tunnel v1

term.clear()
term.setCursorPos(1, 1)
print("Place Coal in Slot 1")
print("Place at least 1 Cobblestone in Slot 2")
print("Place Torches in Slot 3")
print("Make tunnel length an even number.")
print("")
print("Enter tunnel length: ")
tunnellength = read()
term.clear()
term.setCursorPos(1,1)
print("Tunneling  " .. tunnellength .. " blocks, then returning.")
sleep(2)

local torchpos = 0

function fuelcheck()
if turtle.getFuelLevel() < 150 then
turtle.select(1)
turtle.refuel(2)
end
end

function dropcobble()
for i=4,16 do
turtle.select(i)
if turtle.compareTo(2) then
turtle.drop()
end
end
end

function minewallRight()
turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()
turtle.turnRight()
moveforward()
turtle.digDown()
turtle.digUp()
moveforward()
turtle.digDown()
turtle.digUp()
turtle.turnLeft()
torchpos = torchpos + 1
end

function minewallLeft()
turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()
turtle.turnLeft()
moveforward()
turtle.digDown()
turtle.digUp()
moveforward()
turtle.digDown()
turtle.digUp()
turtle.turnRight()
torchpos = torchpos + 1
end

function minecycle()
for z = 1, tunnellength/2 do
minewallRight()
minewallLeft()
placetorch()
end
end

function placetorch()
if torchpos % 4 == 0 then
turtle.select(3)
turtle.turnLeft()
turtle.dig()
turtle.place()
turtle.turnRight()
dropcobble()
fuelcheck()
end
end

function moveforward()
while not turtle.forward() do
turtle.dig()
end
end

function turtlehome()
for y = 1, tunnellength do
turtle.forward()
end
end

fuelcheck()
turtle.digUp()
turtle.up()
minecycle()
turtle.turnLeft()
turtle.turnLeft()
turtlehome()
turtle.down()
turtle.turnRight()
turtle.turnRight()
print("Mining Successful")