bundles/org.eclipse.uomo.xml/src/main/java/org/eclipse/uomo/xml/XMLUtil.java

package org.eclipse.uomo.xml;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public final class XMLUtil {

	private XMLUtil() {}
	
	public static boolean isNMToken(String name) {
		if (name == null)
			return false;
		for (int i = 0; i < name.length(); i++) 
			if (!isNMTokenChar(name.charAt(i)))
				return false;	
		return name.length() > 0;
	}

	public static boolean isNMTokenChar(char c) {
		return isLetter(c) || isDigit(c) || c == '.' || c == '-' || c == '_' || c == ':' || isCombiningChar(c) || isExtender(c);
	}

	private static boolean isDigit(char c) {
		return (c >= '\u0030' && c <= '\u0039') || (c >= '\u0660' && c <= '\u0669') || (c >= '\u06F0' && c <= '\u06F9') || 
			(c >= '\u0966' && c <= '\u096F') || (c >= '\u09E6' && c <= '\u09EF') || (c >= '\u0A66' && c <= '\u0A6F') || 
			(c >= '\u0AE6' && c <= '\u0AEF') || (c >= '\u0B66' && c <= '\u0B6F') || (c >= '\u0BE7' && c <= '\u0BEF') || 
			(c >= '\u0C66' && c <= '\u0C6F') || (c >= '\u0CE6' && c <= '\u0CEF') || (c >= '\u0D66' && c <= '\u0D6F') || 
			(c >= '\u0E50' && c <= '\u0E59') || (c >= '\u0ED0' && c <= '\u0ED9') || (c >= '\u0F20' && c <= '\u0F29');
	}

	private static boolean isCombiningChar(char c) {
		return (c >= '\u0300' && c <= '\u0345') || (c >= '\u0360' && c <= '\u0361') || (c >= '\u0483' && c <= '\u0486') || 
			(c >= '\u0591' && c <= '\u05A1') || (c >= '\u05A3' && c <= '\u05B9') || (c >= '\u05BB' && c <= '\u05BD') || 
			c == '\u05BF' || (c >= '\u05C1' && c <= '\u05C2') || c == '\u05C4' || (c >= '\u064B' && c <= '\u0652') || 
			c == '\u0670' || (c >= '\u06D6' && c <= '\u06DC') || (c >= '\u06DD' && c <= '\u06DF') || (c >= '\u06E0' && c <= '\u06E4') || 
			(c >= '\u06E7' && c <= '\u06E8') || (c >= '\u06EA' && c <= '\u06ED') || (c >= '\u0901' && c <= '\u0903') || c == '\u093C' || 
			(c >= '\u093E' && c <= '\u094C') || c == '\u094D' || (c >= '\u0951' && c <= '\u0954') || (c >= '\u0962' && c <= '\u0963') || 
			(c >= '\u0981' && c <= '\u0983') || c == '\u09BC' || c == '\u09BE' || c == '\u09BF' || (c >= '\u09C0' && c <= '\u09C4') || 
			(c >= '\u09C7' && c <= '\u09C8') || (c >= '\u09CB' && c <= '\u09CD') || c == '\u09D7' || (c >= '\u09E2' && c <= '\u09E3') || 
			c == '\u0A02' || c == '\u0A3C' || c == '\u0A3E' || c == '\u0A3F' || (c >= '\u0A40' && c <= '\u0A42') || 
			(c >= '\u0A47' && c <= '\u0A48') || (c >= '\u0A4B' && c <= '\u0A4D') || (c >= '\u0A70' && c <= '\u0A71') || 
			(c >= '\u0A81' && c <= '\u0A83') || c == '\u0ABC' || (c >= '\u0ABE' && c <= '\u0AC5') || (c >= '\u0AC7' && c <= '\u0AC9') || 
			(c >= '\u0ACB' && c <= '\u0ACD') || (c >= '\u0B01' && c <= '\u0B03') || c == '\u0B3C' || (c >= '\u0B3E' && c <= '\u0B43') || 
			(c >= '\u0B47' && c <= '\u0B48') || (c >= '\u0B4B' && c <= '\u0B4D') || (c >= '\u0B56' && c <= '\u0B57') || 
			(c >= '\u0B82' && c <= '\u0B83') || (c >= '\u0BBE' && c <= '\u0BC2') || (c >= '\u0BC6' && c <= '\u0BC8') || 
			(c >= '\u0BCA' && c <= '\u0BCD') || c == '\u0BD7' || (c >= '\u0C01' && c <= '\u0C03') || (c >= '\u0C3E' && c <= '\u0C44') || 
			(c >= '\u0C46' && c <= '\u0C48') || (c >= '\u0C4A' && c <= '\u0C4D') || (c >= '\u0C55' && c <= '\u0C56') || 
			(c >= '\u0C82' && c <= '\u0C83') || (c >= '\u0CBE' && c <= '\u0CC4') || (c >= '\u0CC6' && c <= '\u0CC8') || 
			(c >= '\u0CCA' && c <= '\u0CCD') || (c >= '\u0CD5' && c <= '\u0CD6') || (c >= '\u0D02' && c <= '\u0D03') || 
			(c >= '\u0D3E' && c <= '\u0D43') || (c >= '\u0D46' && c <= '\u0D48') || (c >= '\u0D4A' && c <= '\u0D4D') || c == '\u0D57' || 
			c == '\u0E31' || (c >= '\u0E34' && c <= '\u0E3A') || (c >= '\u0E47' && c <= '\u0E4E') || c == '\u0EB1' || 
			(c >= '\u0EB4' && c <= '\u0EB9') || (c >= '\u0EBB' && c <= '\u0EBC') || (c >= '\u0EC8' && c <= '\u0ECD') || 
			(c >= '\u0F18' && c <= '\u0F19') || c == '\u0F35' || c == '\u0F37' || c == '\u0F39' || c == '\u0F3E' || c == '\u0F3F' || 
			(c >= '\u0F71' && c <= '\u0F84') || (c >= '\u0F86' && c <= '\u0F8B') || (c >= '\u0F90' && c <= '\u0F95') || c == '\u0F97' || 
			(c >= '\u0F99' && c <= '\u0FAD') || (c >= '\u0FB1' && c <= '\u0FB7') || c == '\u0FB9' || (c >= '\u20D0' && c <= '\u20DC') ||
			c == '\u20E1' || (c >= '\u302A' && c <= '\u302F') || c == '\u3099' || c == '\u309A';
	}

