import { commonjsGlobal } from '../../../../../_virtual/_commonjsHelpers.js';
import { __exports as setImmediate } from '../../../../../_virtual/setImmediate.js';

var hasRequiredSetImmediate;

function requireSetImmediate () {
	if (hasRequiredSetImmediate) return setImmediate;
	hasRequiredSetImmediate = 1;
	(function (global, undefined$1) {

	    if (global.setImmediate) {
	        return;
	    }

	    var nextHandle = 1; // Spec says greater than zero
	    var tasksByHandle = {};
	    var currentlyRunningATask = false;
	    var doc = global.document;
	    var registerImmediate;

	    function setImmediate(callback) {
	      // Callback can either be a function or a string
	      if (typeof callback !== "function") {
	        callback = new Function("" + callback);
	      }
	      // Copy function arguments
	      var args = new Array(arguments.length - 1);
	      for (var i = 0; i < args.length; i++) {
	          args[i] = arguments[i + 1];
	      }
	      // Store and register the task
	      var task = { callback: callback, args: args };
	      tasksByHandle[nextHandle] = task;
	      registerImmediate(nextHandle);
	      return nextHandle++;
	    }

	    function clearImmediate(handle) {
	        delete tasksByHandle[handle];
	    }

	    function run(task) {
	        var callback = task.callback;
	        var args = task.args;
	        switch (args.length) {
	        case 0:
	            callback();
	            break;
	        case 1:
	            callback(args[0]);
	            break;
	        case 2:
	            callback(args[0], args[1]);
	            break;
	        case 3:
	            callback(args[0], args[1], args[2]);
	            break;
	        default:
	            callback.apply(undefined$1, args);
	            break;
	        }
	    }

	    function runIfPresent(handle) {
	        // From the spec: "Wait until any invocations of this algorithm started before this one have completed."
	        // So if we're currently running a task, we'll need to delay this invocation.
	        if (currentlyRunningATask) {
	            // Delay by doing a setTimeout. setImmediate was tried instead, but in Firefox 7 it generated a
	            // "too much recursion" error.
	            setTimeout(runIfPresent, 0, handle);
	        } else {
	            var task = tasksByHandle[handle];
	            if (task) {
	                currentlyRunningATask = true;
	                try {
	                    run(task);
	                } finally {
	                    clearImmediate(handle);
	                    currentlyRunningATask = false;
	                }
	            }
	        }
	    }

	    function installNextTickImplementation() {
	        registerImmediate = function(handle) {
	            process.nextTick(function () { runIfPresent(handle); });
	        };
	    }

	    function canUsePostMessage() {
	        // The test against `importScripts` prevents this implementation from being installed inside a web worker,
	        // where `global.postMessage` means something completely different and can't be used for this purpose.
	        if (global.postMessage && !global.importScripts) {
	            var postMessageIsAsynchronous = true;
	            var oldOnMessage = global.onmessage;
	            global.onmessage = function() {
	                postMessageIsAsynchronous = false;
	            };
	            global.postMessage("", "*");
	            global.onmessage = oldOnMessage;
	            return postMessageIsAsynchronous;
	        }
	    }

	    function installPostMessageImplementation() {
	        // Installs an event handler on `global` for the `message` event: see
	        // * https://developer.mozilla.org/en/DOM/window.postMessage
	        // * http://www.whatwg.org/specs/web-apps/current-work/multipage/comms.html#crossDocumentMessages

	        var messagePrefix = "setImmediate$" + Math.random() + "$";
	        var onGlobalMessage = function(event) {
	            if (event.source === global &&
	                typeof event.data === "string" &&
	                event.data.indexOf(messagePrefix) === 0) {
	                runIfPresent(+event.data.slice(messagePrefix.length));
	            }
	        };

	        if (global.addEventListener) {
	            global.addEventListener("message", onGlobalMessage, false);
	        } else {
	            global.attachEvent("onmessage", onGlobalMessage);
	        }

	        registerImmediate = function(handle) {
	            global.postMessage(messagePrefix + handle, "*");
	        };
	    }

	    function installMessageChannelImplementation() {
	        var channel = new MessageChannel();
	        channel.port1.onmessage = function(event) {
	            var handle = event.data;
	            runIfPresent(handle);
	        };

	        registerImmediate = function(handle) {
	            channel.port2.postMessage(handle);
	        };
	    }

	    function installReadyStateChangeImplementation() {
	        var html = doc.documentElement;
	        registerImmediate = function(handle) {
	            // Create a <script> element; its readystatechange event will be fired asynchronously once it is inserted
	            // into the document. Do so, thus queuing up the task. Remember to clean up once it's been called.
	            var script = doc.createElement("script");
	            script.onreadystatechange = function () {
	                runIfPresent(handle);
	                script.onreadystatechange = null;
	                html.removeChild(script);
	                script = null;
	            };
	            html.appendChild(script);
	        };
	    }

	    function installSetTimeoutImplementation() {
	        registerImmediate = function(handle) {
	            setTimeout(runIfPresent, 0, handle);
	        };
	    }

	    // If supported, we should attach to the prototype of global, since that is where setTimeout et al. live.
	    var attachTo = Object.getPrototypeOf && Object.getPrototypeOf(global);
	    attachTo = attachTo && attachTo.setTimeout ? attachTo : global;

	    // Don't get fooled by e.g. browserify environments.
	    if ({}.toString.call(global.process) === "[object process]") {
	        // For Node.js before 0.9
	        installNextTickImplementation();

	    } else if (canUsePostMessage()) {
	        // For non-IE10 modern browsers
	        installPostMessageImplementation();

	    } else if (global.MessageChannel) {
	        // For web workers, where supported
	        installMessageChannelImplementation();

	    } else if (doc && "onreadystatechange" in doc.createElement("script")) {
	        // For IE 6–8
	        installReadyStateChangeImplementation();

	    } else {
	        // For older browsers
	        installSetTimeoutImplementation();
	    }

	    attachTo.setImmediate = setImmediate;
	    attachTo.clearImmediate = clearImmediate;
	}(typeof self === "undefined" ? typeof commonjsGlobal === "undefined" ? setImmediate : commonjsGlobal : self));
	return setImmediate;
}

export { requireSetImmediate as __require };
//# sourceMappingURL=setImmediate.js.map
