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/*
 * #%L
 * %%
 * Copyright (C) 2011 - 2015 BMW Car IT GmbH
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

// max value for timeout, see
// http://stackoverflow.com/questions/3468607/why-does-settimeout-break-for-large-millisecond-delay-values
define("joynr/util/LongTimer", [], function() {

    /**
     * Implementation for long (>2^31-1 ms) timer functions that only allows timeouts or intervals
     * of 2^31-1 ms (because of SignedInt32 representation)
     *
     * @name LongTimer
     * @class
     */
    var LongTimer = {};

    LongTimer.maxTime = Math.pow(2, 31) - 1;

    var highestTimeoutId = 0;
    LongTimer.timeoutMap = {};

    function timeoutPortion(timeoutId) {
        // retrieve timeout object
        var timeoutObj = LongTimer.timeoutMap[timeoutId];

        // timeout has been cancelled
        if (timeoutObj === undefined) {
            return;
        }

        // if timeout elapsed, remove timeout object and call function
        if (timeoutObj.remainingTimeout === 0) {
            delete LongTimer.timeoutMap[timeoutId];
            timeoutObj.func.apply(this, timeoutObj.args);
            return;
        }

        // recalculate remaining timeout and start next portion of timeout
        var timeToWait = Math.min(LongTimer.maxTime, timeoutObj.remainingTimeout);
        timeoutObj.remainingTimeout -= timeToWait;
        timeoutObj.currentTimeout = setTimeout(timeoutPortion, timeToWait, timeoutId);
    }

    /**
     * Implementation for long (>2^31-1 ms) window.setTimeout only allows intervals of 2^31-1 ms
     * (because of SignedInt32 representation)
     *
     * @function LongTimer#setTimeout
     * @param {Function}
     *            func
     * @param {Number}
     *            timeout
     * @returns {Number} timeout identifier
     * @throws {Error}
     *             if parameters are nullable or not of documented type
     */
    LongTimer.setTimeout = function(func, timeout) {
        // get next timeout id
        var timeoutId = ++highestTimeoutId;

        if (timeout <= LongTimer.maxTime) {
            // put timeout object into map
            LongTimer.timeoutMap[timeoutId] = {
                currentTimeout : setTimeout.apply(null, arguments)
            };
        } else {

            // put timeout object into map
            LongTimer.timeoutMap[timeoutId] = {
                func : func,
                remainingTimeout : timeout,
                args : Array.prototype.slice.call(arguments, 2)
            // get the arbitrary arguments
            };

            // start timeout
            if (timeout === 0) {
                setTimeout(timeoutPortion, 0, timeoutId);
            } else {
                timeoutPortion(timeoutId);
            }
        }

        // return id to
        return timeoutId;
    };

    /**
     * Clears the timeout
     *
     * @function LongTimer#clearTimeout
     * @param timeoutId
     *            the timeout id given by setTimeout
     * @throws {Error}
     *             if parameters are nullable or not of documented type
     */
    LongTimer.clearTimeout = function(timeoutId) {
        // retrieve timeout object
        var timeoutObj = LongTimer.timeoutMap[timeoutId];

        // timeout has run out or been cancelled already
        if (timeoutObj === undefined) {
            return;
        }

        // stop javascript interval and remove timeout object
        clearTimeout(timeoutObj.currentTimeout);
        LongTimer.timeoutMap[timeoutId] = undefined;
    };

    var highestIntervalId = -1;
    var intervalMap = {};

    /**
     * Implementation for long (>2^31-1 ms) window.setInterval only allows intervals of 2^31-1 ms
     * (because of SignedInt32 representation)
     *
     * @function LongTimer#setInterval
     * @param {Function}
     *            func
     * @param {Number}
     *            interval
     * @returns {Number} interval identifier
     * @throws {Error}
     *             if parameters are nullable or not of documented type
     */
    LongTimer.setInterval = function(func, interval) {
        // get next interval id
        var intervalId = ++highestIntervalId;

        function intervalPortion() {
            // retrieve timeout object
            var intervalObj = intervalMap[intervalId];

            // interval has been cancelled
            if (intervalObj === undefined) {
                return;
            }

            // if interval elapsed, call function and reset remaining interval time
            if (intervalObj.remainingInterval === 0) {
                intervalObj.func();
                intervalObj.remainingInterval = intervalObj.interval;
            }

            // recalculate remaining timeout and start next portion of interval
            var timeToWait = Math.min(LongTimer.maxTime, intervalObj.remainingInterval);
            intervalObj.remainingInterval -= timeToWait;
            intervalObj.currentTimeout = setTimeout(intervalPortion, timeToWait);
        }

        // put interval object into map
        intervalMap[intervalId] = {
            func : func,
            remainingInterval : interval,
            interval : interval
        };

        // start interval
        intervalPortion();

        // return id to
        return intervalId;
    };

    /**
     * Clears the interval
     *
     * @function LongTimer#clearInterval
     * @param intervalId
     *            the interval id given by setInterval
     * @throws {Error}
     *             if parameters are nullable or not of documented type
     */
    LongTimer.clearInterval = function(intervalId) {

        // retrieve interval object
        var interval = intervalMap[intervalId];

        // interval has run out or been cancelled already
        if (interval === undefined) {
            return;
        }

        // stop javascript timeout and remove interval object
        clearTimeout(interval.currentTimeout);
        delete intervalMap[intervalId];
    };

    return LongTimer;

});