var		histList = [""]; //history list 
var		histPos = 0; 
var		_scope = {}; //selected scope
var		_win; // a top-level context
var		question;
var		_in; //input box
var		_out; //output area 
var		tooManyMatches = null;
var		lastError = null;
var 	printScrollDown = true;//print direction
var 	_mark = null;

//Object generator, create box and stuff 
function box(){}

box.get = function(alikename) {
	return document.createElement(alikename);	
}
box.text = function(textForTextnode) {
	return document.createTextNode(textForTextnode);	
}

//Object painter, draw stuff on screen in output area, designed so stuff started from the top to bottom, but 
// after any big action the "cursor" is moved to the top.
// it use a big ugly <hr> as a cursor.
function painter(){
}

painter.top = function(){	
	//Move input cursor to the top of the output area
	
	
	var parent = _mark.parentNode;
	if (parent)
		parent.removeChild( _mark );
	//else is deleted,  no need to remove again, just recreate
		
	_mark = box.get("hr");
	_mark.setAttribute("id","mark");
	_mark.setAttribute("style","visibility:hidden");
		
	_out.insertBefore(_mark,_out.childNodes[0]);
}

painter.append = function( newNode ) {
	if (!newNode)
		return;		
	
	var parent = _mark.parentNode;
	
	//insert before the marker
	parent.insertBefore( newNode, _mark );		
}


painter.println = function(s, type){
  if((s=String(s)))  {
    var newdiv = box.get("div");
	newdiv.setAttribute("class","textOutput");
    newdiv.appendChild(box.text(s));
    newdiv.className = type; //humm..?.. is not class already modified?     
    
    this.append( newdiv );   
    return newdiv;
  }
}

painter.print = function(s, type){
  if((s=String(s)))  {	
	var newdiv = box.get("span");
	newdiv.setAttribute("class","textOutput");
    newdiv.appendChild(box.text(s));
    newdiv.className = type;     
    
    this.append( newdiv );    
    return newdiv;
  }
}


painter.printnodes = function(nodes){
    this.append( nodes );    
}


function refocus() {
  _in.blur(); // Needed for Mozilla to scroll correctly.
  	//TODO: redirect internet explorer users to www.getfirefox.com
  _in.focus();
}


/* Initialize vars */
function init() {
  _in = document.getElementById("input"); //our user input textbox
  _out = document.getElementById("output");//our output area
  _mark = document.getElementById("mark");//our shiny new cursor thing
  
  _win = window;//the window mothership :D 

  if (opener && !opener.closed)  {
    _win = opener;
  }

  initTarget();

  recalculateInputHeight();//do things... and stuff.
  refocus();
}

function initTarget(){
  _win.Shell = window;
  //print will be overwritten by a custom function, we save the original on printPage
  _win.printPage = window.print; _win.print = shellCommands.print; 
}


// Unless the user is selected something, refocus the textbox.
// (requested by caillon, brendan, asa)
function keepFocusInTextbox(e){
  var g = e.srcElement ? e.srcElement : e.target; // IE vs. standard
  
  while (!g.tagName) g = g.parentNode;
  
  var tag = g.tagName.toUpperCase();
  
  if (tag=="A" || tag=="INPUT")  return;
    
  if (window.getSelection) {
    // Mozilla
    if (String(window.getSelection()))    return;
  }  else if (document.getSelection) {
    // Opera? Netscape 4?
    if (document.getSelection())      return;
  }  else {
    // IE
    if ( document.selection.createRange().text )   return;
  }
  
  refocus();
}


var isFirstKey = false;
function firstFocusTest(){
	return;
	
	if (isFirstKey == true)
			return;
	
	_in.value = "";
	isFirstKey = true;
}

function inputKeydown(e) {

  //Clear field from information text. "Type here js.." stuff.	
  firstFocusTest();
	
  // Use onkeydown because IE doesn't support onkeypress for arrow keys
  //alert(e.keyCode + " ^ " + e.keycode);

  if (e.shiftKey && e.keyCode == 13) { // shift-enter
    // don't do anything; allow the shift-enter to insert a line break as normal
  } else if (e.keyCode == 13) { // enter
    // execute the input on enter
    try { go(); } catch(er) { alert(er); };
    setTimeout(function() { _in.value = ""; }, 0); // can't preventDefault on input, so clear it later
  } else if (e.keyCode == 38) { // up
    // go up in history if at top or ctrl-up
    if (e.ctrlKey || caretInFirstLine(_in))
      hist(true);
  } else if (e.keyCode == 40) { // down
    // go down in history if at end or ctrl-down
    if (e.ctrlKey || caretInLastLine(_in))
      hist(false);
  } else if (e.keyCode == 9) { // tab
    tabcomplete();
    setTimeout(function() { refocus(); }, 0); // refocus because tab was hit
  } else { }

  setTimeout(recalculateInputHeight, 0);
  
