JavacElement.kt

/*
 * Copyright (C) 2020 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 androidx.room.compiler.processing.javac

import androidx.room.compiler.processing.InternalXAnnotated
import androidx.room.compiler.processing.XAnnotation
import androidx.room.compiler.processing.XAnnotationBox
import androidx.room.compiler.processing.XElement
import androidx.room.compiler.processing.XEquality
import androidx.room.compiler.processing.unwrapRepeatedAnnotationsFromContainer
import com.google.auto.common.MoreElements
import com.google.auto.common.MoreElements.isAnnotationPresent
import com.google.auto.common.SuperficialValidation
import java.util.Locale
import javax.lang.model.element.Element
import kotlin.reflect.KClass

@Suppress("UnstableApiUsage")
internal abstract class JavacElement(
    internal val env: JavacProcessingEnv,
    open val element: Element
) : XElement, XEquality, InternalXAnnotated {
    override fun <T : Annotation> getAnnotations(
        annotation: KClass<T>,
        containerAnnotation: KClass<out Annotation>?
    ): List<XAnnotationBox<T>> {
        // if there is a container annotation and annotation is repeated, we'll get the container.
        if (containerAnnotation != null) {
            MoreElements
                .getAnnotationMirror(element, containerAnnotation.java)
                .orNull()
                ?.box(env, containerAnnotation.java)
                ?.let { containerBox ->
                    // found a container, return
                    return containerBox.getAsAnnotationBoxArray<T>("value").toList()
                }
        }
        // if there is no container annotation or annotation is not repeated, we'll see the
        // individual value
        return MoreElements
            .getAnnotationMirror(element, annotation.java)
            .orNull()
            ?.box(env, annotation.java)
            ?.let {
                listOf(it)
            } ?: emptyList()
    }

    override fun getAllAnnotations(): List<XAnnotation> {
        return element.annotationMirrors.map { mirror -> JavacAnnotation(env, mirror) }
            .flatMap { annotation ->
                annotation.unwrapRepeatedAnnotationsFromContainer() ?: listOf(annotation)
            }
    }

    override fun hasAnnotation(
        annotation: KClass<out Annotation>,
        containerAnnotation: KClass<out Annotation>?
    ): Boolean {
        return isAnnotationPresent(element, annotation.java) ||
            (containerAnnotation != null && isAnnotationPresent(element, containerAnnotation.java))
    }

    override fun toString(): String {
        return element.toString()
    }

    final override val equalityItems: Array<out Any?> by lazy {
        arrayOf(element)
    }

    override fun equals(other: Any?): Boolean {
        return XEquality.equals(this, other)
    }

    override fun hashCode(): Int {
        return XEquality.hashCode(equalityItems)
    }

    override fun kindName(): String {
        return element.kind.name.lowercase(Locale.US)
    }

    override fun hasAnnotationWithPackage(pkg: String): Boolean {
        return element.annotationMirrors.any {
            MoreElements.getPackage(it.annotationType.asElement()).toString() == pkg
        }
    }

    override val docComment: String? by lazy {
        env.elementUtils.getDocComment(element)
    }

    override fun validate(): Boolean {
        return SuperficialValidation.validateElement(element)
    }
}