// pentplacer for main page



var gImages = preLoadImages("images/Pentplacer/wall.gif", "images/Pentplacer/empty.gif", "images/Pentplacer/f.gif", "images/Pentplacer/l.gif", "images/Pentplacer/i.gif", "images/Pentplacer/p.gif", "images/Pentplacer/n.gif", "images/Pentplacer/t.gif", "images/Pentplacer/u.gif", "images/Pentplacer/v.gif", "images/Pentplacer/w.gif", "images/Pentplacer/x.gif", "images/Pentplacer/y.gif", "images/Pentplacer/z.gif");

function preLoadImages() {
	var tmp = new Array();
		
	for( var i = 0; i < preLoadImages.arguments.length; i++) {
		tmp[i] = new Image();
		tmp[i].src = preLoadImages.arguments[i] ;
	}
	return tmp;

}

var gDImages = document.images;

var gPieces = new Array(12); 				

// the 12 pentominoes inof given is place on board of the
// info given is the place an the board of the other 4 squares
// after the upper-left most piece is placed
// the data was based on my first working with an 8x8 board with a border
// some work is needing in the piece placing now that the board size isi different
// it was easier(??) than a new style of data storage

	gPieces[0] = new Array (9,10,11,21, 1,9,10,20, 10,11,12,21, 10,11,19,20, 8,9,10,19, 1,11,12,21, 9,10,11,19, 9,10,20,21); //F
	gPieces[1] = new Array (10,11,12,13, 10,20,29,30, 1,2,3,13, 1,10,20,30, 1,11,21,31, 1,2,3,10, 10,20,30,31, 7,8,9,10); //L
	gPieces[2] = new Array (1,2,3,4, 10,20,30,40); //I
	gPieces[3] = new Array (1,10,11,21, 1,2,10,11, 10,11,20,21, 1,9,10,11, 1,10,11,12, 9,10,19,20, 1,2,11,12, 1,10,11,20); //P
	gPieces[4] = new Array (1,8,9,10, 10,11,21,31, 1,2,9,10, 10,20,21,31, 1,11,12,13, 10,19,20,29, 1,2,12,13, 9,10,19,29); //N
	gPieces[5] = new Array (1,2,11,21, 8,9,10,20, 10,19,20,21, 10,11,12,20); //T
	gPieces[6] = new Array (1,2,10,12, 1,11,20,21, 2,10,11,12); //U
	gPieces[7] = new Array (10,20,21,22, 1,2,10,20, 10,18,19,20, 1,2,12,22); //V
	gPieces[8] = new Array (10,11,21,22, 9,10,18,19, 1,11,12,22, 1,9,10,19); //W
	gPieces[9] = new Array (9,10,11,20); //X
	gPieces[10] = new Array (8,9,10,11, 9,10,20,30, 1,2,3,11, 10,20,21,30, 1,2,3,12, 10,11,20,30, 9,10,11,12, 10,19,20,30); //Y
	gPieces[11] = new Array (1,10,19,20, 10,11,12,22, 1,11,21,22, 8,9,10,18); //Z


var gNumCols = 8;
var gNumRows = 8;
var gMaxCols = 20;
var gMaxRows = 8;
var gBrdLen = (gMaxCols+2) * (gMaxRows+2);
var gRowOff, gColOff;
var gNumBlocked = 0;
var gEightByEight = false;
var gBlocking = false;
var gOffs = new Array(-(gMaxCols+2),gMaxCols+2, -1, 1);  // UP, DN, LT, RT

var gBrd = new Array(gBrdLen);
var gPlaced = new Array(12);
var gIntervalIDs = new Array();
var gNumIntervals = (navigator.appName=="Microsoft Internet Explorer") ? 10 : 1;
var gPNumList = new Array(12);

var gOkToGo = false;



function okPOrder() {
	var i, OK = true;
	var pStr = 'FLIPNTUVWXYZ';
	var used = new Array(12);
	
