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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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
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 *
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import tests.Helper;
import tests.JImageGenerator;


/*
 * @test
 * @summary Compare packaged-modules jlink with a run-time image based jlink to
 *          produce the same result
 * @requires (jlink.packagedModules & vm.compMode != "Xcomp" & os.maxMemory >= 2g)
 * @library ../../lib /test/lib
 * @enablePreview
 * @modules java.base/jdk.internal.jimage
 *          jdk.jlink/jdk.tools.jlink.internal
 *          jdk.jlink/jdk.tools.jlink.plugin
 *          jdk.jlink/jdk.tools.jimage
 * @build tests.* jdk.test.lib.process.OutputAnalyzer
 *        jdk.test.lib.process.ProcessTools
 * @run main/othervm/timeout=1200 -Xmx1g PackagedModulesVsRuntimeImageLinkTest
 */
public class PackagedModulesVsRuntimeImageLinkTest extends AbstractLinkableRuntimeTest {

    public static void main(String[] args) throws Exception {
        PackagedModulesVsRuntimeImageLinkTest test = new PackagedModulesVsRuntimeImageLinkTest();
        test.run();
    }

    @Override
    void runTest(Helper helper, boolean isLinkableRuntime) throws Exception {
        // create a java.se using jmod-less approach
        BaseJlinkSpecBuilder builder = new BaseJlinkSpecBuilder()
                .helper(helper)
                .name("java-se-jmodless")
                .addModule("java.se")
                .validatingModule("java.se");
        if (isLinkableRuntime) {
            builder.setLinkableRuntime();
        }
        Path javaSEruntimeLink = createJavaImageRuntimeLink(builder.build());

        // create a java.se using packaged modules (jmod-full)
        Path javaSEJmodFull = JImageGenerator.getJLinkTask()
                .output(helper.createNewImageDir("java-se-jmodfull"))
                .addMods("java.se").call().assertSuccess();

        compareRecursively(javaSEruntimeLink, javaSEJmodFull);
    }

    // Visit all files in the given directories checking that they're byte-by-byte identical
    private static void compareRecursively(Path javaSEJmodLess,
            Path javaSEJmodFull) throws IOException, AssertionError {
        FilesCapturingVisitor jmodFullVisitor = new FilesCapturingVisitor(javaSEJmodFull);
        FilesCapturingVisitor jmodLessVisitor = new FilesCapturingVisitor(javaSEJmodLess);
        Files.walkFileTree(javaSEJmodFull, jmodFullVisitor);
        Files.walkFileTree(javaSEJmodLess, jmodLessVisitor);
        List<String> jmodFullFiles = jmodFullVisitor.filesVisited();
        List<String> jmodLessFiles = jmodLessVisitor.filesVisited();
        Collections.sort(jmodFullFiles);
        Collections.sort(jmodLessFiles);

        if (jmodFullFiles.size() != jmodLessFiles.size()) {
            throw new AssertionError(String.format("Size of files different for jmod-less (%d) vs jmod-full (%d) java.se jlink", jmodLessFiles.size(), jmodFullFiles.size()));
        }
        String jimageFile = Path.of("lib").resolve("modules").toString();
        // Compare all files except the modules image
        for (int i = 0; i < jmodFullFiles.size(); i++) {
            String jmodFullPath = jmodFullFiles.get(i);
            String jmodLessPath = jmodLessFiles.get(i);
            if (!jmodFullPath.equals(jmodLessPath)) {
                throw new AssertionError(String.format("jmod-full path (%s) != jmod-less path (%s)", jmodFullPath, jmodLessPath));
            }
            if (jmodFullPath.equals(jimageFile)) {
                continue;
            }
            Path a = javaSEJmodFull.resolve(Path.of(jmodFullPath));
            Path b = javaSEJmodLess.resolve(Path.of(jmodLessPath));
            if (Files.mismatch(a, b) != -1L) {
                handleFileMismatch(a, b);
            }
        }
        // Compare jimage contents by iterating its entries and comparing their
        // paths and content bytes
        //
        // Note: The files aren't byte-by-byte comparable (probably due to string hashing
        // and offset differences in container bytes)
        Path jimageJmodLess = javaSEJmodLess.resolve(Path.of("lib")).resolve(Path.of("modules"));
        Path jimageJmodFull = javaSEJmodFull.resolve(Path.of("lib")).resolve(Path.of("modules"));
        List<String> jimageContentJmodLess = JImageHelper.listContents(jimageJmodLess);
        List<String> jimageContentJmodFull = JImageHelper.listContents(jimageJmodFull);
        if (jimageContentJmodLess.size() != jimageContentJmodFull.size()) {
            throw new AssertionError(String.format("Size of jimage content differs for jmod-less (%d) v. jmod-full (%d)", jimageContentJmodLess.size(), jimageContentJmodFull.size()));
        }
        for (int i = 0; i < jimageContentJmodFull.size(); i++) {
            if (!jimageContentJmodFull.get(i).equals(jimageContentJmodLess.get(i))) {
                throw new AssertionError(String.format("Jimage content differs at index %d: jmod-full was: '%s' jmod-less was: '%s'",
                                                       i,
                                                       jimageContentJmodFull.get(i),
                                                       jimageContentJmodLess.get(i)
                                                       ));
            }
            String loc = jimageContentJmodFull.get(i);
            if (isTreeInfoResource(loc)) {
                // Skip container bytes as those are offsets to the content
                // of the container which might be different between jlink runs.
                continue;
            }
            byte[] resBytesFull = JImageHelper.getLocationBytes(loc, jimageJmodFull);
            byte[] resBytesLess = JImageHelper.getLocationBytes(loc, jimageJmodLess);
            if (resBytesFull.length != resBytesLess.length || Arrays.mismatch(resBytesFull, resBytesLess) != -1) {
                throw new AssertionError("Content bytes mismatch for " + loc);
            }
        }
    }

    private static boolean isTreeInfoResource(String path) {
        return path.startsWith("/packages") || path.startsWith("/modules");
    }

    private static void handleFileMismatch(Path a, Path b) {
        throw new AssertionError("Files mismatch: " + a + " vs. " + b);
    }

    static class FilesCapturingVisitor extends SimpleFileVisitor<Path> {
        private final Path basePath;
        private final List<String> filePaths = new ArrayList<>();
        public FilesCapturingVisitor(Path basePath) {
            this.basePath = basePath;
        }

        @Override
        public FileVisitResult visitFile(Path path, BasicFileAttributes attrs) {
            Path relative = basePath.relativize(path);
            filePaths.add(relative.toString());
            return FileVisitResult.CONTINUE;
        }

        List<String> filesVisited() {
            return filePaths;
        }
    }

}