};

function caretInFirstLine(textbox){
  // IE doesn't support selectionStart/selectionEnd
  if (textbox.selectionStart == undefined)
    return true;

  var firstLineBreak = textbox.value.indexOf("\n");
  
  return ((firstLineBreak == -1) || (textbox.selectionStart <= firstLineBreak));
}

function caretInLastLine(textbox){
  // IE doesn't support selectionStart/selectionEnd
  if (textbox.selectionEnd == undefined)
    return true;

  var lastLineBreak = textbox.value.lastIndexOf("\n");
  
  return (textbox.selectionEnd > lastLineBreak);
}

function recalculateInputHeight(){
  var rows = _in.value.split(/\n/).length
    + 1 // prevent scrollbar flickering in Mozilla
    + (window.opera ? 1 : 0); // leave room for scrollbar in Opera
  
  if (_in.rows != rows) // without this check, it is impossible to select text in Opera 7.60 or Opera 8.0.
    _in.rows = rows;
}

function println(s, type){
	painter.println(s,type);
}

function printPropsCommands(s,type,context){
  if((s=String(s)))  {
  	//Create container:  
    var newdiv = document.createElement("span");		    	    	
    newdiv.setAttribute("class","textOutput");
    //Create button/link
    
    //TODO: xul support
    var active = document.createElement("a");    
    active.appendChild(document.createTextNode(s));
    active.setAttribute("href","javascript:go('"+ escape("props("+context+"."+s+",\""+context+"."+s+"\")")+"')");
    
    newdiv.appendChild(active);
    newdiv.className = type;
    
    var separator = document.createElement("span");
    separator.appendChild(document.createTextNode(" | "));
    
    newdiv.appendChild(separator); 
    
    painter.printnodes( newdiv );
   	//_out.insertBefore(newdiv,_out.childNodes[0]);
   	//_out.appendChild(newdiv);
    return newdiv;
  }
}



function printWithRunin(h, s, type){
  var div = printDoCommand(s, type);
  var head = document.createElement("strong");  
  head.appendChild(document.createTextNode(h + ": "));
  div.insertBefore(head, div.firstChild);
}


function printWithLinks(h, elements,type,context){
  var div = shellCommands.print(h);
  
  var len = elements.length;
  if (!len)
  	return div;     
   
  for(var t=0;t<len;t++){
  	 if (elements[t].sort)
  		printPropsCommands(elements[t].sort(),type,context);
  	 else
  	 	printPropsCommands(elements[t] ,type,context);  
  }    	
}       	

var shellCommands = {
	load: function load(url) 	{
	  var s = _win.document.createElement("script");
	  s.type = "text/javascript";
	  s.src = url;
	  _win.document.getElementsByTagName("head")[0].appendChild(s);
	  println("Loading " + url + "...", "message");
	},
	
	clear: function clear()	{		
	  //humm?.. 
	  var CHILDREN_TO_PRESERVE = 0;
	  while (_out.childNodes[CHILDREN_TO_PRESERVE]) 
	    _out.removeChild(_out.childNodes[CHILDREN_TO_PRESERVE]);
	},
	
	print: function print(s) { println(s, "print"); },
	
	// the normal function, "print", shouldn't return a value
	// (suggested by brendan; later noticed it was a problem when showing others)
	pr : function pr(s) { 
	  shellCommands.print(s); // need to specify shellCommands so it doesn't try window.print()!
	  return s;
	},
	
	dumpHelp: function dumpHelp() {		 
		println("Values and functions: ans, print(string), props(object), blink(node), load(scriptURL), scope(object), clear()","message");
		return;
	},
	
	props: function props(e,context) {
	  if (e === null) {
	    println("props called with null argument", "error");
	    return;
	  }
	
	  if (e === undefined) {
	    println("props called with undefined argument", "error");
	    return;
	  }
	  
	  if (!context)
		  context = "window";
	  
