<?php
include '../config.php';
include 'auth.php';

// Check if ID is set
if (!isset($_GET['id']) || empty($_GET['id'])) {
    $_SESSION['error_message'] = 'ไม่พบรหัสใบกำกับภาษีที่ต้องการลบ';
    header("Location: invoice-list.php");
    exit;
}

$id = mysqli_real_escape_string($conn, $_GET['id']);

// Check if invoice exists
$check_query = "SELECT * FROM invoices WHERE id = $id";
$check_result = mysqli_query($conn, $check_query);

if (mysqli_num_rows($check_result) == 0) {
    $_SESSION['error_message'] = 'ไม่พบข้อมูลใบกำกับภาษี';
    header("Location: invoice-list.php");
    exit;
}

// Begin transaction
mysqli_begin_transaction($conn);

try {
    // Delete invoice details
    mysqli_query($conn, "DELETE FROM invoice_details WHERE invoice_id = $id");
    
    // Delete invoice
    mysqli_query($conn, "DELETE FROM invoices WHERE id = $id");
    
    // Commit transaction
    mysqli_commit($conn);
    
    $_SESSION['success_message'] = 'ลบข้อมูลใบกำกับภาษีเรียบร้อยแล้ว';
} catch (Exception $e) {
    // Rollback transaction on error
    mysqli_rollback($conn);
    $_SESSION['error_message'] = 'เกิดข้อผิดพลาด: ' . $e->getMessage();
}

header("Location: invoice-list.php");
exit;
?>