/**
 * Provides interface for ndb database.
 * 
 * See the <a href="https://ndb.nal.usda.gov/ndb/doc/apilist/API-FOOD-REPORTV2.md">
 * official documentation</a> for details.
 */
(function() {
    // Methods description for ndb APIs that return a list.
    var listMethod = {
        get: {
            method: "GET",
            isArray: true,
            transformRequest: function(data, headers) {
                return angular.extend({}, headers,
                                      {'Content-Type': 'application/json'});
            },
            headers: {
                'Content-Type': 'application/json'
            },
            transformResponse: function(data, headersGetter, status) {
                var json = angular.fromJson(data);
                return status < 400 && json.list?
                    json.list.item : json.errors.error;
            }
        }
    };
    // Methods description for ndb APIs that return a report.
    var reportMethod = {
        get: {
            method: "GET",
            transformRequest: function(data, headers) {
                return angular.extend({}, headers, {
                    'Content-Type': 'application/json'
                });
            },
            headers: {
                'Content-Type': 'application/json'
            },
            transformResponse: function(data, headersGetter, status) {
                var json = angular.fromJson(data);
                return status < 400 && json.report.food?
                    json.report.food : json.errors.error;
            }
        }
    };
    angular.module('ndbDatabase', ['ngResource'])
    /*
     * Query the usda ndb database for a list of elements by keyword.
     *
     * See <a href="https://ndb.nal.usda.gov/ndb/doc/apilist/API-SEARCH.md">official reference</a> for details.
     * 
     * @param key USDA NDB api key.
     * @param query Keywords to search
     * @param fg Food group ID
     * @param max Maximum number of items to return
     * @param offset Beginning item in the result set
     * @param sort Either n=name or id. (id varies by type: nutrient number for nutrients, NDBno for foods, food group id for food groups)
     * @returns A list of ndb items matching the query.
     */
        .factory('NDBSearch', ['$resource', function($resource) {
            return $resource('https://api.nal.usda.gov/ndb/search?'+
                             'q=:query&ds=Standard+Reference&api_key=:key&fg=:groups&max=:max&offset=:offset', {}, listMethod);
        }])
    /*
     * Query the usda ndb database for a list of elements.
     *
     * See <a href="https://ndb.nal.usda.gov/ndb/doc/apilist/API-LIST.md">official reference</a> for details.
     * 
     * @param key USDA NDB api key.
     * @param type One of d = derivation codes, f = food , n = all nutrients, ns = speciality nutrients, nr = standard release nutrients,g = food group
     * @param max Maximum number of items to return
     * @param offset Beginning item in the result set
     * @param sort Either n=name or id. (id varies by type: nutrient number for nutrients, NDBno for foods, food group id for food groups)
     * @returns A list of ndb items matching the type.
     */
        .factory('NDBList', ['$resource', function($resource) {
            return $resource('https://api.nal.usda.gov/ndb/list?' +
                             'api_key=:key&lt=:type&sort=:sort&max=:max&offset=:offset', {}, listMethod);
        }])
    /*
     * Gets a detailed list of information about a food.
     * 
     * See <a href="https://ndb.nal.usda.gov/ndb/doc/apilist/API-FOOD-REPORT.md">official reference</a> for details.
     * 
     * @param key USDA NDB api key.
     * @param ndbno Food id number
     * @param type One of [b]asic or [f]ull or [s]tats
     * @returns A report matching the ndb item.
     */
        .factory('NDBFood', ['$resource', function($resource) {
            return $resource('https://api.nal.usda.gov/ndb/reports/?api_key=:key&ndbno=:ndbno&type=:type', {}, reportMethod);
        }])
    /*
     * Gets a detailed list of information about the nutrients in a food.
     *
     * See <a href="https://ndb.nal.usda.gov/ndb/doc/apilist/API-NUTRIENT-REPORT.md">official reference</a> for details.
     * 
     * @param key USDA NDB api key.
     * @param groups Food group ID
     * @param max Maximum number of items to return
     * @param offset Beginning item in the result set
     * @param nums The food to look up
     * @param nutrients A list of up to 20 nutrient_id's to include
     * @param sort Either n=name or id. (id varies by type: nutrient number for nutrients, NDBno for foods, food group id for food groups)
     * @returns A list of ndb items matching the query.
     */
        .factory('NDBNutrients', ['$resource', function($resource) {
            return $resource('https://api.nal.usda.gov/ndb/nutrients?'+
                             'api_key=:key&nbno=:nums&nutrients=:nutrients&fg=:groups&max=:max&offset=:offset&sort=:sort', {}, listMethod);
        }])
    /*
     * Gets the weight information about a food.
     * 
     * @param ndbno Food id number
     * @returns A list of matching the ndb item.
     */
        .factory('NDBWeight', ['$resource', function($resource) {
            return $resource('usda/weight/:ndbno');
        }]);
})();