<?php
require_once 'config.php';
if (file_exists('vendor/autoload.php')) {
    require 'vendor/autoload.php';
} else {
    die('ไม่พบ Library PhpSpreadsheet');
}

use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;

checkLogin();

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['export_data'])) {
    $data = json_decode($_POST['export_data'], true);
    
    if (json_last_error() !== JSON_ERROR_NONE || !is_array($data)) {
        die("Invalid data format for export.");
    }
    
    $spreadsheet = new Spreadsheet();
    $sheet = $spreadsheet->getActiveSheet();
    
    // Write headers dynamically based on data keys
    $colIndex = 1; // 1 = A
    $firstRow = $data[0];
    foreach ($firstRow as $key => $value) {
        $cellCoordinate = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::stringFromColumnIndex($colIndex) . '1';
        $sheet->setCellValue($cellCoordinate, strtoupper($key));
        $sheet->getStyle($cellCoordinate)->getFont()->setBold(true);
        $colIndex++;
    }
    
    // Write data rows
    $rowNum = 2;
    foreach ($data as $row) {
        $colIndex = 1;
        foreach ($row as $key => $value) {
            $cellCoordinate = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::stringFromColumnIndex($colIndex) . $rowNum;
            $sheet->setCellValueExplicit($cellCoordinate, $value, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING);
            $colIndex++;
        }
        $rowNum++;
    }
    
    // Auto-size columns
    $maxCol = count($firstRow);
    for ($i = 1; $i <= $maxCol; $i++) {
        $colStr = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::stringFromColumnIndex($i);
        $sheet->getColumnDimension($colStr)->setAutoSize(true);
    }
    
    // Output file
    $fileName = 'HOSxP_Export_' . date('Ymd_His') . '.xlsx';
    if (!empty($_POST['original_filename'])) {
        $original = $_POST['original_filename'];
        $info = pathinfo($original);
        $basename = $info['filename'];
        $fileName = $basename . '_ตรวจสอบแล้ว.xlsx';
    }
    
    header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
    header('Content-Disposition: attachment;filename="' . $fileName . '"');
    header('Cache-Control: max-age=0');
    
    $writer = new Xlsx($spreadsheet);
    $writer->save('php://output');
    exit;
} else {
    die("No data to export.");
}