/*
 * Copyright 2021 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 androidx.media3.exoplayer.analytics;

import static androidx.media3.common.util.Assertions.checkNotNull;
import static androidx.media3.common.util.Assertions.checkState;

import android.media.metrics.LogSessionId;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.common.util.Util;

/** Identifier for a player instance. */
@UnstableApi
public final class PlayerId {

  /**
   * A player identifier with unset default values that can be used as a placeholder or for testing.
   */
  public static final PlayerId UNSET =
      Util.SDK_INT < 31 ? new PlayerId() : new PlayerId(LogSessionIdApi31.UNSET);

  @Nullable private final LogSessionIdApi31 logSessionIdApi31;

  /** Creates an instance for API &lt; 31. */
  public PlayerId() {
    this(/* logSessionIdApi31= */ (LogSessionIdApi31) null);
    checkState(Util.SDK_INT < 31);
  }

  /**
   * Creates an instance for API &ge; 31.
   *
   * @param logSessionId The {@link LogSessionId} used for this player.
   */
  @RequiresApi(31)
  public PlayerId(LogSessionId logSessionId) {
    this(new LogSessionIdApi31(logSessionId));
  }

  private PlayerId(@Nullable LogSessionIdApi31 logSessionIdApi31) {
    this.logSessionIdApi31 = logSessionIdApi31;
  }

  /** Returns the {@link LogSessionId} for this player instance. */
  @RequiresApi(31)
  public LogSessionId getLogSessionId() {
    return checkNotNull(logSessionIdApi31).logSessionId;
  }

  @RequiresApi(31)
  private static final class LogSessionIdApi31 {

    public static final LogSessionIdApi31 UNSET =
        new LogSessionIdApi31(LogSessionId.LOG_SESSION_ID_NONE);

    public final LogSessionId logSessionId;

    public LogSessionIdApi31(LogSessionId logSessionId) {
      this.logSessionId = logSessionId;
    }
  }
}