7digital-api/lib/resource.js

'use strict';

var _ = require('lodash');
var helpers = require('./helpers');
var responseParser = require('./responseparser');
var request = require('./request');

// A resource on the API, instances of this are used as the prototype of
// instances of each API resource.  This constructor will build up a method
// for each action that can be performed on the resource.
//
// - @param {Object} options
// - @param {Object} schema
//
// The `options` argument should have the following properties:
//
// - `resourceDefinition` - the definition of the resource and its actions from
// the schema definition.
// - `consumerkey` - the oauth consumerkey
// - `consumersecret` the oauth consumersecret
// - `schema` - the schema defintion
// - `format` - the desired response format
// - `logger` - for logging output
function Resource(options, schema) {
	this.logger = options.logger;
	this.resourceName = options.resourceDefinition.resource;
	this.host = options.resourceDefinition.host || schema.host;
	this.sslHost = options.resourceDefinition.sslHost || schema.sslHost;
	this.port = options.resourceDefinition.port || schema.port;
	this.prefix = options.resourceDefinition.prefix || schema.prefix;
	this.consumerkey = options.consumerkey;
	this.consumersecret = options.consumersecret;

	this.logger.silly('Creating constructor for resource: ' +
					this.resourceName);

	_.each(options.resourceDefinition.actions,
		function processAction(action) {
			this.createAction(action, options.userManagement);
		}, this);
}

// Figure out the appropriate method name for an action on a resource on
// the API
//
// - @param {Mixed} - actionDefinition - Either a string if the action method
// name is the same as the action path component on the underlying API call
// or a hash if they differ.
// - @return {String}
Resource.prototype.chooseMethodName = function (actionDefinition) {
	var fnName;

	// Default the action name to getXXX if we only have the URL slug as the
	// action definition.
	if (_.isString(actionDefinition)) {
		fnName = 'get' + helpers.capitalize(actionDefinition);
	} else {
		fnName = actionDefinition.methodName;
	}

	return fnName;
};

// Utility method for creating the necessary methods on the Resource for
// dispatching the request to the 7digital API.
//
// - @param {Mixed} actionDefinition - Either a string if the action method
// name is the same as the action path component on the underlying API call
// or a hash if they differ.
Resource.prototype.createAction = function (actionDefinition, isManaged) {
	var url;
	var fnName = this.chooseMethodName(actionDefinition);
	var action = typeof actionDefinition.apiCall === 'undefined' ?
			actionDefinition : actionDefinition.apiCall;
	var httpMethod = (actionDefinition.method || 'GET').toUpperCase();
	var host = actionDefinition.host || this.host;
	var sslHost = actionDefinition.sslHost || this.sslHost;
	var port = actionDefinition.port || this.port;
	var prefix = actionDefinition.prefix || this.prefix;
	var authType = (actionDefinition.oauth
			&& actionDefinition.oauth === '3-legged' && isManaged)
			? '2-legged'
			: actionDefinition.oauth;

	this.logger.silly('Creating method: ' + fnName + ' for ' + action +
					' action with ' + httpMethod + ' HTTP verb');
	/*jshint validthis: true */
	function invokeAction(requestData, callback) {
		var self = this;
		var endpointInfo = {
			host: invokeAction.host,
			sslHost: invokeAction.sslHost || sslHost,
			port: invokeAction.port,
			prefix: invokeAction.prefix,
			authtype: authType,
			url: helpers.formatPath(invokeAction.prefix, this.resourceName,
				action)
		};
		var credentials = {
			consumerkey: this.consumerkey,
			consumersecret: this.consumersecret
		};

		if (_.isFunction(requestData)) {
			callback = requestData;
			requestData = {};
		}

		function checkAndParse(err, data, response) {
			if (err) {
				return callback(err);
			}

			return responseParser.parse(data, {
				format: self.format,
				logger: self.logger,
				url: endpointInfo.url,
				params: requestData,
				contentType: response.headers['content-type']
			}, getLocationForRedirectsAndCallback);
			function getLocationForRedirectsAndCallback(err, parsed) {
				if (err) {
					return callback(err);
				}

				if (response && response.headers['location']) {
					parsed.location = response.headers['location'];
				}

				return callback(null, parsed);
			}
		}

		_.defaults(requestData, this.defaultParams);

		if (httpMethod === 'GET') {
			// Add the default parameters to the request data
			return request.get(endpointInfo, requestData, this.headers,
				credentials, this.logger, checkAndParse);
		}

		if (httpMethod === 'POST' || httpMethod === 'PUT') {
			return request.postOrPut(httpMethod, endpointInfo, requestData,
				this.headers, credentials, this.logger, checkAndParse);
		}

		return callback(new Error('Unsupported HTTP verb: ' + httpMethod));
	}

	invokeAction.action = action;
	invokeAction.authtype = authType;
	invokeAction.host = host;
	invokeAction.sslHost = sslHost;
	invokeAction.port = port;
	invokeAction.prefix = prefix;
	this[fnName] = invokeAction;
};

module.exports = Resource;