/*
 **********************************************************************
 * Copyright (c) 2002-2004, Google Inc, Unicode Inc, and others.  All Rights Reserved.
 **********************************************************************
 */
package org.unicode.cldr.draft;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.nio.charset.Charset;
import java.util.Collection;
import java.util.Comparator;
import java.util.Date;
import java.util.Set;
import java.util.TreeSet;
import java.util.regex.Matcher;

import org.unicode.cldr.util.PatternCache;

import com.ibm.icu.dev.util.UnicodeMap;
import com.ibm.icu.lang.UCharacter;
import com.ibm.icu.text.DateFormat;
import com.ibm.icu.text.DecimalFormat;
import com.ibm.icu.text.Normalizer;
import com.ibm.icu.text.Normalizer.Mode;
import com.ibm.icu.text.NumberFormat;
import com.ibm.icu.text.SimpleDateFormat;
import com.ibm.icu.text.Transliterator;
import com.ibm.icu.text.UTF16;
import com.ibm.icu.text.UnicodeSet;
import com.ibm.icu.text.UnicodeSetIterator;
import com.ibm.icu.util.VersionInfo;

public class GenerateNormalizeForMatch {
    static boolean TABLE = true;

    // Command choices
    enum ListStyle {
        ALL, SHOW_AGE, ONLY_OLD
    }

    private static ListStyle LIST_STYLE = ListStyle.ALL;

    // Useful objects
    private static final UnicodeSet U50 = (UnicodeSet) new UnicodeSet("[:age=5.0:]").freeze();
    private static final UnicodeSet ASSIGNED = (UnicodeSet) new UnicodeSet("[:ASSIGNED:]").freeze();
    private static final DateFormat ISO_DATE = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss v");
    private static final NumberFormat FORMAT = new DecimalFormat("#,##0");
    public static final Charset UTF8 = Charset.forName("utf-8");

    private static int DEBUG_CODE_POINT = 0x0041; // eg 0xFDFA

    private static final Matcher HEXFORM = PatternCache.get("[0-9A-Fa-f]{4,6}(\\s+[0-9A-Fa-f]{4,6})*").matcher("");

    private static final int DIFF_LIMIT = 10;

    // Fixes to match Jim's names
    private static UnicodeMap<String> JIM_NAMES = new UnicodeMap<String>();
    static {
        JIM_NAMES.putAll(new UnicodeSet("[:block=CJK Unified Ideographs:]"), "<CJK Ideograph>");
        JIM_NAMES.putAll(new UnicodeSet("[:block=CJK Unified Ideographs Extension A:]"), "<CJK Ideograph Extension A>");
        JIM_NAMES.putAll(new UnicodeSet("[:block=CJK Unified Ideographs Extension B:]"), "<CJK Ideograph Extension B>");
        JIM_NAMES.freeze();
    }

    static PrintWriter LOG_WRITER = null;

