package com.fsck.k9.helper;

import android.text.*;
import android.util.Log;
import com.fsck.k9.K9;
import org.xml.sax.XMLReader;

import java.io.IOException;
import java.io.StringReader;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import java.util.regex.Matcher;

/**
 * Contains common routines to convert html to text and vice versa.
 */
public class HtmlConverter
{
    /**
     * When generating previews, Spannable objects that can't be converted into a String are
     * represented as 0xfffc. When displayed, these show up as undisplayed squares. These constants
     * define the object character and the replacement character.
     */
    private static final char PREVIEW_OBJECT_CHARACTER = (char)0xfffc;
    private static final char PREVIEW_OBJECT_REPLACEMENT = (char)0x20;  // space

    /**
     * toHtml() converts non-breaking spaces into the UTF-8 non-breaking space, which doesn't get
     * rendered properly in some clients. Replace it with a simple space.
     */
    private static final char NBSP_CHARACTER = (char)0x00a0;    // utf-8 non-breaking space
    private static final char NBSP_REPLACEMENT = (char)0x20;    // space

    // Number of extra bytes to allocate in a string buffer for htmlification.
    private static final int TEXT_TO_HTML_EXTRA_BUFFER_LENGTH = 512;

    /**
     * Convert an HTML string to a plain text string.
     * @param html HTML string to convert.
     * @return Plain text result.
     */
    public static String htmlToText(final String html)
    {
        return Html.fromHtml(html, null, new HtmlToTextTagHandler()).toString()
               .replace(PREVIEW_OBJECT_CHARACTER, PREVIEW_OBJECT_REPLACEMENT)
               .replace(NBSP_CHARACTER, NBSP_REPLACEMENT);
    }

    /**
     * Custom tag handler to use when converting HTML messages to text. It currently handles text
     * representations of HTML tags that Android's built-in parser doesn't understand and hides code
     * contained in STYLE and SCRIPT blocks.
     */
    private static class HtmlToTextTagHandler implements Html.TagHandler
    {
        // List of tags whose content should be ignored.
        private static final Set<String> TAGS_WITH_IGNORED_CONTENT = Collections.unmodifiableSet(new HashSet<String>()
        {
            {
                add("style");
                add("script");
                add("title");
                add("!");   // comments
            }
        });

        @Override
        public void handleTag(boolean opening, String tag, Editable output, XMLReader xmlReader)
        {
            tag = tag.toLowerCase();
            if (tag.equals("hr") && opening)
            {
                // In the case of an <hr>, replace it with a bunch of underscores. This is roughly
                // the behaviour of Outlook in Rich Text mode.
                output.append("_____________________________________________\n");
            }
            else if (TAGS_WITH_IGNORED_CONTENT.contains(tag))
            {
                handleIgnoredTag(opening, output);
            }
        }

        private static final String IGNORED_ANNOTATION_KEY = "K9_ANNOTATION";
        private static final String IGNORED_ANNOTATION_VALUE = "hiddenSpan";

        /**
         * When we come upon an ignored tag, we mark it with an Annotation object with a specific key
         * and value as above. We don't really need to be checking these values since Html.fromHtml()
         * doesn't use Annotation spans, but we should do it now to be safe in case they do start using
         * it in the future.
         * @param opening If this is an opening tag or not.
         * @param output Spannable string that we're working with.
         */
        private void handleIgnoredTag(boolean opening, Editable output)
        {
            int len = output.length();
            if (opening)
            {
                output.setSpan(new Annotation(IGNORED_ANNOTATION_KEY, IGNORED_ANNOTATION_VALUE), len,
                               len, Spannable.SPAN_MARK_MARK);
            }
            else
            {
                Object start = getOpeningAnnotation(output);
                if (start != null)
                {
                    int where = output.getSpanStart(start);
                    // Remove the temporary Annotation span.
                    output.removeSpan(start);
                    // Delete everything between the start of the Annotation and the end of the string
                    // (what we've generated so far).
                    output.delete(where, len);
                }
            }
        }

