var atomString = ""
var badData=false
numAtoms=new Array(0,0,0,0,0,0,0,0,0,0)
ANofAtom=new Array(0,0,0,0,0,0,0,0,0,0)
var MolarMass="0"
var printS=""
var formula=""
var numElems=""
var capsLockOn=-1

function cmpd(numAtoms,ANofAtom,MM,printString) {
	this.numAtoms=numAtoms
	this.ANofAtom=ANofAtom
	this.MM=MM
	this.printString=printString
}

compound = new cmpd(numAtoms,ANofAtom,MolarMass,printS)
//document.onkeydown = checkKeycode

function parseFormula(formula) {
	var c=0; x=0; y=0; c1=0; marker1=0; marker2=-1; loopCount=0
	multiplier=1
	a1 = new Array(0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0)
	a2 = new Array(0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0)
	while (c <= formula.length - 1 && !badData) {
		AN = findAN(formula.substring(c,c+2))
		if (AN == -1) {
			AN = findAN(formula.substring(c,c+1))
			y=1
		}
		else y=2
		if (AN > -1) {
			marker2=-1
			for (var c2=0; c2<=9; c2++)  {
				if (a2[c2] == AN) { 
					marker2 = c2; break
				}
			}
			if (marker2>=0) {marker1=marker2; loopCount-=1} 
			else marker1=loopCount
			c += y
			a2[marker1] = AN
			var OK = true
			var c3 = 0
			while (OK && c+c3 <= formula.length-1)  {
				AN = findNum(formula.substring(c+c3, c+c3+1))
				if (AN >= 0) c3++; else OK = false
			}
			if (c3>0) {
				if (marker2>=0) {
					a1[marker1] += parseInt(formula.substring(c, c+c3))*multiplier
				}			
				else {
					a1[marker1] = parseInt(formula.substring(c, c+c3))*multiplier
				}		
			}
			else { 
				if (marker2>=0) a1[marker1] += 1*multiplier
				else a1[marker1] = 1*multiplier 
			}
			c += c3;
			loopCount++
		}
		else {
			AN="[]().".indexOf(formula.substring(c,c+1));
			if (AN==-1) {badData=true;break}
			if (AN==0 || AN==2) {
				if (AN==2) {
					var zz=0
					for (x=c;x<=formula.length-1;x++) {
						if (formula.substring(x,x+1)==")"){zz=x; break}
					}
				}
				else {
					for (x=c;x<=formula.length-1;x++) {
						if (formula.substring(x,x+1)=="]"){zz=x; break}
					}
				}
				var c4=1;OK=true
				while (OK && zz+c4 <= formula.length-1)  {
					var AN1 = findNum(formula.substring(zz+c4, zz+c4+1))
					if (AN1 >= 0) c4++; else OK = false
				}
				if (c4>1) {
					var z=parseInt(formula.substring(1+zz, c4+zz));
					multiplier=multiplier*z
				}
				c++
			}
			if (AN==1 || AN==3)  {
				var c5=1;OK=true
				while (OK && c+c5 <= formula.length-1)  {
					var AN1 = findNum(formula.substring(c+c5, c+c5+1))
					if (AN1 >= 0) c5++; else OK = false
				}
				if (c5>1) {
					multiplier=
					Math.round(multiplier /
					parseInt(formula.substring(c+1,c+c5)))
				}
				c+=c5
			}
			if (AN==4)  {
				var c6=1; OK=true
				while (OK && c+c6 <= formula.length-1)  {
					var AN1 = findNum(formula.substring(c+c6, c+c6+1))
					if (AN1 >= 0) c6++; else OK = false
				}
				if (c6>1) {
					multiplier *= parseInt(formula.substring(c+1, c+c6))
				}
				c+=c6
			}
		}
	}
	numElems = loopCount-1
	for (var i=0; i<=numElems; i++)  {
		numAtoms[i] = a1[i]
		ANofAtom[i] = a2[i]
	}
	if (badData==true) {alert("Formula did not parse correctly")}
}
	
function findAN(aSym) {
	var AN = 0
	if (aSym.length == 1) aSym +="*"
	var x = atomString.indexOf(aSym)
	AN = (x == -1) ?  x : (x/2) + 1
	return AN
}
	
function findNum(ch) {
	var numstring = "0123456789"
	var x = numstring.indexOf(ch)
	return x
}
	
function calcMolarMass()  {
	MM = 0
	for (var c=0; c<=numElems; c++)  {
		var x =ANofAtom[c]
		MM += a[x]["mass"]*numAtoms[c]
	}
	MM=Math.round(MM*100)/100
}
	
