// Copyright (c) Microsoft Corporation. All rights reserved.

// Licensed under the MIT License.

import { Disposable, Event } from 'vscode';

import { IPythonEnvsWatcher, PythonEnvsChangedEvent, PythonEnvsWatcher } from './watcher';

/**

* A wrapper around a set of watchers, exposing them as a single watcher.

*

* If any of the wrapped watchers emits an event then this wrapper

* emits that event.

*/

export class PythonEnvsWatchers implements IPythonEnvsWatcher {

public readonly onChanged: Event<PythonEnvsChangedEvent>;

private watcher = new PythonEnvsWatcher();

constructor(watchers: ReadonlyArray<IPythonEnvsWatcher>) {

this.onChanged = this.watcher.onChanged;

watchers.forEach((w) => {

w.onChanged((e) => this.watcher.fire(e));

});

}

}

// This matches the `vscode.Event` arg.

type EnvsEventListener = (e: PythonEnvsChangedEvent) => unknown;

/**

* A watcher wrapper that can be disabled.

*

* If disabled, events emitted by the wrapped watcher are discarded.

*/

export class DisableableEnvsWatcher implements IPythonEnvsWatcher {

protected enabled = true;

constructor(

// To wrap more than one use `PythonEnvWatchers`.

private readonly wrapped: IPythonEnvsWatcher

) {}

/**

* Ensure that the watcher is enabled.

*/

public enable() {

this.enabled = true;

}

/**

* Ensure that the watcher is disabled.

*/

public disable() {

this.enabled = false;

}

// This matches the signature of `vscode.Event`.

public onChanged(listener: EnvsEventListener, thisArgs?: unknown, disposables?: Disposable[]): Disposable {

return this.wrapped.onChanged(

(e: PythonEnvsChangedEvent) => {

if (this.enabled) {

listener(e);

}

},

thisArgs,

disposables

);

}

}