ByteEdit/src/me/ByteEdit/utils/UnicodeUtils.java

package me.ByteEdit.utils;

import me.ByteEdit.edit.HugeStrings;
import me.ByteEdit.edit.HugeStringsRev;

public class UnicodeUtils {

	public static String unescape(HugeStringsRev hsr, String s) {
		return unescape(hsr, s, false);
	}

	public static String unescape(HugeStringsRev hsr, String s, boolean force) {
		if (s == null) {
			return null;
		}
		if (!force && !s.isEmpty() && s.charAt(0) == '#' && s.length() < 12) {
			try {
				int id = Integer.parseInt(s.substring(1));
				return hsr.get(id);
			} catch (NumberFormatException ex) {
				// Doesn't seem like a HugeString
			}
		}
		StringBuilder sb = new StringBuilder();
		char unicodeBuffer = 0;
		int stage = 0;
		for (char c : s.toCharArray()) {
			if (c == '\\' && stage == 0) {
				stage = 1;
				continue;
			}
			if (stage == 1) {
				switch (c) {
				case 'b':
					sb.append('\b');
					stage = 0;
					break;
				case 't':
					sb.append('\t');
					stage = 0;
					break;
				case 'n':
					sb.append('\n');
					stage = 0;
					break;
				case 'r':
					sb.append('\r');
					stage = 0;
					break;
				case 'f':
					sb.append('\f');
					stage = 0;
					break;
				case '"':
					sb.append('"');
					stage = 0;
					break;
				case '\\':
					sb.append('\\');
					stage = 0;
					break;
				case 'u':
					stage++;
					break;
				default:
					throw new IllegalArgumentException("'\\" + c + "' is invalid.");
				}
				continue;
			} else if (stage > 1 && stage < 6) { // \u1234 => up to 6
				try {
					int i = Integer.parseInt(Character.toString(c), 16);
					unicodeBuffer += i << (4 * (5 - stage++)); // 4 bytes each, shift left byte * 4..3..2..1 and add to
																// unicodeBuffer
					if (stage == 6) {
						sb.append(unicodeBuffer);
						stage = 0;
						unicodeBuffer = 0;
					}
				} catch (NumberFormatException e) {
					throw new IllegalArgumentException("'" + c + "' is not a valid hex value.");
				}
				continue;
			}
			sb.append(c);
		}
		if (stage != 0) {
			if (unicodeBuffer != 0)
				throw new IllegalArgumentException("The unicode at the end is incomplete.");
			throw new IllegalArgumentException("'\\' at the end is invalid.");
		}
		return sb.toString();
	}

	public static String escapeWithSpaces(HugeStrings hs, String s) {
		if (s == null) {
			return null;
		}
		if (s.length() > HugeStrings.THRESHOLD) {
			return hs.onString(s);
		}
		StringBuilder sb = new StringBuilder();
		char[] arr = s.toCharArray();
		int i = 0;
		int len = arr.length;
		boolean addSlash = false;

		if (len > 0) {
			if (arr[0] == '/') {
				sb.append("\\u002F");
				i++;
			} else if (arr[0] == '#') {
				sb.append("\\u0023");
				i++;
			}
			if (arr[len - 1] == '/') {
				addSlash = true;
				len--;
			}
		}

		for (; i < len; i++) {
			char c = arr[i];
			switch (c) {
			case 'Ä':
			case 'ä':
			case 'Ö':
			case 'ö':
			case 'Ü':
			case 'ü':
			case 'ß':
			case '€':
			case '©':
			case '®':
			case '«':
			case '»':
			case '§':
			case '£':
			case '¥':
				sb.append(c);
				break;
			case ' ':
				sb.append("\\u0020");
				break;
			case '\b':
				sb.append("\\b");
				break;
			case '\t':
				sb.append("\\t");
				break;
			case '\n':
				sb.append("\\n");
				break;
			case '\r':
				sb.append("\\r");
				break;
			case '\f':
				sb.append("\\f");
				break;
			case '"':
				sb.append("\\\"");
				break;
			case '\\':
				sb.append("\\\\");
				break;
			default:
				if (c > ' ' && c <= '~') {
					sb.append(c);
				} else {
					sb.append(String.format("\\u%04X", (int) c));
				}
				break;
			}
		}

		if (addSlash)
			sb.append("\\u002F");
		return sb.toString();
	}

	public static String escape(HugeStrings hs, String s) {
		return escape(hs, s, false);
	}

	public static String escape(HugeStrings hs, String s, boolean force) {
		if (s == null) {
			return null;
		}
		if (!force && s.length() > HugeStrings.THRESHOLD) {
			return hs.onString(s);
		}
		char[] arr = s.toCharArray();
		StringBuilder sb = new StringBuilder(arr.length);
		int i = 0;
		if (arr.length > 0 && arr[0] == '#') {
			sb.append("\\u0023");
			i++;
		}
		for (; i < arr.length; i++) {
			char c = arr[i];
			switch (c) {
			case 'Ä':
			case 'ä':
			case 'Ö':
			case 'ö':
			case 'Ü':
			case 'ü':
			case 'ß':
			case '€':
			case '©':
			case '®':
			case '«':
			case '»':
			case '§':
			case '£':
			case '¥':
				sb.append(c);
				break;
			case '\b':
				sb.append("\\b");
				break;
			case '\t':
				sb.append("\\t");
				break;
			case '\n':
				sb.append("\\n");
				break;
			case '\r':
				sb.append("\\r");
				break;
			case '\f':
				sb.append("\\f");
				break;
			case '"':
				sb.append("\\\"");
				break;
			case '\\':
				sb.append("\\\\");
				break;
			default:
				if (c >= ' ' && c <= '~') {
					sb.append(c);
				} else {
					sb.append(String.format("\\u%04X", (int) c));
				}
				break;
			}
		}
		return sb.toString();
	}

}