/*

 * Copyright (c) 2012, 2016, 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 com.sun.tools.sjavac;

import java.io.File;

import java.io.PrintWriter;

import java.io.StringWriter;

import java.nio.file.Path;

import java.util.Arrays;

import java.util.Collection;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

import java.util.StringTokenizer;

import java.util.function.Function;

import java.util.regex.Pattern;

import java.util.stream.Collectors;

import java.util.stream.Stream;

/**

 * Utilities.

 *

 *  <p><b>This is NOT part of any supported API.

 *  If you write code that depends on this, you do so at your own risk.

 *  This code and its internal interfaces are subject to change or

 *  deletion without notice.</b>

 */

public class Util {

    public static String toFileSystemPath(String pkgId) {

        if (pkgId == null || pkgId.length()==0) return null;

        String pn;

        if (pkgId.charAt(0) == ':') {

            // When the module is the default empty module.

            // Do not prepend the module directory, because there is none.

            // Thus :java.foo.bar translates to java/foo/bar (or \)

            pn = pkgId.substring(1).replace('.',File.separatorChar);

        } else {

            // There is a module. Thus jdk.base:java.foo.bar translates

            // into jdk.base/java/foo/bar

            int cp = pkgId.indexOf(':');

            String mn = pkgId.substring(0,cp);

            pn = mn+File.separatorChar+pkgId.substring(cp+1).replace('.',File.separatorChar);

        }

        return pn;

    }

    public static String justPackageName(String pkgName) {

        int c = pkgName.indexOf(":");

        if (c == -1)

            throw new IllegalArgumentException("Expected ':' in package name (" + pkgName + ")");

        return pkgName.substring(c+1);

    }

    public static String extractStringOption(String opName, String s) {

        return extractStringOption(opName, s, null);

    }

    public static String extractStringOption(String opName, String s, String deflt) {

        int p = s.indexOf(opName+"=");

        if (p == -1) return deflt;

        p+=opName.length()+1;

        int pe = s.indexOf(',', p);

        if (pe == -1) pe = s.length();

        return s.substring(p, pe);

    }

    public static boolean extractBooleanOption(String opName, String s, boolean deflt) {

        String str = extractStringOption(opName, s);

        return "true".equals(str) ? true

             : "false".equals(str) ? false

             : deflt;

    }

    public static int extractIntOption(String opName, String s) {

        return extractIntOption(opName, s, 0);

    }

    public static int extractIntOption(String opName, String s, int deflt) {

        int p = s.indexOf(opName+"=");

        if (p == -1) return deflt;

        p+=opName.length()+1;

        int pe = s.indexOf(',', p);

        if (pe == -1) pe = s.length();

        int v = 0;

        try {

            v = Integer.parseInt(s.substring(p, pe));

        } catch (Exception e) {}

        return v;

    }

    /**

     * Extract the package name from a fully qualified class name.

     *

     * Example: Given "pkg.subpkg.A" this method returns ":pkg.subpkg".

     * Given "C" this method returns ":".

     *

     * @returns package name of the given class name

     */

    public static String pkgNameOfClassName(String fqClassName) {

        int i = fqClassName.lastIndexOf('.');

        String pkg = i == -1 ? "" : fqClassName.substring(0, i);

        return ":" + pkg;

    }

    /**

     * Clean out unwanted sub options supplied inside a primary option.

     * For example to only had portfile remaining from:

     *    settings="--server:id=foo,portfile=bar"

     * do settings = cleanOptions("--server:",Util.set("-portfile"),settings);

     *    now settings equals "--server:portfile=bar"

     *

     * @param allowedSubOptions A set of the allowed sub options, id portfile etc.

     * @param s The option settings string.

     */

    public static String cleanSubOptions(Set<String> allowedSubOptions, String s) {

        StringBuilder sb = new StringBuilder();

        StringTokenizer st = new StringTokenizer(s, ",");

        while (st.hasMoreTokens()) {

            String o = st.nextToken();

            int p = o.indexOf('=');

            if (p>0) {

                String key = o.substring(0,p);

                String val = o.substring(p+1);

                if (allowedSubOptions.contains(key)) {

                    if (sb.length() > 0) sb.append(',');

                    sb.append(key+"="+val);

                }

            }

        }

        return sb.toString();

    }

    /**

     * Convenience method to create a set with strings.

     */

    public static Set<String> set(String... ss) {

        Set<String> set = new HashSet<>();

        set.addAll(Arrays.asList(ss));

        return set;

    }

    /**

     * Normalize windows drive letter paths to upper case to enable string

     * comparison.

     *

     * @param file File name to normalize

     * @return The normalized string if file has a drive letter at the beginning,

     *         otherwise the original string.

     */

    public static String normalizeDriveLetter(String file) {

        if (file.length() > 2 && file.charAt(1) == ':') {

            return Character.toUpperCase(file.charAt(0)) + file.substring(1);

        } else if (file.length() > 3 && file.charAt(0) == '*'

                   && file.charAt(2) == ':') {

            // Handle a wildcard * at the beginning of the string.

            return file.substring(0, 1) + Character.toUpperCase(file.charAt(1))

                   + file.substring(2);

        }

        return file;

    }

    /**

     * Locate the setting for the server properties.

     */

    public static String findServerSettings(String[] args) {

        for (String s : args) {

            if (s.startsWith("--server:")) {

                return s;

            }

        }

        return null;

    }

    public static <E> Set<E> union(Set<? extends E> s1,

                                   Set<? extends E> s2) {

        Set<E> union = new HashSet<>();

        union.addAll(s1);

        union.addAll(s2);

        return union;

    }

    public static <E> Set<E> subtract(Set<? extends E> orig,

                                      Set<? extends E> toSubtract) {

        Set<E> difference = new HashSet<>(orig);

        difference.removeAll(toSubtract);

        return difference;

    }

    public static String getStackTrace(Throwable t) {

        StringWriter sw = new StringWriter();

        t.printStackTrace(new PrintWriter(sw));

        return sw.toString();

    }

    // TODO: Remove when refactoring from java.io.File to java.nio.file.Path.

    public static File pathToFile(Path path) {

        return path == null ? null : path.toFile();

    }

    public static <E> Set<E> intersection(Collection<? extends E> c1,

                                          Collection<? extends E> c2) {

        Set<E> intersection = new HashSet<E>(c1);

        intersection.retainAll(c2);

        return intersection;

    }

    public static <I, T> Map<I, T> indexBy(Collection<? extends T> c,

                                           Function<? super T, ? extends I> indexFunction) {

        return c.stream().collect(Collectors.<T, I, T>toMap(indexFunction, o -> o));

    }

    public static String fileSuffix(Path file) {

        String fileNameStr = file.getFileName().toString();

        int dotIndex = fileNameStr.indexOf('.');

        return dotIndex == -1 ? "" : fileNameStr.substring(dotIndex);

    }

    public static Stream<String> getLines(String str) {

        return str.isEmpty()

                ? Stream.empty()

                : Stream.of(str.split(Pattern.quote(System.lineSeparator())));

    }

}