        /**
         * Fetch the matching opening Annotation object and verify that it's the one added by K9.
         * @param output Spannable string we're working with.
         * @return Starting Annotation object.
         */
        private Object getOpeningAnnotation(Editable output)
        {
            Object[] objs = output.getSpans(0, output.length(), Annotation.class);
            for (int i = objs.length - 1; i >= 0; i--)
            {
                Annotation span = (Annotation) objs[i];
                if (output.getSpanFlags(objs[i]) == Spannable.SPAN_MARK_MARK
                        && span.getKey().equals(IGNORED_ANNOTATION_KEY)
                        && span.getValue().equals(IGNORED_ANNOTATION_VALUE))
                {
                    return objs[i];
                }
            }
            return null;
        }
    }

    private static final int MAX_SMART_HTMLIFY_MESSAGE_LENGTH = 1024 * 256 ;

    /**
     * Convert a text string into an HTML document. Attempts to do smart replacement for large
     * documents to prevent OOM errors. This method adds headers and footers to create a proper HTML
     * document. To convert to a fragment, use {@link #textToHtmlFragment(String)}.
     * @param text Plain text string.
     * @return HTML string.
     */
    public static String textToHtml(String text)
    {
        // Our HTMLification code is somewhat memory intensive
        // and was causing lots of OOM errors on the market
        // if the message is big and plain text, just do
        // a trivial htmlification
        if (text.length() > MAX_SMART_HTMLIFY_MESSAGE_LENGTH)
        {
            return "<html><head/><body>" +
                   htmlifyMessageHeader() +
                   text +
                   htmlifyMessageFooter() +
                   "</body></html>";
        }
        StringReader reader = new StringReader(text);
        StringBuilder buff = new StringBuilder(text.length() + TEXT_TO_HTML_EXTRA_BUFFER_LENGTH);
        int c;
        try
        {
            while ((c = reader.read()) != -1)
            {
                switch (c)
                {
                    case '&':
                        buff.append("&amp;");
                        break;
                    case '<':
                        buff.append("&lt;");
                        break;
                    case '>':
                        buff.append("&gt;");
                        break;
                    case '\r':
                        break;
                    default:
                        buff.append((char)c);
                }//switch
            }
        }
        catch (IOException e)
        {
            //Should never happen
            Log.e(K9.LOG_TAG, "Could not read string to convert text to HTML:", e);
        }
        text = buff.toString();
        text = text.replaceAll("\\s*([-=_]{30,}+)\\s*","<hr />");
        text = text.replaceAll("(?m)^([^\r\n]{4,}[\\s\\w,:;+/])(?:\r\n|\n|\r)(?=[a-z]\\S{0,10}[\\s\\n\\r])","$1 ");
        text = text.replaceAll("(?m)(\r\n|\n|\r){4,}","\n\n");

        StringBuffer sb = new StringBuffer(text.length() + TEXT_TO_HTML_EXTRA_BUFFER_LENGTH);
        sb.append("<html><head></head><body>");
        sb.append(htmlifyMessageHeader());
        linkifyText(text, sb);
        sb.append(htmlifyMessageFooter());
        sb.append("</body></html>");
        text = sb.toString();

        return text;
    }

    /**
     * Searches for link-like text in a string and turn it into a link. Append the result to
     * <tt>outputBuffer</tt>. <tt>text</tt> is not modified.
     * @param text Plain text to be linkified.
     * @param outputBuffer Buffer to append linked text to.
     */
    private static void linkifyText(final String text, final StringBuffer outputBuffer) {
        Matcher m = Regex.WEB_URL_PATTERN.matcher(text);
        while (m.find())
        {
            int start = m.start();
            if (start == 0 || (start != 0 && text.charAt(start - 1) != '@'))
            {
                if (m.group().indexOf(':') > 0)   // With no URI-schema we may get "http:/" links with the second / missing
                {
                    m.appendReplacement(outputBuffer, "<a href=\"$0\">$0</a>");
                }
                else
                {
                    m.appendReplacement(outputBuffer, "<a href=\"http://$0\">$0</a>");
                }
            }
            else
            {
                m.appendReplacement(outputBuffer, "$0");
            }
        }

        m.appendTail(outputBuffer);
    }

    /*
     * Lightweight method to check whether the message contains emoji or not.
     * Useful to avoid calling the heavyweight convertEmoji2Img method.
     * We don't use String.codePointAt here for performance reasons.
     */
    private static boolean hasEmoji(String html)
    {
        for (int i = 0; i < html.length(); ++i)
        {
            char c = html.charAt(i);
            if (c >= 0xDBB8 && c < 0xDBBC)
                return true;
        }
        return false;
    }

    public static String convertEmoji2Img(String html)
    {
        if (!hasEmoji(html))
        {
            return html;

