/*

 * 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.

 */

import java.io.*;

import java.nio.file.Files;

import java.nio.file.Path;

import java.util.*;

import java.util.function.Function;

import java.util.stream.Collectors;

import javax.tools.DiagnosticCollector;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileObject;

import javax.tools.ToolProvider;

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.ConstantPoolException;

/**

 * Base class for class file attribute tests.

 * Contains methods for compiling generated sources in memory,

 * for reading files from disk and a lot of assert* methods.

 */

public class TestBase {

    public static final String LINE_SEPARATOR = System.lineSeparator();

    public static final boolean isDumpOfSourceEnabled = Boolean.getBoolean("dump.src");

    private <S> InMemoryFileManager compile(

            List<String> options,

            Function<S, ? extends JavaFileObject> src2JavaFileObject,

            List<S> sources)

            throws IOException, CompilationException {

        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

        List<? extends JavaFileObject> src = sources.stream()

                .map(src2JavaFileObject)

                .collect(Collectors.toList());

        DiagnosticCollector<? super JavaFileObject> dc = new DiagnosticCollector<>();

        try (InMemoryFileManager fileManager

                     = new InMemoryFileManager(compiler.getStandardFileManager(null, null, null))) {

            JavaCompiler.CompilationTask task = compiler.getTask(null, fileManager, dc, options, null, src);

            boolean success = task.call();

            if (!success) {

                String errorMessage = dc.getDiagnostics().stream()

                        .map(Object::toString)

                        .collect(Collectors.joining("\n"));

                throw new CompilationException("Compilation Error\n\n" + errorMessage);

            }

            return fileManager;

        }

    }

    /**

     * Compiles sources in memory.

     *

     * @param sources to compile

     * @return in-memory file manager which contains class files and class loader

     */

    public InMemoryFileManager compile(String... sources)

            throws IOException, CompilationException {

        return compile(Collections.emptyList(), sources);

    }

    /**

     * Compiles sources in memory.

     *

     * @param options compiler options.

     * @param sources sources to compile.

     * @return in-memory file manager which contains class files and class loader.

     */

    public InMemoryFileManager compile(List<String> options, String... sources)

            throws IOException, CompilationException {

        return compile(options, ToolBox.JavaSource::new, Arrays.asList(sources));

    }

    /**

     * Compiles sources in memory.

     *

     * @param sources sources[i][0] - name of file, sources[i][1] - sources.

     * @return in-memory file manager which contains class files and class loader.

     */

    public InMemoryFileManager compile(String[]... sources) throws IOException,

            CompilationException {

        return compile(Collections.emptyList(), sources);

    }

    /**

     * Compiles sources in memory.

     *

     * @param options compiler options

     * @param sources sources[i][0] - name of file, sources[i][1] - sources.

     * @return in-memory file manager which contains class files and class loader.

     */

    public InMemoryFileManager compile(List<String> options, String[]... sources)

            throws IOException, CompilationException {

        return compile(options, src -> new ToolBox.JavaSource(src[0], src[1]), Arrays.asList(sources));

    }

    /**

     * Returns class file that is read from {@code is}.

     *

     * @param is an input stream

     * @return class file that is read from {@code is}

     * @throws IOException if I/O error occurs

     * @throws ConstantPoolException if constant pool error occurs

     */

    public ClassFile readClassFile(InputStream is) throws IOException, ConstantPoolException {

        return ClassFile.read(is);

    }

    /**

     * Returns class file that is read from {@code fileObject}.

     *

     * @param fileObject a file object

     * @return class file that is read from {@code fileObject}

     * @throws IOException if I/O error occurs

     * @throws ConstantPoolException if constant pool error occurs

     */

    public ClassFile readClassFile(JavaFileObject fileObject) throws IOException, ConstantPoolException {

        try (InputStream is = fileObject.openInputStream()) {

            return readClassFile(is);

        }

    }

    /**

     * Returns class file that corresponds to {@code clazz}.

     *

     * @param clazz a class

     * @return class file that is read from {@code clazz}

     * @throws IOException if I/O error occurs

     * @throws ConstantPoolException if constant pool error occurs

     */

    public ClassFile readClassFile(Class<?> clazz) throws IOException, ConstantPoolException {

        return readClassFile(getClassFile(clazz));

    }

    /**

     * Returns class file that corresponds to {@code className}.

     *

     * @param className a class name

     * @return class file that is read from {@code className}

     * @throws IOException if I/O error occurs

     * @throws ConstantPoolException if constant pool error occurs

     */

    public ClassFile readClassFile(String className) throws IOException, ConstantPoolException {

        return readClassFile(getClassFile(className + ".class"));

    }

    /**

     * Returns class file that is read from {@code file}.

     *

     * @param file a file

     * @return class file that is read from {@code file}

     * @throws IOException if I/O error occurs

     * @throws ConstantPoolException if constant pool error occurs

     */

    public ClassFile readClassFile(File file) throws IOException, ConstantPoolException {

        try (InputStream is = new FileInputStream(file)) {

            return readClassFile(is);

        }

    }

    public void assertEquals(Object actual, Object expected, String message) {

        if (!Objects.equals(actual, expected))

            throw new AssertionFailedException(String.format("%s%nGot: %s, Expected: %s",

                    message, actual, expected));

    }

    public void assertNull(Object actual, String message) {

        assertEquals(actual, null, message);

    }

    public void assertNotNull(Object actual, String message) {

        if (Objects.isNull(actual)) {

            throw new AssertionFailedException(message + " : Expected not null value");

        }

    }

    public void assertTrue(boolean actual, String message) {

        assertEquals(actual, true, message);

    }

    public void assertFalse(boolean actual, String message) {

        assertEquals(actual, false, message);

    }

    public void assertContains(Set<?> found, Set<?> expected, String message) {

        Set<?> copy = new HashSet<>(expected);

        copy.removeAll(found);

        assertTrue(found.containsAll(expected), message + " : " + copy);

    }

    public void writeToFile(Path path, String source) throws IOException {

        try (BufferedWriter writer = Files.newBufferedWriter(path)) {

            writer.write(source);

        }

    }

    public void writeToFileIfEnabled(Path path, String source) throws IOException {

        if (isDumpOfSourceEnabled) {

            writeToFile(path, source);

        } else {

            System.err.println("Source dumping disabled. To enable, run the test with '-Ddump.src=true'");

        }

    }

    public File getSourceDir() {

        return new File(System.getProperty("test.src", "."));

    }

    public File getClassDir() {

        return new File(System.getProperty("test.classes", TestBase.class.getResource(".").getPath()));

    }

    public File getSourceFile(String fileName) {

        return new File(getSourceDir(), fileName);

    }

    public File getClassFile(String fileName) {

        return new File(getClassDir(), fileName);

    }

    public File getClassFile(Class clazz) {

        return getClassFile(clazz.getName().replace(".", "/") + ".class");

    }

    /**

     * Prints message to standard error. New lines are converted to system dependent NL.

     *

     * @param message string to print.

     */

    public void echo(String message) {

        printf(message + "\n");

    }

    /**

     * Substitutes args in template and prints result to standard error.

     * New lines are converted to system dependent NL.

     *

     * @param template template in standard String.format(...) format.

     * @param args arguments to substitute in template.

     */

    public void printf(String template, Object... args) {

        System.err.printf(String.format(template, args).replace("\n", LINE_SEPARATOR));

    }

    public static class CompilationException extends Exception {

        public CompilationException(String message) {

            super(message);

        }

    }

    public static class AssertionFailedException extends RuntimeException {

        public AssertionFailedException(String message) {

            super(message);

        }

    }

}