/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.mozilla.gecko.gfx;

import android.os.SystemClock;
import android.util.Log;
import java.util.ArrayList;
import java.util.List;

public final class PanningPerfAPI {
  private static final String LOGTAG = "GeckoPanningPerfAPI";

  // make this large enough to avoid having to resize the frame time
  // list, as that may be expensive and impact the thing we're trying
  // to measure.
  private static final int EXPECTED_FRAME_COUNT = 2048;

  private static boolean mRecordingFrames;
  private static List<Long> mFrameTimes;
  private static long mFrameStartTime;

  private static void initialiseRecordingArrays() {
    if (mFrameTimes == null) {
      mFrameTimes = new ArrayList<Long>(EXPECTED_FRAME_COUNT);
    } else {
      mFrameTimes.clear();
    }
  }

  public static void startFrameTimeRecording() {
    if (mRecordingFrames) {
      Log.e(LOGTAG, "Error: startFrameTimeRecording() called while already recording!");
      return;
    }
    mRecordingFrames = true;
    initialiseRecordingArrays();
    mFrameStartTime = SystemClock.uptimeMillis();
  }

  public static List<Long> stopFrameTimeRecording() {
    if (!mRecordingFrames) {
      Log.e(LOGTAG, "Error: stopFrameTimeRecording() called when not recording!");
      return null;
    }
    mRecordingFrames = false;
    return mFrameTimes;
  }

  public static void recordFrameTime() {
    // this will be called often, so try to make it as quick as possible
    if (mRecordingFrames) {
      mFrameTimes.add(SystemClock.uptimeMillis() - mFrameStartTime);
    }
  }

  public static void startCheckerboardRecording() {
    throw new UnsupportedOperationException();
  }

  public static List<Float> stopCheckerboardRecording() {
    throw new UnsupportedOperationException();
  }
}