        }
        StringBuilder buff = new StringBuilder(html.length() + 512);
        for (int i = 0; i < html.length(); i = html.offsetByCodePoints(i, 1))
        {
            int codePoint = html.codePointAt(i);
            String emoji = getEmojiForCodePoint(codePoint);
            if (emoji != null)
                buff.append("<img src=\"file:///android_asset/emoticons/").append(emoji).append(".gif\" alt=\"").append(emoji).append("\" />");
            else
                buff.appendCodePoint(codePoint);

        }
        return buff.toString();
    }

    private static String getEmojiForCodePoint(int codePoint)
    {
        // Derived from http://code.google.com/p/emoji4unicode/source/browse/trunk/data/emoji4unicode.xml
        // XXX: This doesn't cover all the characters.  More emoticons are wanted.
        switch (codePoint)
        {
            case 0xFE000:
                return "sun";
            case 0xFE001:
                return "cloud";
            case 0xFE002:
                return "rain";
            case 0xFE003:
                return "snow";
            case 0xFE004:
                return "thunder";
            case 0xFE005:
                return "typhoon";
            case 0xFE006:
                return "mist";
            case 0xFE007:
                return "sprinkle";
            case 0xFE008:
                return "night";
            case 0xFE009:
                return "sun";
            case 0xFE00A:
                return "sun";
            case 0xFE00C:
                return "sun";
            case 0xFE010:
                return "night";
            case 0xFE011:
                return "newmoon";
            case 0xFE012:
                return "moon1";
            case 0xFE013:
                return "moon2";
            case 0xFE014:
                return "moon3";
            case 0xFE015:
                return "fullmoon";
            case 0xFE016:
                return "moon2";
            case 0xFE018:
                return "soon";
            case 0xFE019:
                return "on";
            case 0xFE01A:
                return "end";
            case 0xFE01B:
                return "sandclock";
            case 0xFE01C:
                return "sandclock";
            case 0xFE01D:
                return "watch";
            case 0xFE01E:
                return "clock";
            case 0xFE01F:
                return "clock";
            case 0xFE020:
                return "clock";
            case 0xFE021:
                return "clock";
            case 0xFE022:
                return "clock";
            case 0xFE023:
                return "clock";
            case 0xFE024:
                return "clock";
            case 0xFE025:
                return "clock";
            case 0xFE026:
                return "clock";
            case 0xFE027:
                return "clock";
            case 0xFE028:
                return "clock";
            case 0xFE029:
                return "clock";
            case 0xFE02A:
                return "clock";
            case 0xFE02B:
                return "aries";
            case 0xFE02C:
                return "taurus";
            case 0xFE02D:
                return "gemini";
            case 0xFE02E:
                return "cancer";
            case 0xFE02F:
                return "leo";
            case 0xFE030:
                return "virgo";
            case 0xFE031:
                return "libra";
            case 0xFE032:
                return "scorpius";
            case 0xFE033:
                return "sagittarius";
            case 0xFE034:
                return "capricornus";
            case 0xFE035:
                return "aquarius";
            case 0xFE036:
                return "pisces";
            case 0xFE038:
                return "wave";
            case 0xFE03B:
                return "night";
            case 0xFE03C:
                return "clover";
            case 0xFE03D:
                return "tulip";
            case 0xFE03E:
                return "bud";
            case 0xFE03F:
                return "maple";
            case 0xFE040:
                return "cherryblossom";
            case 0xFE042:
                return "maple";
            case 0xFE04E:
                return "clover";
            case 0xFE04F:
                return "cherry";
            case 0xFE050:
                return "banana";
            case 0xFE051:
                return "apple";
            case 0xFE05B:
                return "apple";
            case 0xFE190:
                return "eye";
            case 0xFE191:
                return "ear";
            case 0xFE193:
                return "kissmark";
            case 0xFE194:
                return "bleah";
            case 0xFE195:
                return "rouge";
            case 0xFE198:
                return "hairsalon";
            case 0xFE19A:
                return "shadow";
            case 0xFE19B:
                return "happy01";
            case 0xFE19C:
                return "happy01";
            case 0xFE19D:
                return "happy01";
            case 0xFE19E:
                return "happy01";
            case 0xFE1B7:
                return "dog";
            case 0xFE1B8:
                return "cat";
            case 0xFE1B9:
                return "snail";
            case 0xFE1BA:
                return "chick";
            case 0xFE1BB:
                return "chick";
            case 0xFE1BC:
                return "penguin";
            case 0xFE1BD:
                return "fish";
            case 0xFE1BE:
                return "horse";
            case 0xFE1BF:
                return "pig";
            case 0xFE1C8:
                return "chick";
            case 0xFE1C9:
                return "fish";
            case 0xFE1CF:
                return "aries";
            case 0xFE1D0:
                return "dog";
            case 0xFE1D8:
                return "dog";
            case 0xFE1D9:
                return "fish";
            case 0xFE1DB:
                return "foot";
            case 0xFE1DD:
                return "chick";
            case 0xFE1E0:
                return "pig";
            case 0xFE1E3:
                return "cancer";
