$invRow}:C{$invRow}");
        $sheet->setCellValue("B{$invRow}", $meta[1]);
        $sheet->setCellValue("E{$invRow}", $meta[2]);
        $sheet->mergeCells("F{$invRow}:I{$invRow}");
        $sheet->setCellValue("F{$invRow}", $meta[3]);

        $sheet->getStyle("A{$invRow}:C{$invRow}")->applyFromArray([
            'font' => ['bold' => true, 'size' => 11, 'color' => ['argb' => 'FF' . $subHeaderFont]],
            'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['argb' => 'FF' . $subHeaderBg]],
        ]);
        $sheet->getStyle("E{$invRow}")->applyFromArray([
            'font' => ['bold' => true, 'size' => 11, 'color' => ['argb' => 'FF' . $subHeaderFont]],
            'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['argb' => 'FF' . $subHeaderBg]],
        ]);
        $sheet->getRowDimension($invRow)->setRowHeight(24);
        $invRow++;
    }
    $invRow++; 

    // Items Header
    $headers = ['#', 'وصف البند', 'الكمية', 'سعر الوحدة', 'المجموع الجزئي', 'نسبة الضريبة', 'قيمة الضريبة', 'الخصم', 'الصافي'];
    $cols = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I'];
    foreach ($headers as $i => $h) $sheet->setCellValue($cols[$i] . $invRow, $h);

    $sheet->getStyle("A{$invRow}:I{$invRow}")->applyFromArray([
        'font' => ['bold' => true, 'color' => ['argb' => 'FF' . $headerFont]],
        'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['argb' => 'FF' . $headerBg]],
        'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER],
    ]);
    $sheet->getRowDimension($invRow)->setRowHeight(32);
    $invRow++;
    $itemsStart = $invRow;

    if (!empty($lines)) {
        foreach ($lines as $lIdx => $line) {
            $sheet->setCellValue("A{$invRow}", $lIdx + 1);
            $sheet->setCellValue("B{$invRow}", $line['description'] ?? 'بدون وصف');
            $sheet->setCellValue("C{$invRow}", (float)$line['quantity']);
            $sheet->setCellValue("D{$invRow}", (float)$line['unit_price']);
            $sheet->setCellValue("E{$invRow}", "=C{$invRow}*D{$invRow}");
            $sheet->setCellValue("F{$invRow}", (float)$line['tax_rate']);
            $sheet->getStyle("F{$invRow}")->getNumberFormat()->setFormatCode('0%');
            $sheet->setCellValue("G{$invRow}", "=E{$invRow}*F{$invRow}");
            $sheet->setCellValue("H{$invRow}", (float)$line['discount_amount']);
            $sheet->setCellValue("I{$invRow}", "=E{$invRow}+G{$invRow}-H{$invRow}");
            if ($lIdx % 2 === 1) $sheet->getStyle("A{$invRow}:I{$invRow}")->getFill()->setFillType(Fill::FILL_SOLID)->getStartColor()->setARGB('FFF8F7FD');
            foreach (['D','E','G','H','I'] as $c) $sheet->getStyle("{$c}{$invRow}")->getNumberFormat()->setFormatCode('#,##0.000');
            $invRow++;
        }
    } else {
        $sheet->setCellValue("A{$invRow}", 1);
        $sheet->setCellValue("B{$invRow}", 'إجمالي الفاتورة');
        $sheet->setCellValue("C{$invRow}", 1);
        $sheet->setCellValue("D{$invRow}", (float)$inv['subtotal']);
        $sheet->setCellValue("E{$invRow}", "=C{$invRow}*D{$invRow}");
        $sheet->setCellValue("F{$invRow}", 0.16);
        $sheet->getStyle("F{$invRow}")->getNumberFormat()->setFormatCode('0%');
        $sheet->setCellValue("G{$invRow}", "=E{$invRow}*F{$invRow}");
        $sheet->setCellValue("H{$invRow}", (float)$inv['discount_total']);
        $sheet->setCellValue("I{$invRow}", "=E{$invRow}+G{$invRow}-H{$invRow}");
        foreach (['D','E','G','H','I'] as $c) $sheet->getStyle("{$c}{$invRow}")->getNumberFormat()->setFormatCode('#,##0.000');
        $invRow++;
    }

