MailOnline/VPAIDHTML5Client

'use strict';

var IVPAIDAdUnit = require('./IVPAIDAdUnit');
var Subscriber = require('./subscriber');
var checkVPAIDInterface = IVPAIDAdUnit.checkVPAIDInterface;
var utils = require('./utils');
var METHODS = IVPAIDAdUnit.METHODS;
var ERROR = 'AdError';
var AD_CLICK = 'AdClickThru';
var FILTERED_EVENTS = IVPAIDAdUnit.EVENTS.filter(function (event) {
    return event != AD_CLICK;
});

/**
 * This callback is displayed as global member. The callback use nodejs error-first callback style
 * @callback NodeStyleCallback
 * @param {string|null}
 * @param {undefined|object}
 */


/**
 * VPAIDAdUnit
 * @class
 *
 * @param VPAIDCreative
 * @param {HTMLElement} [el] this will be used in initAd environmentVars.slot if defined
 * @param {HTMLVideoElement} [video] this will be used in initAd environmentVars.videoSlot if defined
 */
function VPAIDAdUnit(VPAIDCreative, el, video, iframe) {
    this._isValid = checkVPAIDInterface(VPAIDCreative);
    if (this._isValid) {
        this._creative = VPAIDCreative;
        this._el = el;
        this._videoEl = video;
        this._iframe = iframe;
        this._subscribers = new Subscriber();
        utils.setFullSizeStyle(el);
        $addEventsSubscribers.call(this);
    }
}

VPAIDAdUnit.prototype = Object.create(IVPAIDAdUnit.prototype);

/**
 * isValidVPAIDAd will return if the VPAIDCreative passed in constructor is valid or not
 *
 * @return {boolean}
 */
VPAIDAdUnit.prototype.isValidVPAIDAd = function isValidVPAIDAd() {
    return this._isValid;
};

IVPAIDAdUnit.METHODS.forEach(function(method) {
    //NOTE: this methods arguments order are implemented differently from the spec
    var ignores = [
        'subscribe',
        'unsubscribe',
        'initAd'
    ];

    if (ignores.indexOf(method) !== -1) return;

    VPAIDAdUnit.prototype[method] = function () {
        var ariaty = IVPAIDAdUnit.prototype[method].length;
        // TODO avoid leaking arguments
        // https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#32-leaking-arguments
        var args = Array.prototype.slice.call(arguments);
        var callback = (ariaty === args.length) ? args.pop() : undefined;

        setTimeout(function () {
            var result, error = null;
            try {
                result = this._creative[method].apply(this._creative, args);
            } catch(e) {
                error = e;
            }

            callOrTriggerEvent(callback, this._subscribers, error, result);
        }.bind(this), 0);
    };
});


/**
 * initAd concreate implementation
 *
 * @param {number} width
 * @param {number} height
 * @param {string} viewMode can be 'normal', 'thumbnail' or 'fullscreen'
 * @param {number} desiredBitrate indicates the desired bitrate in kbps
 * @param {object} [creativeData] used for additional initialization data
 * @param {object} [environmentVars] used for passing implementation-specific of js version, if el & video was used in constructor slot & videoSlot will be added to the object
 * @param {NodeStyleCallback} callback
 */
VPAIDAdUnit.prototype.initAd = function initAd(width, height, viewMode, desiredBitrate, creativeData, environmentVars, callback) {
    creativeData = creativeData || {};
    environmentVars = utils.extend({
        slot: this._el,
        videoSlot: this._videoEl
    }, environmentVars || {});

    setTimeout(function () {
        var error;
        try {
            this._creative.initAd(width, height, viewMode, desiredBitrate, creativeData, environmentVars);
        } catch (e) {
            error = e;
        }

        callOrTriggerEvent(callback, this._subscribers, error);
    }.bind(this), 0);
};

/**
 * subscribe
 *
 * @param {string} event
 * @param {nodeStyleCallback} handler
 * @param {object} context
 */
VPAIDAdUnit.prototype.subscribe = function subscribe(event, handler, context) {
    this._subscribers.subscribe(handler, event, context);
};


/**
 * unsubscribe
 *
 * @param {string} event
 * @param {nodeStyleCallback} handler
 */
VPAIDAdUnit.prototype.unsubscribe = function unsubscribe(event, handler) {
    this._subscribers.unsubscribe(handler, event);
};

//alias
VPAIDAdUnit.prototype.on = VPAIDAdUnit.prototype.subscribe;
VPAIDAdUnit.prototype.off = VPAIDAdUnit.prototype.unsubscribe;

IVPAIDAdUnit.GETTERS.forEach(function(getter) {
    VPAIDAdUnit.prototype[getter] = function (callback) {
        setTimeout(function () {

            var result, error = null;
            try {
                result = this._creative[getter]();
            } catch(e) {
                error = e;
            }

            callOrTriggerEvent(callback, this._subscribers, error, result);
        }.bind(this), 0);
    };
});

/**
 * setAdVolume
 *
 * @param volume
 * @param {nodeStyleCallback} callback
 */
VPAIDAdUnit.prototype.setAdVolume = function setAdVolume(volume, callback) {
    setTimeout(function () {

        var result, error = null;
        try {
            this._creative.setAdVolume(volume);
            result = this._creative.getAdVolume();
        } catch(e) {
            error = e;
        }

        if (!error) {
            error = utils.validate(result === volume, 'failed to apply volume: ' + volume);
        }
        callOrTriggerEvent(callback, this._subscribers, error, result);
    }.bind(this), 0);
};

VPAIDAdUnit.prototype._destroy = function destroy() {
    this.stopAd();
    this._subscribers.unsubscribeAll();
};

function $addEventsSubscribers() {
    // some ads implement
    // so they only handle one subscriber
    // to handle this we create our one
    FILTERED_EVENTS.forEach(function (event) {
        this._creative.subscribe($trigger.bind(this, event), event);
    }.bind(this));

    // map the click event to be an object instead of depending of the order of the arguments
    // and to be consistent with the flash
    this._creative.subscribe($clickThruHook.bind(this), AD_CLICK);

    // because we are adding the element inside the iframe
    // the user is not able to click in the video
    if (this._videoEl) {
        var documentElement = this._iframe.contentDocument.documentElement;
        var videoEl = this._videoEl;
        documentElement.addEventListener('click', function(e) {
            if (e.target === documentElement) {
                videoEl.click();
            }
        });
    }
}

function $clickThruHook(url, id, playerHandles) {
    this._subscribers.triggerSync(AD_CLICK, {url: url, id: id, playerHandles: playerHandles});
}

function $trigger(event) {
    // TODO avoid leaking arguments
    // https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#32-leaking-arguments
    this._subscribers.trigger(event, Array.prototype.slice(arguments, 1));
}

function callOrTriggerEvent(callback, subscribers, error, result) {
    if (callback) {
        callback(error, result);
    } else if (error) {
        subscribers.trigger(ERROR, error);
    }
}

module.exports = VPAIDAdUnit;