<?php

namespace AdPresso\Api;

use FilesystemIterator;
use RecursiveDirectoryIterator;
use RecursiveIteratorIterator;
use WP_Error;
use WP_REST_Server;
use WP_REST_Request;
use WP_REST_Response;
use AdPresso\Constants;

defined( 'ABSPATH' ) || exit;

/**
 * Handles the REST API request for extracting HTML5 ZIP files from the Media Library.
 */
class Html5ExtractController {

	/**
	 * File types an HTML5 creative may contain; everything else is removed after extraction.
	 */
	public const ALLOWED_EXTENSIONS = [
		'html',
		'htm',
		'js',
		'mjs',
		'css',
		'json',
		'map',
		'txt',
		'xml',
		'svg',
		'png',
		'jpg',
		'jpeg',
		'gif',
		'webp',
		'avif',
		'bmp',
		'ico',
		'mp4',
		'webm',
		'ogv',
		'mp3',
		'ogg',
		'wav',
		'm4a',
		'woff',
		'woff2',
		'ttf',
		'otf',
		'eot',
	];

	/**
	 * Registers the WP hooks.
	 */
	public function hooks(): void {
		add_action( 'rest_api_init', [ $this, 'register_routes' ] );
	}

	/**
	 * Registers the necessary REST routes.
	 */
	public function register_routes(): void {
		register_rest_route( 'adpresso/v1', '/extract-html5', [
			'methods'             => WP_REST_Server::CREATABLE, // POST
			'callback'            => [ $this, 'extract_zip' ],
			'permission_callback' => [ $this, 'can_extract' ],
			'args'                => [
				'attachment_id' => [
					'required'          => true,
					'type'              => 'integer',
					'minimum'           => 1,
					'sanitize_callback' => 'absint',
				],
			],
		] );
	}

	/**
	 * The creative runs same-origin with scripts, so extracting it needs the same trust as unfiltered HTML.
	 *
	 * @param WP_REST_Request $request The extract request.
	 *
	 * @return bool
	 */
	public function can_extract( WP_REST_Request $request ): bool {
		$attachment_id = absint( $request->get_param( 'attachment_id' ) );

		return current_user_can( 'upload_files' )
			&& current_user_can( 'unfiltered_html' )
			&& ( ! $attachment_id || current_user_can( 'edit_post', $attachment_id ) );
	}

	/**
	 * Handles the extraction process.
	 *
	 * @param WP_REST_Request $request
	 *
	 * @return WP_REST_Response|WP_Error
	 */
	public function extract_zip( WP_REST_Request $request ): WP_Error|WP_REST_Response {
		$attachment_id = absint( $request->get_param( 'attachment_id' ) );

		if ( empty( $attachment_id ) ) {
			return new WP_Error( 'missing_id', __( 'Attachment ID is missing.', 'adpresso' ), [ 'status' => 400 ] );
		}

		$file_path = get_attached_file( $attachment_id );

		if ( ! $file_path || ! file_exists( $file_path ) ) {
			return new WP_Error( 'file_not_found', __( 'ZIP file not found on server.', 'adpresso' ), [ 'status' => 404 ] );
		}

		if ( strtolower( pathinfo( $file_path, PATHINFO_EXTENSION ) ) !== 'zip' ) {
			return new WP_Error( 'not_a_zip', __( 'The selected file is not a ZIP archive.', 'adpresso' ), [ 'status' => 400 ] );
		}

		if ( ! function_exists( 'WP_Filesystem' ) ) {
			require_once ABSPATH . 'wp-admin/includes/file.php';
		}
		WP_Filesystem();
		global $wp_filesystem;

		$upload_dir = wp_upload_dir();
		if ( ! empty( $upload_dir['error'] ) ) {
			return new WP_Error( 'upload_error', $upload_dir['error'], [ 'status' => 500 ] );
		}