            case 0xFE320:
                return "angry";
            case 0xFE321:
                return "sad";
            case 0xFE322:
                return "wobbly";
            case 0xFE323:
                return "despair";
            case 0xFE324:
                return "wobbly";
            case 0xFE325:
                return "coldsweats02";
            case 0xFE326:
                return "gawk";
            case 0xFE327:
                return "lovely";
            case 0xFE328:
                return "smile";
            case 0xFE329:
                return "bleah";
            case 0xFE32A:
                return "bleah";
            case 0xFE32B:
                return "delicious";
            case 0xFE32C:
                return "lovely";
            case 0xFE32D:
                return "lovely";
            case 0xFE32F:
                return "happy02";
            case 0xFE330:
                return "happy01";
            case 0xFE331:
                return "coldsweats01";
            case 0xFE332:
                return "happy02";
            case 0xFE333:
                return "smile";
            case 0xFE334:
                return "happy02";
            case 0xFE335:
                return "delicious";
            case 0xFE336:
                return "happy01";
            case 0xFE337:
                return "happy01";
            case 0xFE338:
                return "coldsweats01";
            case 0xFE339:
                return "weep";
            case 0xFE33A:
                return "crying";
            case 0xFE33B:
                return "shock";
            case 0xFE33C:
                return "bearing";
            case 0xFE33D:
                return "pout";
            case 0xFE33E:
                return "confident";
            case 0xFE33F:
                return "sad";
            case 0xFE340:
                return "think";
            case 0xFE341:
                return "shock";
            case 0xFE342:
                return "sleepy";
            case 0xFE343:
                return "catface";
            case 0xFE344:
                return "coldsweats02";
            case 0xFE345:
                return "coldsweats02";
            case 0xFE346:
                return "bearing";
            case 0xFE347:
                return "wink";
            case 0xFE348:
                return "happy01";
            case 0xFE349:
                return "smile";
            case 0xFE34A:
                return "happy02";
            case 0xFE34B:
                return "lovely";
            case 0xFE34C:
                return "lovely";
            case 0xFE34D:
                return "weep";
            case 0xFE34E:
                return "pout";
            case 0xFE34F:
                return "smile";
            case 0xFE350:
                return "sad";
            case 0xFE351:
                return "ng";
            case 0xFE352:
                return "ok";
            case 0xFE357:
                return "paper";
            case 0xFE359:
                return "sad";
            case 0xFE35A:
                return "angry";
            case 0xFE4B0:
                return "house";
            case 0xFE4B1:
                return "house";
            case 0xFE4B2:
                return "building";
            case 0xFE4B3:
                return "postoffice";
            case 0xFE4B4:
                return "hospital";
            case 0xFE4B5:
                return "bank";
            case 0xFE4B6:
                return "atm";
            case 0xFE4B7:
                return "hotel";
            case 0xFE4B9:
                return "24hours";
            case 0xFE4BA:
                return "school";
            case 0xFE4C1:
                return "ship";
            case 0xFE4C2:
                return "bottle";
            case 0xFE4C3:
                return "fuji";
            case 0xFE4C9:
                return "wrench";
            case 0xFE4CC:
                return "shoe";
            case 0xFE4CD:
                return "shoe";
            case 0xFE4CE:
                return "eyeglass";
            case 0xFE4CF:
                return "t-shirt";
            case 0xFE4D0:
                return "denim";
            case 0xFE4D1:
                return "crown";
            case 0xFE4D2:
                return "crown";
            case 0xFE4D6:
                return "boutique";
            case 0xFE4D7:
                return "boutique";
            case 0xFE4DB:
                return "t-shirt";
            case 0xFE4DC:
                return "moneybag";
            case 0xFE4DD:
                return "dollar";
            case 0xFE4E0:
                return "dollar";
            case 0xFE4E2:
                return "yen";
            case 0xFE4E3:
                return "dollar";
            case 0xFE4EF:
                return "camera";
            case 0xFE4F0:
                return "bag";
            case 0xFE4F1:
                return "pouch";
            case 0xFE4F2:
                return "bell";
            case 0xFE4F3:
                return "door";
            case 0xFE4F9:
                return "movie";
            case 0xFE4FB:
                return "flair";
            case 0xFE4FD:
                return "sign05";
            case 0xFE4FF:
                return "book";
            case 0xFE500:
                return "book";
            case 0xFE501:
                return "book";
            case 0xFE502:
                return "book";
            case 0xFE503:
                return "book";
            case 0xFE505:
                return "spa";
            case 0xFE506:
                return "toilet";
            case 0xFE507:
                return "toilet";
            case 0xFE508:
                return "toilet";
            case 0xFE50F:
                return "ribbon";
            case 0xFE510:
                return "present";
            case 0xFE511:
                return "birthday";
            case 0xFE512:
                return "xmas";
            case 0xFE522:
                return "pocketbell";
            case 0xFE523:
                return "telephone";
            case 0xFE524:
                return "telephone";
