/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package toolbox;

import java.io.File;

import java.io.IOException;

import java.io.PrintWriter;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileManager;

import javax.tools.JavaFileObject;

import javax.tools.StandardJavaFileManager;

import javax.tools.StandardLocation;

import com.sun.tools.javac.api.JavacTaskImpl;

import com.sun.tools.javac.api.JavacTool;

/**

 * A task to configure and run the Java compiler, javac.

 */

public class JavacTask extends AbstractTask<JavacTask> {

    private boolean includeStandardOptions;

    private List<Path> classpath;

    private List<Path> sourcepath;

    private Path outdir;

    private List<String> options;

    private List<String> classes;

    private List<String> files;

    private List<JavaFileObject> fileObjects;

    private JavaFileManager fileManager;

    private JavaCompiler compiler;

    private StandardJavaFileManager internalFileManager;

    /**

     * Creates a task to execute {@code javac} using API mode.

     * @param toolBox the {@code ToolBox} to use

     */

    public JavacTask(ToolBox toolBox) {

        super(toolBox, Task.Mode.API);

    }

    /**

     * Creates a task to execute {@code javac} in a specified mode.

     * @param toolBox the {@code ToolBox} to use

     * @param mode the mode to be used

     */

    public JavacTask(ToolBox toolBox, Task.Mode mode) {

        super(toolBox, mode);

    }

    /**

     * Sets the classpath.

     * @param classpath the classpath

     * @return this task object

     */

    public JavacTask classpath(String classpath) {

        this.classpath = Stream.of(classpath.split(File.pathSeparator))

                .filter(s -> !s.isEmpty())

                .map(s -> Paths.get(s))

                .collect(Collectors.toList());

        return this;

    }

    /**

     * Sets the classpath.

     * @param classpath the classpath

     * @return this task object

     */

    public JavacTask classpath(Path... classpath) {

        this.classpath = Arrays.asList(classpath);

        return this;

    }

    /**

     * Sets the classpath.

     * @param classpath the classpath

     * @return this task object

     */

    public JavacTask classpath(List<Path> classpath) {

        this.classpath = classpath;

        return this;

    }

    /**

     * Sets the sourcepath.

     * @param sourcepath the sourcepath

     * @return this task object

     */

    public JavacTask sourcepath(String sourcepath) {

        this.sourcepath = Stream.of(sourcepath.split(File.pathSeparator))

                .filter(s -> !s.isEmpty())

                .map(s -> Paths.get(s))

                .collect(Collectors.toList());

        return this;

    }

    /**

     * Sets the sourcepath.

     * @param sourcepath the sourcepath

     * @return this task object

     */

    public JavacTask sourcepath(Path... sourcepath) {

        this.sourcepath = Arrays.asList(sourcepath);

        return this;

    }

    /**

     * Sets the sourcepath.

     * @param sourcepath the sourcepath

     * @return this task object

     */

    public JavacTask sourcepath(List<Path> sourcepath) {

        this.sourcepath = sourcepath;

        return this;

    }

    /**

     * Sets the output directory.

     * @param outdir the output directory

     * @return this task object

     */

    public JavacTask outdir(String outdir) {

        this.outdir = Paths.get(outdir);

        return this;

    }

    /**

     * Sets the output directory.

     * @param outdir the output directory

     * @return this task object

     */

    public JavacTask outdir(Path outdir) {

        this.outdir = outdir;

        return this;

    }

    /**

     * Sets the options.

     * @param options the options

     * @return this task object

     */

    public JavacTask options(String... options) {

        this.options = Arrays.asList(options);

        return this;

    }

    /**

     * Sets the options.

     * @param options the options

     * @return this task object

     */

    public JavacTask options(List<String> options) {

        this.options = options;

        return this;

    }

    /**

     * Sets the classes to be analyzed.

     * @param classes the classes

     * @return this task object

     */

    public JavacTask classes(String... classes) {

        this.classes = Arrays.asList(classes);

        return this;

    }

    /**

     * Sets the files to be compiled or analyzed.

     * @param files the files

     * @return this task object

     */

    public JavacTask files(String... files) {

        this.files = Arrays.asList(files);

        return this;

    }

    /**

     * Sets the files to be compiled or analyzed.

     * @param files the files

     * @return this task object

     */

    public JavacTask files(Path... files) {

        this.files = Stream.of(files)

                .map(Path::toString)

                .collect(Collectors.toList());

        return this;

    }

    /**

     * Sets the files to be compiled or analyzed.

     * @param files the files

     * @return this task object

     */

    public JavacTask files(List<Path> files) {

        this.files = files.stream()

                .map(Path::toString)

                .collect(Collectors.toList());

        return this;

    }

    /**

     * Sets the sources to be compiled or analyzed.

     * Each source string is converted into an in-memory object that

     * can be passed directly to the compiler.

     * @param sources the sources

     * @return this task object

     */

    public JavacTask sources(String... sources) {

        fileObjects = Stream.of(sources)

                .map(s -> new ToolBox.JavaSource(s))

                .collect(Collectors.toList());

        return this;

    }

    /**

     * Sets the file manager to be used by this task.

     * @param fileManager the file manager

     * @return this task object

     */

    public JavacTask fileManager(JavaFileManager fileManager) {

        this.fileManager = fileManager;

        return this;

    }

    /**

     * {@inheritDoc}

     * @return the name "javac"

     */

    @Override

    public String name() {

        return "javac";

    }

    /**

     * Calls the compiler with the arguments as currently configured.

