/*
 * Copyright (C) 2015 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;

import android.content.Context;
import android.content.pm.ActivityInfo;
import android.support.annotation.IntDef;
import android.view.OrientationEventListener;
import com.android.dialer.common.LogUtil;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

/**
 * This class listens to Orientation events and overrides onOrientationChanged which gets invoked
 * when an orientation change occurs. When that happens, we notify InCallUI registrants of the
 * change.
 */
public class InCallOrientationEventListener extends OrientationEventListener {

  public static final int SCREEN_ORIENTATION_0 = 0;
  public static final int SCREEN_ORIENTATION_90 = 90;
  public static final int SCREEN_ORIENTATION_180 = 180;
  public static final int SCREEN_ORIENTATION_270 = 270;
  public static final int SCREEN_ORIENTATION_360 = 360;

  /** Screen orientation angles one of 0, 90, 180, 270, 360 in degrees. */
  @Retention(RetentionPolicy.SOURCE)
  @IntDef({
    SCREEN_ORIENTATION_0,
    SCREEN_ORIENTATION_90,
    SCREEN_ORIENTATION_180,
    SCREEN_ORIENTATION_270,
    SCREEN_ORIENTATION_360,
    SCREEN_ORIENTATION_UNKNOWN
  })
  public @interface ScreenOrientation {}

  // We use SCREEN_ORIENTATION_USER so that reverse-portrait is not allowed.
  public static final int ACTIVITY_PREFERENCE_ALLOW_ROTATION = ActivityInfo.SCREEN_ORIENTATION_USER;

  public static final int ACTIVITY_PREFERENCE_DISALLOW_ROTATION =
      ActivityInfo.SCREEN_ORIENTATION_NOSENSOR;

  /**
   * This is to identify dead zones where we won't notify others of orientation changed. Say for e.g
   * our threshold is x degrees. We will only notify UI when our current rotation is within x
   * degrees right or left of the screen orientation angles. If it's not within those ranges, we
   * return SCREEN_ORIENTATION_UNKNOWN and ignore it.
   */
  public static final int SCREEN_ORIENTATION_UNKNOWN = -1;

  // Rotation threshold is 10 degrees. So if the rotation angle is within 10 degrees of any of
  // the above angles, we will notify orientation changed.
  private static final int ROTATION_THRESHOLD = 10;

  /** Cache the current rotation of the device. */
  @ScreenOrientation private static int sCurrentOrientation = SCREEN_ORIENTATION_0;

  private boolean mEnabled = false;

  public InCallOrientationEventListener(Context context) {
    super(context);
  }

  private static boolean isWithinRange(int value, int begin, int end) {
    return value >= begin && value < end;
  }

  private static boolean isWithinThreshold(int value, int center, int threshold) {
    return isWithinRange(value, center - threshold, center + threshold);
  }

  private static boolean isInLeftRange(int value, int center, int threshold) {
    return isWithinRange(value, center - threshold, center);
  }

  private static boolean isInRightRange(int value, int center, int threshold) {
    return isWithinRange(value, center, center + threshold);
  }

  @ScreenOrientation
  public static int getCurrentOrientation() {
    return sCurrentOrientation;
  }

  /**
   * Handles changes in device orientation. Notifies InCallPresenter of orientation changes.
   *
   * <p>Note that this API receives sensor rotation in degrees as a param and we convert that to one
   * of our screen orientation constants - (one of: {@link #SCREEN_ORIENTATION_0}, {@link
   * #SCREEN_ORIENTATION_90}, {@link #SCREEN_ORIENTATION_180}, {@link #SCREEN_ORIENTATION_270}).
   *
   * @param rotation The new device sensor rotation in degrees
   */
  @Override
  public void onOrientationChanged(int rotation) {
    if (rotation == OrientationEventListener.ORIENTATION_UNKNOWN) {
      return;
    }

    final int orientation = toScreenOrientation(rotation);

    if (orientation != SCREEN_ORIENTATION_UNKNOWN && sCurrentOrientation != orientation) {
      LogUtil.i(
          "InCallOrientationEventListener.onOrientationChanged",
          "orientation: %d -> %d",
          sCurrentOrientation,
          orientation);
      sCurrentOrientation = orientation;
      InCallPresenter.getInstance().onDeviceOrientationChange(sCurrentOrientation);
    }
  }

  /**
   * Enables the OrientationEventListener and notifies listeners of current orientation if notify
   * flag is true
   *
   * @param notify true or false. Notify device orientation changed if true.
   */
  public void enable(boolean notify) {
    if (mEnabled) {
      Log.v(this, "enable: Orientation listener is already enabled. Ignoring...");
      return;
    }

    super.enable();
    mEnabled = true;
    if (notify) {
      InCallPresenter.getInstance().onDeviceOrientationChange(sCurrentOrientation);
    }
  }

  /** Enables the OrientationEventListener with notify flag defaulting to false. */
  @Override
  public void enable() {
    enable(false);
  }

  /** Disables the OrientationEventListener. */
  @Override
  public void disable() {
    if (!mEnabled) {
      Log.v(this, "enable: Orientation listener is already disabled. Ignoring...");
      return;
    }

    mEnabled = false;
    super.disable();
  }

  /** Returns true the OrientationEventListener is enabled, false otherwise. */
  public boolean isEnabled() {
    return mEnabled;
  }

  /**
   * Converts sensor rotation in degrees to screen orientation constants.
   *
   * @param rotation sensor rotation angle in degrees
   * @return Screen orientation angle in degrees (0, 90, 180, 270). Returns -1 for degrees not
   *     within threshold to identify zones where orientation change should not be trigerred.
   */
  @ScreenOrientation
  private int toScreenOrientation(int rotation) {
    // Sensor orientation 90 is equivalent to screen orientation 270 and vice versa. This
    // function returns the screen orientation. So we convert sensor rotation 90 to 270 and
    // vice versa here.
    if (isInLeftRange(rotation, SCREEN_ORIENTATION_360, ROTATION_THRESHOLD)
        || isInRightRange(rotation, SCREEN_ORIENTATION_0, ROTATION_THRESHOLD)) {
      return SCREEN_ORIENTATION_0;
    } else if (isWithinThreshold(rotation, SCREEN_ORIENTATION_90, ROTATION_THRESHOLD)) {
      return SCREEN_ORIENTATION_270;
    } else if (isWithinThreshold(rotation, SCREEN_ORIENTATION_180, ROTATION_THRESHOLD)) {
      return SCREEN_ORIENTATION_180;
    } else if (isWithinThreshold(rotation, SCREEN_ORIENTATION_270, ROTATION_THRESHOLD)) {
      return SCREEN_ORIENTATION_90;
    }
    return SCREEN_ORIENTATION_UNKNOWN;
  }
}