/*
  terminal.js: Terminal-like User Interface
  Copyright (C) 2006 Natsuhiro Ichinose <ichinose@genome.ist.i.kyoto-u.ac.jp>
  License: GPL's
  $Id: terminal.js,v 1.3 2006/04/21 18:27:15 ichinose Exp $
*/

var Terminal=(function(){

  function getKey(e){
    if(document.all){return(event.keyCode);}
    else if(document.getElementById){
      return((e.keyCode!==0)?e.keyCode:e.charCode);
    }
    else if(document.layers){
      return(e.which);
    }
  }

  function cancelKey(e){
    if(e.preventDefault){e.preventDefault();}
    if(e.stopPropagation){e.stopPropagation();}
    e.cancelBubble=true;
    e.returnValue=false;
  }

  function scrollBottom(){
    document.body.scrollTop=document.body.scrollHeight;
    window.scrollTo(0,document.body.scrollHeight);
  }

  function CommandHist(){
    this.hist=[];

    this.current="";
    this.pos=0;
    this.prev=function(current){
      if(this.pos==this.hist.length){
        this.current=current;
      }
      if(this.pos>0){this.pos--;}
      if(this.pos==this.hist.length){return(this.current);}
      else{return(this.hist[this.pos]);}
    };

    this.next=function(current){
      if(this.pos==this.hist.length){
        this.current=current;
      }
      if(this.pos<this.hist.length){this.pos++;}
      if(this.pos==this.hist.length){return(this.current);}
      else{return(this.hist[this.pos]);}
    };

    this.push=function(current){
      if(current&&current.length>0){
        if(this.hist.push){this.hist.push(current);}
        else{this.hist[this.hist.length]=current;}
      }
      this.current="";
      this.pos=this.hist.length;
    };
  }

  function Stdout(target){
    this.target=target;
    this.buf="";
    this.write=function(text){
      this.buf+=text;
    };

    this.puts=function(text){
      this.write(text+"\n");
    };

    this.flushTEXT=function(){
      var sp=document.createElement("span");
      var word="",w;

      for(var i=0;i<this.buf.length;i++){
	w=this.buf.substr(i,1);
	if(w=='\n'){
	  if(word.length>0){
	    sp.appendChild(document.createTextNode(word));
	    word="";
	  }
	  sp.appendChild(document.createElement("br"));
	}
	else if(w==' '){
	  if(word.length>0){
	    sp.appendChild(document.createTextNode(word));
	    word="";
	  }
	  sp.appendChild(document.createTextNode("\u00a0"));
	  sp.appendChild(document.createElement("wbr"));
	}
	else{
	  word+=w;
	}
      }
      if(word.length>0){
	sp.appendChild(document.createTextNode(word));
      }

      sp.className="stdout";
      document.body.insertBefore(sp,this.target);
      this.buf="";
    };
    
    this.flushHTML=function(){
      var di=document.createElement("div");
      di.innerHTML=this.buf;
      di.className="stdout";
      document.body.insertBefore(di,this.target);
      this.buf="";
    };

    this.flush=function(){
      if(this.buf.length>0){
	if(this.buf.match(/^[ ]*\</)){
	  this.flushHTML();
	}
	else{
	  this.flushTEXT();
	}
      }
    };
  }

  function Stdin(element){
    this.element=element;
    this.hist=new CommandHist();

    this.gets=function(){
      return(this.element.value);
    };

    this.enter=function(){
      this.hist.push(this.element.value);
      this.element.value="";
    };

    this.histPrevious=function(){
      this.element.value=this.hist.prev(this.element.value);
    };

    this.histNext=function(){
      this.element.value=this.hist.next(this.element.value);
    };

    this.focus=function(){
      this.element.focus();
    };
  }

  var term={
    stdin:null,
    stdout:null,
    promptI:"> ",
    promptC:"* ",
    prompt:"",
    header:"",
    buf:[],
    gid:function(element,id){
      if(element.getElementById){return(element.getElementById(id));}
      else if(element.all){return(element.all[id]);}
      else if(element.layers){return(element.layers[id]);}
    },
    keyHandlerList:[
                    ["histPrevious",true,"ctrlKey","p",16],
                    ["histPrevious",true,"ctrlKey","",80],
                    ["histPrevious",false,"shiftKey","&",63232],
                    ["histNext",true,"ctrlKey","n",14],
                    ["histNext",true,"ctrlKey","N",78],
                    ["histNext",false,"shiftKey","(",63233]
    ],
    stdinfocus:function(){term.stdin.focus();},
    initHook:function(){},
    init:function(){
      var s=term.gid(document,"stdin");

      if(document.addEventListener){
	s.addEventListener("keypress",term.callCommand,true);
	document.body.addEventListener("click",term.stdinfocus,false);
      }
      else if(document.attachEvent){
	s.attachEvent("onkeypress",term.callCommand);
	s.attachEvent("onkeydown",term.callCommand);
	document.body.attachEvent("onclick",term.stdinfocus);
      }
      else{
	s.onkeypress=term.callCommand;
	s.onkeydown=term.callCommand;
	document.body.onclick=term.stdinfocus;
      }

      term.stdin=new Stdin(s);
      term.stdin.focus();
      term.stdout=new Stdout(term.stdin.element);
      if(term.header.length>0){term.stdout.puts(term.header);}

      term.initHook();

      term.prompt=term.promptI;
      term.stdout.write(term.prompt);
      term.stdout.flush();
    },
    history:function(){return(term.stdin.hist.hist);},
    commandCallBack:function(com){},
    callCommand:function(e){
      if(!e){e=event;}
      var key=getKey(e);
      var chara=String.fromCharCode(key);
      var bubflag=false;

      if(e.type=="keypress"&&key==13){
	var line=term.stdin.gets();
	var reg=/\\[ ]*$/;
	term.stdout.puts(line);
	term.stdout.flushTEXT();
	
	if(line.match(reg)){
	  term.buf.push(line.replace(reg,""));
	  term.prompt=term.promptC;
	}
	else{
	  term.commandCallBack(term.buf.join("")+line);
	  term.buf=[];
	  term.prompt=term.promptI;
	}
	term.stdin.enter();
	term.stdout.flush();

	term.stdout.write(term.prompt);
	term.stdout.flush();
	bubflag=true;
      }
      else{
	for(var i=0;i<term.keyHandlerList.length;i++){
	  var l=term.keyHandlerList[i];
	  if(((l[1]&&e[l[2]])||(!l[1]&&!e[l[2]]))&&(l[3]==chara||l[4]==key)){
	    term.stdin[l[0]]();
	    bubflag=true;
	    break;
	  }
	}
      }

      if(bubflag){
	cancelKey(e);
	scrollBottom();
	return(false);
      }
      else{return(true);}
    }
  };
  return(term);
})();