/**
 * GameLib.EntityManager
 * @param parentObject
 * @param apiEntityManager GameLib.API.EntityManager
 * @constructor
 */
GameLib.EntityManager = function(
    parentObject,
    apiEntityManager
) {

    if (GameLib.Utils.UndefinedOrNull(parentObject)) {
        parentObject = null;
    }
    this.parentObject = parentObject;

    GameLib.API.EntityManager.call(
        this,
        apiEntityManager.entities
    );

    this.instance = this.createInstance();
};

GameLib.EntityManager.prototype = Object.create(GameLib.API.EntityManager.prototype);
GameLib.EntityManager.prototype.constructor = GameLib.EntityManager;

/**
 * Creates an Entity Manager instance
 * @returns {*}
 */
GameLib.EntityManager.prototype.createInstance = function() {
    /**
     * Fuck the current ECS bullshit on the internet - both tiny-ecs and ecsjs SUCKS ASS
     */
    return null;
};

/**
 * Creates an GameLib.Entity
 * @returns {*}
 */
GameLib.EntityManager.prototype.createEntity = function(name) {

    var apiEntity = new GameLib.API.Entity(null, name);

    var entity = new GameLib.Entity(this, this, apiEntity);

    this.entities.push(entity);

    return entity;
};

/**
 * Removes an entity
 * @param entity GameLib.D3.Entity
 * @returns boolean true if successful
 */
GameLib.EntityManager.prototype.removeEntity = function(entity) {

    var index = this.entities.indexOf(entity);

    if (index == -1) {
        console.log('failed to remove entity : ', entity);
        return false;
    }

    this.entities.splice(index, 1);
    return true;
};

/**
 * Returns all the objects with the following components
 * @param components GameLib.Component[]
 */
GameLib.EntityManager.prototype.query = function(components) {

    return this.entities.map(
        function(__queryComponents) {
            return function(entity) {
                __queryComponents.map(
                    function(__entity) {
                        return function(queryComponent) {
                            __entity.components.map(
                                function(__queryComponent) {
                                    return function(entityComponent) {
                                        if (__queryComponent == entityComponent.constructor.name) {
                                            // arrow should point towards a window or sergej --->
                                            return entityComponent;
                                        }
                                    }
                                }(queryComponent)
                            );
                        }
                    }(entity)
                )
            }
        }(components)
    );

};

/**
 * Converts a GameLib.Entity to GameLib.API.Entity
 * @returns {GameLib.API.EntityManager}
 */
GameLib.EntityManager.prototype.toApiEntityManager = function() {

    var apiEntities = this.entities.map(
        function (entity) {
            return entity.toApiEntity();
        }
    );

    var apiEntityManager = new GameLib.API.EntityManager(
        apiEntities
    );

    return apiEntityManager;
};

/**
 *
 * @param graphics
 * @param objectEntities Object
 * @constructor
 */
GameLib.EntityManager.FromObjectEntityManager = function(graphics, objectEntities) {

    var apiEntities = objectEntities.entities.map(
        function (objectEntity) {

            objectEntity.components = objectEntity.components.map(
                function (component) {
                    if (component instanceof Object) {
                        if (component.componentType == GameLib.Component.COMPONENT_TYPE_PATH_FOLLOWING) {
                            return GameLib.D3.PathFollowing.FromObjectComponent(graphics, component);
                        } else {
                            console.warn('no component was associated with this object');
                            throw new Error('no component was associated with this object');
                        }
                    } else {
                        return component;
                    }
                }
            );

            return new GameLib.API.Entity(
                objectEntity.id,
                objectEntity.name,
                objectEntity.components
            )
        }
    );

    var apiEntityManager = new GameLib.API.EntityManager(
        apiEntities
    );

    var entityManager = new GameLib.EntityManager(
        this,
        apiEntityManager
    );

    entityManager.entities = entityManager.entities.map(
        function(apiEntity) {
            return new GameLib.Entity(
                entityManager,
                entityManager,
                apiEntity
            )
        }
    );

    return entityManager;
};

/**
 * Links object Ids to actual objects
 * @param idToObject
 */
GameLib.EntityManager.prototype.linkObjects = function(idToObject) {

    this.entities.map(
        function(entity) {
            entity.components.map(
                function (componentId, index, array) {
                    if (componentId instanceof GameLib.Component) {
                        array[index] = componentId;
                    } else {
                        array[index] = idToObject[componentId];
                    }
                }
            )
        }
    );

    // TODO: fix
    // this.components.forEach(
    //     function(currentValue, index, array) {
    //
    //         if (!idToObject[currentValue]) {
    //             //throw new Error('Unable to locate component with ID: ' + currentValue);
    //             console.log('Unable to locate component with ID: ' + currentValue + ' - it must have been deleted before');
    //             array.splice(index, 1);
    //         } else {
    //             array[index] = idToObject[currentValue];
    //         }
    //
    //
    //     }.bind(this)
    // );

};