package com.reactnativedigitalink;

import android.util.Log;

import androidx.annotation.Nullable;

import com.facebook.react.bridge.Promise;
import com.google.android.gms.tasks.Task;
import com.google.android.gms.tasks.Tasks;
import com.google.mlkit.vision.digitalink.DigitalInkRecognizer;
import com.google.mlkit.vision.digitalink.Ink;

import java.util.concurrent.atomic.AtomicBoolean;

/**
 * Task to run asynchronously to obtain recognition results.
 */
public class RecognitionTask {

  private static final String TAG = "MLKD.RecognitionTask";
  private final DigitalInkRecognizer recognizer;
  private final Ink ink;
  @Nullable
  private RecognizedInk currentResult;
  private final AtomicBoolean cancelled;
  private final AtomicBoolean done;

  public RecognitionTask(DigitalInkRecognizer recognizer, Ink ink) {
    this.recognizer = recognizer;
    this.ink = ink;
    this.currentResult = null;
    cancelled = new AtomicBoolean(false);
    done = new AtomicBoolean(false);
  }

  public void cancel() {
    cancelled.set(true);
  }

  public boolean done() {
    return done.get();
  }

  @Nullable
  public RecognizedInk result() {
    return this.currentResult;
  }

  /**
   * Helper class that stores an ink along with the corresponding recognized text.
   */
  public static class RecognizedInk {
    public final Ink ink;
    public final String text;

    RecognizedInk(Ink ink, String text) {
      this.ink = ink;
      this.text = text;
    }
  }

  public Task<String> run(Promise promise) {
    Log.i(TAG, "RecoTask.run");
    return recognizer
      .recognize(this.ink)
      .onSuccessTask(
        result -> {
          if (cancelled.get() || result.getCandidates().isEmpty()) {
            return Tasks.forResult(null);
          }
          currentResult = new RecognizedInk(ink, result.getCandidates().get(0).getText());
          Log.i(TAG, "result: " + currentResult.text);
          done.set(true);
          promise.resolve(currentResult.text);
          return Tasks.forResult(currentResult.text);
        });
  }
}