/*
 * Copyright (c) 2012, 2022, 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 javacserver;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
import java.util.regex.Pattern;
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 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 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;
    }


    /**
     * 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;
    }


    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();
    }

    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 Stream<String> getLines(String str) {
        return str.isEmpty()
                ? Stream.empty()
                : Stream.of(str.split(Pattern.quote(System.lineSeparator())));
    }
}