<?php
/** What WordPress.org knows about a component: a pending update, its package, and whether the project is still maintained. */

namespace Leaplens;

defined( 'ABSPATH' ) || exit;

final class Updates {

	const TEMP_PREFIX = 'leaplens-';

	private static function transient( array $c ) {
		$t = get_site_transient( 'plugin' === $c['type'] ? 'update_plugins' : 'update_themes' );
		return is_object( $t ) ? $t : null;
	}

	/** The update WordPress already found for this component, or null. */
	public static function available( array $c ) {
		$t = self::transient( $c );
		if ( ! $t || empty( $t->response[ $c['id'] ] ) ) {
			return null;
		}
		$u = (array) $t->response[ $c['id'] ];
		if ( empty( $u['new_version'] ) ) {
			return null;
		}
		return array(
			'version'      => (string) $u['new_version'],
			'package'      => isset( $u['package'] ) ? (string) $u['package'] : '',
			'requires_php' => isset( $u['requires_php'] ) ? (string) $u['requires_php'] : '',
		);
	}

	/** True or false when the update check says whether WordPress.org hosts it, null when no check has run yet. */
	public static function on_wporg( array $c ) {
		$t = self::transient( $c );
		if ( ! $t ) {
			return null;
		}
		return ! empty( $t->response[ $c['id'] ] ) || ! empty( $t->no_update[ $c['id'] ] );
	}

	public static function downloadable( $url ) {
		return 'https' === wp_parse_url( (string) $url, PHP_URL_SCHEME ) && 'downloads.wordpress.org' === wp_parse_url( (string) $url, PHP_URL_HOST );
	}

	/** Downloads and unpacks an update into a private temp folder, returns its root; nothing is installed or run. */
	public static function download( array $c, $job_id ) {
		if ( ! self::downloadable( $c['package'] ) ) {
			return new \WP_Error( 'leaplens_package', __( 'The update is not hosted on WordPress.org.', 'leaplens' ) );
		}
		require_once ABSPATH . 'wp-admin/includes/file.php';
		if ( 'direct' !== get_filesystem_method() || ! WP_Filesystem() ) {
			return new \WP_Error( 'leaplens_fs', __( 'Checking the update needs direct file access on this server.', 'leaplens' ) );
		}
		$zip = apply_filters( 'leaplens_pre_download', null, $c['package'] );
		if ( null === $zip ) {
			$zip = download_url( $c['package'], 60 );
		}
		if ( is_wp_error( $zip ) ) {
			return $zip;
		}
		$dest = self::temp_base() . md5( $job_id . $c['key'] . wp_rand() );
		$done = unzip_file( $zip, $dest );
		wp_delete_file( $zip );
		if ( is_wp_error( $done ) ) {
			self::remove( $dest );
			return $done;
		}
		$top = glob( $dest . '/*', GLOB_ONLYDIR );
		return 1 === count( (array) $top ) ? wp_normalize_path( $top[0] ) : $dest;
	}

	/** Temp folder prefix of this site, so installs sharing /tmp never touch each other's downloads. */
	public static function temp_base() {
		$site = substr( md5( get_current_blog_id() . '|' . ABSPATH . '|' . home_url() ), 0, 10 );
		return wp_normalize_path( trailingslashit( get_temp_dir() ) . self::TEMP_PREFIX . $site . '-' );
	}

	public static function remove( $root ) {
		global $wp_filesystem;
		$base = self::temp_base();
		$root = wp_normalize_path( $root );
		if ( 0 !== strpos( $root, $base ) ) {
			return;
		}
		$name = strtok( substr( $root, strlen( $base ) ), '/' );
		$dir  = $base . $name;
		// A link in a shared temp folder may point anywhere: never delete through it.
		if ( false === $name || '' === $name || is_link( $dir ) || ! is_dir( $dir ) ) {
			return;
		}
		require_once ABSPATH . 'wp-admin/includes/file.php';
		if ( WP_Filesystem() && $wp_filesystem ) {
			$wp_filesystem->delete( $dir, true );
		}
	}

	/** Removes this site's update folders a crashed step left behind; only one scan runs per site, so none is in use. */
	public static function sweep() {
		foreach ( (array) glob( self::temp_base() . '*', GLOB_ONLYDIR ) as $dir ) {
			self::remove( $dir );
		}
	}

	/** Directory facts for a component with errors and no update: found, closed, last_updated, support. Cached for 12 hours. */
	public static function directory( array $c ) {
		if ( false === $c['wporg'] ) {
			return array( 'found' => false );
		}
		$cache = 'leaplens_dir_' . md5( $c['type'] . ':' . $c['slug'] );
		$info  = get_transient( $cache );
		if ( is_array( $info ) ) {
			return $info;
		}
		$api  = 'plugin' === $c['type'] ? 'plugins' : 'themes';
		$url  = add_query_arg(
			array(
				'action'                       => 'plugin' === $c['type'] ? 'plugin_information' : 'theme_information',
				'request[slug]'                => $c['slug'],
				'request[fields][sections]'    => 0,
				'request[fields][versions]'    => 0,
				'request[fields][screenshots]' => 0,
			),
			"https://api.wordpress.org/{$api}/info/1.2/"
		);
		$res  = wp_remote_get( $url, array( 'timeout' => 15 ) );
		$body = is_wp_error( $res ) ? null : json_decode( wp_remote_retrieve_body( $res ), true );
		if ( ! is_array( $body ) ) {
			return null;
		}
		$closed = ! empty( $body['closed'] ) || ( isset( $body['error'] ) && 'closed' === $body['error'] );
		$found  = $closed || empty( $body['error'] );
		$info   = array(
			'found'        => $found,
			'closed'       => $closed,
			'last_updated' => $found && ! empty( $body['last_updated'] ) ? gmdate( 'Y-m-d', (int) strtotime( (string) $body['last_updated'] ) ) : '',
			'support'      => $found ? "https://wordpress.org/support/{$c['type']}/{$c['slug']}/" : '',
		);
		set_transient( $cache, $info, 12 * HOUR_IN_SECONDS );
		return $info;
	}
}