    /**
     * Generate new files or reformat old ones, depending on options
     * 
     * @param args
     * @throws IOException
     */
    public static void main(String[] args) throws IOException {
        String sourceFile = null;
        String targetFile = null;
        String oldMappingFile = null;
        String frequencyFile = null;
        String logFile = null;
        boolean fix = false;
        for (int i = 0; i < args.length; ++i) {
            String arg = args[i];
            if (arg.equals("-i")) {
                sourceFile = args[++i];
            } else if (arg.equals("-o")) {
                targetFile = args[++i];
            } else if (arg.equals("-d")) {
                oldMappingFile = args[++i];
            } else if (arg.equals("-l")) {
                logFile = args[++i];
                TABLE = logFile.contains(".htm");
            } else if (arg.equals("-f")) {
                frequencyFile = args[++i];
            } else if (arg.equals("fix")) {
                fix = true;
            } else {
                throw new IllegalArgumentException("Unknown option: " + arg + "\n" +
                    "-o <targetFile>\n" +
                    "-i <inputFile>\n" +
                    "-l <logFile>");
            }
        }
        if (logFile == null) {
            LOG_WRITER = new PrintWriter(System.out);
        } else {
            LOG_WRITER = openUTF8Writer(logFile);
            LOG_WRITER.write(0xFEFF);
            if (TABLE) {
                LOG_WRITER.write("<html>\n" +
                    "<head>\n" +
                    "<meta http-equiv='Content-Type' content='text/html; charset=utf-8'/>\n" +
                    "<style type='text/css'>\n" +
                    "table { border: 1px solid blue; border-collapse: collapse; }" +
                    "td,th { border: 1px solid blue; vertical-align: top; }" +
                    "</style>" +
                    "</head>\n" +
                    "<body>\n" +
                    "<pre>\n");
            }
        }
        if (fix) {
            fixOld(sourceFile, targetFile);
        } else {
            frequencies = new FrequencyData(frequencyFile, true);
            generateMappings(sourceFile, targetFile, oldMappingFile, frequencyFile);
        }
        LOG_WRITER.println("# END");
        if (TABLE) {
            LOG_WRITER.println("</pre></body></html>");
        }
        LOG_WRITER.close();
        System.out.println("DONE");
    }

    private static void logDiffs(UnicodeMap<String> newMappings, String oldMappingFile, String frequencyFile)
        throws IOException {
        LOG_WRITER.println();
        LOG_WRITER.println("# *** Differences from " + new File(oldMappingFile).getName() + " ***");
        LOG_WRITER.println();
        UnicodeMap<String> diffMappings = new UnicodeMap<String>();
        loadMappings(oldMappingFile, diffMappings, false);

        UnicodeSet newSource = newMappings.keySet();
        UnicodeSet diffSourceSet = diffMappings.keySet();
        UnicodeSet union = new UnicodeSet(newSource).addAll(diffSourceSet);

        UnicodeSet isLetter = new UnicodeSet(
            "[[:L:][:M:][:N:]\\u002B\\u005F\\uFF06\\uFF0B\\uFF3F\\u309B\\u309C\\u30a0]");
        showOrderedList("IsLetter", new UnicodeSet(union).retainAll(isLetter), diffMappings, newMappings,
            Integer.MAX_VALUE);
        showOrderedList("NOT IsLetter", new UnicodeSet(union).removeAll(isLetter), diffMappings, newMappings,
            Integer.MAX_VALUE);
    }

    private static void showOrderedList(String title, UnicodeSet charsToShow,
        UnicodeMap<String> oldMappings, UnicodeMap<String> newMappings, int limit) {

        Set<Comparable<? extends Object>[]> ordered = new TreeSet(DOUBLE_STRING_COMP);
        for (UnicodeSetIterator it = new UnicodeSetIterator(charsToShow); it.next();) {
            String oldMapped = getRemapped(it.codepoint, oldMappings);
            String newMapped = getRemapped(it.codepoint, newMappings);
            if (!newMapped.equals(oldMapped)) {
                Long count = frequencies == null ? null : frequencies.getCount(it.codepoint);
                ordered.add(new Comparable[] { count == null ? 0L : count, it.codepoint, oldMapped, newMapped });
            }
        }
        showOrderedList2(title, ordered, limit);
    }

    private static String anchorize(String name) {
        return name.replace(' ', '_').toLowerCase();
    }

    private static void showOrderedList2(String title, Collection<Comparable<? extends Object>[]> ordered, int limit) {
        if (ordered.size() == 0) {
            String msg = "NO CHARACTERS CHANGED";
            if (TABLE) {
                msg = "</pre><b>" + msg + "</b><pre>";
            }
            LOG_WRITER.println(msg);
            return;
        }

        if (TABLE) {
            LOG_WRITER.println("</pre>");
        }

        if (title != null) {
            if (TABLE) {
                title = "<h2><a name='" + anchorize(title) + "'>" + title + "</a></h2>\n";
            }
            LOG_WRITER.println(title);
        }

