define([
    'entity/js/api/DataModel',
    'entity/js/api/DataModelHooks'
], function (
        DataModel,
        DataModelHooks
        ) {

    'use strict';

    /**
     * Entity API shorthand module.
     *
     * <p>Provides various entry-point methods into the Entity API, mainly for
     * aquiring entity instances.</p>
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @exports api/js/Entities
     */
    var Entity = function() {
        AbcsLib.throwStaticClassError();
    };

    /**
     * Finds entity by a given ID - ignoring the case
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @param {String} entityId ID of the entity to get
     * @returns {entity/js/api/Entity} entity
     *
     * @example
     * <caption>
     *  Gets an instance of an entity with a given ID.
     * </caption>
     * var Entities = Abcs.Entities();
     *
     * var entity = Entities.findById('EntityID');
     */
    Entity.findById = function (entityId) {
        var res;
        if (entityId) {
            res = DataModel.getInstance().getEntities().getEntityById(entityId);
            if (!res) {
                // API backwards compatability with migrated entity ids
                res = DataModelHooks.findLegacyId(entityId);
            }
        }

        // Hidden BOs shouldn't be exposed via public API
        if (res && !res.isHidden()) {
            return res;
        }
    };

    /**
     * Gets all entities.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @returns {entity/js/api/Entity[]} array of entities
     *
     * @example
     * <caption>
     *  Gets instances of all entities known to ABCS and prints all their
     *  properties.
     * </caption>
     * var Entities = Abcs.Entities();
     *
     * var entityInstances = Entities.getAll();
     * // do something with the entities
     * entityInstances.forEach(function (entity) {
     *     // do something with the entity, such as:
     *     console.log('Entity ' + entity.getId() + ' has the following properties:');
     *     entity.getProperties().forEach(function (property) {
     *         console.log(property.getId());
     *     };
     * };
     */
    Entity.getAll = function () {
        return DataModel.getInstance().getEntities().getEntities(); //getEntities().getEntities() will be fixed as well :-)
    };

    /**
     * Holds data related to the current logged-in User.
     *
     * <p>
     * This object describes the structure of data records for
     * {@link api/js/System.ENTITY_LOGGED_USER ENTITY_LOGGED_USER} entities.
     * </p>
     *
     * @AbcsAPI stable
     * @memberof module:api/js/Entities
     * @objectLiteral
     *
     * @see {@link module:api/js/System.getLoggedInUser System.getLoggedInUser}
     * @see {@link module:api/js/System.ENTITY_LOGGED_USER System.ENTITY_LOGGED_USER}
     */
    var UserEntity = function() {
    };

    /**
     * Holds currently logged-in user's login name.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @type {string}
     */
    UserEntity.prototype.username = '';

    /**
     * Holds currently logged-in user's full name.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @type {string}
     */
    UserEntity.prototype.fullname = '';

    /**
     * Holds currently logged-in user's email.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @type {string}
     */
    UserEntity.prototype.email = '';

    /**
     * Holds system information.
     *
     * <p>
     * This object describes the structure of data records for
     * {@link api/js/System.ENTITY_SYSTEM_INFO ENTITY_SYSTEM_INFO} entities.
     * </p>
     *
     * @AbcsAPI stable
     * @memberof module:api/js/Entities
     * @objectLiteral
     *
     * @see {@link module:api/js/System.getSystemInfo System.getSystemInfo}
     * @see {@link module:api/js/System.ENTITY_SYSTEM_INFO System.ENTITY_SYSTEM_INFO}
     */
    var SystemInfo = function() {
    };

    /**
     * Holds current date and time.
     *
     * @AbcsAPI stable
     * @version 15.4.5
     * @type {Date}
     */
    SystemInfo.prototype.datetime = null;

    return Entity;

});