chrome/android/java/src/org/chromium/chrome/browser/media/router/caf/CastSessionController.java

// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package org.chromium.chrome.browser.media.router.caf;

import com.google.android.gms.cast.ApplicationMetadata;
import com.google.android.gms.cast.Cast;
import com.google.android.gms.cast.CastDevice;
import com.google.android.gms.cast.framework.CastSession;

import org.chromium.base.Log;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/** Wrapper for {@link CastSession} for Casting. */
public class CastSessionController extends BaseSessionController {
    private static final String TAG = "CafSessionCtrl";

    private List<String> mNamespaces = new ArrayList<String>();
    private final CastListener mCastListener;

    public CastSessionController(CafBaseMediaRouteProvider provider) {
        super(provider);
        mCastListener = new CastListener();
    }

    public List<String> getNamespaces() {
        return mNamespaces;
    }

    @Override
    public void attachToCastSession(CastSession session) {
        super.attachToCastSession(session);
        getSession().addCastListener(mCastListener);
        updateNamespaces();
    }

    @Override
    public void detachFromCastSession() {
        if (getSession() == null) return;

        mNamespaces.clear();
        getSession().removeCastListener(mCastListener);
        super.detachFromCastSession();
    }

    private class CastListener extends Cast.Listener {
        @Override
        public void onApplicationStatusChanged() {
            CastSessionController.this.onApplicationStatusChanged();
        }

        @Override
        public void onApplicationMetadataChanged(ApplicationMetadata metadata) {
            onApplicationStatusChanged();
        }

        @Override
        public void onVolumeChanged() {
            CafMessageHandler messageHandler = getMessageHandler();
            if (messageHandler == null) return;
            messageHandler.onVolumeChanged();
        }
    }

    private void onApplicationStatusChanged() {
        updateNamespaces();

        CafMessageHandler messageHandler = getMessageHandler();
        if (messageHandler != null) {
            messageHandler.broadcastClientMessage(
                    "update_sesssion", messageHandler.buildSessionMessage());
        }
    }

    private void updateNamespaces() {
        if (!isConnected()) return;

        Set<String> namespacesToAdd =
                new HashSet<>(getSession().getApplicationMetadata().getSupportedNamespaces());
        Set<String> namespacesToRemove = new HashSet<String>(mNamespaces);

        namespacesToRemove.removeAll(namespacesToAdd);
        namespacesToAdd.removeAll(mNamespaces);

        for (String namespace : namespacesToRemove) unregisterNamespace(namespace);
        for (String namespace : namespacesToAdd) registerNamespace(namespace);
    }

    private void registerNamespace(String namespace) {
        assert !mNamespaces.contains(namespace);

        if (!isConnected()) return;

        try {
            getSession().setMessageReceivedCallbacks(namespace, this ::onMessageReceived);
            mNamespaces.add(namespace);
        } catch (Exception e) {
            Log.e(TAG, "Failed to register namespace listener for %s", namespace, e);
        }
    }

    private void unregisterNamespace(String namespace) {
        assert mNamespaces.contains(namespace);

        if (!isConnected()) return;

        try {
            getSession().removeMessageReceivedCallbacks(namespace);
            mNamespaces.remove(namespace);
        } catch (Exception e) {
            Log.e(TAG, "Failed to remove the namespace listener for %s", namespace, e);
        }
    }

    @Override
    protected void onMessageReceived(CastDevice castDevice, String namespace, String message) {
        super.onMessageReceived(castDevice, namespace, message);
        CafMessageHandler messageHandler = getMessageHandler();
        if (messageHandler != null) messageHandler.onMessageReceived(namespace, message);
    }

    private CafMessageHandler getMessageHandler() {
        return ((CafMediaRouteProvider) getProvider()).getMessageHandler();
    }
}