-- Tower of Hanoi Puzzle
-- By Andy Kemp (c) 2011
-- Tower of Hanoi Simulation by Andy Kemp is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
-- http://creativecommons.org/licenses/by-nc-sa/3.0/

gc=platform.gc()
disks={{},{},{}}
nodisks=5
Disk = class()
x=0
y=0
moves=0
top={}
pass=0
auto=0
shuffle=0

function on.create()
	h=platform.window:height()
	w=platform.window:width()
	cursor.show()
	diskwidth=math.floor((w-20)/3)
	diskheight=math.floor((h-12)/10)
	reset()
end

function on.paint(gc)
--drawspindles
	drawspindle(gc,1)
	drawspindle(gc,2)				
	drawspindle(gc,3)
	gc:setColorRGB(139,69,19)
	gc:fillRect(5,h-10,3*diskwidth+10,5)

--Draw disks
	for i=1,3 do
		for j=1,table.getn(disks[i]) do
		Disk:draw(gc,i,disks[i][j],j)
		if disks[i][j]=="p" and moving==1 then
			Disk:moving(gc,x,y,movingsize)
		end
	end	
	
-- text Moves
	gc:setColorRGB(0,0,0)
	gc:setFont("sansserif","r",12)	
	if auto~=1 then
	strwidth = gc:getStringWidth("Moves: "..moves)
	gc:drawString("Moves: "..moves,w-10-strwidth,20)
	else
	strwidth = gc:getStringWidth("Auto-Complete Mode")
	gc:drawString("Auto-Complete Mode",w-10-strwidth,20)	
	end
	end

-- End of Game
	if puzzlecomplete==1 then
		gc:setFont("sansserif","r",10)	
		gc:setColorRGB(255, 255, 255)
		gc:fillRect(w/2-150,h/2-30,300,60)	
		gc:setColorRGB(0, 0, 0)
		gc:setPen("thick","smooth")
		gc:drawRect(w/2-150,h/2-30,300,60)
		if shuffle==1 then
			strwidth = gc:getStringWidth("Well Done! You completed it in "..moves.. " moves!")
			strheight = gc:getStringHeight("Well Done! You completed it in "..moves.. " moves!")
			gc:drawString("Well Done! You completed it in "..moves.. " moves!",w/2-strwidth/2,h/2,"middle")	
		else
		strwidth = gc:getStringWidth("Well Done! You completed it in "..moves.. " moves!")
		strheight = gc:getStringHeight("Well Done! You completed it in "..moves.. " moves!")
		gc:drawString("Well Done! You completed it in "..moves.. " moves!",w/2-strwidth/2,h/2-strheight/2,"middle")
		if moves == 2^(nodisks)-1 then
		strwidth = gc:getStringWidth("This is the minimum number of moves!!")
		gc:drawString("This is the minimum number of moves!!",w/2-strwidth/2,h/2+strheight/2,"middle")
		else
			if moves - (2^(nodisks)-1) == 1 then
			strwidth = gc:getStringWidth("But it can be done in ".. moves-(2^(nodisks)-1).." fewer moves!")
			gc:drawString("But it can be done in ".. moves-(2^(nodisks)-1).." fewer move!",w/2-strwidth/2,h/2+strheight/2,"middle")				
			else
			strwidth = gc:getStringWidth("But it can be done in ".. moves-(2^(nodisks)-1).." fewer moves!")
			gc:drawString("But it can be done in ".. moves-(2^(nodisks)-1).." fewer moves!",w/2-strwidth/2,h/2+strheight/2,"middle")
			end
		end
		end
	end
	
