/*
 * Copyright (C) 2016 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.google.android.exoplayer2.testutil;

import static org.junit.Assert.fail;

import android.app.Activity;
import android.content.Context;
import android.net.wifi.WifiManager;
import android.net.wifi.WifiManager.WifiLock;
import android.os.Bundle;
import android.os.ConditionVariable;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.Window;
import android.widget.FrameLayout;
import androidx.annotation.Nullable;
import com.google.android.exoplayer2.util.Assertions;
import com.google.android.exoplayer2.util.Log;
import com.google.android.exoplayer2.util.Util;
import org.checkerframework.checker.nullness.qual.MonotonicNonNull;

/** A host activity for performing playback tests. */
public final class HostActivity extends Activity implements SurfaceHolder.Callback {

  /** Interface for tests that run inside of a {@link HostActivity}. */
  public interface HostedTest {

    /**
     * Called on the main thread when the test is started.
     *
     * <p>The test will not be started until the {@link HostActivity} has been resumed and its
     * {@link Surface} has been created.
     *
     * @param host The {@link HostActivity} in which the test is being run.
     * @param surface The {@link Surface}.
     * @param overlayFrameLayout A {@link FrameLayout} that is on top of the surface.
     */
    void onStart(HostActivity host, Surface surface, FrameLayout overlayFrameLayout);

    /**
     * Called on the main thread to block until the test has stopped or {@link #forceStop()} is
     * called.
     *
     * @param timeoutMs The maximum time to block in milliseconds.
     * @return Whether the test has stopped successful.
     */
    boolean blockUntilStopped(long timeoutMs);

    /**
     * Called on the main thread to force stop the test (if it is not stopped already).
     *
     * @return Whether the test was forced stopped.
     */
    boolean forceStop();

    /**
     * Called on the test thread after the test has finished and been stopped.
     *
     * <p>Implementations may use this method to assert that test criteria were met.
     */
    void onFinished();
  }

  private static final String TAG = "HostActivity";
  private static final String LOCK_TAG = "ExoPlayerTestUtil:" + TAG;
  private static final long START_TIMEOUT_MS = 5000;

  @Nullable private WakeLock wakeLock;
  @Nullable private WifiLock wifiLock;
  private @MonotonicNonNull SurfaceView surfaceView;
  private @MonotonicNonNull FrameLayout overlayFrameLayout;

  @Nullable private HostedTest hostedTest;
  private boolean hostedTestStarted;
  private @MonotonicNonNull ConditionVariable hostedTestStartedCondition;
  private boolean forcedStopped;

  /**
   * Executes a {@link HostedTest} inside the host.
   *
   * @param hostedTest The test to execute.
   * @param timeoutMs The number of milliseconds to wait for the test to finish. If the timeout is
   *     exceeded then the test will fail.
   */
  public void runTest(HostedTest hostedTest, long timeoutMs) {
    runTest(hostedTest, timeoutMs, /* failOnTimeoutOrForceStop= */ true);
  }

  /**
   * Executes a {@link HostedTest} inside the host.
   *
   * @param hostedTest The test to execute.
   * @param timeoutMs The number of milliseconds to wait for the test to finish.
   * @param failOnTimeoutOrForceStop Whether the test fails when a timeout is exceeded or the test
   *     is stopped forcefully.
   */
  public void runTest(
      final HostedTest hostedTest, long timeoutMs, boolean failOnTimeoutOrForceStop) {
    Assertions.checkArgument(timeoutMs > 0);
    Assertions.checkState(Thread.currentThread() != getMainLooper().getThread());
    Assertions.checkState(this.hostedTest == null);
    Assertions.checkNotNull(hostedTest);
    hostedTestStartedCondition = new ConditionVariable();
    forcedStopped = false;
    hostedTestStarted = false;

    runOnUiThread(
        () -> {
          HostActivity.this.hostedTest = hostedTest;
          maybeStartHostedTest();
        });

    if (!hostedTestStartedCondition.block(START_TIMEOUT_MS)) {
      String message =
          "Test failed to start. Display may be turned off or keyguard may be present.";
      Log.e(TAG, message);
      if (failOnTimeoutOrForceStop) {
        fail(message);
      }
    }

    if (hostedTest.blockUntilStopped(timeoutMs)) {
      if (!forcedStopped) {
        Log.d(TAG, "Checking test pass conditions.");
        hostedTest.onFinished();
        Log.d(TAG, "Pass conditions checked.");
      } else {
        String message =
            "Test force stopped. Activity may have been paused whilst " + "test was in progress.";
        Log.e(TAG, message);
        if (failOnTimeoutOrForceStop) {
          fail(message);
        }
      }
    } else {
      runOnUiThread(hostedTest::forceStop);
      String message = "Test timed out after " + timeoutMs + " ms.";
      Log.e(TAG, message);
      if (failOnTimeoutOrForceStop) {
        fail(message);
      }
    }
    this.hostedTest = null;
  }

  // Activity lifecycle

  @Override
  public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(
        getResources().getIdentifier("exo_testutils_host_activity", "layout", getPackageName()));
    surfaceView =
        findViewById(getResources().getIdentifier("surface_view", "id", getPackageName()));
    surfaceView.getHolder().addCallback(this);
    overlayFrameLayout =
        findViewById(getResources().getIdentifier("overlay_frame_layout", "id", getPackageName()));
  }

  @Override
  public void onStart() {
    Context appContext = getApplicationContext();
    WifiManager wifiManager =
        Assertions.checkStateNotNull(
            (WifiManager) appContext.getSystemService(Context.WIFI_SERVICE));
    wifiLock = wifiManager.createWifiLock(WifiManager.WIFI_MODE_FULL_HIGH_PERF, LOCK_TAG);
    wifiLock.acquire();
    PowerManager powerManager =
        Assertions.checkStateNotNull(
            (PowerManager) appContext.getSystemService(Context.POWER_SERVICE));
    wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, LOCK_TAG);
    wakeLock.acquire();
    super.onStart();
  }

  @Override
  public void onPause() {
    super.onPause();
    if (Util.SDK_INT <= 23) {
      maybeStopHostedTest();
    }
  }

  @Override
  public void onStop() {
    super.onStop();
    if (Util.SDK_INT > 23) {
      maybeStopHostedTest();
    }
    if (wakeLock != null) {
      wakeLock.release();
      wakeLock = null;
    }
    if (wifiLock != null) {
      wifiLock.release();
      wifiLock = null;
    }
  }

  // SurfaceHolder.Callback

  @Override
  public void surfaceCreated(SurfaceHolder holder) {
    maybeStartHostedTest();
  }

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) {
    maybeStopHostedTest();
  }

  @Override
  public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    // Do nothing.
  }

  // Internal logic

  private void maybeStartHostedTest() {
    if (hostedTest == null || hostedTestStarted) {
      return;
    }
    @Nullable Surface surface = Util.castNonNull(surfaceView).getHolder().getSurface();
    if (surface != null && surface.isValid()) {
      hostedTestStarted = true;
      Log.d(TAG, "Starting test.");
      Util.castNonNull(hostedTest)
          .onStart(this, surface, Assertions.checkNotNull(overlayFrameLayout));
      Util.castNonNull(hostedTestStartedCondition).open();
    }
  }

  private void maybeStopHostedTest() {
    if (hostedTest != null && hostedTestStarted && !forcedStopped) {
      forcedStopped = hostedTest.forceStop();
    }
  }
}
