// copyright 2010 Laura Shaffer Mills

// circumference/diameter -- treat as constants
var gkMeasureCirc =		0;
var gkMeasureDia =		1;
// country -- treat as constants
var gkCountryAustraliaIrelandUK =	0;
var gkCountryCanadaUS =				1;
var gkCountryChinaJapan =			2;
var gkCountryEurope =				3;
var gkCountryGermanyRussia =		4;
var gkCountrySwitzerland =			5;
// array by country code for letter sizing (not numbers)
var gkAllowLetterSize = [true, false, false, false, false, false]
var gkStrTooSmall = "too small to calculate";
var gkStrTooLarge = "too large to calculate";

// keep original size and units so math stays more accurate
// final ring size (Fn)
var gFnOrigCircOrDia = 0;			// circumference
var gFnOrigUnits = 0;				// mm
var gFnOrigDistance = 0;
var gFnOrigCountry = 1;				// US/Canada
// ring circumference (Cr)
var gCrOrigCountry = 1;				// US/Canada
var gCrOrigSize = 0;
var gCrOrigUnits = 0;				// mm
var gCrCircumference;
// metal clay ring size (Mc)
var gMcOrigCountry = 1;				// US/Canada
var gMcRingSize = 0;				// number for ring size (not letter)
var gMcMetalClay = 0;


// set up "onload" to initialize
window.onload = function() {
	var imageC = new Image();
	var imageD = new Image();
	var imageW = new Image();
	var imageT = new Image();

	// preload rollover images
	imageC.src = "images/ringmeasureC.gif";
	imageD.src = "images/ringmeasureD.gif";
	imageW.src = "images/ringmeasureW.gif";
	imageT.src = "images/ringmeasureT.gif";

	// disable "Enter" key for submitting form
	document.onKeyPress = ignoreEnterKey;

	// set up ring image rollovers
	document.getElementById("ringpictC").onmouseover = function(evt)
		{ changeRingPict("ringpictC",evt); };
	document.getElementById("ringpictC").onmouseout = function(evt)
		{ changeRingPict("off",evt); };
	document.getElementById("ringpictD").onmouseover = function(evt)
		{ changeRingPict("ringpictD",evt); };
	document.getElementById("ringpictD").onmouseout = function(evt)
		{ changeRingPict("off",evt); };
	document.getElementById("ringpictW").onmouseover = function(evt)
		{ changeRingPict("ringpictW",evt); };
	document.getElementById("ringpictW").onmouseout = function(evt)
		{ changeRingPict("off",evt); };
	document.getElementById("ringpictT").onmouseover = function(evt)
		{ changeRingPict("ringpictT",evt); };
	document.getElementById("ringpictT").onmouseout = function(evt)
		{ changeRingPict("off",evt); };

	// set up functions for final ring size
	document.getElementById("inRingCircOrDia1").onchange = changeOriginalUnits;	// circ/dia
	document.getElementById("inRingUnits1").onchange = changeOriginalUnits;	// mm/in
	document.getElementById("inFingerDistance1").onchange = newOriginalNum;	// size number
	// inFingerDistance1Validation
	document.getElementById("inCountry1").onchange = calcFinalRingSize;	// country
	// outRingSize1

	// set up functions for ring circumference
	//	(verification of final ring size, or find metal clay mandrel size)
	document.getElementById("inCountry2").onchange = changeCountryCircumference;	// country
	document.getElementById("inRingSize2").onchange = newOriginalNumCircumference;	// ring size
	// inRingSize2Validation
	document.getElementById("inRingUnits2").onchange = changeFinalUnitsCircumference;	// mm/in
	// outRingCirc2

	// set up functions for metal clay ring size (varies by type of clay)
	document.getElementById("inCountry3").onchange = changeMetalClayCountry;	// country
	document.getElementById("inRingSize3").onchange = newMetalClayRingSizeIn;	// ring size
	document.getElementById("inClayTypeRing3").onchange = changeMetalClayType;	// clay type (for shrinkage)

	initializeConversions();
	makeShrinkageArray();
	fillDropdownClayTypes("inClayTypeRing3");
}			// window.onload()


