/**
 * Provides interface for food apis.
 */
(function() {
    // Basic api template all foods follow
    var abstractFood = function($resource, path) {
        var methods = {
            'get':    {
                url: "food/:id",
                method: 'GET'
            },
            'query':  {
                url: "food/"+path+"query/:query",
                method: 'GET',
                isArray: true
            },
            'delete': {
                url: "food/:id",
                method: 'DELETE'
            }
        };
        if (path == "") {
            return $resource("food/"+path+':id', {id: "@id"}, methods);
        }
        else {
            // Create/Update requires you to know what type of food you're using
            methods.create = {method: 'PUT'};
            methods.update = {method: 'POST'};
            var res = $resource("food/"+path+':id', {id: "@id"}, methods);
            // TODO: Pass arguments generically
            res.prototype.$save = function(success, failure) {
                if (!this.id) {
                    return this.$create(success, failure);
                }
                else {
                    return this.$update(success, failure);
                }
            };
            return res;
        }
    };
    angular.module('Food', ['ngResource'])
    /*
     * Collection of basic food apis.
     *  
     * Methods:
     * get: Gets information for a basic food by id
     * query: Get a list of basic foods whose name contains the given string
     * delete: Deletes a basic food with an id
     * create: Creates a new basic food
     * update: Updates a basic food
     * submit: Save a new basic food or update it if it already exists.
     * fromNdb (static): Returns a new basic food adapted from an ndb object
     */
        .factory('BasicFood', ['$resource', function($resource) {
            var res = abstractFood($resource, 'basic/');
            res.fromNdb = function(ndbItem) {
                return new this({
                    ndbno: parseInt(ndbItem.ndbno),
                    name: ndbItem.name,
                    food_group: ndbItem.fg,
                    default_unit: ndbItem.ru,
                    calories_p_100: ndbItem.nutrients.find(function (nutrient) {
                        // TODO: Replace 208 with soft-loaded value from database
                        // 208 is the id for kCalories
                        return nutrient.nutrient_id == 208;
                    }).value
                });
            };
            return res;
        }])
    /*
     * Collection of recipe apis.
     *  
     * Methods:
     * get: Gets information for a recipe by id
     * query: Get a list of recipes whose name contains the given string
     * delete: Deletes a recipe with an id
     * create: Creates a new recipe
     * update: Updates a recipe
     * submit: Save a new recipe or update it if it already exists.
     */
        .factory('Recipe', ['$resource', function($resource) {
            return abstractFood($resource, 'recipe/');
        }])
    /*
     * Generic Food query interface.
     * 
     * Useful for getting a list of mixed food types.
     * 
     * Methods:
     * get: Gets information for a specific food by id
     * query: Get a list of foods whose name contains the given string
     * delete: Deletes a food with an id
     * cast: Convert from a generic food to it's designated type
     */
        .factory('Food', ['$resource', 'BasicFood', 'Recipe', function($resource, BasicFood, Recipe) {
            var absFood = abstractFood($resource, "");
            absFood.prototype.cast = function() {
                switch (this.type) {
                case "BasicFood":
                    return new BasicFood(this);
                case "Recipe":
                    return new Recipe(this);
                default:
                    throw "Unrecognized food type: "+this.type;
                }
            };
            return absFood;
        }]);
})();