            case 0xFE525:
                return "mobilephone";
            case 0xFE526:
                return "phoneto";
            case 0xFE527:
                return "memo";
            case 0xFE528:
                return "faxto";
            case 0xFE529:
                return "mail";
            case 0xFE52A:
                return "mailto";
            case 0xFE52B:
                return "mailto";
            case 0xFE52C:
                return "postoffice";
            case 0xFE52D:
                return "postoffice";
            case 0xFE52E:
                return "postoffice";
            case 0xFE535:
                return "present";
            case 0xFE536:
                return "pen";
            case 0xFE537:
                return "chair";
            case 0xFE538:
                return "pc";
            case 0xFE539:
                return "pencil";
            case 0xFE53A:
                return "clip";
            case 0xFE53B:
                return "bag";
            case 0xFE53E:
                return "hairsalon";
            case 0xFE540:
                return "memo";
            case 0xFE541:
                return "memo";
            case 0xFE545:
                return "book";
            case 0xFE546:
                return "book";
            case 0xFE547:
                return "book";
            case 0xFE548:
                return "memo";
            case 0xFE54D:
                return "book";
            case 0xFE54F:
                return "book";
            case 0xFE552:
                return "memo";
            case 0xFE553:
                return "foot";
            case 0xFE7D0:
                return "sports";
            case 0xFE7D1:
                return "baseball";
            case 0xFE7D2:
                return "golf";
            case 0xFE7D3:
                return "tennis";
            case 0xFE7D4:
                return "soccer";
            case 0xFE7D5:
                return "ski";
            case 0xFE7D6:
                return "basketball";
            case 0xFE7D7:
                return "motorsports";
            case 0xFE7D8:
                return "snowboard";
            case 0xFE7D9:
                return "run";
            case 0xFE7DA:
                return "snowboard";
            case 0xFE7DC:
                return "horse";
            case 0xFE7DF:
                return "train";
            case 0xFE7E0:
                return "subway";
            case 0xFE7E1:
                return "subway";
            case 0xFE7E2:
                return "bullettrain";
            case 0xFE7E3:
                return "bullettrain";
            case 0xFE7E4:
                return "car";
            case 0xFE7E5:
                return "rvcar";
            case 0xFE7E6:
                return "bus";
            case 0xFE7E8:
                return "ship";
            case 0xFE7E9:
                return "airplane";
            case 0xFE7EA:
                return "yacht";
            case 0xFE7EB:
                return "bicycle";
            case 0xFE7EE:
                return "yacht";
            case 0xFE7EF:
                return "car";
            case 0xFE7F0:
                return "run";
            case 0xFE7F5:
                return "gasstation";
            case 0xFE7F6:
                return "parking";
            case 0xFE7F7:
                return "signaler";
            case 0xFE7FA:
                return "spa";
            case 0xFE7FC:
                return "carouselpony";
            case 0xFE7FF:
                return "fish";
            case 0xFE800:
                return "karaoke";
            case 0xFE801:
                return "movie";
            case 0xFE802:
                return "movie";
            case 0xFE803:
                return "music";
            case 0xFE804:
                return "art";
            case 0xFE805:
                return "drama";
            case 0xFE806:
                return "event";
            case 0xFE807:
                return "ticket";
            case 0xFE808:
                return "slate";
            case 0xFE809:
                return "drama";
            case 0xFE80A:
                return "game";
            case 0xFE813:
                return "note";
            case 0xFE814:
                return "notes";
            case 0xFE81A:
                return "notes";
            case 0xFE81C:
                return "tv";
            case 0xFE81D:
                return "cd";
            case 0xFE81E:
                return "cd";
            case 0xFE823:
                return "kissmark";
            case 0xFE824:
                return "loveletter";
            case 0xFE825:
                return "ring";
            case 0xFE826:
                return "ring";
            case 0xFE827:
                return "kissmark";
            case 0xFE829:
                return "heart02";
            case 0xFE82B:
                return "freedial";
            case 0xFE82C:
                return "sharp";
            case 0xFE82D:
                return "mobaq";
            case 0xFE82E:
                return "one";
            case 0xFE82F:
                return "two";
            case 0xFE830:
                return "three";
            case 0xFE831:
                return "four";
            case 0xFE832:
                return "five";
            case 0xFE833:
                return "six";
            case 0xFE834:
                return "seven";
            case 0xFE835:
                return "eight";
            case 0xFE836:
                return "nine";
            case 0xFE837:
                return "zero";
            case 0xFE960:
                return "fastfood";
            case 0xFE961:
                return "riceball";
            case 0xFE962:
                return "cake";
            case 0xFE963:
                return "noodle";
            case 0xFE964:
                return "bread";
            case 0xFE96A:
                return "noodle";
            case 0xFE973:
                return "typhoon";
            case 0xFE980:
                return "restaurant";
            case 0xFE981:
                return "cafe";
            case 0xFE982:
                return "bar";
