/*
 * Copyright (C) 2019 The Dagger Authors.
 *
 * 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 dagger.hilt.processor.internal.generatesrootinput;

import static net.ltgt.gradle.incap.IncrementalAnnotationProcessorType.ISOLATING;

import com.google.auto.service.AutoService;
import com.google.common.collect.ImmutableSet;
import dagger.hilt.processor.internal.BaseProcessor;
import dagger.hilt.processor.internal.ClassNames;
import dagger.hilt.processor.internal.ProcessorErrors;
import java.util.Set;
import javax.annotation.processing.Processor;
import javax.lang.model.element.Element;
import javax.lang.model.element.ElementKind;
import javax.lang.model.element.TypeElement;
import net.ltgt.gradle.incap.IncrementalAnnotationProcessor;

/**
 * Processes the annotations annotated with {@link dagger.hilt.GeneratesRootInput} which generate
 * input for components and should be processed before component creation.
 */
@IncrementalAnnotationProcessor(ISOLATING)
@AutoService(Processor.class)
public final class GeneratesRootInputProcessor extends BaseProcessor {

  @Override
  public Set<String> getSupportedAnnotationTypes() {
    return ImmutableSet.of(ClassNames.GENERATES_ROOT_INPUT.toString());
  }

  @Override
  public void processEach(TypeElement annotation, Element element) throws Exception {
    ProcessorErrors.checkState(
        element.getKind().equals(ElementKind.ANNOTATION_TYPE),
        element,
        "%s should only annotate other annotations. However, it was found annotating %s",
        annotation,
        element);

    new GeneratesRootInputPropagatedDataGenerator(this.getProcessingEnv(), element).generate();
  }
}