-- About Screen

if about==1 then
	gc:setFont("sansserif","r",10)	
	gc:setColorRGB(255, 255, 255)
	gc:fillRect(w/2-150,h/2-30,300,60)	
	gc:setColorRGB(0, 0, 0)
	gc:setPen("thick","smooth")
	gc:drawRect(w/2-150,h/2-30,300,60)
	strwidth = gc:getStringWidth("Tower of Hanoi")
	strheight = gc:getStringHeight("Tower of Hanoi")
	gc:drawString("Tower of Hanoi",w/2-strwidth/2,h/2-strheight/2,"middle")

	strwidth = gc:getStringWidth("By Andy Kemp (c) 2011")
	gc:drawString("By Andy Kemp (c) 2011",w/2-strwidth/2,h/2+strheight/2,"middle")

end
end

function on.mouseDown(mx,my)
if auto~=1 then

if puzzlecomplete==1 then
	puzzlecomplete=0
	reset()
elseif moving==1 then
	if mx>10 and mx<10+diskwidth then--first spindle
		topdisk = findtopdisk(1)		
	if disks[1][1]=="p" or disks[1][1]==0 then
		if disks[1][1]==0 then
			moves=moves+1
			document.markChanged()
		end
		disks[spindle][oldpos]=0
		disks[1][1]=movingsize	
		moving=0		
		platform.window:invalidate()	
	elseif movingsize>disks[1][topdisk] then
		if disks[1][topdisk]==0 then
			topdisk=0
		end
		if disks[1][topdisk+1]~="p" then
			moves=moves+1
			document.markChanged()
		end
		disks[spindle][oldpos]=0
		disks[1][topdisk+1]=movingsize
		moving=0
		platform.window:invalidate()
	end
	elseif mx>10+diskwidth and mx<10+2*diskwidth  then--second spindle
		topdisk = findtopdisk(2)
		if disks[2][1]=="p" or disks[2][1]==0 then
			if disks[2][1]==0 then
				moves=moves+1
				document.markChanged()
			end
			disks[spindle][oldpos]=0
			disks[2][1]=movingsize	
			moving=0	
			platform.window:invalidate()	
		elseif movingsize>disks[2][topdisk] then
			if disks[2][topdisk]==0 then
				topdisk=0
			end
			if disks[2][topdisk+1]~="p" then
				moves=moves+1
				document.markChanged()
			end
		disks[spindle][oldpos]=0
		disks[2][topdisk+1]=movingsize
		moving=0
		platform.window:invalidate()
		end
	elseif mx>10+2*diskwidth and mx<10+3*diskwidth then--third spindle
		topdisk = findtopdisk(3)
			if disks[3][1]=="p" or disks[3][1]==0 then
				if disks[3][1]==0 then
					moves=moves+1
					document.markChanged()
			end
			disks[spindle][oldpos]=0
			disks[3][1]=movingsize
			moving=0
			platform.window:invalidate()
		elseif movingsize>disks[3][topdisk] then
			if disks[3][topdisk]==0 then
				topdisk=0
			end
			if disks[3][topdisk+1]~="p" then
				moves=moves+1
				document.markChanged()
			end
		disks[spindle][oldpos]=0
		disks[3][topdisk+1]=movingsize
		moving=0
		platform.window:invalidate()
	end
	end	
else
	if mx>10 and mx<10+diskwidth then--first spindle
		topdisk = findtopdisk(1)
		if topdisk~=0 then
		topdiskwidth = diskwidth*0.8^(disks[1][topdisk]-1)
			if (my>h-10-diskheight*topdisk and my<h+10-diskheight*(topdisk-1)) and (mx>10+(diskwidth-topdiskwidth)/2 and mx<10+(diskwidth-topdiskwidth)/2+topdiskwidth) then
				movingsize=disks[1][topdisk]
				disks[1][topdisk]="p"
				spindle=1
				oldpos=topdisk
				xoff=mx-(10+(diskwidth-topdiskwidth)/2)
				yoff=my-(h+10-diskheight*topdisk)
				moving=1
				cursor.set("drag grab")
		end
		end
	elseif mx>10+diskwidth and mx<10+2*diskwidth  then--second spindle
		topdisk = findtopdisk(2)
		if topdisk~=0 then
		topdiskwidth = diskwidth*0.8^(disks[2][topdisk]-1)
			if (my>h-10-diskheight*topdisk and my<h+10-diskheight*(topdisk-1)) and (mx>10+diskwidth+(diskwidth-topdiskwidth)/2 and mx<10+diskwidth+(diskwidth-topdiskwidth)/2+topdiskwidth) then
				movingsize=disks[2][topdisk]
				disks[2][topdisk]="p"
				spindle=2
				oldpos=topdisk
				xoff=mx-(10+diskwidth+(diskwidth-topdiskwidth)/2)
				yoff=my-(h+10-diskheight*topdisk)
				moving=1
				cursor.set("drag grab")
			end
		end
	elseif mx>10+2*diskwidth and mx<10+3*diskwidth then--third spindle
		topdisk = findtopdisk(3)
		if topdisk~=0 then
		topdiskwidth = diskwidth*0.8^(disks[3][topdisk]-1)
			if (my>h-10-diskheight*topdisk and my<h+10-diskheight*(topdisk-1)) and (mx>10+2*diskwidth+(diskwidth-topdiskwidth)/2 and mx<10+2*diskwidth+(diskwidth-topdiskwidth)/2+topdiskwidth) then
				movingsize=disks[3][topdisk]
				disks[3][topdisk]="p"
				spindle=3
				oldpos=topdisk
				xoff=mx-(10+2*diskwidth+(diskwidth-topdiskwidth)/2)
				yoff=my-(h+10-diskheight*topdisk)
				moving=1
				cursor.set("drag grab")
			end
		end
	end
end


