woqlLibrary.js

/// /@ts-check
// we can not import woqlBuilder because woqlBuilder import WOQLLibrary
const WOQLQuery = require('./woqlBuilder');

/**
 * @license Apache Version 2
 * @module WOQLLibrary
 * @constructor WOQLLibrary
 * @description Library Functions to manage the commits graph
 * @example
 *  const woqlLib = WOQLLibrary()
 *  woqlLib.branches()
 *
 *  //or you can call this functions using WOQL Class
 *  WOQL.lib().branches()
 * */
class WOQLLibrary {
  default_schema_resource = 'schema/main';

  default_commit_resource = '_commits';

  default_meta_resource = '_meta';

  masterdb_resource = '_system';

  empty = '';
}

/**
 * General Pattern 4: Retrieves Branches, Their ID, Head Commit ID, Head Commit Time
 * (if present, new branches have no commits)
 */
WOQLLibrary.prototype.branches = function () { // values, variables, cresource) {
  const woql = new WOQLQuery().using('_commits').triple('v:Branch', 'rdf:type', '@schema:Branch')
    .triple('v:Branch', '@schema:name', 'v:Name')
    .opt()
    .triple('v:Branch', '@schema:head', 'v:Head')
    .triple('v:Head', '@schema:identifier', 'v:commit_identifier')
    .triple('v:Head', '@schema:timestamp', 'v:Timestamp');
  return woql;
};

/**
 * get all the commits of a specific branch
 * if a timestamp is given, gets all the commits before the specified timestamp
 * @param {string} [branch] - the branch name
 * @param {number} [limit] - the max number of result
 * @param {number} [start] - the start of the pagination
 * @param {number} [timestamp] - Unix timestamp in seconds
 */

WOQLLibrary.prototype.commits = function (branch = 'main', limit = 0, start = 0, timestamp = 0) {
  const woql = new WOQLQuery().using('_commits');
  if (limit) woql.limit(limit);
  if (start) woql.start(start);
  woql.select('v:Parent ID', 'v:Commit ID', 'v:Time', 'v:Author', 'v:Branch ID', 'v:Message');

  const andArr = [new WOQLQuery().triple('v:Branch', 'name', new WOQLQuery().string(branch))
    .triple('v:Branch', 'head', 'v:Active Commit ID')
    .path('v:Active Commit ID', 'parent*', 'v:Parent', 'v:Path')
    .triple('v:Parent', 'timestamp', 'v:Time')];
  if (timestamp) {
    andArr.push(new WOQLQuery().less('v:Time', timestamp));
  }
  andArr.push(new WOQLQuery().triple('v:Parent', 'identifier', 'v:Commit ID')
    .triple('v:Parent', 'author', 'v:Author')
    .triple('v:Parent', 'message', 'v:Message')
    .opt()
    .triple('v:Parent', 'parent', 'v:Parent ID'));
  return woql.and(...andArr);
};

/**
*get commits older than the specified commit id
* @param {string} [commit_id] - the commit id
* @param {number} [limit] - the max number of result
*/
// eslint-disable-next-line camelcase
WOQLLibrary.prototype.previousCommits = function (commit_id, limit = 10) {
  return new WOQLQuery().using('_commits').limit(limit).select('v:Parent ID', 'v:Message', 'v:Commit ID', 'v:Time', 'v:Author')
    .and(
      new WOQLQuery().and(
        new WOQLQuery().triple('v:Active Commit ID', '@schema:identifier', new WOQLQuery().string(commit_id)),
        new WOQLQuery().path('v:Active Commit ID', '@schema:parent+', 'v:Parent', 'v:Path'),
        new WOQLQuery().triple('v:Parent', '@schema:identifier', 'v:Commit ID'),
        new WOQLQuery().triple('v:Parent', '@schema:timestamp', 'v:Time'),
        new WOQLQuery().triple('v:Parent', '@schema:author', 'v:Author'),
        new WOQLQuery().triple('v:Parent', '@schema:message', 'v:Message'),
        new WOQLQuery().triple('v:Parent', '@schema:parent', 'v:Parent ID'),
        new WOQLQuery().opt().triple('v:Parent', 'parent', 'v:Parent ID'),
      ),
    );
};

/**
 * Finds the id of the very first commit in a database's history
 *
 * This is useful for finding information about when, by who and why the database was created
 * The first commit is the only commit in the database that does not have a parent commit
 *
 */
WOQLLibrary.prototype.first_commit = function () {
  const noparent = new WOQLQuery()
    .using('_commits').select('v:Any Commit IRI')
    .and(
      new WOQLQuery().triple('v:Branch', 'name', new WOQLQuery().string('main'))
        .triple('v:Branch', 'head', 'v:Active Commit ID')
        .path('v:Active Commit ID', 'parent*', 'v:Any Commit IRI', 'v:Path'),

      new WOQLQuery().triple(
        'v:Any Commit IRI',
        '@schema:identifier',
        'v:Commit ID',
      ),
      new WOQLQuery().triple(
        'v:Any Commit IRI',
        '@schema:author',
        'v:Author',
      ),
      new WOQLQuery().triple(
        'v:Any Commit IRI',
        '@schema:message',
        'v:Message',
      ),
      new WOQLQuery()
        .not()
        .triple(
          'v:Any Commit IRI',
          '@schema:parent',
          'v:Parent IRI',
        ),

    );
  return noparent;
};

module.exports = WOQLLibrary;