/**

* Implements asynchronous interface of `AsyncChild` class for `Client'. See

* `common/src/plugins/AsyncChild` class for details. It tracks client states

* like 'running', 'stopping', 'failed' etc and adds appropriate methods to

* parent: isRunning(), isStopping(),...

*

* @author flatline

*/

const AsyncChild = require('./AsyncChild');

const Helper = require('./../Helper');

class AsyncClient extends AsyncChild {

constructor(parent, cfg = null) {

super(parent);

const EVENTS = parent.EVENTS;

this._active = false;

this._running = false;

this._stopping = false;

this._failed = false;

this._openEvent = cfg && cfg.openEvent || EVENTS.GET_ID;

this._onOpenCb = this._onOpen.bind(this);

this._onCloseCb = this._onClose.bind(this);

this._onRunCb = this._onRun.bind(this);

this._onStopCb = this._onStop.bind(this);

parent.on(this._openEvent, this._onOpenCb);

parent.on(EVENTS.CLOSE, this._onCloseCb);

parent.on(EVENTS.DESTROY, this._onCloseCb);

Helper.override(parent, 'run', this._onRunCb);

Helper.override(parent, 'stop', this._onStopCb);

}

destroy() {

const parent = this.parent;

Helper.unoverride(parent, 'stop', this._onStopCb);

Helper.unoverride(parent, 'run', this._onRunCb);

parent.off(parent.EVENTS.OPEN, this._onOpenCb);

parent.off(parent.EVENTS.CLOSE, this._onCloseCb);

parent.off(parent.EVENTS.DESTROY, this._onCloseCb);

this._onOpenCb = null;

this._onCloseCb = null;

this._onRunCb = null;

this._onStopCb = null;

super.destroy();

}

/**

* Says it's active state to caller. Active state is a state of

* running/stopping.

* @return {Boolean}

* @override

*/

isActive() {return this._active}

/**

* Tells it's running state. If it's true, then `isActive()` will

* return `false`. If it's `false` after `true` value, then `isActive()`

* will return `true`

* @return {Boolean}

* @override

*/

isRunning() {return this._running}

/**

* Tells it's running state. If it's true, then `isActive()` will

* return `false`. If it's `false` after `true` value, then `isActive()`

* will return `true`

* @return {Boolean}

* @override

*/

isStopping() {return this._stopping}

/**

* Means, that current class has failed and we shouldn't wait for it's

* asynchronous run or stop.

* @returns {Boolean}

*/

isFailed() {return this._failed}

_onOpen() {this._active = true; this._running = false; this._failed = false}

_onRun() {this._active = false; this._running = true}

_onStop() {this._active = false; this._stopping = true}

_onClose() {

//

// Error occurs at the beginning, before plugin has run. It means

// that this plugin failed to start(run)

//

if (!this._active) {this._failed = true}

this._active = false;

this._stopping = false;

}

}

module.exports = AsyncClient;