	  
	
	  var ns = ["Methods", "Fields", "Unreachables"];
	  var as = [[], [], []]; // array of (empty) arrays of arrays!
	  var p, j, i; // loop variables, several used multiple times
	
	  var protoLevels = 0;
	
	  for (p = e; p; p = p.__proto__)  {
	    for (i=0; i<ns.length; ++i)
	      as[i][protoLevels] = [];
	    ++protoLevels;
	  }
	
	  for(var a in e)  {
	    // Shortcoming: doesn't check that VALUES are the same in object and prototype.	
	    var protoLevel = -1;
	    try   {
	      for (p = e; p && (a in p); p = p.__proto__)
	        ++protoLevel;
	    }
	    catch(er) { protoLevel = 0; } // "in" operator throws when param to props() is a string
	
	    var type = 1;
	    try {
	      if ((typeof e[a]) == "function")
	        type = 0;
	    }
	    catch (er) { type = 2; }
	
	    as[type][protoLevel].push(a);
	  }
	
	  function times(s, n) { return n ? s + times(s, n-1) : ""; }
	
	  for (j=0; j<protoLevels; ++j)
	    for (i=0;i<ns.length;++i)
	      if (as[i][j].length)
        	printWithLinks(
	        	ns[i] + times(" of prototype", j),
	        	as[i][j].sort(),
	        	"propList",
	        	context
        	);
	},
	
	blink: function blink(node)	{
	  if (!node)                     throw("blink: argument is null or undefined.");
	  if (node.nodeType == null)     throw("blink: argument must be a node.");
	  if (node.nodeType == 3)        throw("blink: argument must not be a text node");
	  if (node.documentElement)      throw("blink: argument must not be the document object");
	
	  function setOutline(o) { 
	    return function() {
	      if (node.style.outline != node.style.bogusProperty) {
	        // browser supports outline (Firefox 1.1 and newer, CSS3, Opera 8).
	        node.style.outline = o;
	      } else if (node.style.MozOutline != node.style.bogusProperty) {
	        // browser supports MozOutline (Firefox 1.0.x and older)
	        node.style.MozOutline = o;
	      } else {
	        // browser only supports border (IE). border is a fallback because it moves things around.
	        node.style.border = o;
	      }
	    }
	  } 
	  
	  function focusIt(a) {
	    return function() {
	      a.focus(); 
	    }
	  }
	
	  if (node.ownerDocument) {
	    var windowToFocusNow = (node.ownerDocument.defaultView || node.ownerDocument.parentWindow); // Moz vs. IE
	    if (windowToFocusNow)
	      setTimeout(focusIt(windowToFocusNow.top), 0);
	  }
	
	  for(var i=1;i<7;++i)
	    setTimeout(setOutline((i%2)?'3px solid red':'none'), i*100);
	
	  setTimeout(focusIt(window), 800);
	  setTimeout(focusIt(_in), 810);
	},
	
	scope : function scope(sc)	{
	  if (!sc) sc = {};
	  _scope = sc;
	  println("Scope is now " + sc + ".  If a variable is not found in this scope, window will also be searched.  New variables will still go on window.", "message");
	},
	
	mathHelp : function mathHelp()	{
	  printWithRunin("Math constants", "E, LN2, LN10, LOG2E, LOG10E, PI, SQRT1_2, SQRT2", "propList");
	  printWithRunin("Math methods", "abs, acos, asin, atan, atan2, ceil, cos, exp, floor, log, max, min, pow, random, round, sin, sqrt, tan", "propList");
	},
	
	ans : undefined
};


function hist(up){
  // histList[0] = first command entered, [1] = second, etc.
  // type something, press up --> thing typed is now in "limbo"
  // (last item in histList) and should be reachable by pressing 
  // down again.

  var L = histList.length;

  if (L == 1)
    return;

  if (up)  {
    if (histPos == L-1) {
      // Save this entry in case the user hits the down key.
      histList[histPos] = _in.value;
    }

    if (histPos > 0) {
      histPos--;
      // Use a timeout to prevent up from moving cursor within new text
      // Set to nothing first for the same reason
      setTimeout(
        function() {
          _in.value = ''; 
          _in.value = histList[histPos];
          var caretPos = _in.value.length;
          if (_in.setSelectionRange) 
            _in.setSelectionRange(caretPos, caretPos);
        },
        0
      );
    }
  } else // down
  {
    if (histPos < L-1){
      histPos++;
      _in.value = histList[histPos];
    } else if (histPos == L-1){
      // Already on the current entry: clear but save
      if (_in.value) {
        histList[histPos] = _in.value;
        ++histPos;
        _in.value = "";
      }
    }
  }
}

function tabcomplete(){
  /*
   * Working backwards from s[from], find the spot
   * where this expression starts.  It will scan
   * until it hits a mismatched ( or a space,
   * but it skips over quoted strings.
   * If stopAtDot is true, stop at a '.'
   */
  function findbeginning(s, from, stopAtDot)  {
    /*
     *  Complicated function.
     *
     *  Return true if s[i] == q BUT ONLY IF
     *  s[i-1] is not a backslash.
     */
    function equalButNotEscaped(s,i,q) {
      if(s.charAt(i) != q) // not equal go no further
        return false;

      if(i==0) // beginning of string
        return true;

      if(s.charAt(i-1) == '\\') // escaped?
        return false;

      return true;
    }

    var nparens = 0;
    var i;
    for(i=from; i>=0; i--)  {
      if(s.charAt(i) == ' ')
        break;

      if(stopAtDot && s.charAt(i) == '.')
        break;
        
      if(s.charAt(i) == ')')
        nparens++;
      else if(s.charAt(i) == '(')
        nparens--;

      if(nparens < 0)
        break;

