/*

 * Copyright (c) 1999, 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 sun.net.www.protocol.file;

import java.net.InetAddress;

import java.net.URLConnection;

import java.net.URL;

import java.net.Proxy;

import java.net.MalformedURLException;

import java.net.URLStreamHandler;

import java.io.InputStream;

import java.io.IOException;

import sun.net.www.ParseUtil;

import java.io.File;

/**

 * Open an file input stream given a URL.

 * @author      James Gosling

 */

public class Handler extends URLStreamHandler {

    private String getHost(URL url) {

        String host = url.getHost();

        if (host == null)

            host = "";

        return host;

    }

    protected void parseURL(URL u, String spec, int start, int limit) {

        /*

         * Ugly backwards compatibility. Flip any file separator

         * characters to be forward slashes. This is a nop on Unix

         * and "fixes" win32 file paths. According to RFC 2396,

         * only forward slashes may be used to represent hierarchy

         * separation in a URL but previous releases unfortunately

         * performed this "fixup" behavior in the file URL parsing code

         * rather than forcing this to be fixed in the caller of the URL

         * class where it belongs. Since backslash is an "unwise"

         * character that would normally be encoded if literally intended

         * as a non-seperator character the damage of veering away from the

         * specification is presumably limited.

         */

        super.parseURL(u, spec.replace(File.separatorChar, '/'), start, limit);

    }

    public synchronized URLConnection openConnection(URL url)

        throws IOException {

        return openConnection(url, null);

    }

    public synchronized URLConnection openConnection(URL url, Proxy p)

           throws IOException {

        String path;

        String file = url.getFile();

        String host = url.getHost();

        path = ParseUtil.decode(file);

        path = path.replace('/', '\\');

        path = path.replace('|', ':');

        if ((host == null) || host.isEmpty() ||

                host.equalsIgnoreCase("localhost") ||

                host.equals("~")) {

           return createFileURLConnection(url, new File(path));

        }

        /*

         * attempt to treat this as a UNC path. See 4180841

         */

        path = "\\\\" + host + path;

        File f = new File(path);

        if (f.exists()) {

            return new UNCFileURLConnection(url, f, path);

        }

        /*

         * Now attempt an ftp connection.

         */

        URLConnection uc;

        URL newurl;

        try {

            newurl = new URL("ftp", host, file +

                            (url.getRef() == null ? "":

                            "#" + url.getRef()));

            if (p != null) {

                uc = newurl.openConnection(p);

            } else {

                uc = newurl.openConnection();

            }

        } catch (IOException e) {

            uc = null;

        }

        if (uc == null) {

            throw new IOException("Unable to connect to: " +

                                        url.toExternalForm());

        }

        return uc;

    }

    /**

     * Template method to be overridden by Java Plug-in. [stanleyh]

     */

    protected URLConnection createFileURLConnection(URL url, File file) {

        return new FileURLConnection(url, file);

    }

    /**

     * Compares the host components of two URLs.

     * @param u1 the URL of the first host to compare

     * @param u2 the URL of the second host to compare

     * @return  {@code true} if and only if they

     * are equal, {@code false} otherwise.

     */

    protected boolean hostsEqual(URL u1, URL u2) {

        /*

         * Special case for file: URLs

         * per RFC 1738 no hostname is equivalent to 'localhost'

         * i.e. file:///path is equal to file://localhost/path

         */

        String s1 = u1.getHost();

        String s2 = u2.getHost();

        if ("localhost".equalsIgnoreCase(s1) && (s2 == null || s2.isEmpty()))

            return true;

        if ("localhost".equalsIgnoreCase(s2) && (s1 == null || s1.isEmpty()))

            return true;

        return super.hostsEqual(u1, u2);

    }

}