	for(i = 0; i<12; i++) {
		used[i] = false;
	}
	for(i = 0; i < 12; i++) {
		gPNumList[i] = pStr.indexOf( (eval('document.pentPlacerForm.p'+i).value).toUpperCase() ) ;
		if (gPNumList[i] < 0 || gPNumList[i] > 11 || used[gPNumList[i]]) {
			OK = false;
			gPNumList[i] = -1;
		}
		else {
			used[gPNumList[i]] = true;
		}
	}
	if (!OK) {
		alert('gotta fix some of those letters');
	}
	return OK;
}


function setPieceOrder() {
	var i,tmp, a, b, which;
	var pNames = new Array('F','L','I','P','N','T','U','V','W','X','Y','Z');
	var F=0,L=1,I=2,P=3,N=4,T=5,U=6,V=7,W=8,X=9,Y=10,Z=11;
	var how = document.pentPlacerForm.pOrder.options[document.pentPlacerForm.pOrder.selectedIndex].value ;
	
	
	gOkToGo = false;
	if (how == 'standard' || how == 'random') {
		for (i = 0; i < 12; i++) {
			gPNumList[i] = i;
		}
	}
	if (how == 'standard') {
		gOkToGo = true;
	}
	
	if (how == 'random') {
		for (i = 0; i < 100; i++) {
			a = Math.floor(12*Math.random());
			b = Math.floor(12*Math.random());
			tmp = gPNumList[a]
			gPNumList[a] = gPNumList[b];
			gPNumList[b] = tmp;
		}
		gOkToGo = true;
	}
	
	if (how =='specific') {
		gOkToGo = okPOrder()
	}
	
	for (i = 0; i<12; i++) {
		which = 'document.pentPlacerForm.p'+i; 
		eval(which).value = pNames[gPNumList[i]] ;
	}

}
	


function initBoard() {

	gRowOff = Math.floor( (gMaxRows+2 - gNumRows)/2 );
	gColOff = Math.floor( (gMaxCols+2 - gNumCols)/2 );
	// black it all out
	for (var i = 0; i < gBrdLen; i++) {
		gBrd[i] = -1;
	}
	// open board up
	for (var row = 0; row < gNumRows; row++) {
		for(var col = 0; col < gNumCols; col++) {
			gBrd[(gMaxCols+2)*(row+gRowOff) + col + gColOff] = 0;
		}
	}
	for (i = 0; i < 12; i++) {
		gPlaced[i] = false;
	}
	document.pentPlacerForm.numPlaced.value = 0;
	gNumBlocked = 0;
	gEightByEight = (gNumRows == 8);
	gBlocking = false;
	return;
}	
	
function displayBoard() {
	for (var i = 0; i < gBrdLen; i++) {
		gDImages[i].src = gImages[(gBrd[i]+1)].src;
	}
	return;

}	


function clickAt(spot) {
 	if (gBlocking && (gNumBlocked < 4) ) {
 		if (!gBrd[spot]) {
 			gNumBlocked++;
 			gBrd[spot] = -1;
 			gDImages[spot].src = gImages[0].src;
 		}
 		gBlocking = (gNumBlocked != 4);
 	}
	return;
}

function resetDoIt() {
	// set state variables
	
	doIt.spot = 0;
	doIt.pnumIndex = -1;
	doIt.orient = 0;
	doIt.stack = new Array();

	// set action words
	doIt.orienting = false;
	doIt.removing = false;
	doIt.findingPiece = false;
	doIt.findingSpot = false;
	
