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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * The Universal Permissive License (UPL), Version 1.0
 *
 * Subject to the condition set forth below, permission is hereby granted to any
 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
 * freely licensable by each licensor hereunder covering either (i) the
 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
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 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
 *
 * This license is subject to the following condition:
 *
 * The above copyright notice and either this complete permission notice or at a
 * minimum a reference to the UPL must be included in all copies or substantial
 * portions of the Software.
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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package com.oracle.truffle.regex.tregex.util;

import java.util.Random;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
import com.oracle.truffle.regex.charset.Constants;
import com.oracle.truffle.regex.charset.SortedListOfRanges;
import com.oracle.truffle.regex.util.CompilationFinalBitSet;

public class DebugUtil {

    private static final CompilationFinalBitSet validSpecialCharsForFileNames = CompilationFinalBitSet.valueOf(
                    '^', '$', '.', '*', '+', '-', '?', '(', ')', '[', ']', '{', '}', '|');

    @TruffleBoundary
    public static String charToString(int c) {
        if (Constants.WORD_CHARS.contains(c)) {
            return String.valueOf((char) c);
        } else if (c <= 0xff) {
            return String.format("\\x%02x", c);
        } else if (c <= 0xffff) {
            return String.format("\\u%04x", c);
        } else {
            return String.format("\\u{%06x}", c);
        }
    }

    @TruffleBoundary
    public static String escapeString(String s) {
        StringBuilder ret = new StringBuilder();
        for (int i = 0; i < s.length(); i++) {
            ret.append(charToString(s.charAt(i)));
        }
        return ret.toString();
    }

    @TruffleBoundary
    public static StringBuilder appendNodeId(StringBuilder sb, int id) {
        return sb.append(nodeID(id));
    }

    @TruffleBoundary
    public static String nodeID(int id) {
        return String.format("%04x", id);
    }

    private static final Pattern specialChars = Pattern.compile("[\"\\\\\u0000-\u001F\u007F-\u009F]");

    @TruffleBoundary
    public static String jsStringEscape(String str) {
        StringBuffer escapedString = new StringBuffer();
        Matcher m = specialChars.matcher(str);
        while (m.find()) {
            String replacement;
            char c = str.charAt(m.start());
            if (c == '"') {
                replacement = "\\\\\"";
            } else if (c == '\\') {
                replacement = "\\\\\\\\";
            } else {
                assert Character.isISOControl(c);
                replacement = String.format("\\\\u%04x", (int) c);
            }
            m.appendReplacement(escapedString, replacement);
        }
        m.appendTail(escapedString);
        return escapedString.toString();
    }

    @TruffleBoundary
    public static String randomJsStringFromRanges(SortedListOfRanges ranges, int length) {
        Random random = new Random(System.currentTimeMillis());
        StringBuilder stringBuilder = new StringBuilder(length);
        for (int i = 0; i < length; i++) {
            int rangeIndex = random.nextInt(ranges.size());
            int lo = ranges.getLo(rangeIndex);
            int hi = ranges.getHi(rangeIndex);
            int randChar = lo + random.nextInt((hi + 1) - lo);
            if (randChar == '"') {
                stringBuilder.append("\\\\\"");
            } else if (randChar == '\\') {
                stringBuilder.append("\\\\\\\\");
            } else if (randChar > 0xffff) {
                stringBuilder.append(String.format("\\u{%06x}", randChar));
            } else if (randChar > 0x7f || Character.isISOControl(randChar)) {
                stringBuilder.append(String.format("\\u%04x", randChar));
            } else {
                stringBuilder.append(randChar);
            }
        }
        return stringBuilder.toString();
    }

    public static boolean isValidCharForFileName(int c) {
        return Character.isLetterOrDigit(c) || validSpecialCharsForFileNames.get(c);
    }

    public static class Timer {

        private long startTime = 0;

        public void start() {
            startTime = System.nanoTime();
        }

        public long getElapsed() {
            return System.nanoTime() - startTime;
        }

        public String elapsedToString() {
            return elapsedToString(getElapsed());
        }

        public static String elapsedToString(long elapsed) {
            return String.format("%fms", elapsed / 1e6);
        }
    }
}