function printFormula()  {
	printS=""
	for (var c=0; c<=numElems; c++)  {
		printS += a[ANofAtom[c]["symbol"]]
	if (numAtoms[c]>1) printS += "<sub>"+numAtoms[c]+"</sub>"
	}
}
	
function atomArray(symbol, mass) {
	this.symbol = symbol
	this.mass = mass
}
	
function makeArray(arraySize) {
	this.length = arraySize
	for (var c=1; c <= arraySize; c++) {
	this[c] = 0
	}
	return this
}

a = new makeArray(109)
a[1] = new atomArray("H",1.0079)
a[2] = new atomArray("He",4.0026)
a[3] = new atomArray("Li",6.941)
a[4] = new atomArray("Be",9.0122)
a[5] = new atomArray("B",10.811)
a[6] = new atomArray("C",12.0107)
a[7] = new atomArray("N",14.0067)
a[8] = new atomArray("O",15.9994)
a[9] = new atomArray("F",18.9984)
a[10] = new atomArray("Ne",20.1797)
a[11] = new atomArray("Na",22.9897)
a[12] = new atomArray("Mg",24.305)
a[13] = new atomArray("Al",26.9815)
a[14] = new atomArray("Si",28.0855)
a[15] = new atomArray("P",30.9738)
a[16] = new atomArray("S",32.065)
a[17] = new atomArray("Cl",35.453)
a[18] = new atomArray("Ar",39.948)
a[19] = new atomArray("K",39.0983)
a[20] = new atomArray("Ca",40.078)
a[21] = new atomArray("Sc",44.9559)
a[22] = new atomArray("Ti",47.867)
a[23] = new atomArray("V",50.9415)
a[24] = new atomArray("Cr",51.9961)
a[25] = new atomArray("Mn",54.938)
a[26] = new atomArray("Fe",55.845)
a[27] = new atomArray("Co",58.9332)
a[28] = new atomArray("Ni",58.6934)
a[29] = new atomArray("Cu",63.546)
a[30] = new atomArray("Zn",65.39)
a[31] = new atomArray("Ga",69.723)
a[32] = new atomArray("Ge",72.64)
a[33] = new atomArray("As",74.9216)
a[34] = new atomArray("Se",78.96)
a[35] = new atomArray("Br",79.904)
a[36] = new atomArray("Kr",83.8)
a[37] = new atomArray("Rb",85.4678)
a[38] = new atomArray("Sr",87.62)
a[39] = new atomArray("Y",88.9059)
a[40] = new atomArray("Zr",91.224)
a[41] = new atomArray("Nb",92.9064)
a[42] = new atomArray("Mo",95.94)
a[43] = new atomArray("Tc",98)
a[44] = new atomArray("Ru",101.07)
a[45] = new atomArray("Rh",102.9055)
a[46] = new atomArray("Pd",106.42)
a[47] = new atomArray("Ag",107.8682)
a[48] = new atomArray("Cd",112.411)
a[49] = new atomArray("In",114.818)
a[50] = new atomArray("Sn",118.71)
a[51] = new atomArray("Sb",121.76)
a[52] = new atomArray("Te",127.6)
a[53] = new atomArray("I",126.9045)
a[54] = new atomArray("Xe",131.293)
a[55] = new atomArray("Cs",132.9055)
a[56] = new atomArray("Ba",137.327)
a[57] = new atomArray("La",138.9055)
a[58] = new atomArray("Ce",140.116)
a[59] = new atomArray("Pr",140.9077)
a[60] = new atomArray("Nd",144.24)
a[61] = new atomArray("Pm",145)
a[62] = new atomArray("Sm",150.36)
a[63] = new atomArray("Eu",151.964)
a[64] = new atomArray("Gd",157.25)
a[65] = new atomArray("Tb",158.9253)
a[66] = new atomArray("Dy",162.5)
a[67] = new atomArray("Ho",164.9303)
a[68] = new atomArray("Er",167.259)
a[69] = new atomArray("Tm",168.9342)
a[70] = new atomArray("Yb",173.04)
a[71] = new atomArray("Lu",174.967)
a[72] = new atomArray("Hf",178.49)
a[73] = new atomArray("Ta",180.9479)
a[74] = new atomArray("W",183.84)
a[75] = new atomArray("Re",186.207)
a[76] = new atomArray("Os",190.23)
a[77] = new atomArray("Ir",192.217)
a[78] = new atomArray("Pt",195.078)
a[79] = new atomArray("Au",196.9665)
a[80] = new atomArray("Hg",200.59)
a[81] = new atomArray("Tl",204.3833)
a[82] = new atomArray("Pb",207.2)
a[83] = new atomArray("Bi",208.9804)
a[84] = new atomArray("Po",209)
a[85] = new atomArray("At",210)
a[86] = new atomArray("Rn",222)
a[87] = new atomArray("Fr",223)
a[88] = new atomArray("Ra",226)
a[89] = new atomArray("Ac",227)
a[90] = new atomArray("Th",232.0381)
a[91] = new atomArray("Pa",231.0359)
a[92] = new atomArray("U",238.0289)
a[93] = new atomArray("Np",237)
a[94] = new atomArray("Pu",244)
a[95] = new atomArray("Am",243)
a[96] = new atomArray("Cm",247)
a[97] = new atomArray("Bk",247)
a[98] = new atomArray("Cf",251)
a[99] = new atomArray("Es",252)
a[100] = new atomArray("Fm",257)
a[101] = new atomArray("Md",258)
a[102] = new atomArray("No",259)
a[103] = new atomArray("Lr",262)
a[104] = new atomArray("Rf",261)
a[105] = new atomArray("Db",262)
a[106] = new atomArray("Sg",266)
a[107] = new atomArray("Bh",264)
a[108] = new atomArray("Hs",277)
a[109] = new atomArray("Mt",268)

