/*

 * Copyright (c) 2009, 2019, Oracle and/or its affiliates. All rights reserved.

 * 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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 jdk.nio.zipfs;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.net.URI;

import java.net.URISyntaxException;

import java.nio.channels.AsynchronousFileChannel;

import java.nio.channels.FileChannel;

import java.nio.channels.SeekableByteChannel;

import java.nio.file.*;

import java.nio.file.DirectoryStream.Filter;

import java.nio.file.attribute.BasicFileAttributes;

import java.nio.file.attribute.FileAttribute;

import java.nio.file.attribute.FileAttributeView;

import java.nio.file.spi.FileSystemProvider;

import java.security.AccessController;

import java.security.PrivilegedActionException;

import java.security.PrivilegedExceptionAction;

import java.util.HashMap;

import java.util.Map;

import java.util.Set;

import java.util.concurrent.ExecutorService;

import java.util.zip.ZipException;

/**

 * @author Xueming Shen, Rajendra Gutupalli, Jaya Hangal

 */

public class ZipFileSystemProvider extends FileSystemProvider {

    private final Map<Path, ZipFileSystem> filesystems = new HashMap<>();

    public ZipFileSystemProvider() {}

    @Override

    public String getScheme() {

        return "jar";

    }

    protected Path uriToPath(URI uri) {

        String scheme = uri.getScheme();

        if ((scheme == null) || !scheme.equalsIgnoreCase(getScheme())) {

            throw new IllegalArgumentException("URI scheme is not '" + getScheme() + "'");

        }

        try {

            // only support legacy JAR URL syntax  jar:{uri}!/{entry} for now

            String spec = uri.getRawSchemeSpecificPart();

            int sep = spec.indexOf("!/");

            if (sep != -1) {

                spec = spec.substring(0, sep);

            }

            return Paths.get(new URI(spec)).toAbsolutePath();

        } catch (URISyntaxException e) {

            throw new IllegalArgumentException(e.getMessage(), e);

        }

    }

    private boolean ensureFile(Path path) {

        try {

            BasicFileAttributes attrs =

                Files.readAttributes(path, BasicFileAttributes.class);

            if (!attrs.isRegularFile())

                throw new UnsupportedOperationException();

            return true;

        } catch (IOException ioe) {

            return false;

        }

    }

    @Override

    public FileSystem newFileSystem(URI uri, Map<String, ?> env)

        throws IOException

    {

        Path path = uriToPath(uri);

        synchronized(filesystems) {

            Path realPath = null;

            if (ensureFile(path)) {

                realPath = path.toRealPath();

                if (filesystems.containsKey(realPath))

                    throw new FileSystemAlreadyExistsException();

            }

            ZipFileSystem zipfs = getZipFileSystem(path, env);

            if (realPath == null) {  // newly created

                realPath = path.toRealPath();

            }

            filesystems.put(realPath, zipfs);

            return zipfs;

        }

    }

    @Override

    public FileSystem newFileSystem(Path path, Map<String, ?> env)

        throws IOException

    {

        ensureFile(path);

        return getZipFileSystem(path, env);

    }

    private ZipFileSystem getZipFileSystem(Path path, Map<String, ?> env) throws IOException {

        try {

        } catch (ZipException ze) {

            String pname = path.toString();

            if (pname.endsWith(".zip") || pname.endsWith(".jar"))

                throw ze;

            throw new UnsupportedOperationException();

        }

    }

    @Override

    public Path getPath(URI uri) {

        String spec = uri.getSchemeSpecificPart();

        int sep = spec.indexOf("!/");

        if (sep == -1)

            throw new IllegalArgumentException("URI: "

                + uri

                + " does not contain path info ex. jar:file:/c:/foo.zip!/BAR");

        return getFileSystem(uri).getPath(spec.substring(sep + 1));

    }

    @Override

    public FileSystem getFileSystem(URI uri) {

        synchronized (filesystems) {

            ZipFileSystem zipfs = null;

            try {

                zipfs = filesystems.get(uriToPath(uri).toRealPath());

            } catch (IOException x) {

                // ignore the ioe from toRealPath(), return FSNFE

            }

            if (zipfs == null)

                throw new FileSystemNotFoundException();

            return zipfs;