	private static boolean isExtender(char c) {
		return c == '\u00B7' || c == '\u02D0' || c == '\u02D1' || c == '\u0387' || c == '\u0640' || c == '\u0E46' || 
			c == '\u0EC6' || c == '\u3005' || (c >= '\u3031' && c <= '\u3035') || (c >= '\u309D' && c <= '\u309E') || 
			(c >= '\u30FC' && c <= '\u30FE');
	}

	private static boolean isLetter(char c) {
		return isBaseChar(c) || isIdeographic(c);
	}

	private static boolean isBaseChar(char c) {
		return (c >= '\u0041' && c <= '\u005A') || (c >= '\u0061' && c <= '\u007A') || (c >= '\u00C0' && c <= '\u00D6') || 
			(c >= '\u00D8' && c <= '\u00F6') || (c >= '\u00F8' && c <= '\u00FF') || (c >= '\u0100' && c <= '\u0131') || 
			(c >= '\u0134' && c <= '\u013E') || (c >= '\u0141' && c <= '\u0148') || (c >= '\u014A' && c <= '\u017E') || 
			(c >= '\u0180' && c <= '\u01C3') || (c >= '\u01CD' && c <= '\u01F0') || (c >= '\u01F4' && c <= '\u01F5') || 
			(c >= '\u01FA' && c <= '\u0217') || (c >= '\u0250' && c <= '\u02A8') || (c >= '\u02BB' && c <= '\u02C1') || 
			c == '\u0386' || (c >= '\u0388' && c <= '\u038A') || c == '\u038C' || (c >= '\u038E' && c <= '\u03A1') || 
			(c >= '\u03A3' && c <= '\u03CE') || (c >= '\u03D0' && c <= '\u03D6') || c == '\u03DA' || c == '\u03DC' || c == '\u03DE' || 
			c == '\u03E0' || (c >= '\u03E2' && c <= '\u03F3') || (c >= '\u0401' && c <= '\u040C') || (c >= '\u040E' && c <= '\u044F') || 
			(c >= '\u0451' && c <= '\u045C') || (c >= '\u045E' && c <= '\u0481') || (c >= '\u0490' && c <= '\u04C4') || 
			(c >= '\u04C7' && c <= '\u04C8') || (c >= '\u04CB' && c <= '\u04CC') || (c >= '\u04D0' && c <= '\u04EB') || 
			(c >= '\u04EE' && c <= '\u04F5') || (c >= '\u04F8' && c <= '\u04F9') || (c >= '\u0531' && c <= '\u0556') || 
			c == '\u0559' || (c >= '\u0561' && c <= '\u0586') || (c >= '\u05D0' && c <= '\u05EA') || (c >= '\u05F0' && c <= '\u05F2') || 
			(c >= '\u0621' && c <= '\u063A') || (c >= '\u0641' && c <= '\u064A') || (c >= '\u0671' && c <= '\u06B7') || 
			(c >= '\u06BA' && c <= '\u06BE') || (c >= '\u06C0' && c <= '\u06CE') || (c >= '\u06D0' && c <= '\u06D3') || 
			c == '\u06D5' || (c >= '\u06E5' && c <= '\u06E6') || (c >= '\u0905' && c <= '\u0939') || c == '\u093D' || 
			(c >= '\u0958' && c <= '\u0961') || (c >= '\u0985' && c <= '\u098C') || (c >= '\u098F' && c <= '\u0990') || 