	// set status words
	doIt.foundSpot = false;
	doIt.foundPiece = false;
	
	return;
}

function startStop() { 
	if (document.pentPlacerForm.goButt.value == 'Start') {
		if (doIt.spot > 0) {
			setPieceOrder();
			initBoard();
			displayBoard();
		}
		if (!gOkToGo) {
				return;
		}
		resetDoIt();
		if (gEightByEight) {
			alert('please pick 4 stops to block out!!');
			gBlocking = true;
		}
		for( var i = 0 ; i<gNumIntervals; i++) {
			gIntervalIDs[i] = setInterval('doIt()', 1);
		}
		document.pentPlacerForm.goButt.value = 'Stop';
		document.pentPlacerForm.pauseButt.value = 'Pause';
	}
	else {
		for (var i = 0; i < gNumIntervals; i++ ) {
			clearInterval(gIntervalIDs[i]);
		}
		document.pentPlacerForm.goButt.value = 'Start';
		document.pentPlacerForm.pauseButt.value = 'Pause';
	}
	
	return;
	
}



function pauseResume() {
	if (document.pentPlacerForm.pauseButt.value == 'Pause') {
		for (var i = 0; i < gNumIntervals; i++ ) {
			clearInterval(gIntervalIDs[i]);
		}		
		document.pentPlacerForm.pauseButt.value = 'Resume';
	}
	else {
		for( var i = 0 ; i<gNumIntervals; i++) {
			gIntervalIDs[i] = setInterval('doIt()', 1);
		}		
		document.pentPlacerForm.pauseButt.value = 'Pause';
	}
	return;
}


/* so, the idea here is that the normal recursive thing did not 
	work since browsers in general do not let go of events until 
	they have finished so no screen display show up....
	this way,-- doing things in little bits 
		and checking back thru the setInterval 
		is a way to allow the screen to be updated
	no recursion, just putting on and popping off a stack
	not as elegant but it will display well
*/

function doIt() { 
	if (gBlocking || doIt.findingPiece || doIt.findingSpot || doIt.removing) { // in the middle of a process... come back later
		return;
	}
	
	if (!doIt.foundSpot) { // find next spot to try
		doIt.findingSpot = true;
		doIt.foundSpot = false;
		while( doIt.spot< gBrd.length && (gBrd[doIt.spot]!=0) ) {  // move past walls and already filled in spots
			doIt.spot++;
		}
		if (doIt.spot == gBrd.length) { // made it to the end
			setTimeout('alert("got one");', 5);
			for( var i = 0 ; i<gNumIntervals; i++) {
				gIntervalIDs[i] = setInterval('doIt()', 0.5);
			}
			return ;
		}
		doIt.pnumIndex = -1;
		doIt.orient = 0;
		doIt.foundSpot = true;
		doIt.findingSpot = false;
		return;
	}
	
	if (doIt.foundSpot && !doIt.foundPiece) {// found spot now find piece to try
		 doIt.findingPiece = true;
		 doIt.foundPiece = false;
		 do {
		 	doIt.pnumIndex++;
		 	doIt.pnum = gPNumList[doIt.pnumIndex];
		 } while ( (doIt.pnumIndex < 12) && gPlaced[doIt.pnum]);
		if (doIt.pnumIndex > 11) { // nothing left to try pop state
			doIt.removing = true;
			doRemove();
			doIt.removing = false;
			doIt.findingPiece = false;
			doIt.foundPiece = true;   // continue with last piece trying
			return;
		}
		 doIt.orient = 0;
		 doIt.foundPiece = true;
		 doIt.findingPiece = false;
		 return;
	}
	
	if (doIt.foundPiece) { // ok got piece now rotate it around....
		if (!doIt.orienting) { 
			if (doIt.orient < gPieces[doIt.pnum].length/4) {
				doIt.orienting = true;
				doIt.pieceList = buildList(doIt.spot, doIt.pnum, doIt.orient);
				if (canPlace(doIt.pieceList) ) { // found orientation that works now place it (on stack and on board)
					doIt.stack[doIt.stack.length] = new Array(doIt.spot, doIt.pnumIndex, doIt.orient, doIt.pieceList);
					placePiece(doIt.pnum, doIt.pieceList);
					doIt.foundSpot = false;
					doIt.orienting = false;
					doIt.foundPiece = false;
					return;
				}
				else { // done with this orientation 
					doIt.orient++;
					doIt.orienting =false;
					return;
				} 
			}
			else { // done with this piece
				doIt.orient = 0; 
				doIt.foundPiece = false;
				return;
			}
		}
		return;
	}
	return;
}