if disks[2][nodisks]==nodisks or disks[3][nodisks]==nodisks then
	puzzlecomplete = 1
end
end
end


function Disk:draw(gc,spindle,disksize, diskpos)
		setdiskcolour(gc,disksize)
if disksize~=0 and disksize~="p" then
		gc:fillRect((spindle-1)*diskwidth+10+(diskwidth - (0.8^(disksize-1))*diskwidth)/2,h-10-diskheight*diskpos,(0.8^(disksize-1))*diskwidth,diskheight)
		gc:setColorRGB(0,0,0)
		gc:drawRect((spindle-1)*diskwidth+10+(diskwidth - (0.8^(disksize-1))*diskwidth)/2,h-10-diskheight*diskpos,(0.8^(disksize-1))*diskwidth,diskheight)
end
end

function Disk:moving(gc,x,y,disksize)
		setdiskcolour(gc,disksize)
		gc:fillRect(x-xoff,y-20-yoff,(0.8^(disksize-1))*diskwidth,diskheight)
		gc:setColorRGB(0,0,0)
		gc:drawRect(x-xoff,y-20-yoff,(0.8^(disksize-1))*diskwidth,diskheight)
end

function on.mouseMove(mx,my)
topdisk=nil
if moving==1 then
	x = mx
	y = my
	cursor.set("drag grab")
	platform.window:invalidate()
elseif mx>10 and mx<10+diskwidth then--first spindle
		topdisk=findtopdisk(1)
		if topdisk~=0 then -- check there is a disk on the spindle
		topdiskwidth = diskwidth*0.8^(disks[1][topdisk]-1)
		if (my>h-10-diskheight*topdisk and my<h-10-diskheight*(topdisk-1)) and (mx>10+(diskwidth-topdiskwidth)/2 and mx<10+(diskwidth-topdiskwidth)/2+topdiskwidth) then
			cursor.set("hand open")
		end
		end
elseif mx>10+diskwidth and mx<10+2*diskwidth  then--second spindle
		topdisk=findtopdisk(2)
		if topdisk~=0 then -- check there is a disk on the spindle
		topdiskwidth = diskwidth*0.8^(disks[2][topdisk]-1)
			if (my>h-10-diskheight*topdisk and my<h+10-diskheight*(topdisk-1)) and (mx>10+diskwidth+(diskwidth-topdiskwidth)/2 and mx<10+diskwidth+(diskwidth-topdiskwidth)/2+topdiskwidth) then
				cursor.set("hand open")
			end
		end
elseif mx>10+2*diskwidth and mx<10+3*diskwidth then--third spindle
		topdisk=findtopdisk(3)
		if topdisk~=0 then -- check there is a disk on the spindle
		topdiskwidth = diskwidth*0.8^(disks[3][topdisk]-1)
			if (my>h-10-diskheight*topdisk and my<h+10-diskheight*(topdisk-1)) and (mx>10+2*diskwidth+(diskwidth-topdiskwidth)/2 and mx<10+2*diskwidth+(diskwidth-topdiskwidth)/2+topdiskwidth) then
				cursor.set("hand open")
			end	
		end
else
	cursor.set("default")
end
end

