JavaFunSpec.kt

/*
 * Copyright 2022 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.codegen.java

import androidx.room.compiler.codegen.L
import androidx.room.compiler.codegen.VisibilityModifier
import androidx.room.compiler.codegen.XAnnotationSpec
import androidx.room.compiler.codegen.XCodeBlock
import androidx.room.compiler.codegen.XFunSpec
import androidx.room.compiler.codegen.XTypeName
import androidx.room.compiler.processing.KnownTypeNames.KOTLIN_UNIT
import androidx.room.compiler.processing.XNullability
import com.squareup.javapoet.CodeBlock
import com.squareup.javapoet.MethodSpec
import com.squareup.javapoet.ParameterSpec
import com.squareup.kotlinpoet.javapoet.JTypeName
import javax.lang.model.element.Modifier

internal class JavaFunSpec(
    internal val actual: MethodSpec
) : JavaLang(), XFunSpec {

    internal class Builder(
        internal val actual: MethodSpec.Builder
    ) : JavaLang(), XFunSpec.Builder {

        override fun addCode(code: XCodeBlock) = apply {
            require(code is JavaCodeBlock)
            actual.addCode(code.actual)
        }

        override fun addParameter(
            typeName: XTypeName,
            name: String,
            annotations: List<XAnnotationSpec>
        ) = apply {
            actual.addParameter(
                ParameterSpec.builder(typeName.java, name, Modifier.FINAL)
                    .apply {
                        if (typeName.nullability == XNullability.NULLABLE) {
                            addAnnotation(NULLABLE_ANNOTATION)
                        } else if (typeName.nullability == XNullability.NONNULL) {
                            addAnnotation(NONNULL_ANNOTATION)
                        }
                    }.build()
            )
            // TODO(b/247247439): Add other annotations
        }

        override fun callSuperConstructor(vararg args: XCodeBlock) = apply {
            actual.addStatement(
                "super($L)",
                CodeBlock.join(
                    args.map {
                        check(it is JavaCodeBlock)
                        it.actual
                    },
                    ", "
                )
            )
        }

        override fun returns(typeName: XTypeName) = apply {
            if (typeName.java == JTypeName.VOID || typeName.java == KOTLIN_UNIT) {
                return@apply
            }
            // TODO(b/247242374) Add nullability annotations for non-private methods
            if (!actual.modifiers.contains(Modifier.PRIVATE)) {
                if (typeName.nullability == XNullability.NULLABLE) {
                    actual.addAnnotation(NULLABLE_ANNOTATION)
                } else if (typeName.nullability == XNullability.NONNULL) {
                    actual.addAnnotation(NONNULL_ANNOTATION)
                }
            }
            actual.returns(typeName.java)
        }

        override fun build() = JavaFunSpec(actual.build())
    }
}

internal fun VisibilityModifier.toJavaVisibilityModifier() = when (this) {
    VisibilityModifier.PUBLIC -> Modifier.PUBLIC
    VisibilityModifier.PROTECTED -> Modifier.PROTECTED
    VisibilityModifier.PRIVATE -> Modifier.PRIVATE
}