/*
 * Copyright (C) 2016 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

WI.WorkerManager = class WorkerManager extends WI.Object
{
    constructor()
    {
        super();

        this._workerForId = new Map;

        this._subworkersForWorker = new Multimap;
    }

    // Target

    initializeTarget(target)
    {
        if (target.hasDomain("Worker"))
            target.WorkerAgent.enable();
    }

    // WorkerObserver

    workerCreated(target, workerId, url, name)
    {
        console.assert(target.hasCommand("Worker.sendMessageToWorker"));
        let connection = new InspectorBackend.WorkerConnection;
        let workerTarget = new WI.WorkerTarget(target, workerId, url, name, connection);
        workerTarget.initialize();

        WI.targetManager.addTarget(workerTarget);

        this._workerForId.set(workerId, workerTarget);

        if (target instanceof WI.WorkerTarget)
            this._subworkersForWorker.add(target, workerTarget);

        // Unpause the worker now that we have sent all initialization messages.
        // Ignore errors if a worker went away quickly.
        target.WorkerAgent.initialized(workerId).catch(function(){});
    }

    workerTerminated(workerId)
    {
        let worker = this._workerForId.take(workerId);

        // This may already have been cleaned up if it was a nested subworker
        // of another worker that was terminated first.
        if (!worker)
            return;

        this._cleanUpWorker(worker);
    }

    dispatchMessageFromWorker(workerId, message)
    {
        let worker = this._workerForId.get(workerId);

        console.assert(worker);
        if (!worker)
            return;

        worker.connection.dispatch(message);
    }

    // Private

    _cleanUpWorker(worker)
    {
        // The main `Worker` will be destroyed before any sub-`Worker`, so manually do cleanup here.
        for (let subworker of (this._subworkersForWorker.take(worker) || [])) {
            this._workerForId.delete(subworker.identifier);
            this._cleanUpWorker(subworker);
        }

        WI.targetManager.removeTarget(worker);
    }
};