// calculate the diameter/circumference from the ring size
function calcFinalCircumference(ringValue) {
	var circumferenceMM = -1;

	if (ringValue)
		circumferenceMM = convertRingSize2CircMM(ringValue, gCrOrigCountry);
	if ( (!isNaN(circumferenceMM)) && (circumferenceMM > 0) ) {
		// convert to correct units
		gCrCircumference = convertByUnit(circumferenceMM, gkUnitMillimeters, gCrOrigUnits);	// in gCrOrigUnits
		// round to nearest 1/10
		replaceNodeText("outRingCirc2",createDimensionString(gCrCircumference, gCrOrigUnits));
	}
	else
		replaceNodeText("outRingCirc2","unknown");
}			// calcFinalCircumference()


// calculate the ring sizes
function calcFinalRingSize() {
	var finalSizeRing = "unknown";
	var circumferenceMM = -1;

	gFnOrigCountry = parseInt( document.getElementById("inCountry1").value );
	circumferenceMM = convertByUnit(gFnOrigDistance, gFnOrigUnits, gkUnitMillimeters);
	if (gkMeasureDia == gFnOrigCircOrDia)	// change diameter to circumference?
		circumferenceMM *= Math.PI;
	if (circumferenceMM > 0)
		finalSizeRing = getSize(gFnOrigCountry,circumferenceMM);

	// put answer on page
	replaceNodeText("outRingSize1",finalSizeRing);
}			// calcFinalRingSize()


/*
// calculate metal clay ring size, with shrinkage
function calcMetalClayRingSize() {
	var newRingSize = 0;

	gMcOrigCountry = parseInt( document.getElementById("inCountry3").value );
	gMcMetalClay = parseInt( document.getElementById("inClayTypeRing3").value );
	if (gMcRingSize > 0) {		// valid ring size?
		var circumferenceMM = -1;
		var newCircMM = -1;
		// change ring size to circumference
		circumferenceMM = convertRingSize2CircMM(gMcRingSize, gMcOrigCountry);
		// apply shrinkage to circumference
		newCircMM = circumferenceMM / (1 - gkaShrink[gMcMetalClay]);
		// find ring size for this circumference
		newRingSize = getSize(gMcOrigCountry,newCircMM);
	}
// ### if have string answer (instead of number), this won't print it
	if (newRingSize > 0)	// put on page
		replaceNodeText("outClayRingSize3",newRingSize);
	else
		replaceNodeText("outClayRingSize3","");
}			// calcMetalClayRingSize()
*/
// calculate metal clay ring size, with shrinkage
function calcMetalClayRingSize() {
	var newRingSize = 0;

	gMcOrigCountry = parseInt( document.getElementById("inCountry3").value );
	gMcMetalClay = parseInt( document.getElementById("inClayTypeRing3").value );
	if (gMcRingSize > 0) {		// valid ring size?
		var circumferenceMM = -1;
		var newCircMM = -1;
		var newCircMMMin = -1;
		var newCircMMMax = -1;
		var rangeString = "";

		// change ring size to circumference
		circumferenceMM = convertRingSize2CircMM(gMcRingSize, gMcOrigCountry);
		// AVERAGE - apply shrinkage to circumference
		newCircMM = gkaoShrink[gMcMetalClay].avgFromClay(circumferenceMM);
		// find ring size for this circumference
		newRingSize = getSize(gMcOrigCountry,newCircMM);
		if (gkaoShrink[gMcMetalClay].range) {		// also find min and max
			// apply shrinkage to circumference
			newCircMMMin = gkaoShrink[gMcMetalClay].minFromClay(circumferenceMM);
			newCircMMMax = gkaoShrink[gMcMetalClay].maxFromClay(circumferenceMM);
			rangeString = " (" + getSize(gMcOrigCountry,newCircMMMin) + " - " + 
				getSize(gMcOrigCountry,newCircMMMax) + ")";
		}
	}
	if (newRingSize != 0)	// put on page
		replaceNodeText("outClayRingSize3",newRingSize + rangeString);
	else
		replaceNodeText("outClayRingSize3","");
}			// calcMetalClayRingSize()


// country has changed, so check number again and recalculate answer
function changeCountryCircumference() {
	var ringValue = document.getElementById("inRingSize2").value;

	gCrOrigCountry = document.getElementById("inCountry2").value;

	if ( validateOriginalRingSize(ringValue) )	// may not be valid value for this country
		calcFinalCircumference(gCrOrigSize);
}			// changeCountryCircumference()


