/*
Copyright (c) 2003-2010, CKSource - Frederico Knabben. All rights reserved.
For licensing, see LICENSE.html or http://ckeditor.com/license
*/

/**
 * HTML text parser.
 * @constructor
 * @example
 */
CKEDITOR.htmlParser = function()
{
	this._ =
	{
		htmlPartsRegex : new RegExp( '<(?:(?:\\/([^>]+)>)|(?:!--([\\S|\\s]*?)-->)|(?:([^\\s>]+)\\s*((?:(?:[^"\'>]+)|(?:"[^"]*")|(?:\'[^\']*\'))*)\\/?>))', 'g' )
	};
};

(function()
{
	var attribsRegex	= /([\w\-:.]+)(?:(?:\s*=\s*(?:(?:"([^"]*)")|(?:'([^']*)')|([^\s>]+)))|(?=\s|$))/g,
		emptyAttribs	= {checked:1,compact:1,declare:1,defer:1,disabled:1,ismap:1,multiple:1,nohref:1,noresize:1,noshade:1,nowrap:1,readonly:1,selected:1};

	CKEDITOR.htmlParser.prototype =
	{
		/**
		 * Function to be fired when a tag opener is found. This function
		 * should be overriden when using this class.
		 * @param {String} tagName The tag name. The name is guarantted to be
		 *		lowercased.
		 * @param {Object} attributes An object containing all tag attributes. Each
		 *		property in this object represent and attribute name and its
		 *		value is the attribute value.
		 * @param {Boolean} selfClosing true if the tag closes itself, false if the
		 * 		tag doesn't.
		 * @example
		 * var parser = new CKEDITOR.htmlParser();
		 * parser.onTagOpen = function( tagName, attributes, selfClosing )
		 *     {
		 *         alert( tagName );  // e.g. "b"
		 *     });
		 * parser.parse( "&lt;!-- Example --&gt;&lt;b&gt;Hello&lt;/b&gt;" );
		 */
		onTagOpen	: function() {},

		/**
		 * Function to be fired when a tag closer is found. This function
		 * should be overriden when using this class.
		 * @param {String} tagName The tag name. The name is guarantted to be
		 *		lowercased.
		 * @example
		 * var parser = new CKEDITOR.htmlParser();
		 * parser.onTagClose = function( tagName )
		 *     {
		 *         alert( tagName );  // e.g. "b"
		 *     });
		 * parser.parse( "&lt;!-- Example --&gt;&lt;b&gt;Hello&lt;/b&gt;" );
		 */
		onTagClose	: function() {},

		/**
		 * Function to be fired when text is found. This function
		 * should be overriden when using this class.
		 * @param {String} text The text found.
		 * @example
		 * var parser = new CKEDITOR.htmlParser();
		 * parser.onText = function( text )
		 *     {
		 *         alert( text );  // e.g. "Hello"
		 *     });
		 * parser.parse( "&lt;!-- Example --&gt;&lt;b&gt;Hello&lt;/b&gt;" );
		 */
		onText		: function() {},

		/**
		 * Function to be fired when CDATA section is found. This function
		 * should be overriden when using this class.
		 * @param {String} cdata The CDATA been found.
		 * @example
		 * var parser = new CKEDITOR.htmlParser();
		 * parser.onCDATA = function( cdata )
		 *     {
		 *         alert( cdata );  // e.g. "var hello;"
		 *     });
		 * parser.parse( "&lt;script&gt;var hello;&lt;/script&gt;" );
		 */
		onCDATA		: function() {},

		/**
		 * Function to be fired when a commend is found. This function
		 * should be overriden when using this class.
		 * @param {String} comment The comment text.
		 * @example
		 * var parser = new CKEDITOR.htmlParser();
		 * parser.onText = function( comment )
		 *     {
		 *         alert( comment );  // e.g. " Example "
		 *     });
		 * parser.parse( "&lt;!-- Example --&gt;&lt;b&gt;Hello&lt;/b&gt;" );
		 */
		onComment	: function() {},

		/**
		 * Parses text, looking for HTML tokens, like tag openers or closers,
		 * or comments. This function fires the onTagOpen, onTagClose, onText
		 * and onComment function during its execution.
		 * @param {String} html The HTML to be parsed.
		 * @example
		 * var parser = new CKEDITOR.htmlParser();
		 * // The onTagOpen, onTagClose, onText and onComment should be overriden
		 * // at this point.
		 * parser.parse( "&lt;!-- Example --&gt;&lt;b&gt;Hello&lt;/b&gt;" );
		 */
		parse : function( html )
		{
			var parts,
				tagName,
				nextIndex = 0,
				cdata;	// The collected data inside a CDATA section.

			while ( ( parts = this._.htmlPartsRegex.exec( html ) ) )
			{
				var tagIndex = parts.index;
				if ( tagIndex > nextIndex )
				{
					var text = html.substring( nextIndex, tagIndex );

					if ( cdata )
						cdata.push( text );
					else
						this.onText( text );
				}

				nextIndex = this._.htmlPartsRegex.lastIndex;

				/*
				 "parts" is an array with the following items:
					0 : The entire match for opening/closing tags and comments.
					1 : Group filled with the tag name for closing tags.
					2 : Group filled with the comment text.
					3 : Group filled with the tag name for opening tags.
					4 : Group filled with the attributes part of opening tags.
				 */

				// Closing tag
				if ( ( tagName = parts[ 1 ] ) )
				{
					tagName = tagName.toLowerCase();

					if ( cdata && CKEDITOR.dtd.$cdata[ tagName ] )
					{
						// Send the CDATA data.
						this.onCDATA( cdata.join('') );
						cdata = null;
					}

					if ( !cdata )
					{
						this.onTagClose( tagName );
						continue;
					}
				}

				// If CDATA is enabled, just save the raw match.
				if ( cdata )
				{
					cdata.push( parts[ 0 ] );
					continue;
				}

				// Opening tag
				if ( ( tagName = parts[ 3 ] ) )
				{
					tagName = tagName.toLowerCase();
					var attribs = {},
						attribMatch,
						attribsPart = parts[ 4 ],
						selfClosing = !!( attribsPart && attribsPart.charAt( attribsPart.length - 1 ) == '/' );

					if ( attribsPart )
					{
						while ( ( attribMatch = attribsRegex.exec( attribsPart ) ) )
						{
							var attName = attribMatch[1].toLowerCase(),
								attValue = attribMatch[2] || attribMatch[3] || attribMatch[4] || '';

							if ( !attValue && emptyAttribs[ attName ] )
								attribs[ attName ] = attName;
							else
								attribs[ attName ] = attValue;
						}
					}

					this.onTagOpen( tagName, attribs, selfClosing );

					// Open CDATA mode when finding the appropriate tags.
					if ( !cdata && CKEDITOR.dtd.$cdata[ tagName ] )
						cdata = [];

					continue;
				}

				// Comment
				if ( ( tagName = parts[ 2 ] ) )
					this.onComment( tagName );
			}

			if ( html.length > nextIndex )
				this.onText( html.substring( nextIndex, html.length ) );
		}
	};
})();