/*
 * 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.android.dialer.rtt;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.support.annotation.WorkerThread;
import com.android.dialer.common.Assert;
import com.android.dialer.common.concurrent.DialerExecutorComponent;
import com.android.dialer.common.database.Selection;
import com.android.dialer.rtt.RttTranscriptContract.RttTranscriptColumn;
import com.google.common.collect.ImmutableSet;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.protobuf.InvalidProtocolBufferException;

/** Util class to save and load RTT transcript. */
public final class RttTranscriptUtil {

  public static ListenableFuture<ImmutableSet<String>> getAvailableRttTranscriptIds(
      Context context, ImmutableSet<String> transcriptIds) {
    return DialerExecutorComponent.get(context)
        .backgroundExecutor()
        .submit(() -> checkRttTranscriptAvailability(context, transcriptIds));
  }

  @WorkerThread
  private static ImmutableSet<String> checkRttTranscriptAvailability(
      Context context, ImmutableSet<String> transcriptIds) {
    Assert.isWorkerThread();
    RttTranscriptDatabaseHelper databaseHelper = new RttTranscriptDatabaseHelper(context);
    ImmutableSet.Builder<String> builder = ImmutableSet.builder();
    Selection selection =
        Selection.builder()
            .and(Selection.column(RttTranscriptColumn.TRANSCRIPT_ID).in(transcriptIds))
            .build();

    try (Cursor cursor =
        databaseHelper
            .getReadableDatabase()
            .query(
                RttTranscriptDatabaseHelper.TABLE,
                new String[] {RttTranscriptColumn.TRANSCRIPT_ID},
                selection.getSelection(),
                selection.getSelectionArgs(),
                null,
                null,
                null)) {
      if (cursor != null) {
        while (cursor.moveToNext()) {
          builder.add(cursor.getString(0));
        }
      }
    }
    databaseHelper.close();
    return builder.build();
  }

  static ListenableFuture<RttTranscript> loadRttTranscript(Context context, String transcriptId) {
    return DialerExecutorComponent.get(context)
        .lightweightExecutor()
        .submit(() -> getRttTranscript(context, transcriptId));
  }

  @WorkerThread
  private static RttTranscript getRttTranscript(Context context, String transcriptId) {
    Assert.isWorkerThread();
    RttTranscriptDatabaseHelper databaseHelper = new RttTranscriptDatabaseHelper(context);
    try (Cursor cursor =
        databaseHelper
            .getReadableDatabase()
            .query(
                RttTranscriptDatabaseHelper.TABLE,
                new String[] {RttTranscriptColumn.TRANSCRIPT_DATA},
                RttTranscriptColumn.TRANSCRIPT_ID + " = ?",
                new String[] {transcriptId},
                null,
                null,
                null)) {
      if (cursor != null && cursor.moveToFirst()) {
        try {
          return RttTranscript.parseFrom(cursor.getBlob(0));
        } catch (InvalidProtocolBufferException e) {
          throw new RuntimeException("Parse failed for RTT transcript", e);
        }
      } else {
        return null;
      }
    } finally {
      databaseHelper.close();
    }
  }

  public static ListenableFuture<Void> saveRttTranscript(
      Context context, RttTranscript rttTranscript) {
    return DialerExecutorComponent.get(context)
        .backgroundExecutor()
        .submit(
            () -> {
              save(context, rttTranscript);
              return null;
            });
  }

  @WorkerThread
  private static void save(Context context, RttTranscript rttTranscript) {
    Assert.isWorkerThread();
    RttTranscriptDatabaseHelper databaseHelper = new RttTranscriptDatabaseHelper(context);
    ContentValues value = new ContentValues();
    value.put(RttTranscriptColumn.TRANSCRIPT_ID, rttTranscript.getId());
    value.put(RttTranscriptColumn.TRANSCRIPT_DATA, rttTranscript.toByteArray());
    long id =
        databaseHelper.getWritableDatabase().insert(RttTranscriptDatabaseHelper.TABLE, null, value);
    databaseHelper.close();
    if (id < 0) {
      throw new RuntimeException("Failed to save RTT transcript");
    }
  }
}