interface UpdateFetcherInterface

interface UpdateFetcherInterface {
    
    /**
     * Project's status cannot be checked.
     */
    const NOT_CHECKED = -1;
    
    /**
     * No available update data was found for project.
     */
    const UNKNOWN = -2;
    
    /**
     * There was a failure fetching available update data for this project.
     */
    const NOT_FETCHED = -3;
    
    /**
     * We need to (re)fetch available update data for this project.
     */
    const FETCH_PENDING = -4;
    
    /**
     * Returns the base of the URL to fetch available update data for a project.
     *
     * @param array $project
     *   The array of project information from
     *   \Drupal\update\UpdateManager::getProjects().
     *
     * @return string
     *   The base of the URL used for fetching available update data. This does
     *   not include the path elements to specify a particular project, version,
     *   site_key, etc.
     */
    public function getFetchBaseUrl($project);
    
    /**
     * Retrieves the project information.
     *
     * @param array $project
     *   The array of project information from
     *   \Drupal\update\UpdateManager::getProjects().
     * @param string $site_key
     *   (optional) The anonymous site key hash. Defaults to an empty string.
     *
     * @return string
     *   The project information fetched as string. Empty string upon failure.
     */
    public function fetchProjectData(array $project, $site_key = '');
    
    /**
     * Generates the URL to fetch information about project updates.
     *
     * This figures out the right URL to use, based on the project's .info.yml
     * file and the global defaults. Appends optional query arguments when the
     * site is configured to report usage stats.
     *
     * @param array $project
     *   The array of project information from
     *   \Drupal\update\UpdateManager::getProjects().
     * @param string $site_key
     *   (optional) The anonymous site key hash. Defaults to an empty string.
     *
     * @return string
     *   The URL for fetching information about updates to the specified project.
     *
     * @see \Drupal\update\UpdateProcessor::fetchData()
     * @see \Drupal\update\UpdateProcessor::processFetchTask()
     * @see \Drupal\update\UpdateManager::getProjects()
     */
    public function buildFetchUrl(array $project, $site_key = '');

}