/*
 * Copyright 2012 the original author or 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 org.gradle.api.internal.tasks.scala;

/*
 * Copyright 2012 the original author or 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.
 */

import org.gradle.api.internal.ClassPathRegistry;
import org.gradle.api.internal.tasks.compile.BaseForkOptionsConverter;
import org.gradle.api.internal.tasks.compile.daemon.AbstractDaemonCompiler;
import org.gradle.api.tasks.compile.ForkOptions;
import org.gradle.api.tasks.scala.ScalaForkOptions;
import org.gradle.initialization.ClassLoaderRegistry;
import org.gradle.internal.classloader.FilteringClassLoader;
import org.gradle.internal.classloader.VisitableURLClassLoader;
import org.gradle.internal.classpath.ClassPath;
import org.gradle.internal.classpath.DefaultClassPath;
import org.gradle.language.base.internal.compile.Compiler;
import org.gradle.process.JavaForkOptions;
import org.gradle.process.internal.JavaForkOptionsFactory;
import org.gradle.workers.internal.ActionExecutionSpecFactory;
import org.gradle.workers.internal.DaemonForkOptions;
import org.gradle.workers.internal.DaemonForkOptionsBuilder;
import org.gradle.workers.internal.HierarchicalClassLoaderStructure;
import org.gradle.workers.internal.KeepAliveMode;
import org.gradle.workers.internal.WorkerDaemonFactory;

import java.io.File;

public class DaemonScalaCompiler<T extends ScalaJavaJointCompileSpec> extends AbstractDaemonCompiler<T> {
    private final Class<? extends Compiler<T>> compilerClass;
    private final Object[] compilerConstructorArguments;
    private final Iterable<File> zincClasspath;
    private final JavaForkOptionsFactory forkOptionsFactory;
    private final File daemonWorkingDir;
    private final ClassPathRegistry classPathRegistry;
    private final ClassLoaderRegistry classLoaderRegistry;

    public DaemonScalaCompiler(File daemonWorkingDir, Class<? extends Compiler<T>> compilerClass, Object[] compilerConstructorArguments, WorkerDaemonFactory workerDaemonFactory, Iterable<File> zincClasspath, JavaForkOptionsFactory forkOptionsFactory, ClassPathRegistry classPathRegistry, ClassLoaderRegistry classLoaderRegistry, ActionExecutionSpecFactory actionExecutionSpecFactory) {
        super(workerDaemonFactory, actionExecutionSpecFactory);
        this.compilerClass = compilerClass;
        this.compilerConstructorArguments = compilerConstructorArguments;
        this.zincClasspath = zincClasspath;
        this.forkOptionsFactory = forkOptionsFactory;
        this.daemonWorkingDir = daemonWorkingDir;
        this.classPathRegistry = classPathRegistry;
        this.classLoaderRegistry = classLoaderRegistry;
    }

    @Override
    protected CompilerParameters getCompilerParameters(T spec) {
        return new ScalaCompilerParameters<T>(compilerClass.getName(), compilerConstructorArguments, spec);
    }

    @Override
    protected DaemonForkOptions toDaemonForkOptions(T spec) {
        ForkOptions javaOptions = spec.getCompileOptions().getForkOptions();
        ScalaForkOptions scalaOptions = spec.getScalaCompileOptions().getForkOptions();
        JavaForkOptions javaForkOptions = new BaseForkOptionsConverter(forkOptionsFactory).transform(mergeForkOptions(javaOptions, scalaOptions));
        javaForkOptions.setWorkingDir(daemonWorkingDir);

        ClassPath compilerClasspath = classPathRegistry.getClassPath("SCALA-COMPILER").plus(DefaultClassPath.of(zincClasspath));

        HierarchicalClassLoaderStructure classLoaderStructure = new HierarchicalClassLoaderStructure(classLoaderRegistry.getGradleWorkerExtensionSpec())
                .withChild(getScalaFilterSpec())
                .withChild(new VisitableURLClassLoader.Spec("compiler", compilerClasspath.getAsURLs()));

        return new DaemonForkOptionsBuilder(forkOptionsFactory)
            .javaForkOptions(javaForkOptions)
            .withClassLoaderStructure(classLoaderStructure)
            .keepAliveMode(KeepAliveMode.SESSION)
            .build();
    }

    private FilteringClassLoader.Spec getScalaFilterSpec() {
        FilteringClassLoader.Spec gradleApiAndScalaSpec = classLoaderRegistry.getGradleApiFilterSpec();

        // These should come from the compiler classloader
        gradleApiAndScalaSpec.disallowPackage("org.gradle.api.internal.tasks.scala");

        // Guava
        gradleApiAndScalaSpec.allowPackage("com.google");

        return gradleApiAndScalaSpec;
    }

    public static class ScalaCompilerParameters<T extends ScalaJavaJointCompileSpec> extends CompilerParameters {
        private final T compileSpec;

        public ScalaCompilerParameters(String compilerClassName, Object[] compilerInstanceParameters, T compileSpec) {
            super(compilerClassName, compilerInstanceParameters);
            this.compileSpec = compileSpec;
        }

        @Override
        public T getCompileSpec() {
            return compileSpec;
        }
    }
}