function buildList(spot, piece, orient) {
	var off, hor;
	var index = 4*orient;
	var okToPlace = true;
	var list = new Array();
	
	list[0] = spot;
	for (var i = 0; i < 4; i++) {
		off = (gMaxCols+2) * Math.floor(gPieces[piece][index+i] / 10 ) // take care of vertical stuff
		hor = (gPieces[piece][index+i] % 10)
		off += (hor<5) ? hor : (gMaxCols+2 - (10-hor) );
		list[i+1] = spot+off; 
	}
	return list;
}

function canPlace(plist) { 
	var okToPlace = true;
	
	for (var i = 0; i < 5; i++) {
		okToPlace &= (gBrd[plist[i]]==0); 
	}
	if (okToPlace && document.pentPlacerForm.smart.checked) {
		okToPlace = noHolesP(plist);
	}
	return okToPlace;
}


function noHolesP(checkAround) {
	var noHoles = true;
	var numNeigh = 0;
	var i,j,k, toCheck;
	var theEmpty = 0;
	
	// temporarily put mark on board
	for (i = 0; i < 5; i++) {
		gBrd[checkAround[i]] = 100;
	}
	
	for (i = 0; i < 5; i++) { 
		for ( j = 0; j < 4; j++) { 
			toCheck = checkAround[i] + gOffs[j];
			if ( !gBrd[toCheck] ) {
				numNeigh = 0;
				for(k = 0; k <4; k++) { 
					if (gBrd[toCheck + gOffs[k] ]) {
						numNeigh++;
					}
					else {
						theEmpty = toCheck + gOffs[k];
					}
				}
				if (numNeigh > 3) {
					noHoles = false;
				}
				if (numNeigh == 3) { // check for isolated 2 spot as well - since its easy
					numNeigh = 0;
					for(k = 0; k <4; k++) { 
						if (gBrd[theEmpty + gOffs[k] ]) {
							numNeigh++;
						}
					}
					if (numNeigh == 3) {
						noHoles = false;
					}
				}
			}
		}
	}
				
	
	// remove from board
	
	for (i = 0; i < 5; i++) {
		gBrd[checkAround[i]] = 0;
	}
		
	return noHoles;
}


function placePiece(piece, plist) { 
	
	for(var i = 0; i < 5; i++) {
		gBrd[plist[i]] = piece+1;
		gDImages[plist[i] ].src = gImages[(piece+2 )].src;
	}
	document.pentPlacerForm.numPlaced.value++;
	gPlaced[piece] = true;
	return;
}


function doRemove() {
			// pop stack then remove last piece placed
	doIt.spot = doIt.stack[doIt.stack.length-1][0];
	doIt.pnumIndex = doIt.stack[doIt.stack.length-1][1];
	doIt.pnum = gPNumList[doIt.pnumIndex];
	doIt.orient = doIt.stack[doIt.stack.length-1][2];
	removePiece(doIt.pnum, doIt.stack[doIt.stack.length-1][3]);
	doIt.stack.length--;
	doIt.orient++;
	return;
}

function removePiece(piece, plist) {  
	
	for (var i = 0; i < 5; i++){
		gBrd[plist[i]] = 0;
		gDImages[plist[i]].src = gImages[1].src;
	}
	gPlaced[piece] = false;
	return;
}
	
function setNewBoard() {
	for( var i = 0 ; i<gNumIntervals; i++) {
		clearInterval(gIntervalIDs[i]);
	}
	var num = document.pentPlacerForm.brdSize.options[document.pentPlacerForm.brdSize.selectedIndex].value ;
	gNumCols = Math.floor(num/10);
	gNumRows = num % 10;
	setPieceOrder();
	initBoard();
	displayBoard();
	resetDoIt();
	document.pentPlacerForm.goButt.value = 'Start';
	document.pentPlacerForm.pauseButt.value = 'Pause';
	return;
}