            case 0xFE983:
                return "beer";
            case 0xFE984:
                return "japanesetea";
            case 0xFE985:
                return "bottle";
            case 0xFE986:
                return "wine";
            case 0xFE987:
                return "beer";
            case 0xFE988:
                return "bar";
            case 0xFEAF0:
                return "upwardright";
            case 0xFEAF1:
                return "downwardright";
            case 0xFEAF2:
                return "upwardleft";
            case 0xFEAF3:
                return "downwardleft";
            case 0xFEAF4:
                return "up";
            case 0xFEAF5:
                return "down";
            case 0xFEAF6:
                return "leftright";
            case 0xFEAF7:
                return "updown";
            case 0xFEB04:
                return "sign01";
            case 0xFEB05:
                return "sign02";
            case 0xFEB06:
                return "sign03";
            case 0xFEB07:
                return "sign04";
            case 0xFEB08:
                return "sign05";
            case 0xFEB0B:
                return "sign01";
            case 0xFEB0C:
                return "heart01";
            case 0xFEB0D:
                return "heart02";
            case 0xFEB0E:
                return "heart03";
            case 0xFEB0F:
                return "heart04";
            case 0xFEB10:
                return "heart01";
            case 0xFEB11:
                return "heart02";
            case 0xFEB12:
                return "heart01";
            case 0xFEB13:
                return "heart01";
            case 0xFEB14:
                return "heart01";
            case 0xFEB15:
                return "heart01";
            case 0xFEB16:
                return "heart01";
            case 0xFEB17:
                return "heart01";
            case 0xFEB18:
                return "heart02";
            case 0xFEB19:
                return "cute";
            case 0xFEB1A:
                return "heart";
            case 0xFEB1B:
                return "spade";
            case 0xFEB1C:
                return "diamond";
            case 0xFEB1D:
                return "club";
            case 0xFEB1E:
                return "smoking";
            case 0xFEB1F:
                return "nosmoking";
            case 0xFEB20:
                return "wheelchair";
            case 0xFEB21:
                return "free";
            case 0xFEB22:
                return "flag";
            case 0xFEB23:
                return "danger";
            case 0xFEB26:
                return "ng";
            case 0xFEB27:
                return "ok";
            case 0xFEB28:
                return "ng";
            case 0xFEB29:
                return "copyright";
            case 0xFEB2A:
                return "tm";
            case 0xFEB2B:
                return "secret";
            case 0xFEB2C:
                return "recycle";
            case 0xFEB2D:
                return "r-mark";
            case 0xFEB2E:
                return "ban";
            case 0xFEB2F:
                return "empty";
            case 0xFEB30:
                return "pass";
            case 0xFEB31:
                return "full";
            case 0xFEB36:
                return "new";
            case 0xFEB44:
                return "fullmoon";
            case 0xFEB48:
                return "ban";
            case 0xFEB55:
                return "cute";
            case 0xFEB56:
                return "flair";
            case 0xFEB57:
                return "annoy";
            case 0xFEB58:
                return "bomb";
            case 0xFEB59:
                return "sleepy";
            case 0xFEB5A:
                return "impact";
            case 0xFEB5B:
                return "sweat01";
            case 0xFEB5C:
                return "sweat02";
            case 0xFEB5D:
                return "dash";
            case 0xFEB5F:
                return "sad";
            case 0xFEB60:
                return "shine";
            case 0xFEB61:
                return "cute";
            case 0xFEB62:
                return "cute";
            case 0xFEB63:
                return "newmoon";
            case 0xFEB64:
                return "newmoon";
            case 0xFEB65:
                return "newmoon";
            case 0xFEB66:
                return "newmoon";
            case 0xFEB67:
                return "newmoon";
            case 0xFEB77:
                return "shine";
            case 0xFEB81:
                return "id";
            case 0xFEB82:
                return "key";
            case 0xFEB83:
                return "enter";
            case 0xFEB84:
                return "clear";
            case 0xFEB85:
                return "search";
            case 0xFEB86:
                return "key";
            case 0xFEB87:
                return "key";
            case 0xFEB8A:
                return "key";
            case 0xFEB8D:
                return "search";
            case 0xFEB90:
                return "key";
            case 0xFEB91:
                return "recycle";
            case 0xFEB92:
                return "mail";
            case 0xFEB93:
                return "rock";
            case 0xFEB94:
                return "scissors";
            case 0xFEB95:
                return "paper";
            case 0xFEB96:
                return "punch";
            case 0xFEB97:
                return "good";
            case 0xFEB9D:
                return "paper";
            case 0xFEB9F:
                return "ok";
            case 0xFEBA0:
                return "down";
            case 0xFEBA1:
                return "paper";
            case 0xFEE10:
                return "info01";
            case 0xFEE11:
                return "info02";
            case 0xFEE12:
                return "by-d";
            case 0xFEE13:
                return "d-point";
            case 0xFEE14:
                return "appli01";
            case 0xFEE15:
                return "appli02";
            case 0xFEE1C:
                return "movie";
            default:
                return null;
        }
    }