        }

    }

    // Checks that the given file is a UnixPath

    private static ZipPath toZipPath(Path path) {

        if (path == null)

            throw new NullPointerException();

        if (!(path instanceof ZipPath))

            throw new ProviderMismatchException();

        return (ZipPath)path;

    }

    @Override

    public void checkAccess(Path path, AccessMode... modes) throws IOException {

        toZipPath(path).checkAccess(modes);

    }

    @Override

    public void copy(Path src, Path target, CopyOption... options)

        throws IOException

    {

        toZipPath(src).copy(toZipPath(target), options);

    }

    @Override

    public void createDirectory(Path path, FileAttribute<?>... attrs)

        throws IOException

    {

        toZipPath(path).createDirectory(attrs);

    }

    @Override

    public final void delete(Path path) throws IOException {

        toZipPath(path).delete();

    }

    @Override

    public <V extends FileAttributeView> V

        getFileAttributeView(Path path, Class<V> type, LinkOption... options)

    {

        return toZipPath(path).getFileAttributeView(type);

    }

    @Override

    public FileStore getFileStore(Path path) throws IOException {

        return toZipPath(path).getFileStore();

    }

    @Override

    public boolean isHidden(Path path) {

        return toZipPath(path).isHidden();

    }

    @Override

    public boolean isSameFile(Path path, Path other) throws IOException {

        return toZipPath(path).isSameFile(other);

    }

    @Override

    public void move(Path src, Path target, CopyOption... options)

        throws IOException

    {

        toZipPath(src).move(toZipPath(target), options);

    }

    @Override

    public AsynchronousFileChannel newAsynchronousFileChannel(Path path,

            Set<? extends OpenOption> options,

            ExecutorService exec,

            FileAttribute<?>... attrs)

    {

        throw new UnsupportedOperationException();

    }

    @Override

    public SeekableByteChannel newByteChannel(Path path,

                                              Set<? extends OpenOption> options,

                                              FileAttribute<?>... attrs)

        throws IOException

    {

        return toZipPath(path).newByteChannel(options, attrs);

    }

    @Override

    public DirectoryStream<Path> newDirectoryStream(

        Path path, Filter<? super Path> filter) throws IOException

    {

        return toZipPath(path).newDirectoryStream(filter);

    }

    @Override

    public FileChannel newFileChannel(Path path,

                                      Set<? extends OpenOption> options,

                                      FileAttribute<?>... attrs)

        throws IOException

    {

        return toZipPath(path).newFileChannel(options, attrs);

    }

    @Override

    public InputStream newInputStream(Path path, OpenOption... options)

        throws IOException

    {

        return toZipPath(path).newInputStream(options);

    }

    @Override

    public OutputStream newOutputStream(Path path, OpenOption... options)

        throws IOException

    {

        return toZipPath(path).newOutputStream(options);

    }

    @Override

    public <A extends BasicFileAttributes> A

        readAttributes(Path path, Class<A> type, LinkOption... options)

        throws IOException

    {

        return toZipPath(path).readAttributes(type);

    }

    @Override

    public Map<String, Object>

        readAttributes(Path path, String attributes, LinkOption... options)

        throws IOException

    {

        return toZipPath(path).readAttributes(attributes, options);

    }

    @Override

    public Path readSymbolicLink(Path link) {

        throw new UnsupportedOperationException("Not supported.");

    }

    @Override

    public void setAttribute(Path path, String attribute,

                             Object value, LinkOption... options)

        throws IOException

    {

        toZipPath(path).setAttribute(attribute, value, options);

    }

    //////////////////////////////////////////////////////////////

    void removeFileSystem(Path zfpath, ZipFileSystem zfs) throws IOException {

        synchronized (filesystems) {

            Path tempPath = zfpath;

            PrivilegedExceptionAction<Path> action = tempPath::toRealPath;

            try {

                zfpath = AccessController.doPrivileged(action);

            } catch (PrivilegedActionException e) {

                throw (IOException) e.getException();

            }

            if (filesystems.get(zfpath) == zfs)

                filesystems.remove(zfpath);

        }

    }

}