      // skip quoted strings
      if(s.charAt(i) == '\'' || s.charAt(i) == '\"'){
        //dump("skipping quoted chars: ");
        var quot = s.charAt(i);
        i--;
        while(i >= 0 && !equalButNotEscaped(s,i,quot)) {
          //dump(s.charAt(i));
          i--;
        }
        //dump("\n");
      }
    }
    return i;
  }

  // XXX should be used more consistently (instead of using selectionStart/selectionEnd throughout code)
  // XXX doesn't work in IE, even though it contains IE-specific code
  function getcaretpos(inp)  {
    if(inp.selectionEnd != null)
      return inp.selectionEnd;
      
    if(inp.createTextRange){
      var docrange = _win.Shell.document.selection.createRange();
      var inprange = inp.createTextRange();
      if (inprange.setEndPoint)
      {
        inprange.setEndPoint('EndToStart', docrange);
        return inprange.text.length;
      }
    }

    return inp.value.length; // sucks, punt
  }

  function setselectionto(inp,pos)  {
    if(inp.selectionStart) {
      inp.selectionStart = inp.selectionEnd = pos;
    }
    else if(inp.createTextRange) {
      var docrange = _win.Shell.document.selection.createRange();
      var inprange = inp.createTextRange();
      inprange.move('character',pos);
      inprange.select();
    }
    else { // err...
    /*
      inp.select();
      if(_win.Shell.document.getSelection())
        _win.Shell.document.getSelection() = "";
        */
    }
  }
    // get position of cursor within the input box
    var caret = getcaretpos(_in);

    if(caret) {
      //dump("----\n");
      var dotpos, spacepos, complete, obj;
      //dump("caret pos: " + caret + "\n");
      // see if there's a dot before here
      dotpos = findbeginning(_in.value, caret-1, true);
      //dump("dot pos: " + dotpos + "\n");
      if(dotpos == -1 || _in.value.charAt(dotpos) != '.') {
        dotpos = caret;
//dump("changed dot pos: " + dotpos + "\n");
      }

      // look backwards for a non-variable-name character
      spacepos = findbeginning(_in.value, dotpos-1, false);
      //dump("space pos: " + spacepos + "\n");
      // get the object we're trying to complete on
      if(spacepos == dotpos || spacepos+1 == dotpos || dotpos == caret) {
        // try completing function args
        if(_in.value.charAt(dotpos) == '(' ||
 (_in.value.charAt(spacepos) == '(' && (spacepos+1) == dotpos))
        {
          var fn,fname;
  var from = (_in.value.charAt(dotpos) == '(') ? dotpos : spacepos;
          spacepos = findbeginning(_in.value, from-1, false);

          fname = _in.value.substr(spacepos+1,from-(spacepos+1));
  //dump("fname: " + fname + "\n");
          try {
            with(_win.Shell._scope)
              with(_win)
                with(Shell.shellCommands)
                  fn = eval(fname);
          }
          catch(er) {
            //dump('fn is not a valid object\n');
            return;
          }
          if(fn == undefined) {
             //dump('fn is undefined');
             return;
          }
          if(fn instanceof Function)
          {
            // Print function definition, including argument names, but not function body
            if(!fn.toString().match(/function .+?\(\) +\{\n +\[native code\]\n\}/))
              println(fn.toString().match(/function .+?\(.*?\)/), "tabcomplete");
          }

          return;
        }
        else
          obj = _win;
      }
      else
      {
        var objname = _in.value.substr(spacepos+1,dotpos-(spacepos+1));
        //dump("objname: |" + objname + "|\n");
        try {
          with(_win.Shell._scope)
            with(_win)
                obj = eval(objname);
        }
        catch(er) {
          printError(er); 
          return;
        }
        if(obj == undefined) {
          // sometimes this is tabcomplete's fault, so don't print it :(
          // e.g. completing from "print(document.getElements"
          // println("Can't complete from null or undefined expression " + objname, "error");
          return;
        }
      }
      //dump("obj: " + obj + "\n");
      // get the thing we're trying to complete
      if(dotpos == caret)   {
        if(spacepos+1 == dotpos || spacepos == dotpos) {
          // nothing to complete
          //dump("nothing to complete\n");
          return;
        }

        complete = _in.value.substr(spacepos+1,dotpos-(spacepos+1));
      } else {
        complete = _in.value.substr(dotpos+1,caret-(dotpos+1));
      }
      //dump("complete: " + complete + "\n");
      
