/*!
 * Base64 class
 * @version 1.0
 * @author M.F.Endenburg
 * @copyright (c) Denbel Systems, 2008
 */

// load namespace
Denbel.load( 'core.Base64' );

( function(){
    /**
     * Base64 class
     */
    Denbel.core.Base64 =
    {
        /**
         * key strings
         * @var string
         */
        _keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",

	    /**
	     * Encodes a string to base64
	     * @param string
	     * @return string
	     */
	    encode: function( input )
	    {
	        var output = "";
	        var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
	        var i = 0;
	
	        input = Denbel.core.Base64._utf8_encode( input );

	        while( i < input.length )
	        {
	            chr1 = input.charCodeAt( i++ );
	            chr2 = input.charCodeAt( i++ );
	            chr3 = input.charCodeAt( i++ );
	
	            enc1 = chr1 >> 2;
	            enc2 = ( ( chr1 & 3 ) << 4 ) | ( chr2 >> 4 );
	            enc3 = ( ( chr2 & 15 ) << 2 ) | ( chr3 >> 6 );
	            enc4 = chr3 & 63;
	
	            if( isNaN( chr2 ) )
	            {
	                enc3 = enc4 = 64;
	            }
	            else if( isNaN( chr3 ) )
	            {
	                enc4 = 64;
	            }
	
	            output = output + this._keyStr.charAt( enc1 ) + this._keyStr.charAt( enc2 ) + this._keyStr.charAt( enc3 ) + this._keyStr.charAt( enc4 );
	        }

	        return output;
	    },
	
	    /**
	     * Decodes a base64 value
	     * @param string
	     * @return string
	     */
	    decode: function( input )
	    {
	        var output = "";
	        var chr1, chr2, chr3;
	        var enc1, enc2, enc3, enc4;
	        var i = 0;
	
	        input = input.replace( /[^A-Za-z0-9\+\/\=]/g, "" );
	
	        while( i < input.length )
	        {
	            enc1 = this._keyStr.indexOf( input.charAt( i++ ) );
	            enc2 = this._keyStr.indexOf( input.charAt( i++ ) );
	            enc3 = this._keyStr.indexOf( input.charAt( i++ ) );
	            enc4 = this._keyStr.indexOf( input.charAt( i++ ) );
	
	            chr1 = ( enc1 << 2 ) | ( enc2 >> 4 );
	            chr2 = ( ( enc2 & 15 ) << 4 ) | ( enc3 >> 2 );
	            chr3 = ( ( enc3 & 3 ) << 6 ) | enc4;
	
	            output = output + String.fromCharCode( chr1 );
	
	            if( enc3 != 64 )
	            {
	                output = output + String.fromCharCode( chr2 );
	            }
	            if( enc4 != 64 )
	            {
	                output = output + String.fromCharCode( chr3 );
	            }
	
	        }
	
	        output = Denbel.core.Base64._utf8_decode( output );
	
	        return output;
	
	    },
	
	    /**
	     * Encodes a string to UTF-8
	     * @param string
	     * @return string
	     */
	    _utf8_encode: function( string )
	    {
	        string = string.replace( /\r\n/g, "\n" );
	        var utftext = "";
	
	        for( var n = 0; n < string.length; n++ )
	        {
	            var c = string.charCodeAt( n );
	
	            if( c < 128 )
	            {
	                utftext += String.fromCharCode( c );
	            }
	            else if( ( c > 127 ) && ( c < 2048 ) )
	            {
	                utftext += String.fromCharCode( ( c >> 6 ) | 192 );
	                utftext += String.fromCharCode( ( c & 63 ) | 128 );
	            }
	            else
	            {
	                utftext += String.fromCharCode( ( c >> 12 ) | 224 );
	                utftext += String.fromCharCode( ( ( c >> 6 ) & 63 ) | 128 );
	                utftext += String.fromCharCode( ( c & 63 ) | 128 );
	            }
	
	        }
	
	        return utftext;
	    },
	
	    /**
	     * Decodes an UTF-8 string
	     * @param string
	     * @return string
	     */
	    _utf8_decode: function( utftext )
	    {
	        var string = "";
	        var i = 0;
	        var c = c1 = c2 = 0;
	
	        while ( i < utftext.length )
	        {
	            c = utftext.charCodeAt( i );
	
	            if( c < 128 )
	            {
	                string += String.fromCharCode( c );
	                i++;
	            }
	            else if( ( c > 191 ) && ( c < 224 ) )
	            {
	                c2 = utftext.charCodeAt( i + 1 );
	                string += String.fromCharCode( ( ( c & 31 ) << 6 ) | ( c2 & 63 ) );
	                i += 2;
	            }
	            else
	            {
	                c2 = utftext.charCodeAt( i + 1 );
	                c3 = utftext.charCodeAt( i + 2 );
	                string += String.fromCharCode( ( ( c & 15 ) << 12 ) | ( ( c2 & 63 ) << 6 ) | ( c3 & 63 ) );
	                i += 3;
	            }
	
	        }
	
	        return string;
	    }
    };
} )();