        final boolean longEnough = ordered.size() > 1;
        if (longEnough) {
            String footer = "Characters total:\t" + FORMAT.format(ordered.size());
            if (ordered.size() > limit) {
                footer += "\tOmitted from sample below:\t" + FORMAT.format(ordered.size() - limit);
            }
            if (TABLE) {
                footer = "<table><tr><td>" + footer.replace("\t", "</td><td>") + "</td></tr></table><br>";
            }
            LOG_WRITER.println(footer);
        }

        if (TABLE) {
            LOG_WRITER.println("<table>");
            if (longEnough) {
                LOG_WRITER.println(
                    "<tr>\n" +
                        "<th>Code</th>" +
                        "<th>New Map</th>" +
                        "<th>Freq.</th>" +
                        "<th>Name</th>" +
                        "<th>↛ Old Map Name</th>" +
                        "<th>→ New Map Name</th></tr>");
            }
        }

        int counter = 0;
        for (Comparable<?>[] items : ordered) {
            counter++;
            if (counter > limit) {
                break;
            }
            final long count = (Long) items[0];
            final int cp = (Integer) items[1];
            final String oldMapped = (String) items[2];
            final String newMapped = (String) items[3];
            final String countStr = count == 0 ? "0" : "1/" + FORMAT.format(frequencies.getTotal() / count);

            String line = com.ibm.icu.impl.Utility.hex(cp) + " ; "
                + hex(newMapped, " ") + " ; "
                + countStr + " ; # "
                + showChanged(UTF16.valueOf(cp), oldMapped, newMapped, Form.codeStringAndName);

            if (TABLE) {
                line = "<tr><td>" + line.replace("\t", "</td><td>").replace(" ; ", "</td><td>") + "</td></tr>";
            }
            LOG_WRITER.println(line);
        }
        if (TABLE) {
            LOG_WRITER.println("</table>\n");
            LOG_WRITER.println("<pre>\n");
        }
    }

    static Comparator<Comparable<Object>[]> DOUBLE_STRING_COMP = new Comparator<Comparable<Object>[]>() {
        // only handle the case where the lengths are equal
        public int compare(Comparable<Object>[] o1, Comparable<Object>[] o2) {
            for (int i = 0; i < o1.length; ++i) {
                int result = o1[i].compareTo(o2[i]);
                if (result != 0) {
                    return -result;
                }
            }
            return 0;
        }
    };

    /**
     * Generate new mapping file, based on exceptions file. See normalizeForMatchExceptions.txt for the format.
     * 
     * @param specialMappingsFile
     *            TODO
     * @param outputFile
     *            TODO
     * @param diffSource
     * @param frequencyData
     * @param frequencyFile
     * @throws IOException
     */
    static void generateMappings(String specialMappingsFile, String outputFile, String diffSource, String frequencyFile)
        throws IOException {
        PrintWriter out = openUTF8Writer(outputFile);
        out.println("# Generated from: " + new File(specialMappingsFile).getName());
        out.println("# Date: " + ISO_DATE.format(new Date()));
        out.println("#");

        // special mappings
        UnicodeMap<String> SPECIAL_MAPPINGS = new UnicodeMap<String>();

        loadMappings(specialMappingsFile, SPECIAL_MAPPINGS, true);

        UnicodeMap<String> mappings = new UnicodeMap<String>();
        for (UnicodeSetIterator it = new UnicodeSetIterator(ASSIGNED); it.next();) {
            if (LIST_STYLE == ListStyle.ONLY_OLD && !U50.contains(it.codepoint)) {
                continue;
            }
            String str = it.getString();
            String other = getRemapped(it.codepoint, SPECIAL_MAPPINGS);
            if (other.equals(str)) continue;
            mappings.put(it.codepoint, other);
        }