			(c >= '\u0993' && c <= '\u09A8') || (c >= '\u09AA' && c <= '\u09B0') || c == '\u09B2' || 
			(c >= '\u09B6' && c <= '\u09B9') || (c >= '\u09DC' && c <= '\u09DD') || (c >= '\u09DF' && c <= '\u09E1') || 
			(c >= '\u09F0' && c <= '\u09F1') || (c >= '\u0A05' && c <= '\u0A0A') || (c >= '\u0A0F' && c <= '\u0A10') || 
			(c >= '\u0A13' && c <= '\u0A28') || (c >= '\u0A2A' && c <= '\u0A30') || (c >= '\u0A32' && c <= '\u0A33') || 
			(c >= '\u0A35' && c <= '\u0A36') || (c >= '\u0A38' && c <= '\u0A39') || (c >= '\u0A59' && c <= '\u0A5C') || 
			c == '\u0A5E' || (c >= '\u0A72' && c <= '\u0A74') || (c >= '\u0A85' && c <= '\u0A8B') || c == '\u0A8D' || 
			(c >= '\u0A8F' && c <= '\u0A91') || (c >= '\u0A93' && c <= '\u0AA8') || (c >= '\u0AAA' && c <= '\u0AB0') || 
			(c >= '\u0AB2' && c <= '\u0AB3') || (c >= '\u0AB5' && c <= '\u0AB9') || c == '\u0ABD' || c == '\u0AE0' || 
			(c >= '\u0B05' && c <= '\u0B0C') || (c >= '\u0B0F' && c <= '\u0B10') || (c >= '\u0B13' && c <= '\u0B28') || 
			(c >= '\u0B2A' && c <= '\u0B30') || (c >= '\u0B32' && c <= '\u0B33') || (c >= '\u0B36' && c <= '\u0B39') || 
			c == '\u0B3D' || (c >= '\u0B5C' && c <= '\u0B5D') || (c >= '\u0B5F' && c <= '\u0B61') || 
			(c >= '\u0B85' && c <= '\u0B8A') || (c >= '\u0B8E' && c <= '\u0B90') || (c >= '\u0B92' && c <= '\u0B95') || 
			(c >= '\u0B99' && c <= '\u0B9A') || c == '\u0B9C' || (c >= '\u0B9E' && c <= '\u0B9F') || 
			(c >= '\u0BA3' && c <= '\u0BA4') || (c >= '\u0BA8' && c <= '\u0BAA') || (c >= '\u0BAE' && c <= '\u0BB5') || 
			(c >= '\u0BB7' && c <= '\u0BB9') || (c >= '\u0C05' && c <= '\u0C0C') || (c >= '\u0C0E' && c <= '\u0C10') || 
			(c >= '\u0C12' && c <= '\u0C28') || (c >= '\u0C2A' && c <= '\u0C33') || (c >= '\u0C35' && c <= '\u0C39') || 
			(c >= '\u0C60' && c <= '\u0C61') || (c >= '\u0C85' && c <= '\u0C8C') || (c >= '\u0C8E' && c <= '\u0C90') || 
			(c >= '\u0C92' && c <= '\u0CA8') || (c >= '\u0CAA' && c <= '\u0CB3') || (c >= '\u0CB5' && c <= '\u0CB9') || 
			c == '\u0CDE' || (c >= '\u0CE0' && c <= '\u0CE1') || (c >= '\u0D05' && c <= '\u0D0C') || 
			(c >= '\u0D0E' && c <= '\u0D10') || (c >= '\u0D12' && c <= '\u0D28') || (c >= '\u0D2A' && c <= '\u0D39') || 
			(c >= '\u0D60' && c <= '\u0D61') || (c >= '\u0E01' && c <= '\u0E2E') || c == '\u0E30' || 
			(c >= '\u0E32' && c <= '\u0E33') || (c >= '\u0E40' && c <= '\u0E45') || (c >= '\u0E81' && c <= '\u0E82') || 
