package com.mysema.rdfbean.model.io;

/**
 * @author tiwe
 * 
 */
final class TurtleUtil {

    public static String encodeString(String s) {
        StringBuilder builder = new StringBuilder(s.length());
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c == '\\') {
                builder.append("\\\\");
            } else if (c == '\t') {
                builder.append("\\t");
            } else if (c == '\n') {
                builder.append("\\n");
            } else if (c == '\r') {
                builder.append("\\r");
            } else if (c == '\"') {
                builder.append("\\\"");
            } else {
                builder.append(c);
            }
        }
        return builder.toString();
    }

    public static String encodeLongString(String s) {
        StringBuilder builder = new StringBuilder(s.length());
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c == '\\') {
                builder.append("\\\\");
            } else if (c == '\"') {
                builder.append("\\\"");
            } else {
                builder.append(c);
            }
        }
        return builder.toString();
    }

    public static boolean isPrefixChar(int c) {
        return isNameChar(c);
    }

    public static boolean isPrefixStartChar(int c) {
        return Character.isLetter(c) ||
                c >= 0x00C0 && c <= 0x00D6 ||
                c >= 0x00D8 && c <= 0x00F6 ||
                c >= 0x00F8 && c <= 0x02FF ||
                c >= 0x0370 && c <= 0x037D ||
                c >= 0x037F && c <= 0x1FFF ||
                c >= 0x200C && c <= 0x200D ||
                c >= 0x2070 && c <= 0x218F ||
                c >= 0x2C00 && c <= 0x2FEF ||
                c >= 0x3001 && c <= 0xD7FF ||
                c >= 0xF900 && c <= 0xFDCF ||
                c >= 0xFDF0 && c <= 0xFFFD ||
                c >= 0x10000 && c <= 0xEFFFF;
    }

    public static boolean isNameStartChar(int c) {
        return c == '_' || isPrefixStartChar(c);
    }

    public static boolean isNameChar(int c) {
        return isNameStartChar(c) ||
                Character.isDigit(c) ||
                c == '-' ||
                c == 0x00B7 ||
                c >= 0x0300 && c <= 0x036F ||
                c >= 0x203F && c <= 0x2040;
    }

    public static boolean isName(String str) {
        if (isNameStartChar(str.charAt(0))) {
            for (int i = 1; i < str.length(); i++) {
                if (!isNameChar(str.charAt(i))) {
                    return false;
                }
            }
            return true;
        } else {
            return false;
        }
    }

    private TurtleUtil() {
    }
}