        // Transitively close the mapping
        while (true) {
            UnicodeMap<String> deltaMappings = new UnicodeMap<String>();
            UnicodeSet done = new UnicodeSet();
            for (UnicodeSetIterator it = new UnicodeSetIterator(mappings.keySet()); it.next();) {
                String target = (String) mappings.getValue(it.codepoint);
                String recursed = replace(target, mappings);
                if (recursed != target) {
                    deltaMappings.put(it.codepoint, recursed);
                    done.add(it.codepoint);
                }
            }
            if (done.size() == 0) {
                break;
            }
            showOrderedList("Recursive Closure", done, mappings, deltaMappings, Integer.MAX_VALUE);
            mappings.putAllFiltered(deltaMappings, done);
        }
        ;

        // print them
        for (UnicodeSetIterator it = new UnicodeSetIterator(mappings.keySet()); it.next();) {
            writeMapping(out, it.getString(), (String) mappings.getValue(it.codepoint));
        }
        out.close();

        if (diffSource != null) {
            logDiffs(mappings, diffSource, frequencyFile);
        }
    }

    private static String replace(String target, UnicodeMap<String> mappings) {
        if (target.indexOf('\u2044') >= 0) {
            // System.out.println("?debug?");
        }
        StringBuilder result = new StringBuilder();
        boolean changed = false;
        int cp;
        for (int i = 0; i < target.length(); i += UTF16.getCharCount(cp)) {
            cp = UTF16.charAt(target, i);
            String remapped = (String) mappings.getValue(cp);
            if (remapped != null) {
                result.append(remapped);
                changed = true;
            } else {
                result.appendCodePoint(cp);
            }
        }
        return changed ? result.toString() : target;
    }

    private static String getRemapped(int codepoint, UnicodeMap<String> mapping) {
        return getRemapped(codepoint, (String) mapping.getValue(codepoint));
    }

    enum RuleMappings {
        __ok, __nfc, __caseonly, __bracket, __bracket_up, __bracket_circle, __bracket_down, __delete, __exclude
    }

    /**
     * Remap a string based on a special flag (usually gotten from the special_mappings, but
     * broken out so that we can see the effects of new rules).
     * 
     * @param codepoint
     * @param special
     *            either "exclude", or "caseonly", or null, or actual result.
     * @return
     */
    private static String getRemapped(int codepoint, String special) {
        String other = UTF16.valueOf(codepoint);
        if (codepoint == DEBUG_CODE_POINT) {
            System.out.println("?debug?");
        }
        if (special == null) {
            // no change
        } else if (!special.startsWith("__")) {
            other = special;
        } else {
            switch (RuleMappings.valueOf(special)) {
            case __ok:
                other = normalizeAndCaseFold(other, Normalizer.NFKC);
                break;
            case __nfc:
                other = Normalizer.normalize(other, Normalizer.NFC, 0);
                break;
            case __caseonly:
                other = normalizeAndCaseFold(other, Normalizer.NFC);
                break;
            case __bracket:
                other = " " + normalizeAndCaseFold(other, Normalizer.NFKC) + " ";
                break;
            case __bracket_down:
                other = "⌜" + normalizeAndCaseFold(other, Normalizer.NFKC) + "⌝";
                break;
            case __bracket_up:
                other = "⌞" + normalizeAndCaseFold(other, Normalizer.NFKC) + "⌟";
                break;
            case __bracket_circle:
                other = "(" + normalizeAndCaseFold(other, Normalizer.NFKC) + ")";
                break;
            default:
                throw new IllegalArgumentException("Missing rule");
            }
        }
        return other;
    }

    /**
     * Do the standard normalization & casefold
     * 
     * @param other
     * @return
     */
    private static String normalizeAndCaseFold(String other, Mode normalizerType) {
        String defaultChange = Normalizer.normalize(other, normalizerType, 0);
        defaultChange = UCharacter.foldCase(defaultChange, true);
        defaultChange = Normalizer.normalize(defaultChange, normalizerType, 0);
        return defaultChange;
    }

