odoo.define('mail.model.CCThrottleFunctionObject', function (require) {
"use strict";

var Class = require('web.Class');

/**
 * This object models the behaviour of the clearable and cancellable (CC)
 * throttle version of a provided function.
 */
var CCThrottleFunctionObject = Class.extend({

    /**
     * @param {Object} params
     * @param {integer} params.duration duration of the 'cooldown' phase, i.e.
     *   the minimum duration between the most recent function call that has
     *   been made and the following function call.
     * @param {function} params.func provided function for making the CC
     *   throttled version.
     */
    init: function (params) {
        this._arguments = undefined;
        this._cooldownTimeout = undefined;
        this._duration = params.duration;
        this._func = params.func;
        this._shouldCallFunctionAfterCD = false;
    },

    //--------------------------------------------------------------------------
    // Public
    //--------------------------------------------------------------------------

    /**
     * Cancel any buffered function call, but keep the cooldown phase running.
     */
    cancel: function () {
        this._arguments = undefined;
        this._shouldCallFunctionAfterCD = false;
    },
    /**
     * Clear the internal throttle timer, so that the following function call
     * is immediate. For instance, if there is a cooldown stage, it is aborted.
     */
    clear: function () {
        if (this._cooldownTimeout) {
            clearTimeout(this._cooldownTimeout);
            this._onCooldownTimeout();
        }
    },
    /**
     * Called when there is a call to the function. This function is throttled,
     * so the time it is called depends on whether the "cooldown stage" occurs
     * or not:
     *
     * - no cooldown stage: function is called immediately, and it starts
     *      the cooldown stage when successful.
     * - in cooldown stage: function is called when the cooldown stage has
     *      ended from timeout.
     *
     * Note that after the cooldown stage, only the last attempted function
     * call will be considered.
     */
    do: function () {
        this._arguments = Array.prototype.slice.call(arguments);
        if (this._cooldownTimeout === undefined) {
            this._callFunction();
        } else {
            this._shouldCallFunctionAfterCD = true;
        }
    },

    //--------------------------------------------------------------------------
    // Private
    //--------------------------------------------------------------------------

    /**
     * Immediately calls the function with arguments of last buffered function
     * call. It initiates the cooldown stage after this function call.
     *
     * @private
     */
    _callFunction: function () {
        this._func.apply(null, this._arguments);
        this._cooldown();
    },
    /**
     * Called when the function has been successfully called. The following
     * calls to the function with this object should suffer a "cooldown stage",
     * which prevents the function from being called until this stage has ended.
     *
     * @private
     */
    _cooldown: function () {
        this.cancel();
        this._cooldownTimeout = setTimeout(
            this._onCooldownTimeout.bind(this),
            this._duration
        );
    },

    //--------------------------------------------------------------------------
    // Handlers
    //--------------------------------------------------------------------------

    /**
     * Called when the cooldown stage ended from timeout. Calls the function if
     * a function call was buffered.
     *
     * @private
     */
    _onCooldownTimeout: function () {
        if (this._shouldCallFunctionAfterCD) {
            this._callFunction();
        } else {
            this._cooldownTimeout = undefined;
        }
    },
});

return CCThrottleFunctionObject;

});


odoo.define('mail.model.CCThrottleFunction', function (require) {
"use strict";

var CCThrottleFunctionObject = require('mail.model.CCThrottleFunctionObject');

/**
 * A function that creates a cancellable and clearable (CC) throttle version
 * of a provided function.
 *
 * This throttle mechanism allows calling a function at most once during a
 * certain period:
 *
 * - When a function call is made, it enters a 'cooldown' phase, in which any
 *     attempt to call the function is buffered until the cooldown phase ends.
 * - At most 1 function call can be buffered during the cooldown phase, and the
 *     latest one in this phase will be considered at its end.
 * - When a cooldown phase ends, any buffered function call will be performed
 *     and another cooldown phase will follow up.
 *
 * This throttle version has the following interesting properties:
 *
 * - cancellable: it allows removing a buffered function call during the
 *     cooldown phase, but it keeps the cooldown phase running.
 * - clearable: it allows to clear the internal clock of the throttled function,
 *     so that any cooldown phase is immediately ending.
 *
 * @param {Object} params
 * @param {integer} params.duration a duration for the throttled behaviour,
 *   in milli-seconds.
 * @param {function} params.func the function to throttle
 * @returns {function} the cancellable and clearable throttle version of the
 *   provided function in argument.
 */
var CCThrottleFunction = function (params) {
    var duration = params.duration;
    var func = params.func;

    var throttleFunctionObject = new CCThrottleFunctionObject({
        duration: duration,
        func: func,
    });

    var callable = function () {
        return throttleFunctionObject.do.apply(throttleFunctionObject, arguments);
    };
    callable.cancel = function () {
        throttleFunctionObject.cancel();
    };
    callable.clear = function () {
        throttleFunctionObject.clear();
    };

    return callable;
};

return CCThrottleFunction;

});