class Auto_Save_External_Images {

	public function __construct() {
		add_filter('content_save_pre', array($this, 'save_external_images_to_media'));
	}

	public function save_external_images_to_media($content) {
		if (isset($_POST['save']) || isset($_POST['publish'])) {
			set_time_limit(240);
			global $post;
			if (!is_object($post) || empty($post->ID)) return $content;

			$post_id = $post->ID;
			$host = $_SERVER['HTTP_HOST'];

			// Tìm tất cả các ảnh
			preg_match_all('/<img[^>]+src=[\'"]([^\'"]+)[\'"]/i', stripslashes($content), $matches);
			if (!empty($matches[1])) {
				foreach ($matches[1] as $image_url) {
					if (empty($image_url)) continue;

					$img_host = parse_url($image_url, PHP_URL_HOST);
					if ($img_host && $img_host !== $host) {
						// Là ảnh ngoài -> tải về
						$res = $this->download_image($image_url, $post_id);
						if (!empty($res['url'])) {
							$content = str_replace($image_url, $res['url'], $content);
						}
					}
				}
			}
		}
		// Chỉ xử lý 1 lần
		remove_filter('content_save_pre', array($this, 'save_external_images_to_media'));
		return $content;
	}

	private function download_image($image_url, $post_id) {
		$image_data = @file_get_contents($image_url);
		if ($image_data === false) return ['url' => $image_url]; // fallback giữ nguyên link

		$post = get_post($post_id);
		$post_title = sanitize_title($post->post_title);
		$ext = pathinfo(parse_url($image_url, PHP_URL_PATH), PATHINFO_EXTENSION);
		if (!$ext) $ext = 'jpg';

		$filename = $post_title . '-' . $post_id . '-' . md5($image_url) . '.' . $ext;
		$upload = wp_upload_bits($filename, null, $image_data);

		if (!$upload || !empty($upload['error'])) return ['url' => $image_url];

		$this->attach_to_post($upload['file'], $post_id);

		return $upload;
	}

	private function attach_to_post($filepath, $post_id) {
		$wp_filetype = wp_check_filetype($filepath);
		$upload_dir = wp_upload_dir();

		$attachment = array(
			'guid'           => $upload_dir['url'] . '/' . basename($filepath),
			'post_mime_type' => $wp_filetype['type'],
			'post_title'     => preg_replace('/\.[^.]+$/', '', basename($filepath)),
			'post_content'   => '',
			'post_status'    => 'inherit'
		);

		$attach_id = wp_insert_attachment($attachment, $filepath, $post_id);
		require_once(ABSPATH . 'wp-admin/includes/image.php');
		$attach_data = wp_generate_attachment_metadata($attach_id, $filepath);
		wp_update_attachment_metadata($attach_id, $attach_data);
	}
}

new Auto_Save_External_Images();