content: /*
   * Copyright (C) 2018 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.database;
  
  import static java.lang.annotation.ElementType.TYPE_USE;
  
  import android.content.ContentValues;
  import android.database.Cursor;
  import android.database.SQLException;
  import android.database.sqlite.SQLiteDatabase;
  import androidx.annotation.IntDef;
  import com.google.android.exoplayer2.ExoPlayerLibraryInfo;
  import com.google.android.exoplayer2.util.Util;
  import java.lang.annotation.Documented;
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  import java.lang.annotation.Target;
  
  /**
   * Utility methods for accessing versions of media library database components. This allows them to
   * be versioned independently to the version of the containing database.
   */
  public final class VersionTable {
  
    static {
      ExoPlayerLibraryInfo.registerModule("goog.exo.database");
    }
  
    /** Returned by {@link #getVersion(SQLiteDatabase, int, String)} if the version is unset. */
    public static final int VERSION_UNSET = -1;
    /** Version of tables used for offline functionality. */
    public static final int FEATURE_OFFLINE = 0;
    /** Version of tables used for cache content metadata. */
    public static final int FEATURE_CACHE_CONTENT_METADATA = 1;
    /** Version of tables used for cache file metadata. */
    public static final int FEATURE_CACHE_FILE_METADATA = 2;
    /** Version of tables used from external features. */
    public static final int FEATURE_EXTERNAL = 1000;
  
    private static final String TABLE_NAME = DatabaseProvider.TABLE_PREFIX + "Versions";
  
    private static final String COLUMN_FEATURE = "feature";
    private static final String COLUMN_INSTANCE_UID = "instance_uid";
    private static final String COLUMN_VERSION = "version";
  
    private static final String WHERE_FEATURE_AND_INSTANCE_UID_EQUALS =
        COLUMN_FEATURE + " = ? AND " + COLUMN_INSTANCE_UID + " = ?";
  
    private static final String PRIMARY_KEY =
        "PRIMARY KEY (" + COLUMN_FEATURE + ", " + COLUMN_INSTANCE_UID + ")";
    private static final String SQL_CREATE_TABLE_IF_NOT_EXISTS =
        "CREATE TABLE IF NOT EXISTS "
            + TABLE_NAME
            + " ("
            + COLUMN_FEATURE
            + " INTEGER NOT NULL,"
            + COLUMN_INSTANCE_UID
            + " TEXT NOT NULL,"
            + COLUMN_VERSION
            + " INTEGER NOT NULL,"
            + PRIMARY_KEY
            + ")";
  
    @Documented
    @Retention(RetentionPolicy.SOURCE)
    @Target(TYPE_USE)
    @IntDef({
      FEATURE_OFFLINE,
      FEATURE_CACHE_CONTENT_METADATA,
      FEATURE_CACHE_FILE_METADATA,
      FEATURE_EXTERNAL
    })
    private @interface Feature {}
  
    private VersionTable() {}
  
    /**
     * Sets the version of a specified instance of a specified feature.
     *
     * @param writableDatabase The database to update.
     * @param feature The feature.
     * @param instanceUid The unique identifier of the instance of the feature.
     * @param version The version.
     * @throws DatabaseIOException If an error occurs executing the SQL.
     */
    public static void setVersion(
        SQLiteDatabase writableDatabase, @Feature int feature, String instanceUid, int version)
        throws DatabaseIOException {
      try {
        writableDatabase.execSQL(SQL_CREATE_TABLE_IF_NOT_EXISTS);
        ContentValues values = new ContentValues();
        values.put(COLUMN_FEATURE, feature);
        values.put(COLUMN_INSTANCE_UID, instanceUid);
        values.put(COLUMN_VERSION, version);
        writableDatabase.replaceOrThrow(TABLE_NAME, /* nullColumnHack= */ null, values);
      } catch (SQLException e) {
        throw new DatabaseIOException(e);
      }
    }
  
    /**
     * Removes the version of a specified instance of a feature.
     *
     * @param writableDatabase The database to update.
     * @param feature The feature.
     * @param instanceUid The unique identifier of the instance of the feature.
     * @throws DatabaseIOException If an error occurs executing the SQL.
     */
    public static void removeVersion(
        SQLiteDatabase writableDatabase, @Feature int feature, String instanceUid)
        throws DatabaseIOException {
      try {
        if (!Util.tableExists(writableDatabase, TABLE_NAME)) {
          return;
        }
        writableDatabase.delete(
            TABLE_NAME,
            WHERE_FEATURE_AND_INSTANCE_UID_EQUALS,
            featureAndInstanceUidArguments(feature, instanceUid));
      } catch (SQLException e) {
        throw new DatabaseIOException(e);
      }
    }
  
    /**
     * Returns the version of a specified instance of a feature, or {@link #VERSION_UNSET} if no
     * version is set.
     *
     * @param database The database to query.
     * @param feature The feature.
     * @param instanceUid The unique identifier of the instance of the feature.
     * @return The version, or {@link #VERSION_UNSET} if no version is set.
     * @throws DatabaseIOException If an error occurs executing the SQL.
     */
    public static int getVersion(SQLiteDatabase database, @Feature int feature, String instanceUid)
        throws DatabaseIOException {
      try {
        if (!Util.tableExists(database, TABLE_NAME)) {
          return VERSION_UNSET;
        }
        try (Cursor cursor =
            database.query(
                TABLE_NAME,
                new String[] {COLUMN_VERSION},
                WHERE_FEATURE_AND_INSTANCE_UID_EQUALS,
                featureAndInstanceUidArguments(feature, instanceUid),
                /* groupBy= */ null,
                /* having= */ null,
                /* orderBy= */ null)) {
          if (cursor.getCount() == 0) {
            return VERSION_UNSET;
          }
          cursor.moveToNext();
          return cursor.getInt(/* COLUMN_VERSION index */ 0);
        }
      } catch (SQLException e) {
        throw new DatabaseIOException(e);
      }
    }
  
    private static String[] featureAndInstanceUidArguments(int feature, String instance) {
      return new String[] {Integer.toString(feature), instance};
    }
  }
  