<?php
include_once __DIR__ . '/../config.php';
include_once __DIR__ . '/../functions.php';
include_once __DIR__ . '/../includes/auth_check.php';
// requireRole(['admin', 'supply_manager']);

$message = '';
$message_type = 'danger';
$supply_id = 0; // Initialize

// --- Define Upload Directory ---
// Assumes 'uploads/supplies/' exists in the root directory
$upload_dir = __DIR__ . '/../uploads/supplies/';
$upload_url_base = BASE_URL . '/uploads/supplies/'; // For constructing URLs

if ($_SERVER["REQUEST_METHOD"] == "POST" && isset($_POST['supply_id'])) {
    $supply_id = intval($_POST['supply_id']);

    // --- Get and Sanitize Data ---
    $supply_code = isset($_POST['supply_code']) ? sanitize_input($conn, strtoupper($_POST['supply_code'])) : ''; // Usually read-only, but sanitize anyway
    $supply_name = isset($_POST['supply_name']) ? sanitize_input($conn, $_POST['supply_name']) : '';
    $category_id = isset($_POST['category_id']) ? intval($_POST['category_id']) : 0;
    $unit = isset($_POST['unit']) ? sanitize_input($conn, $_POST['unit']) : '';
    $min_stock_level = isset($_POST['min_stock_level']) ? intval($_POST['min_stock_level']) : 0;
    $description = isset($_POST['description']) ? sanitize_input($conn, $_POST['description']) : '';
    $status = isset($_POST['status']) && in_array($_POST['status'], ['active', 'inactive']) ? sanitize_input($conn, $_POST['status']) : 'inactive';
    $delete_image = isset($_POST['delete_image']) ? true : false;
    $existing_image = isset($_POST['existing_image']) ? $_POST['existing_image'] : ''; // Get current filename

    // --- Validate Data ---
    if ($supply_id <= 0 || empty($supply_code) || empty($supply_name) || $category_id <= 0 || empty($unit)) {
        $message = "ข้อมูลไม่ถูกต้อง กรุณากรอกข้อมูลที่จำเป็นให้ครบ";
    } elseif ($min_stock_level < 0) {
        $message = "จุดสั่งซื้อขั้นต่ำต้องไม่ติดลบ";
    } else {
        $image_filename_to_update = $existing_image; // Start with the existing image name
        $old_image_to_delete = null; // Track if we need to delete the old file later

        // --- Image Handling ---
        // 1. Check for Delete Request
        if ($delete_image && !empty($existing_image)) {
            $old_image_path = $upload_dir . $existing_image;
            if (file_exists($old_image_path)) {
                if (@unlink($old_image_path)) { // Try to delete
                    $image_filename_to_update = NULL; // Set to NULL in DB
                } else {
                    $message = "คำเตือน: ไม่สามารถลบรูปภาพเก่า ($existing_image) ได้ กรุณาตรวจสอบสิทธิ์ของโฟลเดอร์";
                    // Continue with DB update but keep old filename for now
                    $image_filename_to_update = $existing_image;
                }
            } else {
                $image_filename_to_update = NULL; // File doesn't exist, just update DB to NULL
            }
            $existing_image = ''; // Clear existing image variable as it's marked for deletion
        }

        // 2. Check for New Upload
        if (isset($_FILES['supply_image']) && $_FILES['supply_image']['error'] == UPLOAD_ERR_OK) {
            $file_info = $_FILES['supply_image'];
            $file_name = basename($file_info['name']);
            $file_tmp = $file_info['tmp_name'];
            $file_size = $file_info['size'];
            $file_ext = strtolower(pathinfo($file_name, PATHINFO_EXTENSION));
            $allowed_ext = ['jpg', 'jpeg', 'png', 'gif'];