    // Totals row for individual sheet
    $lastItemRow = $invRow - 1;
    $sheet->mergeCells("A{$invRow}:B{$invRow}");
    $sheet->setCellValue("A{$invRow}", 'المجموع الكلي');
    $sheet->setCellValue("C{$invRow}", "=SUM(C{$itemsStart}:C{$lastItemRow})");
    $sheet->setCellValue("E{$invRow}", "=SUM(E{$itemsStart}:E{$lastItemRow})");
    $sheet->setCellValue("G{$invRow}", "=SUM(G{$itemsStart}:G{$lastItemRow})");
    $sheet->setCellValue("H{$invRow}", "=SUM(H{$itemsStart}:H{$lastItemRow})");
    $sheet->setCellValue("I{$invRow}", "=SUM(I{$itemsStart}:I{$lastItemRow})");
    $sheet->getStyle("G{$invRow}:I{$invRow}")->applyFromArray([
        'font' => ['bold' => true, 'color' => ['argb' => 'FF' . $totalFont]],
        'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['argb' => 'FF' . $totalBg]],
    ]);
    foreach (['C','E','G','H','I'] as $c) $sheet->getStyle("{$c}{$invRow}")->getNumberFormat()->setFormatCode('#,##0.000');
    $invRow += 2;
    $sheet->setCellValue("A{$invRow}", 'تم إنشاء هذا التقرير تلقائياً من منصة مُصادَق — ' . date('Y-m-d H:i'));
}

// Final Summary Row with totals
$lastSummaryRow = $row - 1;
$summarySheet->mergeCells("A{$row}:D{$row}");
$summarySheet->setCellValue("A{$row}", 'المجموع الكلي النهائي');
$summarySheet->setCellValue("G{$row}", "=SUM(G{$summaryStartRow}:G{$lastSummaryRow})");
$summarySheet->setCellValue("I{$row}", "=SUM(I{$summaryStartRow}:I{$lastSummaryRow})");
$summarySheet->setCellValue("J{$row}", "=SUM(J{$summaryStartRow}:J{$lastSummaryRow})");

$summarySheet->getStyle("A{$row}:J{$row}")->applyFromArray([
    'font' => ['bold' => true, 'size' => 13, 'color' => ['argb' => 'FF' . $totalFont]],
    'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['argb' => 'FF' . $totalBg]],
    'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER],
]);

foreach (['F', 'G', 'I', 'J'] as $c) {
    $summarySheet->getStyle("{$c}{$summaryStartRow}:{$c}{$row}")->getNumberFormat()->setFormatCode('#,##0.000');
}
$summarySheet->getStyle("H{$summaryStartRow}:H{$row}")->getNumberFormat()->setFormatCode('0%');

// Set first sheet as active
$spreadsheet->setActiveSheetIndex(0);

// ══════════════════════════════════════════
// SEND FILE
// ══════════════════════════════════════════

$filename = 'musadaq_invoices_' . date('Y-m-d_His') . '.xlsx';

header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
header('Content-Disposition: attachment; filename="' . $filename . '"');
header('Cache-Control: max-age=0');
header('Pragma: public');

$writer = new Xlsx($spreadsheet);
$writer->save('php://output');
$spreadsheet->disconnectWorksheets();
unset($spreadsheet);
exit;

} catch (\Exception $e) {
    if (ob_get_length()) ob_end_clean();
    header('Content-Type: text/plain; charset=utf-8');
    file_put_contents(STORAGE_PATH . '/logs/export_errors.log', "[" . date('Y-m-d H:i:s') . "] " . $e->getMessage() . "\n" . $e->getTraceAsString(), FILE_APPEND);
    die("خطأ في التصدير: " . $e->getMessage());
}