<?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

// Process each invoice
$sheetIndex = 0;

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();

    // Create sheet (reuse first sheet for first invoice)
    if ($sheetIndex === 0) {
        $sheet = $spreadsheet->getActiveSheet();
    } else {
        $sheet = $spreadsheet->createSheet();
    }

    $invoiceNum = $inv['invoice_number'] ?? ('INV-' . ($sheetIndex + 1));
    $sheetTitle = mb_substr(preg_replace('/[^a-zA-Z0-9\x{0600}-\x{06FF}\s\-]/u', '', $invoiceNum), 0, 31) ?: ('فاتورة ' . ($sheetIndex + 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)

    $row = 1;

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

    // Invoice meta data (2 columns layout)
    $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) {
        $sheet->setCellValue("A{$row}", $meta[0]);
        $sheet->mergeCells("B{$row}:C{$row}");
        $sheet->setCellValue("B{$row}", $meta[1]);
        $sheet->setCellValue("E{$row}", $meta[2]);
        $sheet->mergeCells("F{$row}:I{$row}");
        $sheet->setCellValue("F{$row}", $meta[3]);

        // Style labels
        $sheet->getStyle("A{$row}")->applyFromArray([
            'font' => ['bold' => true, 'size' => 11, 'color' => new Color($subHeaderFont)],
            'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => new Color($subHeaderBg)],
        ]);
        $sheet->getStyle("E{$row}")->applyFromArray([
            'font' => ['bold' => true, 'size' => 11, 'color' => new Color($subHeaderFont)],
            'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => new Color($subHeaderBg)],
        ]);
        $sheet->getRowDimension($row)->setRowHeight(24);
        $row++;
    }
    $row++; // Empty spacer row

    // ── LINE ITEMS TABLE HEADER ─────────────────
    $headers = ['#', 'وصف البند', 'الكمية', 'سعر الوحدة', 'المجموع الجزئي', 'نسبة الضريبة', 'قيمة الضريبة', 'قيمة الخصم', 'الصافي'];
    $cols = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I'];
    $headerRow = $row;

    foreach ($headers as $i => $header) {
        $sheet->setCellValue($cols[$i] . $row, $header);
    }

    $sheet->getStyle("A{$row}:I{$row}")->applyFromArray([
        'font' => ['bold' => true, 'size' => 12, 'color' => new Color($headerFont)],
        'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => new Color($headerBg)],
        'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER, 'vertical' => Alignment::VERTICAL_CENTER],
        'borders' => [
            'allBorders' => ['borderStyle' => Border::BORDER_THIN, 'color' => new Color($headerBg)],
        ],
    ]);
    $sheet->getRowDimension($row)->setRowHeight(32);
    $row++;

    // ── LINE ITEMS WITH FORMULAS ────────────────
    $firstDataRow = $row;

    if (!empty($lines)) {
        foreach ($lines as $lineIdx => $line) {
            $lineNum = $lineIdx + 1;
            $quantity = is_numeric($line['quantity'] ?? null) ? (float)$line['quantity'] : 1;
            $unitPrice = is_numeric($line['unit_price'] ?? null) ? (float)$line['unit_price'] : 0;
            $taxRate = is_numeric($line['tax_rate'] ?? null) ? (float)$line['tax_rate'] : 0.16;
            $discount = is_numeric($line['discount_amount'] ?? null) ? (float)$line['discount_amount'] : 0;

            // A: Line number
            $sheet->setCellValue("A{$row}", $lineNum);

            // B: Description
            $sheet->setCellValue("B{$row}", $line['description'] ?? 'بدون وصف');

            // C: Quantity (value)
            $sheet->setCellValue("C{$row}", $quantity);

            // D: Unit Price (value)
            $sheet->setCellValue("D{$row}", $unitPrice);

            // E: Subtotal = Quantity × Unit Price (FORMULA)
            $sheet->setCellValue("E{$row}", "=C{$row}*D{$row}");

            // F: Tax Rate (as percentage)
            $sheet->setCellValue("F{$row}", $taxRate);
            $sheet->getStyle("F{$row}")->getNumberFormat()->setFormatCode('0%');

            // G: Tax Amount = Subtotal × Tax Rate (FORMULA)
            $sheet->setCellValue("G{$row}", "=E{$row}*F{$row}");

            // H: Discount amount (value)
            $sheet->setCellValue("H{$row}", $discount);

            // I: Net Total = Subtotal + Tax - Discount (FORMULA)
            $sheet->setCellValue("I{$row}", "=E{$row}+G{$row}-H{$row}");

            // Alternating row colors
            if ($lineIdx % 2 === 1) {
                $sheet->getStyle("A{$row}:I{$row}")->applyFromArray([
                    'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => new Color($altRowBg)],
                ]);
            }

            // Number formatting for currency columns
            foreach (['D', 'E', 'G', 'H', 'I'] as $col) {
                $sheet->getStyle("{$col}{$row}")->getNumberFormat()->setFormatCode('#,##0.000');
            }
            $sheet->getStyle("C{$row}")->getNumberFormat()->setFormatCode('#,##0');

