var EQ_top_location = "EQ_top_location";
var EQ_parent = "EQ_parent";
var EQ_self = "EQ_self";

var EQ_old_onclick = document.onclick;
document.onclick = function()
{ 
	EQ_top_location = top.location;
	EQ_parent = parent;
	EQ_self = self;
	document.onclick = EQ_old_onclick;
}


// lookup array for names of URL components
var URLCompName = [ "full", "scheme", "host", "port", "path", "param", "query", "anchor" ];

// removes whitespace from both ends of string
function trimString( s ) {
  return s.replace( /^\s*/, "" ).replace( /\s*$/, "" );
}

// assign annotInfo.url to EQ_baseURL
// BNF for URL from RFC1808 
// http://www.cis.ohio-state.edu/htbin/rfc/rfc1808.html#id1257
function EQ_fix_url( relURL ) {

  EQ_baseURL = trimString( EQ_baseURL );
  relURL = trimString( relURL );

  // case 0: return EQ_baseURL if relURL is empty
  if ( relURL.length == 0 )
    return EQ_baseURL;

  // case 1: relURL is absolute if it contains a scheme
  if ( /^[\w\-\.\+]+:/.test( relURL ) )
    return relURL;

  // case 2: relURL is absolute if it starts with //
  if ( /^\/\//.test( relURL ) )
    return "http:" + relURL;

  // relevant BNF
  // regular expression for full url
  // net_loc = *( pchar | ";" | "?" )
  // query/fragment = *( pchar | reserved )
  //                = [\w\$\-_\.\+!\*'\(\)%;\/\?:@&=]
  // pchar = uchar | ":" | "@" | "&" | "="
  // uchar = [\w\$\-_\.\+!\*'\(\)%]
  // reserved = ";" | "/" | "?" | ":" | "@" | "&" | "="
  // remarks about differences from RFC 1808:
  //   In order to deal with base URLs such as "http://foo.com/blah&q=http://bar.com"
  //   paths may not contain '&' while queries may start with '&'. 
  // (RFC allows '&' in paths and does not allow queries to start with '&'.

  var fullURL = /^([\w\-\.\+]+:)\/\/([\w\$\-_\.\+!\*'\(\)%@&=;\?]*)(:\d+)?([~\/\w\$\-_\.\+!\*'\(\)%:@=]*)?(;[;\/\w\$\-_\.\+!\*'\(\)%:@&=]*)?([\?&][\w\$\-_\.\+!\*'\(\)%;\/\?:@&=]*)?(#.*)?$/;
  var result = EQ_baseURL.match( fullURL );

  // if the base URL is invalid, return the relative URL
  if ( result == null )
    return relURL;

  // assign parts of match result to variable with some meaningful names
  var temp = "number of variables matched = " + result.length;
  for (var i=0; i<result.length; i++)
    if ( result[i].length > 0 )
      temp += "\n" + URLCompName[i] + ":\t" + result[i];

  // use more meaningful names for URL components
  var baseScheme = result[1];
  var baseHost   = result[2];
  var basePort   = result[3];
  var basePath   = result[4];
  var baseParam  = result[5];
  var baseQuery  = result[6];
  var baseAnchor = result[7];

  // replace scheme with "http"
  if ( /https/.test( baseScheme ) ) 
    baseScheme = "https://";
  else
	baseScheme = "http://";

  // case 3: relURL starts from root directory
  //         doesn't try to optimize relative path in this case
  //         ie. all .. and . references in relative path will
  //         be retained.
  if ( /^\//.test( relURL ) )
    return baseScheme + baseHost + basePort + relURL; 

  // case 4: relURL starts with ;
  if ( /^;/.test( relURL ) )
    return baseScheme + baseHost + basePort + basePath + 
           relURL; 
  
  // case 5: relURL starts with ?
  if ( /^\?/.test( relURL ) )
    return baseScheme + baseHost + basePort + basePath + 
           baseParam + relURL; 
  
  // case 6: relURL starts with #
  if ( /^\#/.test( relURL ) )
    return baseScheme + baseHost + basePort + basePath + 
           baseParam + baseQuery + relURL; 
  
  basePathList = basePath.replace(/^\//gi, "" ).split("/");
  relPathList = relURL.split("/");

  // try to pop off filename
  if ( ( basePathList.length>0 && 
         /\./.test( basePathList[basePathList.length-1] ) ) ||
       /\/$/.test( basePath ) )
    basePathList.length--;

  // combine both arrays with basePathList at the beginning
  basePathList = basePathList.concat( relPathList );

  // expand array to hold maximum number of tokens first
  // resize after parsing is done
  relPathList.length = basePathList.length; 
  var curSize = 0;
  var minSize = 0; // highest level of parent recursion possible
  for (var i=0; i<basePathList.length; i++) {
    var curToken = basePathList[i];
    if ( curToken.length == 0 ) // double slashes in URL
      ; // do nothing
    else if ( curToken == ".." ) {
      if ( curSize > minSize )
        curSize--;
      else { // insert ".." into path
        minSize++; // can't recurse above this ".." directory
        relPathList[ curSize++ ] = curToken;
      }
    }
    else if ( curToken == "." ) {
      if ( i == basePathList.length-1 ) // last token
        relPathList[ curSize++ ] = "";
    }
    else // default action is to insert into path
      relPathList[ curSize++ ] = curToken;
  }
  relPathList.length = curSize;


  return baseScheme+baseHost + basePort + 
         "/" + relPathList.join( "/" );
}

function EQ_newWindowOpen() {
  if ( arguments.length == 0 )
    return EQ_originalWindowOpen();
    
  // create the new absolute URL and replace the first argument with it.
  arguments[0] = EQ_fix_url( arguments[0] );

  // Netscape has a nice apply() function which is 
  // a static method of the function object which allows
  // you to pass an array (ie. the arguments object) to
  // a function variable (ie. oldOpen) 
  // usage: function.apply( oldOpen, arguments );
  // for now, since window.open has a maximum of 4 arguments,
  // we can pass in the arguments individually.
  switch ( arguments.length ) {
    case 2:
      return EQ_originalWindowOpen( arguments[0], arguments[1] );
      break; 
    case 3:
      return EQ_originalWindowOpen( arguments[0], arguments[1], 
               arguments[2] );
       break; 
    case 4:
      return EQ_originalWindowOpen( arguments[0], arguments[1], 
               arguments[2], arguments[3] );
      break; 
    default:
      return EQ_originalWindowOpen( arguments[0] );
  }
  return EQ_originalWindowOpen();
}

// override window.open
var EQ_originalWindowOpen = window.open;
window.open = EQ_newWindowOpen;