Arakne / SwfLangLoader

 * This file is part of ArakneLangLoader.

 *

 * ArakneLangLoader is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Lesser General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * ArakneLangLoader 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 Lesser General Public License for more details.

 *

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

 * along with ArakneLangLoader.  If not, see <https://www.gnu.org/licenses/>.

 *

 * Copyright (c) 2020 Vincent Quatrevieux

 */

package fr.arakne.swflangloader.loader;

import com.jpexs.decompiler.flash.AbortRetryIgnoreHandler;

import com.jpexs.decompiler.flash.SWF;

import com.jpexs.decompiler.flash.exporters.modes.ScriptExportMode;

import com.jpexs.decompiler.flash.exporters.settings.ScriptExportSettings;

import fr.arakne.swflangloader.parser.mapper.MapperHydrator;

import java.io.*;

import java.net.URL;

import java.nio.file.*;

import java.nio.file.attribute.BasicFileAttributes;

import java.util.Collections;

import java.util.List;

import java.util.stream.Collectors;

import java.util.stream.Stream;

/**

 * Load the SWF file to extract AS3 sources

 */

final public class SwfFileLoader {

    final private Path tempDir;

    final private boolean cache;

    public SwfFileLoader() {

        this(Paths.get("./tmp"), true);

    }

    /**

     * @param tempDir The temporary directory used for extract action script files

     * @param cache Enable cache (i.e. keep tmp files)

     */

    public SwfFileLoader(Path tempDir, boolean cache) {

        this.tempDir = tempDir;

        this.cache = cache;

    }

    /**

     * Load the SWF file and hydrate the target structure

     *

     * @param file SWF file URL

     * @param target The target structure

     * @param hydrator Hydrator to use

     * @param <T> The structure type

     *

     * @throws IOException When error occurs during loading the SWF file

     */

    public synchronized <T extends AbstractSwfFile> void load(URL file, T target, MapperHydrator<T> hydrator) throws IOException, InterruptedException {

        final String filename = extractFilename(file);

        parseFilename(target, filename);

        Path outdir = tempDir.resolve(filename);

        Files.createDirectories(outdir);

        try {

            List<File> sources = loadFilesFromCache(outdir);

            if (sources.isEmpty()) {

                sources = loadFilesFromSwf(file, outdir);

            }

            for (File source : sources) {

                parseFile(source, target, hydrator);

            }

        } finally {

            if (!cache) {

                clearTemp(tempDir);

            }

        }

    }

    /**

     * Clear the cache

     *

     * @throws IOException When removing cache files failed

     */

    public void clear() throws IOException {

        clearTemp(tempDir);

    }

    private String extractFilename(URL file) {

        final String path = file.getFile();

        final int filenamePos = path.lastIndexOf('/');

        return path.substring(filenamePos + 1, path.length() - 4);

    }

    private void parseFilename(AbstractSwfFile target, String filename) {

        final String[] parts = filename.split("_", 3);

        if (parts.length != 3) {

            return;

        }

        target.setName(parts[0]);

        target.setLanguage(parts[1]);

        try {

            target.setVersion(Integer.parseInt(parts[2]));

        } catch (NumberFormatException e) {

            // Ignore

        }

    }

    private List<File> loadFilesFromSwf(URL url, Path outdir) throws IOException, InterruptedException {

        try (InputStream stream = url.openStream()) {

            SWF swf = new SWF(stream, false);

            return swf.exportActionScript(

                new AbortRetryIgnoreHandler() {

                    @Override

                    public AbortRetryIgnoreHandler getNewInstance() {

                        return this;

                    }

                },

                outdir.toAbsolutePath().toString(),

                new ScriptExportSettings(ScriptExportMode.AS, false, true),

                false,

                null

            );

        }

    }

    private List<File> loadFilesFromCache(Path cacheDir) throws IOException {

        if (!cache) {

            return Collections.emptyList();

        }

        try (final Stream<Path> files = Files.walk(cacheDir)) {

            return files

                .filter(Files::isRegularFile)

                .filter(path -> path.endsWith(".as"))

                .map(Path::toFile)

                .collect(Collectors.toList())

            ;

        }

    }

    /**

     * Parse file lines

     */

    private <T> void parseFile(File file, T target, MapperHydrator<T> hydrator) throws IOException {

        try (BufferedReader reader = new BufferedReader(new InputStreamReader(Files.newInputStream(file.toPath())))) {

            for (String line = reader.readLine(); line != null; line = reader.readLine()) {

                hydrator.hydrate(target, line);

            }

        }

    }

    /**

     * Recursive clear cache directory

     */

    private void clearTemp(Path tempdir) throws IOException {

        if (!Files.exists(tempdir)) {

            return;

        }

        Files.walkFileTree(tempdir, new SimpleFileVisitor<Path>() {

            @Override

            public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {

                Files.delete(dir);

                return FileVisitResult.CONTINUE;

            }

            @Override

            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {

                Files.delete(file);

                return FileVisitResult.CONTINUE;

            }

        });

    }

}