    /**
     * Write out a mapping line
     * 
     * @param out
     * @param source
     * @param target
     */
    private static void writeMapping(PrintWriter out, String source, String target) {
        String otherName = jimName(target);
        String age = (LIST_STYLE == ListStyle.SHOW_AGE) && (!U50.containsAll(source) || !U50.containsAll(target))
            ? showVersion(getNewest(source + target)) + " " : "";
        out.println(hex(source, " ")
            + " ; " + hex(target, " ").replace(",", " ")
            + " ; # " + age + UCharacter.getName(source, " + ")
            + " => " + otherName
            );
    }

    /**
     * Show the version in a nice format
     * 
     * @param newest
     * @return
     */
    private static String showVersion(VersionInfo newest) {
        return "[" + newest.getMajor() + "." + newest.getMinor()
            + (newest.getMilli() == 0 ? "" : "." + newest.getMilli())
            + "]";
    }

    /**
     * Get the age of the newest character in the string.
     * 
     * @param string
     * @return
     */
    private static VersionInfo getNewest(String string) {
        int cp;
        VersionInfo oldest = null;
        for (int i = 0; i < string.length(); i += UTF16.getCharCount(cp)) {
            cp = UTF16.charAt(string, i);
            VersionInfo age = UCharacter.getAge(cp);
            if (oldest == null || oldest.compareTo(age) < 0) {
                oldest = age;
            }
        }
        return oldest;
    }

    /**
     * Load the special mappings from a file.
     * 
     * @param filename
     *            TODO
     * @param resultMappings
     * @param printWriter
     *            TODO
     * @throws IOException
     */
    private static void loadMappings(String filename, UnicodeMap<String> resultMappings, boolean printWriter)
        throws IOException {
        // SPECIAL_MAPPINGS.putAll(0,0x10FFFF, "exclude");
        BufferedReader in = openUTF8Reader(filename);
        int lineNumber = 0;
        while (true) {
            String line = in.readLine();
            if (line == null) break;
            getMappingFromSemiLine(lineNumber++, line, true, resultMappings, printWriter);
        }
        in.close();
        resultMappings.freeze();
    }

    /**
     * Process each special mapping line from a file
     * 
     * @param lineNumber
     * @param line
     * @param skipIfIdentical
     * @param resultMappings
     * @param printWriter
     *            TODO
     * @param mappings
     */
    private static void getMappingFromSemiLine(int lineNumber, String line, boolean skipIfIdentical,
        UnicodeMap<String> resultMappings, boolean printWriter) {
        line = line.trim();
        if (line.startsWith("\uFEFF")) {
            line = line.substring(1);
        }
        if (printWriter) {
            LOG_WRITER.println(lineNumber + ":\t" + line);
        }
        int commentPos = line.indexOf("#");
        if (commentPos >= 0) {
            line = line.substring(0, commentPos);
        }
        line = line.trim();
        if (line.length() == 0) return;
        if (line.startsWith("@")) {
            line = line.toUpperCase().replace(" ", "").replace("\t", ""); // remove spaces, tabs
            if (line.startsWith("@LIST=")) {
                LIST_STYLE = ListStyle.valueOf(line.substring(6).toUpperCase());
            } else {
                throw new IllegalArgumentException("Illegal command: " + line);
            }
            return;
        }

        String[] pieces = line.split("\\s*;\\s*");
        final String sourcePiece = pieces[0];
        final String target = pieces.length < 2 ? "" : pieces[1];
        UnicodeSet source = new UnicodeSet();
        if (UnicodeSet.resemblesPattern(sourcePiece, 0)) {
            source.applyPattern(sourcePiece);
        } else if (UTF16.countCodePoint(sourcePiece) == 1) {
            source.add(UTF16.charAt(sourcePiece, 0));
        } else {
            String[] starts = sourcePiece.split("\\s*-\\s*");
            int start = Integer.parseInt(starts[0], 16);
            int end = starts.length == 1 ? start : Integer.parseInt(starts[1], 16);
            source.add(start, end);
        }

