/*

 * 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

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 *

 * THIS FILE WAS MODIFIED BY SUN MICROSYSTEMS, INC.

 */

package com.sun.xml.internal.fastinfoset.sax;

import java.io.*;

public class SystemIdResolver {

    public SystemIdResolver() {

    }

    public static String getAbsoluteURIFromRelative(String localPath) {

        if (localPath == null || localPath.length() == 0) {

            return "";

        }

        String absolutePath = localPath;

        if (!isAbsolutePath(localPath)) {

            try {

                absolutePath = getAbsolutePathFromRelativePath(localPath);

            }

            catch (SecurityException se) {

                return "file:" + localPath;

            }

        }

        String urlString;

        if (null != absolutePath) {

            urlString = absolutePath.startsWith(File.separator) ?

                ("file://" + absolutePath) :

                ("file:///" + absolutePath);

        }

        else {

            urlString = "file:" + localPath;

        }

        return replaceChars(urlString);

    }

    private static String getAbsolutePathFromRelativePath(String relativePath) {

        return new File(relativePath).getAbsolutePath();

    }

    public static boolean isAbsoluteURI(String systemId) {

        if (systemId == null) {

            return false;

        }

        if (isWindowsAbsolutePath(systemId)) {

            return false;

        }

        final int fragmentIndex = systemId.indexOf('#');

        final int queryIndex = systemId.indexOf('?');

        final int slashIndex = systemId.indexOf('/');

        final int colonIndex = systemId.indexOf(':');

        int index = systemId.length() -1;

        if (fragmentIndex > 0) {

            index = fragmentIndex;

        }

        if (queryIndex > 0 && queryIndex < index) {

            index = queryIndex;

        }

        if (slashIndex > 0 && slashIndex <index) {

            index = slashIndex;

        }

        return (colonIndex > 0) && (colonIndex < index);

    }

    public static boolean isAbsolutePath(String systemId) {

        if(systemId == null)

            return false;

        final File file = new File(systemId);

        return file.isAbsolute();

    }

    private static boolean isWindowsAbsolutePath(String systemId) {

        if(!isAbsolutePath(systemId))

            return false;

        if (systemId.length() > 2

        && systemId.charAt(1) == ':'

        && Character.isLetter(systemId.charAt(0))

        && (systemId.charAt(2) == '\\' || systemId.charAt(2) == '/'))

            return true;

        else

            return false;

    }

    private static String replaceChars(String str) {

        StringBuffer buf = new StringBuffer(str);

        int length = buf.length();

        for (int i = 0; i < length; i++) {

            char currentChar = buf.charAt(i);

            // Replace space with "%20"

            if (currentChar == ' ') {

                buf.setCharAt(i, '%');

                buf.insert(i+1, "20");

                length = length + 2;

                i = i + 2;

            }

            // Replace backslash with forward slash

            else if (currentChar == '\\') {

                buf.setCharAt(i, '/');

            }

        }

        return buf.toString();

    }

    public static String getAbsoluteURI(String systemId) {

        String absoluteURI = systemId;

        if (isAbsoluteURI(systemId)) {

            if (systemId.startsWith("file:")) {

                String str = systemId.substring(5);

                if (str != null && str.startsWith("/")) {

                    if (str.startsWith("///") || !str.startsWith("//")) {

                        int secondColonIndex = systemId.indexOf(':', 5);

                        if (secondColonIndex > 0) {

                            String localPath = systemId.substring(secondColonIndex-1);

                            try {

                                if (!isAbsolutePath(localPath))

                                    absoluteURI = systemId.substring(0, secondColonIndex-1) +

                                    getAbsolutePathFromRelativePath(localPath);

                            }

                            catch (SecurityException se) {

                                return systemId;

                            }

                        }

                    }

                }

                else {

                    return getAbsoluteURIFromRelative(systemId.substring(5));

                }

                return replaceChars(absoluteURI);

            }

            else  {

                return systemId;

            }

        }

        else {

            return getAbsoluteURIFromRelative(systemId);

        }

    }

}