function drawspindle(gc,spindle)
	gc:setColorRGB(139,69,19)
	gc:fillRect((spindle-1)*diskwidth+5+diskwidth/2,30,10,h-40)
end	

function reset()
toolpalette.enable("Puzzle", "Auto-Complete", true) -- enable the autocomplete command
timer.stop() -- check the timer is stopped
disks={{},{},{}} -- clear the grid
	for j=1,nodisks do -- set the disks
		disks[1][j]=j
		disks[2][j]=0
		disks[3][j]=0
	end
	shuffle=0
	moves=0
	pass=0
	cursor.show()
	platform.window:invalidate()
end

function on.enterKey()
	if puzzlecomplete==1 then
		puzzlecomplete=0
		reset()
	end
end

function on.escapeKey()
	if puzzlecomplete==1 then
		puzzlecomplete=0
		reset()
	end
	if auto==1 then
		auto=0
		timer.stop()
		reset()
	end
end

function on.resize(width,height)
	w=width
	h=height
	diskwidth=math.floor((w-20)/3)
	diskheight=math.floor((h-12)/10)
end

function nextMove()
-- a messy auto-complete algorithm!
if disks[2][nodisks]~=nodisks and disks[3][nodisks]~=nodisks then

	if math.floor(nodisks/2)==nodisks/2 then -- find the parity of the disks
		parity = 0
	else
		parity = 1
	end

top1 = findtopdisk(1)
top2 = findtopdisk(2)
top3 = findtopdisk(3)

sp1top = disks[1][top1]
sp2top = disks[2][top2]
sp3top = disks[3][top3]

if sp1top==nil then
	sp1top = 0
end

if sp2top==nil then
	sp2top = 0
end

if sp3top==nil then
	sp3top = 0
end

if parity == 0 then
	--make the legal move between pegs A and B
	--make the legal move between pegs A and C
	--make the legal move between pegs B and C
	--repeat
if pass==0 then
	if sp1top>sp2top then
		moveddisk = disks[1][top1]
		disks[1][top1]=0
		disks[2][top2+1]=moveddisk
		pass=(pass+1)%3
	else
		moveddisk = disks[2][top2]
		disks[2][top2]=0
		disks[1][top1+1]=moveddisk
		pass=(pass+1)%3
	end
elseif pass==1 then				
	if sp1top>sp3top then
		moveddisk = disks[1][top1]
		disks[1][top1]=0
		disks[3][top3+1]=moveddisk
		pass=(pass+1)%3
	else
		moveddisk = disks[3][top3]
		disks[3][top3]=0
		disks[1][top1+1]=moveddisk
		pass=(pass+1)%3
	end	
elseif pass==2 then
	if sp2top>sp3top then
		moveddisk = disks[2][top2]
		disks[2][top2]=0
		disks[3][top3+1]=moveddisk
		pass=(pass+1)%3
	else
		moveddisk = disks[3][top3]
		disks[3][top3]=0
		disks[2][top2+1]=moveddisk	
		pass=(pass+1)%3	
	end
end