        UnicodeSet targetFilter = pieces.length < 3 || pieces[2].length() == 0 ? new UnicodeSet(ASSIGNED)
            : new UnicodeSet(pieces[2]);
        addMappings(source, target, targetFilter, resultMappings, printWriter);
    }

    /**
     * Add exceptions based on a line from the special mapping files
     * 
     * @param source
     * @param target
     * @param targetFilter
     * @param resultMappings
     * @param printWriter
     *            TODO
     * @param mappings
     */
    private static void addMappings(UnicodeSet source, String target, UnicodeSet targetFilter,
        UnicodeMap<String> resultMappings, boolean printWriter) {
        // remap options

        if (target.equalsIgnoreCase("delete")) {
            target = "";
        } else if (target.equalsIgnoreCase("exclude")) {
            target = null;
        } else {
            try {
                RuleMappings x = RuleMappings.valueOf("__" + target.toLowerCase());
                target = x.toString();
            } catch (IllegalArgumentException e) {
                if (HEXFORM.reset(target).matches()) {
                    target = fromHex(target);
                }
            }
        }

        // show a sample of what changed
        // and absorb new mappings, where they make a difference
        UnicodeSet affected = new UnicodeSet(source).retainAll(ASSIGNED);
        UnicodeMap<String> deltaMappings = new UnicodeMap<String>();
        UnicodeSet done = new UnicodeSet();

        for (UnicodeSetIterator it = new UnicodeSetIterator(affected); it.next();) {
            String willGet = getRemapped(it.codepoint, target);
            if (!targetFilter.containsAll(willGet)) {
                continue;
            }
            if (it.codepoint == DEBUG_CODE_POINT) {
                System.out.println("?debug?");
            }

            String didGet = getRemapped(it.codepoint, resultMappings);

            if (willGet.equals(didGet)) {
                // skip cases where we already covered this mapping
                continue;
            }
            deltaMappings.put(it.codepoint, willGet);
            done.add(it.codepoint);

            // // show what we are doing
            //
            // if (++count > 6) {
            // remainder.add(it.codepoint);
            // continue;
            // }
            // final String string = it.getString();
            // //final String normalizedAndCaseFolded = normalizeAndCaseFold(string);
            // //final String caseFolded = UCharacter.foldCase(string, true);
            //
            // if (printWriter != null) {
            // printWriter.println("\t" + codeAndName(string, Form.codeStringAndName) + "\t;\t" + oldTarget
            // + "\t; #\t" + showChanged(string, didGet, willGet, Form.string));
            // }
        }

        if (printWriter) {
            showOrderedList(null, done, resultMappings, deltaMappings, DIFF_LIMIT);
        }
        resultMappings.putAllFiltered(deltaMappings, done);
    }

    enum Form {
        string, codeStringAndName
    }

    private static String showChanged(final String string, String didGet, String willGet, Form form) {
        final String didGetStr = string.equals(didGet) ? "[unchanged]" : codeAndName(didGet, form);
        return codeAndName(string, form)
            + "\t ↛ " + didGetStr
            + "\t → " + codeAndName(willGet, form);
    }

    static final UnicodeSet BIDI = new UnicodeSet("[[:bidiclass=R:][:bidiclass=AL:]]");
    static final UnicodeSet DI = new UnicodeSet("[[:C:][:Default_Ignorable_Code_Point:]]");
    static final UnicodeSet FISHY = new UnicodeSet(
        "[\\<\\&\\>\\\"[:C:][:Z:][:whitespace:][:Default_Ignorable_Code_Point:]]");

    private static final String RULES =
        "'<' > '&lt;' ;" +
            "'&' > '&amp;' ;" +
            "'>' > '&gt;' ;" +
            "'\"' > '&quot;' ; " +
            ":: [[:C:][:Default_Ignorable_Code_Point:]-[\\u0020\\u0009\\u000A\\u000D]] hex/java ; ";

    public static final Transliterator toHTMLControl = Transliterator.createFromRules(
        "any-html", RULES, Transliterator.FORWARD);

    private static FrequencyData frequencies;

    private static String quote(String input) {
        String source = input;
        if (FISHY.containsSome(source)) {
            // if (false && source.length() > 20) {
            // System.out.println("?debug?");
            // }
            source = toHTMLControl.transform(source);
            // if (false) {
            // System.out.println(input + "=>" + source);
            // }
            System.out.flush();
        }
        if (BIDI.containsSome(source)) {
            source = "\u200E" + source + "\u200E";
        }
        return source;
    }