            // Center align numbers
            $sheet->getStyle("A{$row}:I{$row}")->getAlignment()->setHorizontal(Alignment::HORIZONTAL_CENTER);
            $sheet->getStyle("B{$row}")->getAlignment()->setHorizontal(Alignment::HORIZONTAL_RIGHT);

            $sheet->getRowDimension($row)->setRowHeight(26);
            $row++;
        }
    } else {
        // If no line items, create a single row from invoice totals
        $sheet->setCellValue("A{$row}", 1);
        $sheet->setCellValue("B{$row}", 'إجمالي الفاتورة (بدون تفاصيل بنود)');
        $sheet->setCellValue("C{$row}", 1);
        $sheet->setCellValue("D{$row}", (float)($inv['subtotal'] ?? 0));
        $sheet->setCellValue("E{$row}", "=C{$row}*D{$row}");
        $sheet->setCellValue("F{$row}", 0.16);
        $sheet->getStyle("F{$row}")->getNumberFormat()->setFormatCode('0%');
        $sheet->setCellValue("G{$row}", "=E{$row}*F{$row}");
        $sheet->setCellValue("H{$row}", (float)($inv['discount_total'] ?? 0));
        $sheet->setCellValue("I{$row}", "=E{$row}+G{$row}-H{$row}");

        foreach (['D', 'E', 'G', 'H', 'I'] as $col) {
            $sheet->getStyle("{$col}{$row}")->getNumberFormat()->setFormatCode('#,##0.000');
        }
        $sheet->getStyle("A{$row}:I{$row}")->getAlignment()->setHorizontal(Alignment::HORIZONTAL_CENTER);
        $sheet->getRowDimension($row)->setRowHeight(26);
        $row++;
    }

    $lastDataRow = $row - 1;

    // ── DATA AREA BORDERS ──
    $sheet->getStyle("A{$headerRow}:I{$lastDataRow}")->applyFromArray([
        'borders' => [
            'allBorders' => ['borderStyle' => Border::BORDER_THIN, 'color' => new Color($borderColor)],
        ],
    ]);

    // ── TOTALS ROW WITH SUM FORMULAS ────────────
    $sheet->mergeCells("A{$row}:B{$row}");
    $sheet->setCellValue("A{$row}", 'المجموع الكلي');

    // C: Sum of quantities
    $sheet->setCellValue("C{$row}", "=SUM(C{$firstDataRow}:C{$lastDataRow})");

    // D: (empty — unit price sum doesn't make sense)
    $sheet->setCellValue("D{$row}", '');

    // E: Sum of subtotals
    $sheet->setCellValue("E{$row}", "=SUM(E{$firstDataRow}:E{$lastDataRow})");

    // F: (empty — average tax rate doesn't belong here)
    $sheet->setCellValue("F{$row}", '');

    // G: Sum of tax amounts
    $sheet->setCellValue("G{$row}", "=SUM(G{$firstDataRow}:G{$lastDataRow})");

    // H: Sum of discounts
    $sheet->setCellValue("H{$row}", "=SUM(H{$firstDataRow}:H{$lastDataRow})");

    // I: Sum of net totals
    $sheet->setCellValue("I{$row}", "=SUM(I{$firstDataRow}:I{$lastDataRow})");

    // Style totals row
    $sheet->getStyle("A{$row}:I{$row}")->applyFromArray([
        'font' => ['bold' => true, 'size' => 13, 'color' => new Color($totalFont)],
        'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => new Color($totalBg)],
        'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER, 'vertical' => Alignment::VERTICAL_CENTER],
        'borders' => [
            'allBorders' => ['borderStyle' => Border::BORDER_MEDIUM, 'color' => new Color('059669')],
        ],
    ]);
    $sheet->getStyle("A{$row}")->getAlignment()->setHorizontal(Alignment::HORIZONTAL_CENTER);
    foreach (['C', 'E', 'G', 'H', 'I'] as $col) {
        $sheet->getStyle("{$col}{$row}")->getNumberFormat()->setFormatCode('#,##0.000');
    }
    $sheet->getRowDimension($row)->setRowHeight(36);

    $row += 2;

    // ── FOOTER ──
    $sheet->mergeCells("A{$row}:I{$row}");
    $sheet->setCellValue("A{$row}", 'تم إنشاء هذا التقرير تلقائياً من منصة مُصادَق — ' . date('Y-m-d H:i'));
    $sheet->getStyle("A{$row}")->applyFromArray([
        'font' => ['italic' => true, 'size' => 9, 'color' => new Color('8B82B0')],
        'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER],
    ]);

    // ── Print settings ──
    $sheet->getPageSetup()->setOrientation(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE);
    $sheet->getPageSetup()->setFitToWidth(1);

    $sheetIndex++;
}

// 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());
}