if not os.loadAPI("button") then
	error("Checkers util API requires the button API by minecraftwarlock to run")
end

mon = peripheral.wrap("left")

button.default()

xSize,ySize = mon.getSize()

turn = "white"
piecesInit = false
turnNum = 1

function getKeys(tbl)
	local out = {}
	for k,v in ipairs(tbl) do
		table.insert(out,k)
	end
	return out
end

function toggleTurn()
	if turn == "white" then
		turn = "black"
	else
		turn = "white"
	end
end

function offset(x,coord)
	if string.lower(coord) == "x" then
		return math.floor(xSize / 2) + x
	elseif string.lower(coord) == "y" then
		return math.floor(ySize / 2) + x
	end
end

boardX = offset(-3,"x")
boardY = offset(-3,"y")

menuButtons = {}

pieces = {
white = {
"piece1" = {x = 1 , y = 1 , moves = 0 , taken = 0 , alive = true , king = false} , "piece2" = {x = 1 , y = 3 , moves = 0 , taken = 0 , alive = true , king = false} ,
"piece3" = {x = 1,y = 5,moves = 0,taken = 0,alive = true,king = false},"piece4" = {x = 1,y = 7,moves = 0,taken = 0,alive = true,king = false},
"piece5" = {x = 2,y = 2,moves = 0,taken = 0,alive = true,king = false},"piece6" = {x = 2,y = 4,moves = 0,taken = 0,alive = true,king = false},
"piece7" = {x = 2,y = 6,moves = 0,taken = 0,alive = true,king = false},"piece8" = {x = 2,y = 8,moves = 0,taken = 0,alive = true,king = false},
"piece9" = {x = 3,y = 1,moves = 0,taken = 0,alive = true,king = false},"piece10" = {x = 3,y = 3,moves = 0,taken = 0,alive = true,king = false},
"piece11" = {x = 3,y = 5,moves = 0,taken = 0,alive = true,king = false},"piece12" = {x = 3,y = 7,moves = 0,taken = 0,alive = true,king = false}
},
black = {
"piece13" = {x = 1,y = 1,moves = 0,taken = 0,alive = true,king = false},"piece14" = {x = 1,y = 3,moves = 0,taken = 0,alive = true,king = false},
"piece15" = {x = 1,y = 5,moves = 0,taken = 0,alive = true,king = false},"piece16" = {x = 1,y = 7,moves = 0,taken = 0,alive = true,king = false},
"piece17" = {x = 2,y = 2,moves = 0,taken = 0,alive = true,king = false},"piece18" = {x = 2,y = 4,moves = 0,taken = 0,alive = true,king = false},
"piece19" = {x = 2,y = 6,moves = 0,taken = 0,alive = true,king = false},"piece20" = {x = 2,y = 8,moves = 0,taken = 0,alive = true,king = false},
"piece21" = {x = 3,y = 1,moves = 0,taken = 0,alive = true,king = false},"piece22" = {x = 3,y = 3,moves = 0,taken = 0,alive = true,king = false},
"piece23" = {x = 3,y = 5,moves = 0,taken = 0,alive = true,king = false},"piece24" = {x = 3,y = 7,moves = 0,taken = 0,alive = true,king = false}
}
}

alive = {white = {},black = {}}
dead = {white = {},black = {}}

function getAlive()
	for i in pairs(pieces)	
		for k,v in ipairs(pieces.i) do
			if v.alive then
				table.insert(alive.i,k)
			elseif not v.alive
				table.insert(dead.i,k)
				pieces.k.alive = "false"
			end
		end
	end
end

function getRealCoords(x,y)
	return boardX + x - 1,boardY + y - 1
end

function cntrdTxt(txt,x,y)
	mon.setBackgroundColor(colors.black)
	mon.setTextColor(colors.white)
	mon.setCursorPos(offset(-1 * (math.floor(string.len(txt) / 2 + x ) - 1),"x"),1 + x)
	mon.write(txt)
end

mods = {}

function drawRow(side,x,y)
	mon.setCursorPos(x,y)
	for i=1,4 do
		if side == 1 then
			mon.setBackgroundColor(colors.red)
			mon.write(" ")
			mon.setBackgroundColor(colors.black)
			mon.write(" ")
		elseif side == 2 then
			mon.setBackgroundColor(colors.black)
			mon.write(" ")
			mon.setBackgroundColor(colors.red)
			mon.write(" ")
		end
	end
end

function board()
	local y = boardY
	for i=1,4 do
		drawRow(1,boardX,y)
		y = y + 1
		drawRow(2,boardX,y)
		y = y + 1
	end
end

function mainMenu()
	cntrdTxt("Checkers",0,0)
	button.define("lcl","Local",offset(-6,"x"),offset(-1,"y"),colors.white,colors.red,true)
	button.define("glbl","Globlal",offset(2,"x"),offset(-1,"y"),colors.lightGray,colors.gray,true)
	button.draw("all")
	button.deactivate("glbl")
	local pressed = button.click()
	button.deactivate("all")
	button.erase("all")
	return pressed
end

function findPlayer()
	local id = rednet.lookup("cg","cg")
	if type(x) == number then
		os.queueEvent("found_player",id)
	end
end
print("Checkers util API (by minecraftwarlock) loaded")

function getMods(path)
	if fs.exists(path) and fs.isDir(path) then
		local rawmods = fs.list(path)
		local mods = {}
		for index,mod in ipairs(rawmods) do
			if not fs.isDir(path.."/"..mod) then
				table.insert(mods,mod)
			end
		end
		return mods
	else 
		error("directory: "..path.." not found")
	end
end

function definePieces()
	for k,v in ipairs(pieces) do	
		if not piecesInit then	
			for key,value in ipairs(pieces.k) do
				local x1,y1 = getRealCoords(value.x,value.y)
				if not value.king then
					button.define(key,"O",x1,y1,colors.k,colors.red,false)
				else
					button.define(key,"K",x1,y1,colors.k,colors.red,false)
			end
		else
			for key,value in ipairs(dead.k) do
				button.delete(value)
			end
		end
	end
	dead = {white = {},black = {}}
end

function nextTurn()
	toggleTurn()
	getAlive()
	definePieces()
	if turnNum == 1 then
		local pieceKeys = {table.unpack(alive.white),table.unpack(alive.black)}
		button.draw(pieceKeys)
		button.deactivate("white")
	else
		if turn == "black" then
			button.draw(alive.black)
			button.deactivate(alive.white)
		else
			button.draw(alive.white)
			button.deactivate(alive.black)
		end
	end
end