    /**
     * Printing convenience function
     * 
     * @param defaultChange
     * @return
     */
    private static String codeAndName(String defaultChange, Form form) {
        final String quotedChar = DI.containsAll(defaultChange) ? "«»" : "«" + quote(defaultChange) + "»";
        switch (form) {
        default:
            return quotedChar;
        case codeStringAndName:
            return hex(defaultChange, " ") + " " + quotedChar + " " + UCharacter.getName(defaultChange, " + ");
        }
    }

    /**
     * Printing convenience function
     * 
     * @param spaceDelimitedHex
     * @return
     */
    static String fromHex(String spaceDelimitedHex) {
        spaceDelimitedHex = spaceDelimitedHex.trim();
        if (spaceDelimitedHex.length() == 0) {
            return "";
        }
        StringBuilder result = new StringBuilder();
        String[] pieces = spaceDelimitedHex.split("\\s+");
        for (String piece : pieces) {
            result.append(UTF16.valueOf(Integer.parseInt(piece, 16)));
        }
        return result.toString();
    }

    /**
     * Printing convenience function
     * 
     * @param other
     * @return
     */
    private static String jimName(String other) {
        String otherName = UTF16.countCodePoint(other) != 1 ? null
            : (String) JIM_NAMES.getValue(UTF16.charAt(other, 0));
        if (otherName == null) {
            otherName = UCharacter.getName(other, " + ");
        }
        return otherName;
    }

    /**
     * Printing convenience function
     * 
     * @param s
     * @param separator
     * @return
     */
    public static String hex(String s, String separator) {
        StringBuffer result = new StringBuffer();
        int cp = 0;
        for (int i = 0; i < s.length(); i += UTF16.getCharCount(cp)) {
            if (i != 0) result.append(separator);
            cp = UTF16.charAt(s, i);
            result.append(com.ibm.icu.impl.Utility.hex(cp, 4));
        }
        return result.toString();
    }

    private static PrintWriter openUTF8Writer(String filename) throws IOException {
        File file = new File(filename);
        System.out.println("Writing:\t" + file.getCanonicalPath());
        return new PrintWriter(new OutputStreamWriter(new FileOutputStream(file), UTF8));
    }

    static BufferedReader openUTF8Reader(String filename) throws IOException {
        File file = new File(filename);
        System.out.println("Reading:\t" + file.getCanonicalPath());
        return new BufferedReader(new InputStreamReader(new FileInputStream(file), UTF8), 1024 * 64);
    }

    /**
     * Used to reformat files into consistent form.
     * 
     * @param sourceFile
     * @param targetFile
     * @throws IOException
     */
    private static void fixOld(String sourceFile, String targetFile) throws IOException {
        UnicodeMap<String> oldMap = new UnicodeMap<String>();
        BufferedReader in = openUTF8Reader(sourceFile);
        int lineNumber = 0;
        while (true) {
            String line = in.readLine();
            if (line == null) break;
            getMappingFromSemiLine(lineNumber++, line, false, oldMap, false);
        }
        in.close();
        PrintWriter out = openUTF8Writer(targetFile);
        for (UnicodeSetIterator it = new UnicodeSetIterator(oldMap.keySet()); it.next();) {
            String str = it.getString();
            String other = (String) oldMap.getValue(it.codepoint);
            writeMapping(out, str, other);
        }
        out.close();
    }
}
