var ctrace = false;
var ridx = 0;

function recalcNodeList(list){
	var n = list[0];
	var recalclist = new Array();
	for(var j=0;j<100;j++){		// loop limiter
		if(list.length==0) return;
		if(ctrace) console.log(j, list);
		for(var i in list) recalcNode(list[i], recalclist);
		list = recalclist;
		recalclist = new Array();
	}
	console.log(n,'looping...');
}

function recalcNode(node, recalclist){
	if(node==ngnd) return;
	if(node==npwr) return;
	var group = getNodeGroup(node);
	var newv = getNodeValue(group);
	if(ctrace) console.log('recalc', node, group);
	for(var i in group){
		var n = nodes[group[i]];
		if(n.state!=newv && ctrace) console.log(group[i], n.state, newv);
		n.state = newv;
		for(var t in n.gates) recalcTransistor(n.gates[t], recalclist);
	}
}

function recalcTransistor(tn, recalclist){
	var t = transistors[tn];
	if(isNodeHigh(t.gate)) turnTransistorOn(t, recalclist);
	else turnTransistorOff(t, recalclist);
}

function turnTransistorOn(t, recalclist){
	if(t.on) return;
	if(ctrace) console.log(t.name, 'on', t.gate, t.c1, t.c2);
	t.on = true;
	addRecalcNode(t.c1, recalclist);
	addRecalcNode(t.c2, recalclist);
}

function turnTransistorOff(t, recalclist){
	if(!t.on) return;
	if(ctrace) console.log(t.name, 'off', t.gate, t.c1, t.c2);
	t.on = false;
	floatnode(t.c1);
	floatnode(t.c2);
	addRecalcNode(t.c1, recalclist);
	addRecalcNode(t.c2, recalclist);
}

function floatnode(nn){
	if(nn==ngnd) return;
	if(nn==npwr) return;
	var n = nodes[nn];
	if(n.state=='gnd') n.state = 'fl';
	if(n.state=='pd') n.state = 'fl';
	if(n.state=='vcc') n.state = 'fh';
	if(n.state=='pu') n.state = 'fh';
	if(ctrace) console.log('floating', nn, 'to', n.state);
}

function addRecalcNode(nn, recalclist){
	if(nn==ngnd) return;
	if(nn==npwr) return;
	if(arrayContains(recalclist, nn)) return;
	recalclist.push(nn);
//	setAdd(recalclist, nn);
}

function getNodeGroup(i){
	var group = new Array();
	addNodeToGroup(i, group);
	return group;
}

function addNodeToGroup(i, group){
	if(arrayContains(group, i)) return;
	group.push(i);
	if(i==ngnd) return;
	if(i==npwr) return;
	for(var t in nodes[i].c1c2s) addNodeTransistor(i, nodes[i].c1c2s[t], group);
}

function addNodeTransistor(node, t, group){
	var tr = transistors[t];
	if(!tr.on) return;
	var other;
	if(tr.c1==node) other=tr.c2;
	if(tr.c2==node) other=tr.c1;
	addNodeToGroup(other, group);
}


function getNodeValue(group){
	if(arrayContains(group, ngnd)) return 'gnd';
	if(arrayContains(group, npwr)) return 'vcc';
	var flstate;
	for(var i in group){
		var nn = group[i];
		var n = nodes[nn];
		if(n.pullup) return 'pu';
		if(n.pulldown) return 'pd';
		if((n.state=='fl')&&(flstate==undefined)) flstate = 'fl';
		if(n.state=='fh') flstate = 'fh';
	}
	if(flstate==undefined) console.log(group);
	return flstate;
}


function isNodeHigh(nn){
	return arrayContains(['vcc','pu','fh'], nodes[nn].state);
}

function saveString(name, str){
	var request = new XMLHttpRequest();
	request.onreadystatechange=function(){};
	request.open('PUT', 'save.php?name='+name, true);
	request.setRequestHeader('Content-Type', 'text/plain');
	request.send(str);
}

function allNodes(){
	var res = new Array();
	for(var i in nodes) if((i!=npwr)&&(i!=ngnd)) res.push(i);
	return res;
}

function stateString(){
	var codes = {gnd: 'g', vcc: 'v', pu: 'p', pd: 'd', fh: 'f', fl: 'l'};
	var res = '';
	for(var i=0;i<1725;i++){
		var n = nodes[i];
		if(n==undefined) res+='x';
		else if(i==ngnd) res+='g';
		else if(i==npwr) res+='v';
		else res+= codes[n.state];
	}
	return res;
}

function showState(str){
	var codes = {g: 'gnd', v: 'vcc', p: 'pu', d: 'pd', f: 'fh', l: 'fl'};
	for(var i=0;i<str.length;i++){
		if(str[i]=='x') continue;
		nodes[i].state = codes[str[i]];
		var gates = nodes[i].gates;
		for(var t in gates) transistors[gates[t]].on = isNodeHigh(i);
	}
	refresh();
}


function setPd(name){
	var nn = nodenames[name];
	nodes[nn].pullup = false;
	nodes[nn].pulldown = true;
}

function setHigh(name){
	var nn = nodenames[name];
	nodes[nn].pullup = true;
	nodes[nn].pulldown = false;
	recalcNodeList([nn]);
}

function setLow(name){
	var nn = nodenames[name];
	nodes[nn].pullup = false;
	nodes[nn].pulldown = true;
	recalcNodeList([nn]);
}

function setAdd(arr, el){
	var idx = ridx%(arr.length+1);
	ridx+=131;
	ridx%=123;
	arr.splice(idx, 0, el);
	return arr;
}

function arrayContains(arr, el){return arr.indexOf(el)!=-1;}