			c == '\u0E84' || (c >= '\u0E87' && c <= '\u0E88') || c == '\u0E8A' || c == '\u0E8D' || (c >= '\u0E94' && c <= '\u0E97') || 
			(c >= '\u0E99' && c <= '\u0E9F') || (c >= '\u0EA1' && c <= '\u0EA3') || c == '\u0EA5' || c == '\u0EA7' || 
			(c >= '\u0EAA' && c <= '\u0EAB') || (c >= '\u0EAD' && c <= '\u0EAE') || c == '\u0EB0' || 
			(c >= '\u0EB2' && c <= '\u0EB3') || c == '\u0EBD' || (c >= '\u0EC0' && c <= '\u0EC4') || 
			(c >= '\u0F40' && c <= '\u0F47') || (c >= '\u0F49' && c <= '\u0F69') || (c >= '\u10A0' && c <= '\u10C5') || 
			(c >= '\u10D0' && c <= '\u10F6') || c == '\u1100' || (c >= '\u1102' && c <= '\u1103') || 
			(c >= '\u1105' && c <= '\u1107') || c == '\u1109' || (c >= '\u110B' && c <= '\u110C') || 
			(c >= '\u110E' && c <= '\u1112') || c == '\u113C' || c == '\u113E' || c == '\u1140' || c == '\u114C' || 
			c == '\u114E' || c == '\u1150' || (c >= '\u1154' && c <= '\u1155') || c == '\u1159' || 
			(c >= '\u115F' && c <= '\u1161') || c == '\u1163' || c == '\u1165' || c == '\u1167' || c == '\u1169' || 
			(c >= '\u116D' && c <= '\u116E') || (c >= '\u1172' && c <= '\u1173') || c == '\u1175' || 
			c == '\u119E' || c == '\u11A8' || c == '\u11AB' || (c >= '\u11AE' && c <= '\u11AF') || 
			(c >= '\u11B7' && c <= '\u11B8') || c == '\u11BA' || (c >= '\u11BC' && c <= '\u11C2') || 
			c == '\u11EB' || c == '\u11F0' || c == '\u11F9' || (c >= '\u1E00' && c <= '\u1E9B') || (c >= '\u1EA0' && c <= '\u1EF9') || 
			(c >= '\u1F00' && c <= '\u1F15') || (c >= '\u1F18' && c <= '\u1F1D') || (c >= '\u1F20' && c <= '\u1F45') || 
			(c >= '\u1F48' && c <= '\u1F4D') || (c >= '\u1F50' && c <= '\u1F57') || c == '\u1F59' || c == '\u1F5B' || c == '\u1F5D' || 
			(c >= '\u1F5F' && c <= '\u1F7D') || (c >= '\u1F80' && c <= '\u1FB4') || (c >= '\u1FB6' && c <= '\u1FBC') || 
			c == '\u1FBE' || (c >= '\u1FC2' && c <= '\u1FC4') || (c >= '\u1FC6' && c <= '\u1FCC') || 
			(c >= '\u1FD0' && c <= '\u1FD3') || (c >= '\u1FD6' && c <= '\u1FDB') || (c >= '\u1FE0' && c <= '\u1FEC') || 
			(c >= '\u1FF2' && c <= '\u1FF4') || (c >= '\u1FF6' && c <= '\u1FFC') || c == '\u2126' || 
			(c >= '\u212A' && c <= '\u212B') || c == '\u212E' || (c >= '\u2180' && c <= '\u2182') || 
			(c >= '\u3041' && c <= '\u3094') || (c >= '\u30A1' && c <= '\u30FA') || (c >= '\u3105' && c <= '\u312C') || 
			(c >= '\uAC00' && c <= '\uD7A3');
	}

