/*

 * Copyright (c) 1997, 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.jar;

import java.io.IOException;

import java.net.*;

import sun.net.www.ParseUtil;

/*

 * Jar URL Handler

 */

public class Handler extends java.net.URLStreamHandler {

    private static final String separator = "!/";

    protected java.net.URLConnection openConnection(URL u)

    throws IOException {

        return new JarURLConnection(u, this);

    }

    private static int indexOfBangSlash(String spec) {

        int indexOfBang = spec.length();

        while((indexOfBang = spec.lastIndexOf('!', indexOfBang)) != -1) {

            if ((indexOfBang != (spec.length() - 1)) &&

                (spec.charAt(indexOfBang + 1) == '/')) {

                return indexOfBang + 1;

            } else {

                indexOfBang--;

            }

        }

        return -1;

    }

    /**

     * Compare two jar URLs

     */

    @Override

    protected boolean sameFile(URL u1, URL u2) {

        if (!u1.getProtocol().equals("jar") || !u2.getProtocol().equals("jar"))

            return false;

        String file1 = u1.getFile();

        String file2 = u2.getFile();

        int sep1 = file1.indexOf(separator);

        int sep2 = file2.indexOf(separator);

        if (sep1 == -1 || sep2 == -1) {

            return super.sameFile(u1, u2);

        }

        String entry1 = file1.substring(sep1 + 2);

        String entry2 = file2.substring(sep2 + 2);

        if (!entry1.equals(entry2))

            return false;

        URL enclosedURL1 = null, enclosedURL2 = null;

        try {

            enclosedURL1 = new URL(file1.substring(0, sep1));

            enclosedURL2 = new URL(file2.substring(0, sep2));

        } catch (MalformedURLException unused) {

            return super.sameFile(u1, u2);

        }

        if (!super.sameFile(enclosedURL1, enclosedURL2)) {

            return false;

        }

        return true;

    }

    @Override

    protected int hashCode(URL u) {

        int h = 0;

        String protocol = u.getProtocol();

        if (protocol != null)

            h += protocol.hashCode();

        String file = u.getFile();

        int sep = file.indexOf(separator);

        if (sep == -1)

            return h + file.hashCode();

        URL enclosedURL = null;

        String fileWithoutEntry = file.substring(0, sep);

        try {

            enclosedURL = new URL(fileWithoutEntry);

            h += enclosedURL.hashCode();

        } catch (MalformedURLException unused) {

            h += fileWithoutEntry.hashCode();

        }

        String entry = file.substring(sep + 2);

        h += entry.hashCode();

        return h;

    }

    public String checkNestedProtocol(String spec) {

        if (spec.regionMatches(true, 0, "jar:", 0, 4)) {

            return "Nested JAR URLs are not supported";

        } else {

            return null;

        }

    }

    @Override

    @SuppressWarnings("deprecation")

    protected void parseURL(URL url, String spec,

                            int start, int limit) {

        String file = null;

        String ref = null;

        // first figure out if there is an anchor

        int refPos = spec.indexOf('#', limit);

        boolean refOnly = refPos == start;

        if (refPos > -1) {

            ref = spec.substring(refPos + 1, spec.length());

            if (refOnly) {

                file = url.getFile();

            }

        }

        // then figure out if the spec is

        // 1. absolute (jar:)

        // 2. relative (i.e. url + foo/bar/baz.ext)

        // 3. anchor-only (i.e. url + #foo), which we already did (refOnly)

        boolean absoluteSpec = false;

        if (spec.length() >= 4) {

            absoluteSpec = spec.substring(0, 4).equalsIgnoreCase("jar:");

        }

        spec = spec.substring(start, limit);

        String exceptionMessage = checkNestedProtocol(spec);

        if (exceptionMessage != null) {

            // NPE will be transformed into MalformedURLException by the caller

            throw new NullPointerException(exceptionMessage);

        }

        if (absoluteSpec) {

            file = parseAbsoluteSpec(spec);

        } else if (!refOnly) {

            file = parseContextSpec(url, spec);

            // Canonize the result after the bangslash

            int bangSlash = indexOfBangSlash(file);

            String toBangSlash = file.substring(0, bangSlash);

            String afterBangSlash = file.substring(bangSlash);

            sun.net.www.ParseUtil canonizer = new ParseUtil();

            afterBangSlash = canonizer.canonizeString(afterBangSlash);

            file = toBangSlash + afterBangSlash;

        }

        setURL(url, "jar", "", -1, file, ref);

    }

    private String parseAbsoluteSpec(String spec) {

        URL url = null;

        int index = -1;

        // check for !/

        if ((index = indexOfBangSlash(spec)) == -1) {

            throw new NullPointerException("no !/ in spec");

        }

        // test the inner URL

        try {

            String innerSpec = spec.substring(0, index - 1);

            url = new URL(innerSpec);

        } catch (MalformedURLException e) {

            throw new NullPointerException("invalid url: " +

                                           spec + " (" + e + ")");

        }

        return spec;

    }

    private String parseContextSpec(URL url, String spec) {

        String ctxFile = url.getFile();

        // if the spec begins with /, chop up the jar back !/

        if (spec.startsWith("/")) {

            int bangSlash = indexOfBangSlash(ctxFile);

            if (bangSlash == -1) {

                throw new NullPointerException("malformed " +

                                               "context url:" +

                                               url +

                                               ": no !/");

            }

            ctxFile = ctxFile.substring(0, bangSlash);

        }

        if (!ctxFile.endsWith("/") && (!spec.startsWith("/"))){

            // chop up the last component

            int lastSlash = ctxFile.lastIndexOf('/');

            if (lastSlash == -1) {

                throw new NullPointerException("malformed " +

                                               "context url:" +

                                               url);

            }

            ctxFile = ctxFile.substring(0, lastSlash + 1);

        }

        return (ctxFile + spec);

    }

}