(function () {
    'use strict';

    var serviceId = 'commentsDataContext';
    angular.module('comments').factory(serviceId, ['$q', '$http', 'commentsConfig', datacontext]);


    function datacontext($q, $http, config, $modal) {

        var service = {
            getCommentByExternalId: getCommentByExternalId,
            createComment: createComment,
            getCommentById: getCommentById,
            deleteComment: deleteComment
        };

        return service;

        function handleError(response) {

            // The API response from the server should be returned in a
            // nomralized format. However, if the request was not handled by the
            // server (or what not handles properly - ex. server error), then we
            // may have to normalize it on our end, as best we can.
            if (
                !angular.isObject(response.data) ||
                !response.data.message
                ) {

                return ($q.reject("An unknown error occurred."));
            }

            // Otherwise, use expected error message.
            return ($q.reject(response.data.message));
        }


        // I transform the successful response, unwrapping the application data
        // from the API response payload.
        function handleSuccess(response) {
            return (response.data);
        }

        function getCommentByExternalId(externalId, userId) {
            var request = $http({
                method: "get",
                url: config.commentsUrl + 'comments/external/' + externalId + '/user/' + userId,
            });

            return (request.then(handleSuccess, handleError));
        }

        function getCommentById(commentId) {
            var request = $http({
                method: "get",
                url: config.commentsUrl + 'comments/' + commentId,
            });

            return (request.then(handleSuccess, handleError));
        }

        function createComment(comment) {
            var request = $http({
                method: "post",
                url: config.commentsUrl + 'comments',
                data: comment
            });

            return (request.then(handleSuccess, handleError));
        }

        function deleteComment(comment) {
            var request = $http({
                method: "delete",
                url: config.commentsUrl + 'comments/' + comment.id,
            });

            return (request.then(handleSuccess, handleError));
        }

    }


})();