/**
 * Runtime Entity
 * @param apiEntity GameLib.D3.API.Entity
 * @constructor
 */
GameLib.Entity = function (
    apiEntity
) {
    if (GameLib.Utils.UndefinedOrNull(apiEntity)) {
        apiEntity = {};
    }

	if (apiEntity instanceof GameLib.Entity) {
		return apiEntity;
	}

    GameLib.API.Entity.call(
        this,
        apiEntity.id,
        apiEntity.name,
        apiEntity.components,
        apiEntity.parentEntity,
        apiEntity.parentEntityManager
    );

    this.componentToCreate = 0;

    GameLib.Component.call(
        this,
        GameLib.Component.COMPONENT_ENTITY,
        {
            'components' : [GameLib.Component],
            'activeComponent' : GameLib.Component
        }
    );
};

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

/**
 * Creates an entity instance
 */
GameLib.Entity.prototype.createInstance = function() {
    /**
     * FUCK ecsjs and tiny-ecs - no client-side support and shitty code (only takes constructors as args)
     */
    this.instance = true;
    GameLib.Component.prototype.createInstance.call(this);
};

/**
 * Adds a component to this entity through the instance (should notify the entity manager instance)
 * @param component
 */
GameLib.Entity.prototype.addComponent = function(component) {

    GameLib.Utils.PushUnique(this.components, component);

    if (component instanceof GameLib.D3.Mesh) {

        /**
         * For meshes, simply get the children components
         * @type {Array}
         */
        component.getChildrenComponents().map(function(childComponent){
            GameLib.Utils.PushUnique(this.components, childComponent);
            childComponent.parentEntity = this;
        }.bind(this))

    } else {
        /**
         * Here we will dig into this component - find all its 'parentEntity' members - and update them accordingly
         */
        component.buildIdToObject();

        /**
         * Also add the child components of this component as components of this entity
         */
        for (var property in component.idToObject) {
            if (component.idToObject.hasOwnProperty(property) &&
                component.idToObject[property] !== component &&
                component.idToObject[property] instanceof GameLib.Component
            ) {
                GameLib.Utils.PushUnique(this.components, component.idToObject[property]);
                component.idToObject[property].parentEntity = this;
            }
        }
    }


	/**
     * Finally, we are the boss component - update my parent entity
	 * @type {GameLib.Entity}
	 */
	component.parentEntity = this;

};

/**
 * Returns all components of type 'constructor'
 * @param constructor
 */
GameLib.Entity.prototype.getComponents = function(constructor) {

    var components = this.components.reduce(
        function(result, component) {
            if (component instanceof constructor) {
                result.push(component);
            }
			return result;
        },
        []
    );

    return components;
};

/**
 * Returns the first component or null
 * @param constructor
 */
GameLib.Entity.prototype.getFirstComponent = function(constructor) {

    var components = this.getComponents(constructor);

    if (components.length > 0) {
        return components[0];
    }

    return null;
};

/**
 * Returns true when this entity has a certain component, false otherwise
 * @param constructor
 */
GameLib.Entity.prototype.hasComponent = function(constructor) {

    var has = this.components.reduce(
        function(result, component) {
            if (component instanceof constructor) {
                result = true;
            }
            return result;
        },
        false
    );

    return has;
};

/**
 *
 * @param component
 */
GameLib.Entity.prototype.removeComponent = function(component) {

	if (GameLib.Utils.UndefinedOrNull(component)) {
		component = this.activeComponent;
	}

    var childIndex = this.components.indexOf(component);
    if (childIndex !== -1) {
        this.components.splice(childIndex, 1);
    } else {
        console.error('component not found');
    }

    /**
     * Break the dependency to the parent
     */
    component.parentEntity = null;

    return true;
};

/**
 * Updates an entity instance
 */
GameLib.Entity.prototype.updateInstance = function() {
    console.log('entity update instance called');
};

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

    var apiComponents = this.components.reduce(
        function(result, component) {
            if (typeof component.toApiObject === 'function') {
                result.push(component.toApiObject());
            } else {
                console.log('ignored runtime component : ' + component.name);
            }
            return result;
        },
        []
    );

    return new GameLib.API.Entity(
        this.id,
        this.name,
        apiComponents,
        GameLib.Utils.IdOrNull(this.parentEntity),
        GameLib.Utils.IdOrNull(this.parentEntityManager)
    );

};

/**
 * Entity from Object
 * @param objectEntity Object
 * @param parentEntityManager GameLib.D3.EntityManager
 * @returns {GameLib.Entity}
 * @constructor
 */
GameLib.Entity.FromObject = function(objectEntity, parentEntityManager) {

    var apiEntity = GameLib.API.Entity.FromObject(objectEntity);

    var entity = new GameLib.Entity(
        apiEntity
    );

    if (GameLib.Utils.UndefinedOrNull(parentEntityManager)) {
        return entity;
    }

    parentEntityManager.addEntity(entity);

    return entity;
};