elseif parity == 1 then
	--make the legal move between pegs A and C
	--make the legal move between pegs A and B
	--make the legal move between pegs B and C
	--repeat
	if pass==0 then
		if sp1top>sp3top then
			moveddisk = disks[1][top1]
			disks[1][top1]=0
			disks[3][top3+1]=moveddisk
			pass=(pass+1)%3
		else
			moveddisk = disks[3][top3]
			disks[3][top3]=0
			disks[1][top1+1]=moveddisk
			pass=(pass+1)%3
		end
	elseif pass==1	then			
		if sp1top>sp2top then
			moveddisk = disks[1][top1]
			disks[1][top1]=0
			disks[2][top2+1]=moveddisk
			pass=(pass+1)%3
		else
			moveddisk = disks[2][top2]
			disks[2][top2]=0
			disks[1][top1+1]=moveddisk
			pass=(pass+1)%3
		end	
	elseif pass==2 then
		if sp2top>sp3top then
			moveddisk = disks[2][top2]
			disks[2][top2]=0
			disks[3][top3+1]=moveddisk
			pass=(pass+1)%3
		else
			moveddisk = disks[3][top3]
			disks[3][top3]=0
			disks[2][top2+1]=moveddisk
			pass=(pass+1)%3		
		end
	end

end
else
	auto=0
	reset()
	timer.stop()
end

end

function on.timer()
	if auto==1 then
		nextMove()
		platform.window:invalidate()
	end
	if about==1 then
		about = 0
		timer.stop()
		platform.window:invalidate()
	end
end

function shuffledisks()
shuffle=1
platform.window:invalidate()
--math.randomseed(os.time()) -- seed random number generator
toolpalette.enable("Puzzle", "Auto-Complete", false) -- disable auto-complete when in random mode as it fails!
disks={{},{},{}} -- clear the grid
for i=1,nodisks do -- zero the grid
	disks[1][i]=0
	disks[2][i]=0
	disks[3][i]=0
end

for i=1,nodisks do
	spindle=math.random(1,3)
	topdisk = findtopdisk(spindle)
	disks[spindle][topdisk+1]=i
end

platform.window:invalidate()
end	

function findtopdisk(spindle)			
topdisk=0
	for j=1,nodisks do
		if disks[spindle][j]~=0 and disks[spindle][j]~="p" then
		topdisk=j
		end
	end
return topdisk
end

function setdiskcolour(gc,disksize)
	if disksize==1 then
		gc:setColorRGB(255,0,0)
	elseif disksize==2 then
		gc:setColorRGB(0,255,0)	
	elseif disksize==3 then
		gc:setColorRGB(0,0,255)
	elseif disksize==4 then
		gc:setColorRGB(255,255,0)
	elseif disksize==5 then
		gc:setColorRGB(0,255,255)
	elseif disksize==6 then
		gc:setColorRGB(255,0,255)	
	elseif disksize==7 then
		gc:setColorRGB(100,0,0)
	elseif disksize==8 then
		gc:setColorRGB(0,150,0)	
	end
end

menu={
	{"Puzzle",		
		{"Reset", function() reset() end},	   
		{"Auto-Complete", function() auto=1 reset() timer.start(0.5) end},                                      
		{"Shuffle Disks", function() shuffledisks() end},   
		{"About", function() about=1 platform.window:invalidate() timer.start(4) end},   
},
	{"Disks",		
		{"3 Disks", function() nodisks=3 reset() end},	  
		{"4 Disks", function() nodisks=4 reset() end},	 
		{"5 Disks", function() nodisks=5 reset() end},	 
		{"6 Disks", function() nodisks=6 reset() end},	 
		{"7 Disks", function() nodisks=7 reset() end},	 
		{"8 Disks", function() nodisks=8 reset() end},	                                         
},
}	
toolpalette.register(menu)