/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.server.hdmi;

import android.hardware.hdmi.HdmiControlManager;
import android.hardware.hdmi.IHdmiControlCallback;
import android.util.Slog;

import com.android.internal.annotations.VisibleForTesting;

/**
 * Feature action for routing control. Exchanges routing-related commands with other devices
 * to determine the new active source.
 *
 * <p>This action is initiated by various cases:
 * <ul>
 * <li> Manual TV input switching
 * <li> Routing change of a CEC switch other than TV
 * <li> New CEC device at the tail of the active routing path
 * <li> Removed CEC device from the active routing path
 * <li> Routing at CEC enable time
 * </ul>
 */
final class RoutingControlAction extends HdmiCecFeatureAction {
    private static final String TAG = "RoutingControlAction";

    // State in which we wait for <Routing Information> to arrive. If timed out, we use the
    // latest routing path to set the new active source.
    @VisibleForTesting
    static final int STATE_WAIT_FOR_ROUTING_INFORMATION = 1;

    // Time out in millseconds used for <Routing Information>
    @VisibleForTesting
    static final int TIMEOUT_ROUTING_INFORMATION_MS = 1000;

    // If set to true, call {@link HdmiControlService#invokeInputChangeListener()} when
    // the routing control/active source change happens. The listener should be called if
    // the events are triggered by external events such as manual switch port change or incoming
    // <Inactive Source> command.
    private final boolean mNotifyInputChange;

    // The latest routing path. Updated by each <Routing Information> from CEC switches.
    private int mCurrentRoutingPath;

    RoutingControlAction(HdmiCecLocalDevice localDevice, int path, IHdmiControlCallback callback) {
        super(localDevice, callback);
        mCurrentRoutingPath = path;
        // Callback is non-null when routing control action is brought up by binder API. Use
        // this as an indicator for the input change notification. These API calls will get
        // the result through this callback, not through notification. Any other events that
        // trigger the routing control is external, for which notifcation is used.
        mNotifyInputChange = (callback == null);
    }

    @Override
    public boolean start() {
        mState = STATE_WAIT_FOR_ROUTING_INFORMATION;
        addTimer(mState, TIMEOUT_ROUTING_INFORMATION_MS);
        return true;
    }

    @Override
    public boolean processCommand(HdmiCecMessage cmd) {
        int opcode = cmd.getOpcode();
        byte[] params = cmd.getParams();
        if (mState == STATE_WAIT_FOR_ROUTING_INFORMATION
                && opcode == Constants.MESSAGE_ROUTING_INFORMATION) {
            // Keep updating the physicalAddress as we receive <Routing Information>.
            // If the routing path doesn't belong to the currently active one, we should
            // ignore it since it might have come from other routing change sequence.
            int routingPath = HdmiUtils.twoBytesToInt(params);
            if (!HdmiUtils.isInActiveRoutingPath(mCurrentRoutingPath, routingPath)) {
                return true;
            }
            mCurrentRoutingPath = routingPath;
            // Stop possible previous routing change sequence if in progress.
            removeActionExcept(RoutingControlAction.class, this);
            addTimer(mState, TIMEOUT_ROUTING_INFORMATION_MS);
            return true;
        }
        return false;
    }

    private void updateActiveInput() {
        HdmiCecLocalDeviceTv tv = tv();
        tv.setPrevPortId(tv.getActivePortId());
        tv.updateActiveInput(mCurrentRoutingPath, mNotifyInputChange);
    }

    private void sendSetStreamPath() {
        sendCommand(HdmiCecMessageBuilder.buildSetStreamPath(getSourceAddress(),
                mCurrentRoutingPath));
    }

    @Override
    public void handleTimerEvent(int timeoutState) {
        if (mState != timeoutState || mState == STATE_NONE) {
            Slog.w("CEC", "Timer in a wrong state. Ignored.");
            return;
        }
        switch (timeoutState) {
            case STATE_WAIT_FOR_ROUTING_INFORMATION:
                updateActiveInput();
                sendSetStreamPath();
                finishWithCallback(HdmiControlManager.RESULT_SUCCESS);
                return;
            default:
                Slog.e("CEC", "Invalid timeoutState (" + timeoutState + ").");
                return;
        }
    }
}