content: /*
   * 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.drm;
  
  import static java.lang.annotation.ElementType.FIELD;
  import static java.lang.annotation.ElementType.LOCAL_VARIABLE;
  import static java.lang.annotation.ElementType.METHOD;
  import static java.lang.annotation.ElementType.PARAMETER;
  import static java.lang.annotation.ElementType.TYPE_USE;
  
  import android.media.MediaDrm;
  import androidx.annotation.IntDef;
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.PlaybackException;
  import com.google.android.exoplayer2.decoder.CryptoConfig;
  import java.io.IOException;
  import java.lang.annotation.Documented;
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  import java.lang.annotation.Target;
  import java.util.Map;
  import java.util.UUID;
  
  /** A DRM session. */
  public interface DrmSession {
  
    /**
     * Acquires {@code newSession} then releases {@code previousSession}.
     *
     * <p>Invokes {@code newSession's} {@link #acquire(DrmSessionEventListener.EventDispatcher)} and
     * {@code previousSession's} {@link #release(DrmSessionEventListener.EventDispatcher)} in that
     * order (passing {@code eventDispatcher = null}). Null arguments are ignored. Does nothing if
     * {@code previousSession} and {@code newSession} are the same session.
     */
    static void replaceSession(
        @Nullable DrmSession previousSession, @Nullable DrmSession newSession) {
      if (previousSession == newSession) {
        // Do nothing.
        return;
      }
      if (newSession != null) {
        newSession.acquire(/* eventDispatcher= */ null);
      }
      if (previousSession != null) {
        previousSession.release(/* eventDispatcher= */ null);
      }
    }
  
    /** Wraps the throwable which is the cause of the error state. */
    class DrmSessionException extends IOException {
  
      /** The {@link PlaybackException.ErrorCode} that corresponds to the failure. */
      public final @PlaybackException.ErrorCode int errorCode;
  
      public DrmSessionException(Throwable cause, @PlaybackException.ErrorCode int errorCode) {
        super(cause);
        this.errorCode = errorCode;
      }
    }
  
    /**
     * The state of the DRM session. One of {@link #STATE_RELEASED}, {@link #STATE_ERROR}, {@link
     * #STATE_OPENING}, {@link #STATE_OPENED} or {@link #STATE_OPENED_WITH_KEYS}.
     */
    // @Target list includes both 'default' targets and TYPE_USE, to ensure backwards compatibility
    // with Kotlin usages from before TYPE_USE was added.
    @Documented
    @Retention(RetentionPolicy.SOURCE)
    @Target({FIELD, METHOD, PARAMETER, LOCAL_VARIABLE, TYPE_USE})
    @IntDef({STATE_RELEASED, STATE_ERROR, STATE_OPENING, STATE_OPENED, STATE_OPENED_WITH_KEYS})
    @interface State {}
    /** The session has been released. This is a terminal state. */
    int STATE_RELEASED = 0;
    /**
     * The session has encountered an error. {@link #getError()} can be used to retrieve the cause.
     * This is a terminal state.
     */
    int STATE_ERROR = 1;
    /** The session is being opened. */
    int STATE_OPENING = 2;
    /** The session is open, but does not have keys required for decryption. */
    int STATE_OPENED = 3;
    /** The session is open and has keys required for decryption. */
    int STATE_OPENED_WITH_KEYS = 4;
  
    /**
     * Returns the current state of the session, which is one of {@link #STATE_ERROR}, {@link
     * #STATE_RELEASED}, {@link #STATE_OPENING}, {@link #STATE_OPENED} and {@link
     * #STATE_OPENED_WITH_KEYS}.
     */
    @State
    int getState();
  
    /** Returns whether this session allows playback of clear samples prior to keys being loaded. */
    default boolean playClearSamplesWithoutKeys() {
      return false;
    }
  
    /**
     * Returns the cause of the error state, or null if {@link #getState()} is not {@link
     * #STATE_ERROR}.
     */
    @Nullable
    DrmSessionException getError();
  
    /** Returns the DRM scheme UUID for this session. */
    UUID getSchemeUuid();
  
    /**
     * Returns a {@link CryptoConfig} for the open session, or null if called before the session has
     * been opened or after it's been released.
     */
    @Nullable
    CryptoConfig getCryptoConfig();
  
    /**
     * Returns a map describing the key status for the session, or null if called before the session
     * has been opened or after it's been released.
     *
     * <p>Since DRM license policies vary by vendor, the specific status field names are determined by
     * each DRM vendor. Refer to your DRM provider documentation for definitions of the field names
     * for a particular DRM engine plugin.
     *
     * @return A map describing the key status for the session, or null if called before the session
     *     has been opened or after it's been released.
     * @see MediaDrm#queryKeyStatus(byte[])
     */
    @Nullable
    Map<String, String> queryKeyStatus();
  
    /**
     * Returns the key set id of the offline license loaded into this session, or null if there isn't
     * one.
     */
    @Nullable
    byte[] getOfflineLicenseKeySetId();
  
    /**
     * Returns whether this session requires use of a secure decoder for the given MIME type. Assumes
     * a license policy that requires the highest level of security supported by the session.
     *
     * <p>The session must be in {@link #getState() state} {@link #STATE_OPENED} or {@link
     * #STATE_OPENED_WITH_KEYS}.
     */
    boolean requiresSecureDecoder(String mimeType);
  
    /**
     * Increments the reference count. When the caller no longer needs to use the instance, it must
     * call {@link #release(DrmSessionEventListener.EventDispatcher)} to decrement the reference
     * count.
     *
     * @param eventDispatcher The {@link DrmSessionEventListener.EventDispatcher} used to route
     *     DRM-related events dispatched from this session, or null if no event handling is needed.
     */
    void acquire(@Nullable DrmSessionEventListener.EventDispatcher eventDispatcher);
  
    /**
     * Decrements the reference count. If the reference count drops to 0 underlying resources are
     * released, and the instance cannot be re-used.
     *
     * @param eventDispatcher The {@link DrmSessionEventListener.EventDispatcher} to disconnect when
     *     the session is released (the same instance (possibly null) that was passed by the caller to
     *     {@link #acquire(DrmSessionEventListener.EventDispatcher)}).
     */
    void release(@Nullable DrmSessionEventListener.EventDispatcher eventDispatcher);
  }
  