            // Basic Validation
            if (!in_array($file_ext, $allowed_ext)) {
                $message = "รูปแบบไฟล์รูปภาพไม่ถูกต้อง (อนุญาตเฉพาะ JPG, PNG, GIF)";
            } elseif ($file_size > 2 * 1024 * 1024) { // Max 2MB
                $message = "ขนาดไฟล์รูปภาพเกิน 2MB";
            } else {
                // Generate a unique filename (e.g., supplyID_timestamp.ext)
                $new_filename = "supply_" . $supply_id . "_" . time() . "." . $file_ext;
                $destination = $upload_dir . $new_filename;

                if (move_uploaded_file($file_tmp, $destination)) {
                    // Upload successful
                    $image_filename_to_update = $new_filename; // Set new filename for DB update

                    // If there was an old image that wasn't marked for deletion, delete it now
                    if (!empty($existing_image) && !$delete_image) {
                         $old_image_path = $upload_dir . $existing_image;
                         if (file_exists($old_image_path)) {
                              @unlink($old_image_path); // Try deleting old file
                         }
                    }
                } else {
                    $message = "เกิดข้อผิดพลาดในการอัปโหลดไฟล์รูปภาพ";
                }
            }
        }
        // End Image Handling

        // --- Proceed with DB Update only if no critical file errors occurred ---
        if (empty($message) || strpos($message, 'คำเตือน:') === 0) { // Allow update even if old file deletion failed

             // Prepare SQL UPDATE Statement
            $image_sql_part = ($image_filename_to_update === NULL) ? "NULL" : "'". mysqli_real_escape_string($conn, $image_filename_to_update) ."'";

             $sql_update = "UPDATE supplies SET
                                supply_name = '$supply_name',
                                category_id = $category_id,
                                unit = '$unit',
                                min_stock_level = $min_stock_level,
                                description = '$description',
                                image_filename = $image_sql_part,
                                status = '$status',
                                updated_at = NOW() -- Update timestamp
                            WHERE id = $supply_id AND supply_code = '$supply_code'"; // Use code as extra check

             if (mysqli_query($conn, $sql_update)) {
                 if (mysqli_affected_rows($conn) > 0) {
                     $message = "แก้ไขข้อมูลพัสดุ '" . htmlspecialchars($supply_name) . "' สำเร็จแล้ว. " . $message; // Append warning if any
                     $message_type = 'success';
                 } else {
                      // Check if the record exists with the specific code, maybe data wasn't changed
                      $sql_verify = "SELECT id FROM supplies WHERE id = $supply_id AND supply_code = '$supply_code'";
                      $res_verify = mysqli_query($conn, $sql_verify);
                      if(mysqli_num_rows($res_verify) > 0){
                          $message = "ไม่มีข้อมูลที่เปลี่ยนแปลง หรือ ไม่พบรายการที่ตรงกัน. " . $message;
                          $message_type = 'warning';
                      } else {
                           $message = "ไม่พบรายการพัสดุ ID: $supply_id หรือรหัส $supply_code ไม่ถูกต้อง.";
                           $message_type = 'danger';
                      }
                       if($res_verify) mysqli_free_result($res_verify);

                 }
                 $_SESSION['message'] = $message;
                 $_SESSION['message_type'] = $message_type;
                 mysqli_close($conn);
                 redirect('index.php'); // Redirect back to list

             } else {
                 $message = "เกิดข้อผิดพลาดในการบันทึกข้อมูล: " . mysqli_error($conn);
                 $message_type = 'danger';
             }
        }
    } // End validation check
} else {
    // If accessed directly without POST or supply_id, redirect
    $message = 'ข้อมูลไม่ถูกต้อง';
    $_SESSION['message'] = $message;
    $_SESSION['message_type'] = $message_type;
    redirect('index.php');
}

// --- Display Error Message if Redirect Failed ---
if (!empty($message)) {
    $_SESSION['message'] = $message;
    $_SESSION['message_type'] = $message_type;
    // Attempt to redirect back to the edit form with the ID
    if ($supply_id > 0) {
        redirect('supply_edit.php?id=' . $supply_id);
    } else {
        redirect('index.php'); // Fallback redirect
    }
}
?>