var _ = require("underscore");

var Fiber = require("fibers");

exports.parallelEach = function (collection, callback, context) {

const errors = [];

context = context || null;

const results = Promise.all(_.map(collection, (...args) => {

async function run() {

return callback.apply(context, args);

}

return run().catch(error => {

// Collect the errors but do not propagate them so that we can

// re-throw the first error after all iterations have completed.

errors.push(error);

});

})).await();

if (errors.length > 0) {

throw errors[0];

}

return results;

};

function disallowedYield() {

throw new Error("Can't call yield in a noYieldsAllowed block!");

}

// Allow testing Fiber.yield.disallowed.

disallowedYield.disallowed = true;

exports.noYieldsAllowed = function (f, context) {

var savedYield = Fiber.yield;

Fiber.yield = disallowedYield;

try {

return f.call(context || null);

} finally {

Fiber.yield = savedYield;

}

};

// Borrowed from packages/meteor/dynamics_nodejs.js

// Used by buildmessage

exports.nodeCodeMustBeInFiber = function () {

if (!Fiber.current) {

throw new Error("Meteor code must always run within a Fiber. " +

"Try wrapping callbacks that you pass to non-Meteor " +

"libraries with Meteor.bindEnvironment.");

}

};

var nextSlot = 0;

exports.EnvironmentVariable = function (defaultValue) {

var self = this;

self.slot = 'slot' + nextSlot++;

self.defaultValue = defaultValue;

};

_.extend(exports.EnvironmentVariable.prototype, {

get: function () {

var self = this;

exports.nodeCodeMustBeInFiber();

if (!Fiber.current._meteorDynamics) {

return self.defaultValue;

}

if (!_.has(Fiber.current._meteorDynamics, self.slot)) {

return self.defaultValue;

}

return Fiber.current._meteorDynamics[self.slot];

},

withValue: function (value, func) {

var self = this;

exports.nodeCodeMustBeInFiber();

if (!Fiber.current._meteorDynamics) {

Fiber.current._meteorDynamics = {};

}

var currentValues = Fiber.current._meteorDynamics;

var saved = _.has(currentValues, self.slot)

? currentValues[self.slot] : self.defaultValue;

currentValues[self.slot] = value;

try {

return func();

} finally {

currentValues[self.slot] = saved;

}

}

});

// This is like Meteor.bindEnvironment.

// Experimentally, we are NOT including onException or _this in this version.

exports.bindEnvironment = function (func) {

exports.nodeCodeMustBeInFiber();

var boundValues = _.clone(Fiber.current._meteorDynamics || {});

return function (...args) {

var self = this;

var runWithEnvironment = function () {

var savedValues = Fiber.current._meteorDynamics;

try {

// Need to clone boundValues in case two fibers invoke this

// function at the same time

Fiber.current._meteorDynamics = _.clone(boundValues);

return func.apply(self, args);

} finally {

Fiber.current._meteorDynamics = savedValues;

}

};

if (Fiber.current) {

return runWithEnvironment();

}

Fiber(runWithEnvironment).run();

};

};

// Returns a Promise that supports .resolve(result) and .reject(error).

exports.makeFulfillablePromise = function () {

var resolve, reject;

var promise = new Promise(function (res, rej) {

resolve = res;

reject = rej;

});

promise.resolve = resolve;

promise.reject = reject;

return promise;

};