/*

 * Copyright (c) 2014, 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 jdk.jshell;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import java.util.Locale;

import java.util.regex.Pattern;

import java.util.stream.Stream;

import java.util.stream.StreamSupport;

import javax.lang.model.element.Name;

/**

 * Assorted shared utilities and constants.

 */

class Util {

    /**

     * The package name of all wrapper classes.

     */

    static final String REPL_PACKAGE = "REPL";

    /**

     * The prefix for all wrapper class names.

     */

    static final String REPL_CLASS_PREFIX = "$JShell$";

    /**

     * The name of the invoke method.

     */

    static final String DOIT_METHOD_NAME = "do_it$";

    /**

     * A pattern matching the full or simple class name of a wrapper class.

     */

    static final Pattern PREFIX_PATTERN = Pattern.compile(

            "(" + REPL_PACKAGE + "\\.)?"

            + "(?<class>" + Pattern.quote(REPL_CLASS_PREFIX)

            + "\\w+" + ")" + "[\\$\\.]?");

    static final String REPL_DOESNOTMATTER_CLASS_NAME = REPL_CLASS_PREFIX + "DOESNOTMATTER";

    static final Locale PARSED_LOCALE = Locale.ROOT;

    static boolean isDoIt(Name name) {

        return isDoIt(name.toString());

    }

    static boolean isDoIt(String sname) {

        return sname.equals(DOIT_METHOD_NAME);

    }

    static String expunge(String s) {

        StringBuilder sb = new StringBuilder();

        for (String comp : PREFIX_PATTERN.split(s)) {

            sb.append(comp);

        }

        return sb.toString();

    }

    static String asLetters(int i) {

        if (i == 0) {

            return "";

        }

        char buf[] = new char[33];

        int charPos = 32;

        i = -i;

        while (i <= -26) {

            buf[charPos--] = (char) ('A'-(i % 26));

            i = i / 26;

        }

        buf[charPos] = (char) ('A'-i);

        return new String(buf, charPos, (33 - charPos));

    }

    static String trimEnd(String s) {

        int last = s.length() - 1;

        int i = last;

        while (i >= 0 && Character.isWhitespace(s.charAt(i))) {

            --i;

        }

        if (i != last) {

            return s.substring(0, i + 1);

        } else {

            return s;

        }

    }

    static <T> Stream<T> stream(Iterable<T> iterable) {

        return StreamSupport.stream(iterable.spliterator(), false);

    }

    static String[] join(String[] a1, String[] a2) {

        List<String> result = new ArrayList<>();

        result.addAll(Arrays.asList(a1));

        result.addAll(Arrays.asList(a2));

        return result.toArray(new String[0]);

    }

    static class Pair<T, U> {

        final T first;

        final U second;

        Pair(T first, U second) {

            this.first = first;

            this.second = second;

        }

    }

}