function makeAtomString()  {
	for (var c=1; c <= a.length; c++)  {
		atomString += a[c]["symbol"]
		if (a[c]["symbol"].length == 1) atomString += "*"
	}
	return atomString
}

function prepare(form) {
	form.inputFormula.value = "CH3COOH"
	findChemicalFormula(form)
	writeOut()
}

function findChemicalFormula(form) {
	numPulldownMenus = document.entryForm.elements.length -2
	for (i=0; i<numPulldownMenus; i++) {
		arrayOptions = form.elements[i].options
		numOptions = arrayOptions.length
		for (j=0; j<numOptions; j++) {
			if(arrayOptions[j].value == form.inputFormula.value) {
				arrayOptions.selectedIndex = j
				return null
			}
			else {
				arrayOptions.selectedIndex = 0
			}			
		}
	}	
}


function setChemicalFormula(pulldownMenu) {	
	if (pulldownMenu.selectedIndex !== 0) {
		document.entryForm.inputFormula.value = pulldownMenu.value
		numPulldownMenus = document.entryForm.elements.length -2
		for (i=0; i<numPulldownMenus; i++) {
			if (document.entryForm.elements[i].id !== pulldownMenu.id) {
				document.entryForm.elements[i].selectedIndex = 0
			}
		}
		writeOut()
	}
	else {
		document.entryForm.inputFormula.focus()
	}
}

function writeOut()  {
	var numCols = 5
	var numHeadRows = 2
	var numFootRows = 1
	var numSignificance = 2
	var numRows = document.getElementById("outputTable").rows.length - numHeadRows - numFootRows
	
	makeAtomString()
	formula = document.entryForm.inputFormula.value
	parseFormula(formula)
	if (badData==false) {
	
		calcMolarMass()
		document.outputForm.outputMM.value = MM.toFixed(numSignificance)
	
		for(iN=0; iN<(numRows); iN++) {
				document.getElementById('outputTable').deleteRow(numHeadRows)
		}
		
		for(var i=0; i<=numElems; i++) {
			var newRow = document.getElementById('outputTable').insertRow(i+numHeadRows)
			for(var j=0; j<numCols; j++) {
				var newCell = newRow.insertCell(j)
				newCell.style.textAlign = "center"
				newCell.style.height = "22px"
				
				if (j==0) {newCell.innerText = numAtoms[i]}
				else if (j==1) {newCell.innerText = a[ANofAtom[i]].symbol}
				else if (j==2) {newCell.innerText = parseFloat(a[ANofAtom[i]].mass).toFixed(numSignificance)}
				else if (j==3) {newCell.innerText = parseFloat(a[ANofAtom[i]].mass*numAtoms[i] / MM * 100).toFixed(numSignificance)}
				else if (j==4) {newCell.innerText = parseFloat(a[ANofAtom[i]].mass*numAtoms[i]).toFixed(numSignificance)}
				else {alert("This page operates incorrect. Please help Lenntech and report the failure.")}
			}
		}
	}
	else {
	;
	}
	badData=false
	document.entryForm.inputFormula.select()
	document.entryForm.inputFormula.focus()	
}