/**
 * Typewriter style output to screen.
 *
 * Usage:
 *	$('#element').typeThis(html,ondone);
 *
 * Parameters:
 * 	html	-- HTML text to type
 *		or object of options that includes a html member.
 * 	ondone	-- function to execute when typing is done
 *		or URL to redirect the browser to when done.
 *
 * Version 3.0
 * Copyright 2004,2011, Mack Pexton, mackpexton.com
 * License http://www.opensource.org/licenses/mit-license.php
 */

(function($){
	var default_options = {
		html : '',			// html to type
		ondone : null,			// url to redirect to or function to call after typing complete
		timing: [	// milli-second pauses before and after characters
				//regexp,   before  after
				[ /[\w,:]/,   50,    50 ],	// regular characters
				[ /&.{2,7};/, 50,    50 ],	// html entities
				[ / /,        50,   300 ],	// space character (pause between words)
				[ /\W/,      750,    50 ],	// punctuation
				[ /./,        50,    50 ]	// everything else
			],
		ondone_pause: 1500,		// pause before invoking function/url when done
		};

	$.fn.typeThis = function(arg,ondone) {
		var opt = $.extend({},default_options,(
				  (arg == null)		   ? {}
				: (typeof arg == 'string') ? { 'html' : arg }
				: (typeof arg == 'object') ? arg
				: {}
				),(
				  (ondone == null)	        ? {}
				: (typeof ondone == 'function')	? { 'ondone' : ondone }
				: (typeof ondone == 'string')   ? { 'ondone' : function(){location.href = ondone;} }
				: {}
				)),
		    $this = $(this),
		    scurr = $this.html(),		// initialize displayed string
		    sarr = opt['html'].split(''),	// make array of individual characters
		    index = 0,				// initialize counter
		    beforeChar=1, afterChar=2, state=afterChar,
		    html_tags = function() {
			// return html tags
			var i = index, l = sarr.length,
			    c, s = '',
			    j, lookahead;
			TAG:while (i < l) {
				c = sarr[i];
				if (c != '<') break;

				// Look for tag closing bracket.
				lookahead = c;
				for (j=i+1; j<l; j++) {
					lookahead += sarr[j];
					if (sarr[j] == '>') {
						s += lookahead;
						i = j + 1;
						continue TAG;
					}
				}
				// End bracket of tag not found.
				break;
			}
			index = i;	// readjust global index to sarr array
			return s;
		    },
		    typer = function() {
			var i, l, c, s;

			if (state == beforeChar) {
				state = afterChar;	// next state

				// Search timing array for time to wait before displaying next character.
				c = sarr[index-1];
				for (i=0,l=opt['timing'].length; i<l; i++) {
					if (opt['timing'][i][0].test(c)) {
						setTimeout(arguments.callee,opt['timing'][i][1]);
						return;
					}
				}

				// Should not be here if timing array properly defined. 
				setTimeout(arguments.callee,50);
				return;
			}

			// Add any following html tags to current output.
			scurr += html_tags();

			// Display current output string.
			$this.html(scurr + '_');

			if (index < sarr.length) {

				// Process next character.
				c = sarr[index++];
				if (c == '&') {
					// Gather HTML entity
					s = c;
					for (i=index,l=Math.floor(index+7,sarr.length); i<=l; i++) {
						s += sarr[i];
						// Look for entity closing character.
						if (sarr[i] == ';') {
							scurr += s;
							index = i+1;
							c = sarr[index++];
							break;
						}
					}
					// Entity closing semi-colon not found, just output '&'.
					scurr += c;
				}
				else {
					scurr += c;
				}

				state = beforeChar;	// next state

				// Search timing array for time to wait till after displaying next character.
				for (i=0,l=opt['timing'].length; i<l; i++) {
					if (opt['timing'][i][0].test(c)) {
						setTimeout(arguments.callee,opt['timing'][i][2]);
						return;
					}
				}

				// Should not be here if timing array properly defined. 
				setTimeout(arguments.callee,50);
				return;
			}
			else {
				$this.html(scurr + ' ');	// remove typing cursor _
				if (opt['ondone']) setTimeout(opt['ondone'],opt['ondone_pause']);
				return;
			}
		    };
		typer();	// start typing

		return this;
	}
})(jQuery);