/*
 * Copyright (C) 2013 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.incallui.audiomode;

import android.content.Context;
import android.media.AudioDeviceInfo;
import android.media.AudioManager;
import android.telecom.CallAudioState;
import com.android.dialer.common.LogUtil;
import java.util.ArrayList;
import java.util.List;

/** Proxy class for getting and setting the audio mode. */
public class AudioModeProvider {
  private static final int SUPPORTED_AUDIO_ROUTE_ALL =
      CallAudioState.ROUTE_EARPIECE
          | CallAudioState.ROUTE_BLUETOOTH
          | CallAudioState.ROUTE_WIRED_HEADSET
          | CallAudioState.ROUTE_SPEAKER;

  private static final AudioModeProvider instance = new AudioModeProvider();
  private final List<AudioModeListener> listeners = new ArrayList<>();
  private CallAudioState audioState =
      new CallAudioState(false, CallAudioState.ROUTE_EARPIECE, SUPPORTED_AUDIO_ROUTE_ALL);

  public static AudioModeProvider getInstance() {
    return instance;
  }

  public void onAudioStateChanged(CallAudioState audioState) {
    if (!this.audioState.equals(audioState)) {
      this.audioState = audioState;
      for (AudioModeListener listener : listeners) {
        listener.onAudioStateChanged(audioState);
      }
    }
  }

  public void addListener(AudioModeListener listener) {
    if (!listeners.contains(listener)) {
      listeners.add(listener);
      listener.onAudioStateChanged(audioState);
    }
  }

  public void removeListener(AudioModeListener listener) {
    listeners.remove(listener);
  }

  public CallAudioState getAudioState() {
    return audioState;
  }

  /**
   * Sets a approximated audio state before {@link #onAudioStateChanged} is called. Classes such as
   * {@link com.android.incallui.ProximitySensor} fetches the audio state before it is updated by
   * telecom. This method attempts to guess the correct routing based on connected audio devices.
   * The audio state may still be wrong on a second call due to a bug, telecom setting the
   * route back to earpiece when a call ends.
   */
  public void initializeAudioState(Context context) {
    onAudioStateChanged(
        new CallAudioState(false, getApproximatedAudioRoute(context), SUPPORTED_AUDIO_ROUTE_ALL));
  }

  private static int getApproximatedAudioRoute(Context context) {
    AudioManager audioManager = context.getSystemService(AudioManager.class);
    boolean hasBluetooth = false;
    boolean hasHeadset = false;
    for (AudioDeviceInfo info : audioManager.getDevices(AudioManager.GET_DEVICES_OUTPUTS)) {
      switch (info.getType()) {
        case AudioDeviceInfo.TYPE_BLUETOOTH_A2DP:
        case AudioDeviceInfo.TYPE_BLUETOOTH_SCO:
          hasBluetooth = true;
          continue;
        case AudioDeviceInfo.TYPE_WIRED_HEADSET:
          hasHeadset = true;
          continue;
        default:
          continue;
      }
    }
    if (hasBluetooth) {
      LogUtil.i("AudioModeProvider.getApproximatedAudioRoute", "Routing to bluetooth");
      return CallAudioState.ROUTE_BLUETOOTH;
    }
    if (hasHeadset) {
      LogUtil.i("AudioModeProvider.getApproximatedAudioRoute", "Routing to headset");
      return CallAudioState.ROUTE_WIRED_HEADSET;
    }
    LogUtil.i("AudioModeProvider.getApproximatedAudioRoute", "Routing to earpiece");
    return CallAudioState.ROUTE_EARPIECE;
  }

  /** Notified on changes to audio mode. */
  public interface AudioModeListener {

    void onAudioStateChanged(CallAudioState audioState);
  }
}