br.com.objectos.code.AnnotationExecutor Maven / Gradle / Ivy

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/*
 * Copyright 2016 Objectos, Fábrica de Software LTDA.
 *
 * 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 br.com.objectos.code;

import java.util.ArrayList;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import java.util.stream.Stream;

import javax.annotation.processing.RoundEnvironment;
import javax.lang.model.element.Element;
import javax.lang.model.element.TypeElement;

/**
 * @author [email protected] (Marcio Endo)
 */
class AnnotationExecutor {

  private final ProcessingEnvironmentWrapper processingEnv;
  private final List artifactGeneratorList;
  private final ProcessorListener listener;

  private final Set elementRetrySet = new LinkedHashSet<>();

  public AnnotationExecutor(ProcessingEnvironmentWrapper processingEnv,
                            List artifactGeneratorList,
                            ProcessorListener listener) {
    this.processingEnv = processingEnv;
    this.artifactGeneratorList = artifactGeneratorList;
    this.listener = listener;
  }

  public void onInit() {
    listener.onInit(processingEnv);
  }

  public boolean process(Set annotations, RoundEnvironment roundEnv) {
    try {
      listener.onStart(annotations, roundEnv);

      List elementRetryList = new ArrayList<>(elementRetrySet);
      Stream retryStream = elementRetryList
          .stream()
          .map(el -> el.retry(processingEnv));
      Stream roundStream = roundStream(annotations, roundEnv);
      Stream.concat(retryStream, roundStream)
          .flatMap(this::generateIfPossible)
          .peek(listener::peek)
          .forEach(this::execute);

      return listener.onSuccess(annotations, roundEnv);

    } catch (Throwable e) {
      String msg = Throwables.getStackTraceAsString(e);
      processingEnv.compilationError("Processor threw an exception: " + msg);
      return listener.onError(annotations, roundEnv, e);

    } finally {
      listener.onFinish(annotations, roundEnv);
    }
  }

  void execute(Artifact artifact) {
    artifact.execute(processingEnv.unwrap());
  }

  private Stream generateIfPossible(Element element) {
    Stream.Builder stream = Stream.builder();
    ElementRetry elementRetry = ElementRetry.of(element);

    for (ArtifactGenerator generator : artifactGeneratorList) {
      if (generator.test(element)) {
        try {
          Artifact artifact = generator.generateArtifact(processingEnv, element);
          if (artifact == null) {
            processingEnv.compilationError("ArtifactGenerator returned null.");
          } else {
            stream.accept(artifact);
          }
          elementRetry.removeFrom(elementRetrySet);
        } catch (CodeGenerationIncompleteException e) {
          elementRetry.addTo(elementRetrySet);
        } catch (Exception e) {
          String msg = Throwables.getStackTraceAsString(e);
          processingEnv.compilationError("Processor threw an exception: " + msg);
        }
      }
    }
    return stream.build();
  }

  private Stream roundStream(Set annotations, RoundEnvironment roundEnv) {
    return annotations.stream()
        .map(annotationType -> roundEnv.getElementsAnnotatedWith(annotationType))
        .flatMap(Set::stream);
  }

}