     * @return a Result object indicating the outcome of the compilation

     * and the content of any output written to stdout, stderr, or the

     * main stream by the compiler.

     * @throws TaskError if the outcome of the task is not as expected.

     */

    @Override

    public Task.Result run() {

        if (mode == Task.Mode.EXEC)

            return runExec();

        AbstractTask.WriterOutput direct = new AbstractTask.WriterOutput();

        // The following are to catch output to System.out and System.err,

        // in case these are used instead of the primary (main) stream

        AbstractTask.StreamOutput sysOut = new AbstractTask.StreamOutput(System.out, System::setOut);

        AbstractTask.StreamOutput sysErr = new AbstractTask.StreamOutput(System.err, System::setErr);

        int rc;

        Map<Task.OutputKind, String> outputMap = new HashMap<>();

        try {

            switch (mode == null ? Task.Mode.API : mode) {

                case API:

                    rc = runAPI(direct.pw);

                    break;

                case CMDLINE:

                    rc = runCommand(direct.pw);

                    break;

                default:

            }

        } catch (IOException e) {

            toolBox.out.println("Exception occurred: " + e);

            rc = 99;

        } finally {

            outputMap.put(Task.OutputKind.STDOUT, sysOut.close());

            outputMap.put(Task.OutputKind.STDERR, sysErr.close());

            outputMap.put(Task.OutputKind.DIRECT, direct.close());

        }

        return checkExit(new Task.Result(toolBox, this, rc, outputMap));

    }

    private int runAPI(PrintWriter pw) throws IOException {

        try {

//                if (compiler == null) {

                // TODO: allow this to be set externally

//                    compiler = ToolProvider.getSystemJavaCompiler();

                compiler = JavacTool.create();

//                }

            if (fileManager == null)

                fileManager = internalFileManager = compiler.getStandardFileManager(null, null, null);

            if (outdir != null)

                setLocationFromPaths(StandardLocation.CLASS_OUTPUT, Collections.singletonList(outdir));

            if (classpath != null)

                setLocationFromPaths(StandardLocation.CLASS_PATH, classpath);

            if (sourcepath != null)

                setLocationFromPaths(StandardLocation.SOURCE_PATH, sourcepath);

            List<String> allOpts = new ArrayList<>();

            if (options != null)

                allOpts.addAll(options);

            Iterable<? extends JavaFileObject> allFiles = joinFiles(files, fileObjects);

            JavaCompiler.CompilationTask task = compiler.getTask(pw,

                    fileManager,

                    null,  // diagnostic listener; should optionally collect diags

                    allOpts,

                    classes,

                    allFiles);

            return ((JavacTaskImpl) task).doCall().exitCode;

        } finally {

            if (internalFileManager != null)

                internalFileManager.close();

        }

    }

    private void setLocationFromPaths(StandardLocation location, List<Path> files) throws IOException {

        if (!(fileManager instanceof StandardJavaFileManager))

            throw new IllegalStateException("not a StandardJavaFileManager");

        ((StandardJavaFileManager) fileManager).setLocationFromPaths(location, files);

    }

    private int runCommand(PrintWriter pw) {

        List<String> args = getAllArgs();

        String[] argsArray = args.toArray(new String[args.size()]);

        return com.sun.tools.javac.Main.compile(argsArray, pw);

    }

    private Task.Result runExec() {

        List<String> args = new ArrayList<>();

        Path javac = toolBox.getJDKTool("javac");

        args.add(javac.toString());

        if (includeStandardOptions) {

            args.addAll(toolBox.split(System.getProperty("test.tool.vm.opts"), " +"));

            args.addAll(toolBox.split(System.getProperty("test.compiler.opts"), " +"));

        }

        args.addAll(getAllArgs());

        String[] argsArray = args.toArray(new String[args.size()]);

        ProcessBuilder pb = getProcessBuilder();

        pb.command(argsArray);

        try {

            return runProcess(toolBox, this, pb.start());

        } catch (IOException | InterruptedException e) {

            throw new Error(e);

        }

    }

    private List<String> getAllArgs() {

        List<String> args = new ArrayList<>();

        if (options != null)

            args.addAll(options);

        if (outdir != null) {

            args.add("-d");

            args.add(outdir.toString());

        }

        if (classpath != null) {

            args.add("-classpath");

            args.add(toSearchPath(classpath));

        }

        if (sourcepath != null) {

            args.add("-sourcepath");

            args.add(toSearchPath(sourcepath));

        }

        if (classes != null)

            args.addAll(classes);

        if (files != null)

            args.addAll(files);

        return args;

    }

    private String toSearchPath(List<Path> files) {

        return files.stream()

            .map(Path::toString)

            .collect(Collectors.joining(File.pathSeparator));

    }

    private Iterable<? extends JavaFileObject> joinFiles(

            List<String> files, List<JavaFileObject> fileObjects) {

        if (files == null)

            return fileObjects;

        if (internalFileManager == null)

            internalFileManager = compiler.getStandardFileManager(null, null, null);

        Iterable<? extends JavaFileObject> filesAsFileObjects =

                internalFileManager.getJavaFileObjectsFromStrings(files);

        if (fileObjects == null)

            return filesAsFileObjects;

        List<JavaFileObject> combinedList = new ArrayList<>();

        for (JavaFileObject o : filesAsFileObjects)

            combinedList.add(o);

        combinedList.addAll(fileObjects);

        return combinedList;

    }

}