    private static String htmlifyMessageHeader()
    {
        if (K9.messageViewFixedWidthFont())
        {
            return "<pre style=\"white-space: pre-wrap; word-wrap:break-word; \">";
        }
        else
        {
            return "<div style=\"white-space: pre-wrap; word-wrap:break-word; \">";
        }
    }

    private static String htmlifyMessageFooter()
    {
        if (K9.messageViewFixedWidthFont())
        {
            return "</pre>";
        }
        else
        {
            return "</div>";
        }
    }

    /**
     * Convert a plain text string into an HTML fragment.
     * @param text Plain text.
     * @return HTML fragment.
     */
    public static String textToHtmlFragment(final String text)
    {
        // Escape the entities and add newlines.
        String htmlified = TextUtils.htmlEncode(text);

        // Linkify the message.
        StringBuffer linkified = new StringBuffer(htmlified.length() + TEXT_TO_HTML_EXTRA_BUFFER_LENGTH);
        linkifyText(htmlified, linkified);

        // Add newlines and unescaping.
        //
        // For some reason, TextUtils.htmlEncode escapes ' into &apos;, which is technically part of the XHTML 1.0
        // standard, but Gmail doesn't recognize it as an HTML entity. We unescape that here.
        return linkified.toString().replace("\n", "<br>\n").replace("&apos;", "&#39;");
    }
}