// recalculate answer for changed units
function changeFinalUnitsCircumference() {
	var circumference;
	var newUnits = document.getElementById("inRingUnits2").value;

	circumference = convertByUnit(gCrCircumference, gCrOrigUnits, newUnits);
	replaceNodeText("outRingCirc2",createDimensionString(circumference, newUnits));
}			// changeFinalUnitsCircumference()


// change country for metal clay
function changeMetalClayCountry() {
	calcMetalClayRingSize();
}			// changeMetalClayCountry()


// change metal clay type (shrinkage)
function changeMetalClayType() {
	calcMetalClayRingSize();
}			// changeMetalClayType()


// change the original value to new units
// still keep the value and units *originally* entered, to keep math more consistent
function changeOriginalUnits() {
	var newOrigSize = 0;
	var newMeasure = document.getElementById("inRingCircOrDia1").value;
	var newUnits = document.getElementById("inRingUnits1").value;

	if (gFnOrigUnits  == newUnits) {			// units as originally entered
		newOrigSize = gFnOrigDistance;
	}
	else {
		// the "original" units have changed, so recalculate "original" size value
		// use gFnOrigDistance for calculation; find newOrigSize in newUnits
		newOrigSize = convertByUnit(gFnOrigDistance, gFnOrigUnits, newUnits);
	}

	// if changed circumference/diameter, must recalculate size or change number
	if (gFnOrigCircOrDia  != newMeasure) {			// circumference/diameter changed
		gFnOrigCircOrDia = newMeasure;
		calcFinalRingSize();		// recalculate answer
	}

	document.getElementById("inFingerDistance1").value = newOrigSize.toFixed(2);
}			// changeOriginalUnits()


// change ring picture as needed
function changeRingPict(pictVersion,evt) {
	evt = (evt) ? evt : window.event;	// some browsers won't pass event

	switch (pictVersion) {
		case "off":
			document.getElementById("ringdim").src = "images/ringmeasure.gif";
			break;
		case "ringpictC":
			document.getElementById("ringdim").src = "images/ringmeasureC.gif"
			break;
		case "ringpictD":
			document.getElementById("ringdim").src = "images/ringmeasureD.gif"
			break;
		case "ringpictW":
			document.getElementById("ringdim").src = "images/ringmeasureW.gif"
			break;
		case "ringpictT":
			document.getElementById("ringdim").src = "images/ringmeasureT.gif"
			break;
		// otherwise, don't change picture
	}
}			// changeRingPict()


// find circumference in mm from ring size and country
function convertRingSize2CircMM(ringSize, country) {
	var circumferenceMM = -1;	// ring circumference to return

// need to validate ring size (not negative, for instance) before call this ###

	if (ringSize >= 0) {
		switch (parseInt(country,10)) {
			case gkCountryAustraliaIrelandUK:
				circumferenceMM = (ringSize-1) * 1.25 + 37.5;	// ringSize "A" = 1
				break;
			case gkCountryCanadaUS:
				circumferenceMM = (1.43 + parseFloat(ringSize) * 0.102) * 25.4;
				break;
			case gkCountryChinaJapan:
				circumferenceMM = Math.PI * ( 13 + (parseFloat(ringSize) - 1) / 3 );
				break;
			case gkCountryEurope:
				circumferenceMM = parseFloat(ringSize);
				break;
			case gkCountryGermanyRussia:
				circumferenceMM = parseFloat(ringSize) * Math.PI;
				break;
			case gkCountrySwitzerland:
				circumferenceMM = parseFloat(ringSize) + 39;
				break;
		}
	}
	return(circumferenceMM);
}			// convertRingSize2CircMM()


// convert size to new units and circumference/diameter
function convertUnits(inSize, inUnits, inMeasureType, outUnits, outMeasureType) {
	var newSize = 0;

	// change inUnits to outUnits
	if (inUnits == outUnits) {
		newSize = inSize;
	}
	else
		newSize = convertByUnit(inSize, inUnits, outUnits);

	// change inMeasureType to outMeasureType
	if (inMeasureType != outMeasureType) {
		if (gkMeasureCirc == inMeasureType) {	// convert from cirumference to diameter
			newSize = newSize / Math.PI;
		}
		else {									// convert from diameter to circumference
			newSize = Math.PI * newSize;
		}
	}

	return(newSize);
}			// convertUnits()


