/**
 * Copyright (c) 2014 Petka Antonov
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:</p>
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 * 
 */
"use strict";
var ASSERT = require("./assert.js");
var schedule = require("./schedule.js");
var Queue = require("./queue.js");
var errorObj = require("./util.js").errorObj;
var tryCatch1 = require("./util.js").tryCatch1;

function Async() {
    this._isTickUsed = false;
    this._length = 0;
    this._lateBuffer = new Queue();
    this._functionBuffer = new Queue(25000 * 3);
    var self = this;
    this.consumeFunctionBuffer = function Async$consumeFunctionBuffer() {
        self._consumeFunctionBuffer();
    };
}

Async.prototype.haveItemsQueued = function Async$haveItemsQueued() {
    return this._length > 0;
};

Async.prototype.invokeLater = function Async$invokeLater(fn, receiver, arg) {
    this._lateBuffer.push(fn, receiver, arg);
    this._queueTick();
};

Async.prototype.invoke = function Async$invoke(fn, receiver, arg) {
    var functionBuffer = this._functionBuffer;
    functionBuffer.push(fn, receiver, arg);
    this._length = functionBuffer.length();
    this._queueTick();
};

Async.prototype._consumeFunctionBuffer =
function Async$_consumeFunctionBuffer() {
    var functionBuffer = this._functionBuffer;
    while(functionBuffer.length() > 0) {
        var fn = functionBuffer.shift();
        var receiver = functionBuffer.shift();
        var arg = functionBuffer.shift();
        fn.call(receiver, arg);
    }
    this._reset();
    this._consumeLateBuffer();
};

Async.prototype._consumeLateBuffer = function Async$_consumeLateBuffer() {
    var buffer = this._lateBuffer;
    while(buffer.length() > 0) {
        var fn = buffer.shift();
        var receiver = buffer.shift();
        var arg = buffer.shift();
        var res = tryCatch1(fn, receiver, arg);
        if (res === errorObj) {
            this._queueTick();
            throw res.e;
        }
    }
};

Async.prototype._queueTick = function Async$_queue() {
    if (!this._isTickUsed) {
        schedule(this.consumeFunctionBuffer);
        this._isTickUsed = true;
    }
};

Async.prototype._reset = function Async$_reset() {
    this._isTickUsed = false;
    this._length = 0;
};

module.exports = new Async();