// Copyright 2007 Google, Inc.
// This sample code is under the Apache2 license, see
// http://www.apache.org/licenses/LICENSE-2.0 for license details.
/**
* @fileoverview Wrapper for Time Tracking
*/

/**
* @class Time Tracking component.
*     This class encapsulates all logic for time tracking on a particular
*     page. Time tracking could be for any object within a page or the page
*     itself.
*
* @param {Array.<Number>} arg1 Optional array that represents the bucket
* @constructor
*/
var TimeTracker = function (opt_bucket) {
    if (opt_bucket) {
        this.bucket_ = opt_bucket.sort(this.sortNumber);
    } else {
        this.bucket_ = TimeTracker.DEFAULT_BUCKET;
    }
};

TimeTracker.prototype.startTime_;
TimeTracker.prototype.stopTime_;
TimeTracker.prototype.bucket_;
TimeTracker.DEFAULT_BUCKET = [100, 500, 1500, 2500, 5000];

/**
* Calculates time difference between start and stop
* @return {Number} The time difference between start and stop
*/
TimeTracker.prototype._getTimeDiff = function () {
    return (this.stopTime_ - this.startTime_);
};

/**
* Helper function to sort an Array of numbers
* @param {Number} arg1 The first number
* @param {Number} arg2 The second number
* @return {Number} The difference used to sort
*/
TimeTracker.prototype.sortNumber = function (a, b) {
    return (a - b);
}

/**
* Records the start time
* @param {Number} arg1 Optional start time specified by user
*/
TimeTracker.prototype._recordStartTime = function (opt_time) {
    if (opt_time != undefined) {
        this.startTime_ = opt_time;
    } else {
        this.startTime_ = (new Date()).getTime();
    }
};

/**
* Records the stop time
* @param {Number} arg1 Optional stop time specified by user
*/
TimeTracker.prototype._recordEndTime = function (opt_time) {
    if (opt_time != undefined) {
        this.stopTime_ = opt_time;
    } else {
        this.stopTime_ = (new Date()).getTime();
    }
};

/**
* Tracks the event. Calculates time and sends information to
* the event tracker passed
* @param {Object} arg1 GA tracker created by user
* @param {String} arg2 Optional event object name
* @param {String} arg3 Optional event label
*/
TimeTracker.prototype._track = function (tracker,
                                        opt_event_obj_name,
                                        opt_event_label) {
    var eventTracker;
    if (opt_event_obj_name != undefined && opt_event_obj_name.length != 0) {
        eventTracker = tracker._createEventTracker(opt_event_obj_name);
    } else {
        eventTracker = tracker._createEventTracker('TimeTracker');
    }

    var i;
    var bucketString;
    for (i = 0; i < this.bucket_.length; i++) {
        if ((this._getTimeDiff()) < this.bucket_[i]) {
            if (i == 0) {
                bucketString = "0-" + (this.bucket_[0]);
                break;
            } else {
                bucketString = this.bucket_[i - 1] + "-" + (this.bucket_[i] - 1);
                break;
            }
        }
    }
    if (!bucketString) {
        bucketString = this.bucket_[i - 1] + "+";
    }
    eventTracker._trackEvent(bucketString, opt_event_label, this._getTimeDiff());
};

/**
* Sets the bucket for histogram generation in GA
* @param {Array.<Number>} The bucket array
*/
TimeTracker.prototype._setHistogramBuckets = function (buckets_array) {
    this.bucket_ = buckets_array.sort(this.sortNumber);
};