      // ok, now look at all the props/methods of this obj
      // and find ones starting with 'complete'
      var matches = [];
      var bestmatch = null;
      for(var a in obj) {
        //a = a.toString();
        //XXX: making it lowercase could help some cases,
        // but screws up my general logic.
        if(a.substr(0,complete.length) == complete) {
          matches.push(a);
          ////dump("match: " + a + "\n");
          // if no best match, this is the best match
          if(bestmatch == null) {
            bestmatch = a;
          } else {
            // the best match is the longest common string
            function min(a,b){ return ((a<b)?a:b); }
            var i;
            for(i=0; i< min(bestmatch.length, a.length); i++)
            {
              if(bestmatch.charAt(i) != a.charAt(i))
                break;
            }
            bestmatch = bestmatch.substr(0,i);
            ////dump("bestmatch len: " + i + "\n");
          }
          ////dump("bestmatch: " + bestmatch + "\n");
        }
      }
      bestmatch = (bestmatch || "");
      ////dump("matches: " + matches + "\n");
      var objAndComplete = (objname || obj) + "." + bestmatch;
      //dump("matches.length: " + matches.length + ", tooManyMatches: " + tooManyMatches + ", objAndComplete: " + objAndComplete + "\n");
      if(matches.length > 1 && (tooManyMatches == objAndComplete || matches.length <= 10)) {
        printWithRunin("Matches: ", matches.join(', '), "tabcomplete");
        tooManyMatches = null;
      } else if(matches.length > 10){
        println(matches.length + " matches.  Press tab again to see them all", "tabcomplete");
        tooManyMatches = objAndComplete;
      } else {
        tooManyMatches = null;
      }
      
      if(bestmatch != "") {
        var sstart;
        if(dotpos == caret) {
          sstart = spacepos+1;
        }
        else {
          sstart = dotpos+1;
        }
        _in.value = _in.value.substr(0, sstart)
                  + bestmatch
                  + _in.value.substr(caret);
        setselectionto(_in,caret + (bestmatch.length - complete.length));
      }
    }
}


function dumpHelp(){
	println("Values and functions: ans, print(string), props(object), blink(node), load(scriptURL), scope(object), clear()","nomalOutput");
	refocus();
}


function printQuestion(q){
  println(q, "input");
}

function printAnswer(a){
  if (a !== undefined) {
    println(a, "normalOutput");
    shellCommands.ans = a;
  }
}

function printError(er){ 
  var lineNumberString;

  lastError = er; // for debugging the shell
  if (er.name)  {
    // lineNumberString should not be "", to avoid a very wacky bug in IE 6.
    lineNumberString = (er.lineNumber != undefined) ? (" on line " + er.lineNumber + ": ") : ": ";
    println(er.name + lineNumberString + er.message, "error"); // Because IE doesn't have error.toString.
  } else
    println(er, "error"); // Because security errors in Moz /only/ have toString.
}

function go(s){
	
  _in.value = question = s ? s : _in.value;

  if (question == "") {
    return;
  }
  
  
  histList[histList.length-1] = question;
  histList[histList.length] = "";
  histPos = histList.length - 1;
  
  // Unfortunately, this has to happen *before* the JavaScript is run, so that 
  // print() output will go in the right place.
  _in.value='';
  recalculateInputHeight();
  
  //painter.savePoint();
  
  printQuestion(question);

  if (_win.closed) {
    printError("Target window has been closed.");
    painter.top();
    return;
  }
  
  try { ("Shell" in _win) }
  catch(er) {
    printError("The JavaScript Shell cannot access variables in the target window.  The most likely reason is that the target window now has a different page loaded and that page has a different hostname than the original page.");
    painter.top();
    return;
  }

  if (!("Shell" in _win))
    initTarget(); // silent

  // Evaluate Shell.question using _win's eval (this is why eval isn't in the |with|, IIRC).
  _win.location.href = "javascript:try{ Shell.printAnswer(eval('with(Shell._scope) with(Shell.shellCommands) {' + Shell.question + String.fromCharCode(10) + '}')); } catch(er) { Shell.printError(er); }; setTimeout(Shell.refocus, 0); void 0";
  painter.top();
}