/*
 * Copyright (c) 2012, 2020, 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
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 */

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.
 
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.
/**
 * 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);
    }

    private static String extractStringOptionWithDelimiter(String opName, String s, String deflt, char delimiter) {
        int p = s.indexOf(opName+"=");
        if (p == -1) return deflt;
        p+=opName.length()+1;
        int pe = s.indexOf(delimiter, p);
        if (pe == -1) pe = s.length();
        return s.substring(p, pe);
    }

    public static String extractStringOption(String opName, String s, String deflt) {
        return extractStringOptionWithDelimiter(opName, s, deflt, ',');
    }

    public static String extractStringOptionLine(String opName, String s, String deflt) {
        return extractStringOptionWithDelimiter(opName, s, deflt, '\n').strip();
    }

    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/**
     * 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"
Params:
allowedSubOptions – A set of the allowed sub options, id portfile etc.
s – The option settings string./**
     * 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.
/**
     * 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.
Params:
file – File name to normalize
Returns:
The normalized string if file has a drive letter at the beginning,
        otherwise the original string./**
     * 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.
/**
     * 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())));
    }
}