/**
 * Service for interacting with RESTful services.
 */

import Http from './http/index';
import {assign, each, merge} from './util';

export default function Resource(url, params, actions, options) {

    var self = this || {}, resource = {};

    actions = assign({},
        Resource.actions,
        actions
    );

    each(actions, (action, name) => {

        action = merge({url, params: assign({}, params)}, options, action);

        resource[name] = function () {
            return (self.$http || Http)(opts(action, arguments));
        };
    });

    return resource;
}

function opts(action, args) {

    var options = assign({}, action), params = {}, body;

    switch (args.length) {

        case 2:

            params = args[0];
            body = args[1];

            break;

        case 1:

            if (/^(POST|PUT|PATCH)$/i.test(options.method)) {
                body = args[0];
            } else {
                params = args[0];
            }

            break;

        case 0:

            break;

        default:

            throw 'Expected up to 2 arguments [params, body], got ' + args.length + ' arguments';
    }

    options.body = body;
    options.params = assign({}, options.params, params);

    return options;
}

Resource.actions = {

    get: {method: 'GET'},
    save: {method: 'POST'},
    query: {method: 'GET'},
    update: {method: 'PUT'},
    remove: {method: 'DELETE'},
    delete: {method: 'DELETE'}

};