hoschi/sweetp-service-project-context-manager

var _ = require('lodash');
var async = require('async');
var sweetp = require('sweetp-base');
var log = require('./log');
var dbHelper = require('./dbHelper');

function mapWith (fn) {
    return function (list) {
        return _.map(list, fn);
    };
}

module.exports = function callServices (serviceNames, db, url, project, context, callback) {
    var params, callServicesFor, serviceCalls, finalCallback;

    if (!serviceNames || serviceNames.length <= 0) {
        return callback(null);
    }

    params = {
        context: JSON.stringify(context)
    };

    // create service calls from map with service names
    callServicesFor = mapWith(function (service) {
        // call service specified with context, use next service call as callback
        return function (serviceHandlerResponses, lastContext, next) {
            if (lastContext) {
                params.context = JSON.stringify(lastContext);
            }
            log.debug("{" + serviceNames + "}", "call service:", service, "params:", params);
            sweetp.callService(url, project, service, params, false, function (err, response) {
                var currentContext;
                if (err) {
                    return next(err, serviceHandlerResponses, lastContext);
                }

                // successfull call, refresh props
                serviceHandlerResponses.push(response.msg);
                currentContext = response.context;

                // call next service in list
                next(err, serviceHandlerResponses, currentContext);
            });
        };
    });

    serviceCalls = [];

    // initialize service responses
    serviceCalls.push(function (next) {
        next(undefined, [], undefined);
    });

    // create service calls from map
    serviceCalls = serviceCalls.concat(callServicesFor(serviceNames));

    finalCallback = function (err, serviceHandlerResponses) {
        if (err) {
            log.error("Some service call didn't succeed:", err);
            // add successfull service responses also to list, this way the
            // user knows what service calls worked already
            err = new Error(JSON.stringify(serviceHandlerResponses) + "\n" + err);
        }

        return callback(err, serviceHandlerResponses);
    };

    // call each service one after the other
    async.waterfall(serviceCalls, function (err, serviceHandlerResponses, contextFromServiceCalls) {
        if (contextFromServiceCalls) {
            log.error('There is a context from some succeeded service calls, try to save it.');
            db.document.put(contextFromServiceCalls._id, contextFromServiceCalls, dbHelper.liftDbError(function (putError) {
                if (putError) {
                    if (!err) {
                        err = "All services ran without errors.";
                    }
                    err += "\nAdditionally there was an error when saving context from service calls!\n:" + putError.toString();
                    finalCallback(err, serviceHandlerResponses);
                } else {
                    finalCallback(err, serviceHandlerResponses);
                }


            }));
        } else {
            finalCallback(err, serviceHandlerResponses);
        }
    });
};