java/com/google/android/textclassifier/ActionsSuggestionsModel.java

/*
 * 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.textclassifier;

import java.util.concurrent.atomic.AtomicBoolean;

/**
 * Java wrapper for ActionsSuggestions native library interface. This library is used to suggest
 * actions and replies in a given conversation.
 *
 * @hide
 */
public final class ActionsSuggestionsModel implements AutoCloseable {
  private final AtomicBoolean isClosed = new AtomicBoolean(false);

  static {
    System.loadLibrary("textclassifier");
  }

  private long actionsModelPtr;
  private AnnotatorModel annotator;

  /**
   * Creates a new instance of Actions predictor, using the provided model image, given as a file
   * descriptor.
   */
  public ActionsSuggestionsModel(int fileDescriptor) {
    this(fileDescriptor, null);
  }

  public ActionsSuggestionsModel(int fileDescriptor, AnnotatorModel annotator) {
    actionsModelPtr = nativeNewActionsModel(fileDescriptor);
    if (actionsModelPtr == 0L) {
      throw new IllegalArgumentException("Couldn't initialize actions model from file descriptor.");
    }
    setAnnotator(annotator);
  }

  /**
   * Creates a new instance of Actions predictor, using the provided model image, given as a file
   * path.
   */
  public ActionsSuggestionsModel(String path) {
    this(path, null);
  }

  public ActionsSuggestionsModel(String path, AnnotatorModel annotator) {
    actionsModelPtr = nativeNewActionsModelFromPath(path);
    if (actionsModelPtr == 0L) {
      throw new IllegalArgumentException("Couldn't initialize actions model from given file.");
    }
    setAnnotator(annotator);
  }

  /** Suggests actions / replies to the given conversation. */
  public ActionSuggestion[] suggestActions(
      Conversation conversation, ActionSuggestionOptions options) {
    return nativeSuggestActions(actionsModelPtr, conversation, options);
  }

  /** Frees up the allocated memory. */
  @Override
  public void close() {
    if (isClosed.compareAndSet(false, true)) {
      nativeCloseActionsModel(actionsModelPtr);
      actionsModelPtr = 0L;
    }
  }

  @Override
  protected void finalize() throws Throwable {
    try {
      close();
    } finally {
      super.finalize();
    }
  }

  /** Returns a comma separated list of locales supported by the model as BCP 47 tags. */
  public static String getLocales(int fd) {
    return nativeGetLocales(fd);
  }

  /** Returns the version of the model. */
  public static int getVersion(int fd) {
    return nativeGetVersion(fd);
  }

  /** Returns the name of the model. */
  public static String getName(int fd) {
    return nativeGetName(fd);
  }

  /** Action suggestion that contains a response text and the type of the response. */
  public static final class ActionSuggestion {
    private final String responseText;
    private final String actionType;
    private final float score;

    public ActionSuggestion(String responseText, String actionType, float score) {
      this.responseText = responseText;
      this.actionType = actionType;
      this.score = score;
    }

    public String getResponseText() {
      return responseText;
    }

    public String getActionType() {
      return actionType;
    }

    /** Confidence score between 0 and 1 */
    public float getScore() {
      return score;
    }
  }

  /** Represents a single message in the conversation. */
  public static final class ConversationMessage {
    private final int userId;
    private final String text;
    private final long referenceTimeMsUtc;
    private final String locales;

    public ConversationMessage(int userId, String text, long referenceTimeMsUtc, String locales) {
      this.userId = userId;
      this.text = text;
      this.referenceTimeMsUtc = referenceTimeMsUtc;
      this.locales = locales;
    }

    /** The identifier of the sender */
    public int getUserId() {
      return userId;
    }

    public String getText() {
      return text;
    }

    /**
     * Return the reference time of the message, for example, it could be compose time or send time.
     * {@code 0} means unspecified.
     */
    public long getReferenceTimeMsUtc() {
      return referenceTimeMsUtc;
    }

    /** Returns a comma separated list of locales supported by the model as BCP 47 tags. */
    public String getLocales() {
      return locales;
    }
  }

  /** Represents conversation between multiple users. */
  public static final class Conversation {
    public final ConversationMessage[] conversationMessages;

    public Conversation(ConversationMessage[] conversationMessages) {
      this.conversationMessages = conversationMessages;
    }

    public ConversationMessage[] getConversationMessages() {
      return conversationMessages;
    }
  }

  /** Represents options for the SuggestActions call. */
  public static final class ActionSuggestionOptions {
    private final AnnotatorModel.AnnotationOptions annotationOptions;

    public ActionSuggestionOptions() {
      this.annotationOptions = null;
    }

    public ActionSuggestionOptions(AnnotatorModel.AnnotationOptions annotationOptions) {
      this.annotationOptions = annotationOptions;
    }

    public AnnotatorModel.AnnotationOptions getAnnotationOptions() {
      return annotationOptions;
    }
  }

  /** Sets and annotator to use for actions suggestions. */
  private void setAnnotator(AnnotatorModel annotator) {
    this.annotator = annotator;
    if (annotator != null) {
      nativeSetAnnotator(annotator.getNativeAnnotator());
    }
  }

  private static native long nativeNewActionsModel(int fd);

  private static native long nativeNewActionsModelFromPath(String path);

  private static native String nativeGetLocales(int fd);

  private static native int nativeGetVersion(int fd);

  private static native String nativeGetName(int fd);

  private native ActionSuggestion[] nativeSuggestActions(
      long context, Conversation conversation, ActionSuggestionOptions options);

  private native void nativeCloseActionsModel(long context);

  private native void nativeSetAnnotator(long annotatorPtr);
}