/*

 * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 *   - Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 *

 *   - Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 *

 *   - Neither the name of Oracle nor the names of its

 *     contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/*

 * This source code is provided to illustrate the usage of a given feature

 * or technique and has been deliberately simplified. Additional steps

 * required for a production-quality application, such as security checks,

 * input validation and proper error handling, might not be present in

 * this sample code.

 */

package com.sun.nio.zipfs;

import java.io.*;

import java.nio.channels.*;

import java.nio.file.*;

import java.nio.file.DirectoryStream.Filter;

import java.nio.file.attribute.*;

import java.nio.file.spi.FileSystemProvider;

import java.net.URI;

import java.net.URISyntaxException;

import java.util.HashMap;

import java.util.Map;

import java.util.Set;

import java.util.zip.ZipError;

import java.util.concurrent.ExecutorService;

/*

 *

 * @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

            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 = null;

            try {

                zipfs = new ZipFileSystem(this, path, env);

            } catch (ZipError ze) {

                String pname = path.toString();

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

                    throw ze;

                // assume NOT a zip/jar file

                throw new UnsupportedOperationException();

            }

            filesystems.put(realPath, zipfs);

            return zipfs;

        }

    }

    @Override

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

        throws IOException

    {

        if (path.getFileSystem() != FileSystems.getDefault()) {

            throw new UnsupportedOperationException();

        }

        ensureFile(path);

        try {

            return new ZipFileSystem(this, path, env);

        } catch (ZipError 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

    static final 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

    @SuppressWarnings("unchecked")

    public <V extends FileAttributeView> V

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

    {

        return ZipFileAttributeView.get(toZipPath(path), 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)

            throws IOException

    {

        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

    {

        if (type == BasicFileAttributes.class || type == ZipFileAttributes.class)

            return (A)toZipPath(path).getAttributes();

        return null;

    }

    @Override

    public Map<String, Object>

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

        throws IOException

    {

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

    }

    @Override

    public Path readSymbolicLink(Path link) throws IOException {

        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) {

            zfpath = zfpath.toRealPath();

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

                filesystems.remove(zfpath);

        }

    }

}