/*
 * Copyright 2014 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.language.java.plugins;

import org.gradle.api.DefaultTask;
import org.gradle.api.Plugin;
import org.gradle.api.Project;
import org.gradle.api.Task;
import org.gradle.api.artifacts.dsl.RepositoryHandler;
import org.gradle.api.internal.artifacts.ArtifactDependencyResolver;
import org.gradle.api.internal.artifacts.repositories.ResolutionAwareRepository;
import org.gradle.internal.Transformers;
import org.gradle.internal.service.ServiceRegistry;
import org.gradle.jvm.JvmBinarySpec;
import org.gradle.jvm.JvmByteCode;
import org.gradle.jvm.internal.DependencyResolvingClasspath;
import org.gradle.jvm.internal.JarBinarySpecInternal;
import org.gradle.language.base.LanguageSourceSet;
import org.gradle.language.base.internal.SourceTransformTaskConfig;
import org.gradle.language.base.internal.registry.LanguageTransform;
import org.gradle.language.base.internal.registry.LanguageTransformContainer;
import org.gradle.language.base.plugins.ComponentModelBasePlugin;
import org.gradle.language.java.JavaSourceSet;
import org.gradle.language.java.internal.DefaultJavaLanguageSourceSet;
import org.gradle.language.java.tasks.PlatformJavaCompile;
import org.gradle.language.jvm.plugins.JvmResourcesPlugin;
import org.gradle.model.Mutate;
import org.gradle.model.RuleSource;
import org.gradle.model.internal.manage.schema.ModelSchemaStore;
import org.gradle.platform.base.BinarySpec;
import org.gradle.platform.base.LanguageType;
import org.gradle.platform.base.LanguageTypeBuilder;
import org.gradle.util.CollectionUtils;

import java.io.File;
import java.util.Collections;
import java.util.List;
import java.util.Map;

/**
 * Plugin for compiling Java code. Applies the {@link org.gradle.language.base.plugins.ComponentModelBasePlugin} and {@link org.gradle.language.jvm.plugins.JvmResourcesPlugin}. Registers "java"
 * language support with the {@link JavaSourceSet}.
 */
public class JavaLanguagePlugin implements Plugin<Project> {

    public void apply(Project project) {
        project.getPluginManager().apply(ComponentModelBasePlugin.class);
        project.getPluginManager().apply(JvmResourcesPlugin.class);
    }

    @SuppressWarnings("UnusedDeclaration")
    static class Rules extends RuleSource {
        @LanguageType
        void registerLanguage(LanguageTypeBuilder<JavaSourceSet> builder) {
            builder.setLanguageName("java");
            builder.defaultImplementation(DefaultJavaLanguageSourceSet.class);
        }

        @Mutate
        void registerLanguageTransform(LanguageTransformContainer languages, ServiceRegistry serviceRegistry) {
            ModelSchemaStore schemaStore = serviceRegistry.get(ModelSchemaStore.class);
            languages.add(new Java(schemaStore));
        }
    }

    private static class Java implements LanguageTransform<JavaSourceSet, JvmByteCode> {
        private final ModelSchemaStore schemaStore;

        public Java(ModelSchemaStore schemaStore) {
            this.schemaStore = schemaStore;
        }

        public Class<JavaSourceSet> getSourceSetType() {
            return JavaSourceSet.class;
        }

        public Map<String, Class<?>> getBinaryTools() {
            return Collections.emptyMap();
        }

        public Class<JvmByteCode> getOutputType() {
            return JvmByteCode.class;
        }

        public SourceTransformTaskConfig getTransformTask() {
            return new SourceTransformTaskConfig() {
                public String getTaskPrefix() {
                    return "compile";
                }

                public Class<? extends DefaultTask> getTaskType() {
                    return PlatformJavaCompile.class;
                }

                public void configureTask(Task task, BinarySpec binarySpec, LanguageSourceSet sourceSet, ServiceRegistry serviceRegistry) {
                    PlatformJavaCompile compile = (PlatformJavaCompile) task;
                    JavaSourceSet javaSourceSet = (JavaSourceSet) sourceSet;
                    JarBinarySpecInternal binary = (JarBinarySpecInternal) binarySpec;

                    ArtifactDependencyResolver dependencyResolver = serviceRegistry.get(ArtifactDependencyResolver.class);
                    RepositoryHandler repositories = serviceRegistry.get(RepositoryHandler.class);
                    List<ResolutionAwareRepository> resolutionAwareRepositories = CollectionUtils.collect(repositories, Transformers.cast(ResolutionAwareRepository.class));

                    compile.setDescription(String.format("Compiles %s.", javaSourceSet));
                    compile.setDestinationDir(binary.getClassesDir());
                    compile.setToolChain(binary.getToolChain());
                    compile.setPlatform(binary.getTargetPlatform());

                    compile.setSource(javaSourceSet.getSource());
                    DependencyResolvingClasspath classpath = new DependencyResolvingClasspath(binary, javaSourceSet, dependencyResolver, schemaStore, resolutionAwareRepositories);
                    compile.setClasspath(classpath);
                    compile.setTargetCompatibility(binary.getTargetPlatform().getTargetCompatibility().toString());
                    compile.setSourceCompatibility(binary.getTargetPlatform().getTargetCompatibility().toString());

                    compile.setDependencyCacheDir(new File(compile.getProject().getBuildDir(), "jvm-dep-cache"));
                    compile.dependsOn(javaSourceSet);

                    binary.getTasks().getJar().dependsOn(compile);
                    binary.getApiJar().builtBy(compile);
                }
            };
        }

        public boolean applyToBinary(BinarySpec binary) {
            return binary instanceof JvmBinarySpec;
        }
    }

}