// make string for diameter or circumference value
function createDimensionString(size, units) {
	var myString = "";
	var temp;
	var whole;					// whole number part
	var numerator;
	var denominator = 16;

	switch (parseInt(units)) {
		case gkUnitMillimeters:
			// if units are in mm, use decimal (round to 0.1mm)
			temp = Math.round(size * 10) / 10;		// to 1/10
			myString = "" + temp;		// convert to string
			break;
		case gkUnitInches:
			// if units are in inches, round and use 1/16 in.
			whole = Math.floor(size);		// integer part
			temp = size - whole;	// decimal part
			numerator = Math.round(temp * denominator);		// number of 1/16ths
			if (numerator == denominator) {		// rounds to next whole number
				whole++;
				numerator = 0;
			}
			while ( (numerator > 0) && ( 0 == (numerator % 2) ) ) {		// divisible by 2?
				numerator /= 2;
				denominator /= 2;
			}
			myString = "" + whole;		// convert to string -- integer part
			if (numerator > 0) {
				myString = myString + " " + numerator + "/" + denominator;
			}
			break;
	}
	return(myString);
}			// createDimensionString()


// validate that the value (circumference or diameter) is a number; if not, reset to zero
function getEntryValues(value) {
	// when user changes number for size, reset units to current value
	gFnOrigCircOrDia = document.getElementById("inRingCircOrDia1").value;
	gFnOrigUnits = document.getElementById("inRingUnits1").value;
	gFnOrigDistance = validatePosNumber(value, "inFingerDistance1Validation", "Enter a number.");
}			// getEntryValues()


// find size from circumference (rounds size)
function getSize(country,circumferenceMM) {
	var ringSize = 0;	// ring size to return
	var diameterMM = circumferenceMM / Math.PI;
	var temp;

	switch (country) {
		case gkCountryAustraliaIrelandUK:	// start A at 37.5; 1.25mm each
			var letterSize = "";
			var plusNumber = "";
			var numberPart;				// starts at zero; convert to letter later
			var decimalPart;			// 0, 1, 2, 3, 4 for quarters
			if (circumferenceMM >= 37.5) {
				temp = ( (circumferenceMM - 37.5) / 1.25 );
				numberPart = Math.floor(temp);
				decimalPart = Math.round( (temp - numberPart) * 4 );	// nearest 1/4 size
				if (4 == decimalPart)
				{						// must round up
					numberPart++;
					decimalPart = 0;
				}
				if ( numberPart > 25 )		// past "Z"
				{				// after Z 1/2: goes to Z + 1, Z + 1 1/2, etc.
					var extra = numberPart - 25;
					numberPart -= extra;
					plusNumber = " + " + extra + " ";
					//ringSize = gkStrTooLarge;
				}
				letterSize = numberPart + "A".charCodeAt(0);	// convert to letter code
				switch (decimalPart) {
					case 1:
						ringSize = String.fromCharCode(letterSize) + plusNumber + " 1/4";
						break;
					case 2:
						ringSize = String.fromCharCode(letterSize) + plusNumber + " 1/2";
						break;
					case 3:
						ringSize = String.fromCharCode(letterSize) + plusNumber + " 3/4";
						break;
					case 4:			// shouldn't get here
						// fall through
					default:		// no decimal part
						ringSize = String.fromCharCode(letterSize) + plusNumber;
						break;
				}
			}
			else
				ringSize = gkStrTooSmall;
			break;
		case gkCountryCanadaUS:	// size 0 at 1.43in circ; goes by 1/10 inch (but OLD inch is 1.02)
			var circumferenceIn = circumferenceMM / 25.4;
			if (circumferenceIn >= 1.43) {
				temp = (circumferenceIn - 1.43) / 0.102;
				ringSize = Math.round(temp * 4) / 4;	// round to nearest 1/4 size
			}
			else
				ringSize = gkStrTooSmall;
			break;
		case gkCountryChinaJapan:	// start size 1 at 13mm dia; add 1/3mm dia
			if (diameterMM >= 13) {
				temp = 1 + ( (diameterMM - 13) * 3 );
				ringSize = Math.round(temp * 4) / 4;	// round to nearest 1/4 size
			}
			else
				ringSize = gkStrTooSmall;
			break;
		case gkCountryEurope:		// circ in mm
			ringSize = Math.round(circumferenceMM * 4) / 4;	// round to nearest 1/4 size
			break;
		case gkCountryGermanyRussia:	// straight mm dia
			ringSize = Math.round(diameterMM * 4) / 4;	// round to nearest 1/4 size
			break;
		case gkCountrySwitzerland:	// 40mm size 1; straight circ in mm
			if (circumferenceMM >= 40) {
				var temp = circumferenceMM - 40 + 1;	// subtract 40mm
				ringSize = Math.round(temp * 4) / 4;	// round to nearest 1/4 size
			}
			else
				ringSize = gkStrTooSmall;
			break;
	}
	return(ringSize);
}			// getSize()


function newMetalClayRingSizeIn() {
	var ringValue = document.getElementById("inRingSize3").value;

