<?php
defined( 'ABSPATH' ) or die( 'Cheatin&#8217; uh?' );

/**
 * Salt Keys scan class.
 *
 * @package SecuPress
 * @subpackage SecuPress_Scan
 * @since 1.0
 */
class SecuPress_Scan_Salt_Keys extends SecuPress_Scan implements SecuPress_Scan_Interface {

	/** Constants. ============================================================================== */

	/**
	 * Class version.
	 *
	 * @var (string)
	 */
	const VERSION = '1.0.1';


	/** Properties. ============================================================================= */

	/**
	 * The reference to the *Singleton* instance of this class.
	 *
	 * @var (object)
	 */
	protected static $_instance;


	/** Init and messages. ====================================================================== */

	/**
	 * Init.
	 *
	 * @since 1.0
	 */
	protected function init() {
		$this->title    = __( 'Check if the security keys are correctly set.', 'secupress' );
		$this->more     = __( 'WordPress provides 8 security keys, each key has its own purpose. These keys must be set with long random strings: don\'t keep the default value, don\'t store them in the database, don\'t hardcode them.', 'secupress' );
		$this->more_fix = __( 'Create a <a href="https://codex.wordpress.org/Must_Use_Plugins">must-use plugin</a> to replace your actual keys stored in <code>wp-config.php</code> or in your database to keep them safer.', 'secupress' );
	}


	/**
	 * Get messages.
	 *
	 * @since 1.0
	 *
	 * @param (int) $message_id A message ID.
	 *
	 * @return (string|array) A message if a message ID is provided. An array containing all messages otherwise.
	 */
	public static function get_messages( $message_id = null ) {
		$messages = array(
			// "good"
			0   => __( 'All security keys are properly set.', 'secupress' ),
			// "warning"
			100 => __( 'This fix is <strong>pending</strong>, please reload the page to apply it now.', 'secupress' ),
			101 => __( 'The <code>wp-config.php</code> file could not be located.', 'secupress' ),
			// "bad"
			200 => __( 'The following security keys are not set correctly:', 'secupress' ),
			201 => _n_noop( '<strong>&middot; Not Set:</strong> %s.',       '<strong>&middot; Not Set:</strong> %s.',       'secupress' ),
			202 => _n_noop( '<strong>&middot; Default Value:</strong> %s.', '<strong>&middot; Default Value:</strong> %s.', 'secupress' ),
			203 => _n_noop( '<strong>&middot; Too Short:</strong> %s.',     '<strong>&middot; Too Short:</strong> %s.',     'secupress' ),
			204 => _n_noop( '<strong>&middot; Hardcoded:</strong> %s.',     '<strong>&middot; Hardcoded:</strong> %s.',     'secupress' ),
			205 => _n_noop( '<strong>&middot; From DB:</strong> %s.',       '<strong>&middot; From DB:</strong> %s.',       'secupress' ),
			// "cantfix"
			300 => __( 'The <code>wp-config.php</code> file is not writable, security keys could not be changed.', 'secupress' ),
			301 => __( 'The security keys fix has been applied but there is still keys that could not be modified so far.', 'secupress' ),
		);

		if ( isset( $message_id ) ) {
			return isset( $messages[ $message_id ] ) ? $messages[ $message_id ] : __( 'Unknown message', 'secupress' );
		}

		return $messages;
	}


	/** Getters. ================================================================================ */

	/**
	 * Get the documentation URL.
	 *
	 * @since 1.2.3
	 *
	 * @return (string)
	 */
	public static function get_docs_url() {
		return __( 'http://docs.secupress.me/article/92-security-keys-scan', 'secupress' );
	}


	/** Scan. =================================================================================== */

	/**
	 * Scan for flaw(s).
	 *
	 * @since 1.0
	 *
	 * @return (array) The scan results.
	 */
	public function scan() {

		$activated = secupress_filter_scanner( __CLASS__ );
		if ( true === $activated ) {
			$this->add_message( 0 );
			return parent::scan();
		}

		$wpconfig_filepath = secupress_find_wpconfig_path();

		if ( ! $wpconfig_filepath ) {
			// "warning"
			$this->add_message( 100 );
			return parent::scan();
		}

		// Get code only from `wp-config.php`.
		$wp_config_content = php_strip_whitespace( $wpconfig_filepath );
		$keys              = $this->get_keys();
		$bad_keys          = array(
			201 => array(),
			202 => array(),
			203 => array(),
			204 => array(),
			205 => array(),
		);

		preg_match_all( '/' . implode( '|', $keys ) . '/', $wp_config_content, $matches );

		if ( ! empty( $matches[0] ) ) {
			// Hardcoded.
			$bad_keys[204] = self::wrap_in_tag( $matches[0] );
		}

		foreach ( $keys as $key ) {
			// Check constant.
			$constant = defined( $key ) ? constant( $key ) : null;

			switch ( true ) {
				case is_null( $constant ) :
					// Not Set.
					$bad_keys[201][] = '<code>' . $key . '</code>';
					break;
				case 'put your unique phrase here' === $constant :
					// Default Value.
					$bad_keys[202][] = '<code>' . $key . '</code>';
					break;
				case strlen( $constant ) < 64 :
					// Too Short.
					$bad_keys[203][] = '<code>' . $key . '</code>';
					break;
			}

			// Check DB.
			$key = strtolower( $key );
			$db  = get_site_option( $key, null );

			if ( ! is_null( $db ) ) {
				// From DB.
				$bad_keys[205][] = '<code>' . $key . '</code>';
			}
		}

		$bad_keys = array_filter( $bad_keys );

		if ( count( $bad_keys ) ) {
			// "bad"
			$this->add_message( 200 );

			foreach ( $bad_keys as $message_id => $keys ) {
				$this->add_message( $message_id, array( count( $keys ), $keys ) );
			}
		}

		// "good"
		$this->maybe_set_status( 0 );

		return parent::scan();
	}


	/** Fix. ==================================================================================== */

	/**
	 * Try to fix the flaw(s).
	 *
	 * @since 1.0
	 *
	 * @return (array) The fix results.
	 */
	public function fix() {
		global $current_user;

		$is_wpconfig_writable = secupress_is_wpconfig_writable();

		if ( defined( 'SECUPRESS_SALT_KEYS_ACTIVE' ) ) {
			// "cantfix"
			$this->add_fix_message( 301 );
		}

		if ( is_null( $is_wpconfig_writable ) ) {
			// "warning"
			$this->add_fix_message( 101 );
		} elseif ( ! $is_wpconfig_writable ) {
			// "cantfix"
			$this->add_fix_message( 300 );
		}

		if ( isset( $current_user->ID ) ) {
			secupress_set_site_transient( 'secupress-add-salt-muplugin', array( 'ID' => $current_user->ID, 'username' => $current_user->user_login ) );
			// "warning"
			$this->add_fix_message( 100 );
		}

		// "good"
		$this->maybe_set_fix_status( 0 );

		return parent::fix();
	}


	/** Tools. ================================================================================== */

	/**
	 * Get salt keys.
	 *
	 * @since 1.0
	 *
	 * @return (array)
	 */
	protected static function get_keys() {
		return array( 'AUTH_KEY', 'SECURE_AUTH_KEY', 'LOGGED_IN_KEY', 'NONCE_KEY', 'AUTH_SALT', 'SECURE_AUTH_SALT', 'LOGGED_IN_SALT', 'NONCE_SALT' );
	}
}