	private static boolean isIdeographic(char c) {
		return (c >= '\u4E00' && c <= '\u9FA5') || c == '\u3007' || (c >= '\u3021' && c <= '\u3029');
	}

	public static String determineEncoding(InputStream stream) throws IOException {
		stream.mark(20000);
		try {
			int b0 = stream.read();
			int b1 = stream.read();
			int b2 = stream.read();
			int b3 = stream.read();

			if (b0 == 0xFE && b1 == 0xFF)
				return "UTF-16BE"; //$NON-NLS-1$
			else if (b0 == 0xFF && b1 == 0xFE)
				return "UTF-16LE"; //$NON-NLS-1$
			else if (b0 == 0xEF && b1 == 0xBB && b2 == 0xBF )
				return "UTF-8"; //$NON-NLS-1$
			else if (b0 == 0x00 && b1 == 0x3C && b2 == 0x00 && b3 == 0x3F)
				return "UTF-16BE"; //$NON-NLS-1$
			else if (b0 == 0x3C && b1 == 0x00 && b2 == 0x3F && b3 == 0x00)
				return "UTF-16LE"; //$NON-NLS-1$
			else if (b0 == 0x3C && b1 == 0x3F && b2 == 0x78 && b3 == 0x6D) {
//				UTF-8, ISO 646, ASCII, some part of ISO 8859, Shift-JIS, EUC, or any other 7-bit, 8-bit, or mixed-width encoding 
//				which ensures that the characters of ASCII have their normal positions, width, and values; the actual encoding 
//				declaration must be read to detect which of these applies, but since all of these encodings use the same bit patterns 
//				for the relevant ASCII characters, the encoding declaration itself may be read reliably
				InputStreamReader rdr = new InputStreamReader(stream, "US-ASCII"); //$NON-NLS-1$
				String hdr = readFirstLine(rdr);
				return extractEncoding(hdr); 
			} else
				return null;
		} finally {
			stream.reset();
		}
	}

	private static String extractEncoding(String hdr) {
		int i = hdr.indexOf("encoding="); //$NON-NLS-1$
		if (i == -1)
			return null;
		hdr = hdr.substring(i+9);
		char sep = hdr.charAt(0);
		hdr = hdr.substring(1);
		i = hdr.indexOf(sep);
		if (i == -1)
			return null;
		return hdr.substring(0, i);
	}

	private static String readFirstLine(InputStreamReader rdr) throws IOException {
		char[] buf = new char[1];
		StringBuffer bldr = new StringBuffer();
		rdr.read(buf);
		while (buf[0] != '>') {
			bldr.append(buf[0]);
			rdr.read(buf);
		}
		return bldr.toString();
	}

	
    public static boolean charSetImpliesAscii(String charset) {
		return charset.equals("ISO-8859-1") || charset.equals("US-ASCII"); //$NON-NLS-1$ //$NON-NLS-2$
	}

	
	/**
	 * Converts the raw characters to XML escape characters.
	 * 
	 * @param rawContent
	 * @param charset Null when charset is not known, so we assume it's unicode
	 * @param isNoLines
	 * @return escape string
	 */
	public static String escapeXML(String rawContent, String charset, boolean isNoLines) {
		if (rawContent == null)
			return ""; //$NON-NLS-1$
		else {
			StringBuffer sb = new StringBuffer();

			for (int i = 0; i < rawContent.length(); i++) {
				char ch = rawContent.charAt(i);
				if (ch == '\'')
					sb.append("&#39;"); //$NON-NLS-1$
				else if (ch == '&')
					sb.append("&amp;"); //$NON-NLS-1$
				else if (ch == '"')
					sb.append("&quot;"); //$NON-NLS-1$
				else if (ch == '<')
					sb.append("&lt;"); //$NON-NLS-1$
				else if (ch == '>')
					sb.append("&gt;"); //$NON-NLS-1$
				else if (ch > '~' && charset != null && charSetImpliesAscii(charset)) 
					// TODO - why is hashcode the only way to get the unicode number for the character
					// in jre 5.0?
					sb.append("&#x"+Integer.toHexString(new Character(ch).hashCode()).toUpperCase()+";"); //$NON-NLS-1$ //$NON-NLS-2$
				else if (isNoLines) {
					if (ch == '\r')
						sb.append("&#xA;"); //$NON-NLS-1$
					else if (ch != '\n')
						sb.append(ch);
				}
				else
					sb.append(ch);
			}
			return sb.toString();
		}
	}
	
}