local params = {...}

-- Validade Params
if(tonumber(params[1]) < 1) then
	term.write("Param [".. params[1] .."] is invalid")
	return
elseif(tonumber(params[2]) < 1) then
	term.write("Param [".. params[2] .."] is invalid")
	return
elseif(tonumber(params[3]) < 1) then
	term.write("Param [".. params[3] .."] is invalid")
	return
end
params[1] = tonumber(params[1])
params[2] = tonumber(params[2])
params[3] = tonumber(params[3])

-- Variables
local posX = 0
local posY = 0
local posZ = 0
local rot = 0
-- 0 = forward
-- 1 = right
-- 2 = back
-- 3 = left

local turn = 0;

-- Moviment
function DirectionOperator()
	if(rot < 2) then
		return 1;
	else
		return -1;
	end
end

function Forward()
	if(turtle.forward()) then
		if(rot == 0) then
			posZ = posZ + 1;
		elseif(rot == 1) then
			posX = posX - 1;
		elseif(rot == 2) then
			posZ = posZ - 1;
		elseif(rot == 3) then
			posX = posX + 1;
		end
	end
end

function Right()
	turtle.turnRight()
	rot = rot + 1
	if(rot > 3) then
		rot = 0
	end
end

function Left()
	turtle.turnLeft()
	rot = rot - 1
	if(rot < 0) then
		rot = 3
	end
end

function Up()
	if(turtle.up()) then
		posY = posY + 1
	end
end

function Down()
	if(turtle.down()) then
		posY = posY - 1
	end
end

-- Functions
function Dig()
	if(posY + 1 < params[2]) then
		turtle.digUp()
	end
	if(posY - 1 >= 0) then
		turtle.digDown()
	end
	if(rot == 0) then
		if(posZ + 1 <= params[3]) then
			turtle.dig()
		end
	elseif(rot == 2) then
		if(posZ - 1 > 0) then
			turtle.dig()
		end
	end
end

function EndRowRight()
	Right()
	turtle.dig()
	Forward()
	Right()
end

function EndRowLeft()
	Left()
	turtle.dig()
	Forward()
	Left()
end

function EndLevel()
	-- +1 already digged, +2 wont dig up, +3 will dig up
	if(posY + 3 < params[2]) then
		Up()
		turtle.digUp()
		Up()
		turtle.digUp()
		Up()
	elseif(posY + 2 < params[2]) then
		Up()
		turtle.digUp()
		Up()
	else
		return
	end
	Right()
	Right()
end

function NextTurn()
	if(turn == 0) then
		if(posZ == params[3] or posZ == 1) then
			EndRowLeft()
			turn = 1
			--print("Turn set to 1")
		end
	else
		if(posZ == params[3] or posZ == 1) then
			EndRowRight()
			turn = 0
			--print("Turn set to 0")
		end
	end
end

-- Dig Loop
--::dig::

local levels = math.ceil(params[2] / 3)
if(params[2] > 1) then
	turtle.digUp()
	Up()
end
turtle.dig()
Forward()

for loopY = 1, levels do
	for loopX = 1, params[1] do
		for loopZ = 1, (params[3] - 1) do
			Dig()
			Forward()
			--print(loopZ .." ".. params[3] .." | ".. posX .." ".. posZ)
		end
		if(posY + 1 < params[2]) then
			turtle.digUp()
		end
		if(posY - 1 >= 0) then
			turtle.digDown()
		end

		if(loopX ~= params[1]) then
			--print("NextTurn")
			NextTurn()
		end
	end
	if(loopY ~= levels) then
		EndLevel()
	end
end