	// see if ring size valid for this country
	if ( true == validateFinalRingSize(ringValue) )
		calcMetalClayRingSize();			// calculate answer
}			// newMetalClayRingSizeIn()


// verify input
function newOriginalNum() {
	getEntryValues(this.value);
	calcFinalRingSize();
}			// newOriginalNum()


// verify input
function newOriginalNumCircumference() {
	var ringValue = document.getElementById("inRingSize2").value;

	validateOriginalRingSize(ringValue);	// may not be valid value for this country
	calcFinalCircumference(gCrOrigSize);
}			// newOriginalNumCircumference()


// validate that the final size is a number or character size; if not, reset to zero
function validateFinalRingSize(value) {
	var goodNum = false;
	var country = document.getElementById("inCountry3").value;

	gMcRingSize = -1;
	// this must allow a character for the size, depending on country
	if (gkAllowLetterSize[country]) {
		// check if it is letter
		gMcRingSize = validateLetterSize(value, "inRingSize3Validation",
			"Enter a letter, letter.number, or Z + number.");
	}
	else {		// must be number
		gMcRingSize = validatePosNumber(value, "inRingSize3Validation",
			"Enter a number.");
//		if (gMcRingSize < 0) {		// check min. values by country? ###
//			replaceNodeText("inRingSize3Validation","Number too small.");
//		}
	}

	if (gMcRingSize >= 0)
		goodNum = true;
	// ### put country and units into globals as well?

	return(goodNum);
}			// validateFinalRingSize()


// check that have letter, or letter "dot" number for ring size
// returns a number for the ring size (even if started with letter)
function validateLetterSize(value, errorStrID, errorStr) {
	var ringSize = -1;
	var regExpPatt1 = /^[A-Z]\.?(\d+)?$/i;		// single letter; opt. decimal, opt. number(s)
	var regExpPatt2 = /^Z\+?(\d+)?\.?(\d+)?$/i;	// single "Z"; opt. plus, opt. number(s), opt. decimal, opt. number(s)

// + 1 or more
// * 0 or more
// ? 0 or 1
// | or
// ^ $ beginning end
// \. period
// \s whitespace
// \d digit

	value = value.toUpperCase();		// change case
	value = value.replace(/\s/g,"");	// remove whitespace

	if ( (value.search(regExpPatt1) >= 0) || (value.search(regExpPatt2) >= 0) ) {	// letter or letter/number
		// convert to number where A = 1
		ringSize = value.charCodeAt(0) - "A".charCodeAt(0) + 1;		// letter part (uppercase)

		if (value.length > 2) {		// must have letter, decimal, number; or letter, plus, number
			// and add decimal part back, if exists
			ringSize += parseFloat(value.substring(1));	// from decimal at position 1
		}

		if (errorStrID)
			replaceNodeText(errorStrID,"");	// no error message
	}
	else {							// only have number -- not right
		if (errorStrID)
			replaceNodeText(errorStrID,errorStr);		// error message
	}
	return(ringSize);
}			// validateLetterSize()


// validate that the original size is a number or character size; if not, reset to zero
function validateOriginalRingSize(value) {
	var goodNum = false;
	var country = document.getElementById("inCountry2").value;

	// this must allow a character for the size, depending on country
	gCrOrigUnits = document.getElementById("inRingUnits2").value;
	if (gkAllowLetterSize[country]) {
		// check if it is letter
		gCrOrigSize = validateLetterSize(value, "inRingSize2Validation",
			"Enter a letter, letter.number, or Z + number.");
	}
	else {		// must be number
		gCrOrigSize = validatePosNumber(value, "inRingSize2Validation",
			"Enter a number.");
//		if (gCrOrigSize < 0) {		// check min. values by country? ###
//			replaceNodeText("inRingSize2Validation","Number too small.");
//		}
	}

	if (gCrOrigSize >= 0)
		goodNum = true;

	// ### put country and units into globals as well?

	return(goodNum);
}			// validateOriginalRingSize()