/*!
 * DecafMUD v0.9.0
 * http://decafmud.kicks-ass.net
 *
 * Copyright 2010, Stendec <stendec365@gmail.com>
 */

 /**
 * @fileOverview DecafMUD Character Encoding: Code Page 437 (IBM PC)
 * @author Stendec <stendec365@gmail.com>
 * @version 0.9.0
 */

(function(DecafMUD) {

// This first list contains the characters 0x00 to 0x1F, with onl a couple
// of exclusions for things like new lines.
var lows = ["\u2007","\u263A","\u263B","\u2665","\u2666","\u2663","\u2660", //  0 -  6
			"\x07","\x08","\x09","\x0A","\x0B","\x0C","\x0D",				//  7 - 13
			"\u266B","\u263C","\u25BA","\u25C4","\u2195","\u203C","\u00B6", // 14 - 20
			"\u00A7","\u25AC","\u21A8","\u2191","\u2193","\u2192","\x1B",	// 21 - 27
			"\u221F","\u2194","\u25B2","\u25BC"], // 28 - 31

// This is a list of cp437 characters in unicode, for the binary characters
// 0x80 to 0xFF, with index 0 coresponding to 0x80.
	chars =["\u00c7","\u00fc","\u00e9","\u00e2","\u00e4","\u00e0","\u00e5",
			"\u00e7","\u00ea","\u00eb","\u00e8","\u00ef","\u00ee","\u00ec",
			"\u00c4","\u00c5","\u00c9","\u00e6","\u00c6","\u00f4","\u00f6",
			"\u00f2","\u00fb","\u00f9","\u00ff","\u00d6","\u00dc","\u00a2",
			"\u00a3","\u00a5","\u20a7","\u0192","\u00e1","\u00ed","\u00f3",
			"\u00fa","\u00f1","\u00d1","\u00aa","\u00ba","\u00bf","\u2310",
			"\u00ac","\u00bd","\u00bc","\u00a1","\u00ab","\u00bb","\u2591",
			"\u2592","\u2593","\u2502","\u2524","\u2561","\u2562","\u2556",
			"\u2555","\u2563","\u2551","\u2557","\u255d","\u255c","\u255b",
			"\u2510","\u2514","\u2534","\u252c","\u251c","\u2500","\u253c",
			"\u255e","\u255f","\u255a","\u2554","\u2569","\u2566","\u2560",
			"\u2550","\u256c","\u2567","\u2568","\u2564","\u2565","\u2559",
			"\u2558","\u2552","\u2553","\u256b","\u256a","\u2518","\u250c",
			"\u2588","\u2584","\u258c","\u2590","\u2580","\u03b1","\u00df",
			"\u0393","\u03c0","\u03a3","\u03c3","\u00b5","\u03c4","\u03a6",
			"\u0398","\u03a9","\u03b4","\u221e","\u03c6","\u03b5","\u2229",
			"\u2261","\u00b1","\u2265","\u2264","\u2320","\u2321","\u00f7",
			"\u2248","\u00b0","\u2219","\u00b7","\u221a","\u207f","\u00b2",
			"\u25a0","\u00a0"],

	decode = function(data) {
		return [data.replace(/[\x00-\x1F\x80-\xFF]/g, function(m) {
			var c = m.charCodeAt(0);
			if ( c < 0x80 && c < lows.length ) {
				return lows[c];
			} else if ( c >= 0x80 ) {
				c -= 0x80;
				if ( c < chars.length ) { return chars[c]; }
			}
			return m;
		}), '']; },
	
	encode = function(data) {
		return data.replace(/[\u00A0-\u266B]/g, function(m) {
			var c = chars.indexOf(m);
			if ( c !== -1 ) {
				return String.fromCharCode(0x80 + c);
			} else {
				c = lows.indexOf(m);
				if ( c !== -1 ) {
					return String.fromCharCode(c); }
			}
			return m;
		}); };

// Find the lowest (thats greater than FF) and the highest.
var lowest = 65535, highest = 0;
for(var i=0;i<lows.length;i++) {
	var c = lows[i].charCodeAt(0);
	if ( c < lowest && c > 0xFF ) { lowest = c; }
	if ( c > highest ) { highest = c; }
}
for(var i=0;i<chars.length;i++) {
	var c = chars[i].charCodeAt(0);
	if ( c < lowest && c > 0xFF ) { lowest = c; }
	if ( c > highest ) { highest = c; }
}
//console.debug('Low: ' + lowest + '    High: ' + highest);

// var o='';for(var i=0;i<256;i++){o+=String.fromCharCode(i)}DecafMUD.plugins.Encoding.cp437.encode(DecafMUD.plugins.Encoding.cp437.decode(o))

// Expose to Decaf
/** This provides support for the <a href="http://en.wikipedia.org/wiki/Code_page_437">CP437</a>
 *  character encoding to DecafMUD by translating the characters into their
 *  unicode equivilents.
 * @example
 * alert(DecafMUD.plugins.Encoding.cp437.decode("This is some text!"));
 * @namespace DecafMUD Character Encoding: Code Page 437 (IBM PC) */
DecafMUD.plugins.Encoding.cp437 = {
	proper : 'CP437',

    /** Replace CP437-encoded characters with their unicode equivilents.
     * @example
     * DecafMUD.plugins.Encoding.cp437.decode("\xB2");
     * // Becomes: "\u2593"
     * @function
     * @param {String} data The text to decode. */
	decode: decode,
    
    /** Replace the unicode equivilents of CP437 characters with the
     *  CP437-encoded values.
     * @example
     * DecafMUD.plugins.Encoding.cp437.encode("\u2593");
     * // Becomes: "\xB2"
     * @function
     * @param {String} data The text to encode. */
	encode: encode
};

})(DecafMUD);