		// Random suffix: the public folder name must not be guessable.
		$relative_base_dir = defined( 'AdPresso\Constants::HTML5_DIR' ) ? Constants::HTML5_DIR : 'adpresso-html5';
		$unique_dir_name   = 'ad_' . $attachment_id . '_' . time() . '_' . strtolower( wp_generate_password( 12, false, false ) );
		$relative_path     = trailingslashit( $relative_base_dir ) . $unique_dir_name;
		$absolute_dir      = trailingslashit( $upload_dir['basedir'] ) . $relative_path;

		// Extracted and filtered outside the uploads folder, so no disallowed file is ever publicly reachable.
		$temp_dir = trailingslashit( get_temp_dir() ) . 'adpresso-html5-' . wp_generate_password( 20, false, false );
		if ( ! $wp_filesystem->mkdir( $temp_dir, FS_CHMOD_DIR ) ) {
			return new WP_Error( 'mkdir_failed', __( 'Could not create target directory.', 'adpresso' ), [ 'status' => 500 ] );
		}

		$result = unzip_file( $file_path, $temp_dir );

		if ( true !== $result ) {
			$wp_filesystem->rmdir( $temp_dir, true );
			$error_msg = is_wp_error( $result ) ? $result->get_error_message() : __( 'Failed to extract ZIP.', 'adpresso' );

			return new \WP_Error( 'extract_failed', $error_msg, [ 'status' => 500 ] );
		}

		self::remove_disallowed_files( $temp_dir );

		if ( ! self::move_dir( $temp_dir, $absolute_dir ) ) {
			$wp_filesystem->rmdir( $temp_dir, true );

			return new WP_Error( 'move_failed', __( 'Could not move the extracted files into the uploads folder.', 'adpresso' ), [ 'status' => 500 ] );
		}

		return new WP_REST_Response( [ 'directory' => $relative_path ], 200 );
	}

	/**
	 * Moves the filtered folder into uploads; copies when a rename across filesystems fails.
	 *
	 * @param string $from Filtered temp folder.
	 * @param string $to   Target folder (must not exist yet).
	 *
	 * @return bool
	 */
	private static function move_dir( string $from, string $to ): bool {
		global $wp_filesystem;

		if ( ! wp_mkdir_p( dirname( $to ) ) ) {
			return false;
		}
		if ( $wp_filesystem->move( $from, $to ) ) {
			return true;
		}
		if ( ! $wp_filesystem->mkdir( $to, FS_CHMOD_DIR ) ) {
			return false;
		}
		if ( true !== copy_dir( $from, $to ) ) {
			$wp_filesystem->rmdir( $to, true );

			return false;
		}
		$wp_filesystem->rmdir( $from, true );

		return true;
	}

	/**
	 * Keeps only creative file types in the public uploads folder: no PHP, no .htaccess, no links.
	 *
	 * @param string $dir Extracted directory.
	 *
	 * @return string[] Removed paths.
	 */
	public static function remove_disallowed_files( string $dir ): array {
		if ( ! is_dir( $dir ) ) {
			return [];
		}

		$removed  = [];
		$iterator = new RecursiveIteratorIterator(
			new RecursiveDirectoryIterator( $dir, FilesystemIterator::SKIP_DOTS ),
			RecursiveIteratorIterator::CHILD_FIRST
		);

		foreach ( $iterator as $entry ) {
			$path = $entry->getPathname();
			if ( $entry->isLink() ) {
				unlink( $path ); // phpcs:ignore WordPress.WP.AlternativeFunctions.unlink_unlink -- inside our own fresh extraction dir.
				$removed[] = $path;
			} elseif ( $entry->isFile() ) {
				$name      = $entry->getFilename();
				$extension = strtolower( $entry->getExtension() );
				// Also "x.php.png": some server setups run any file with a .php part.
				$executable = (bool) preg_match( '/\.(php\d?|phtml|phar|pht|phps|cgi|pl|py|sh|asp|aspx|jsp)(\.|$)/i', $name );
				if ( str_starts_with( $name, '.' ) || $executable || ! in_array( $extension, self::ALLOWED_EXTENSIONS, true ) ) {
					wp_delete_file( $path );
					$removed[] = $path;
				}
			}
		}

		return $removed;
	}
}