v4

term.clear()
term.setCursorPos(1, 1)

repeat
print("Enter tunnel length (even digit): ")
tunnellength = read()
until tunnellength % 2 == 0

term.clear()
term.setCursorPos(1, 1)

print("Place Fuel in Slot 1")
print("Enter number for fuel type: ")
print("")
print("No Fuel Required = 0")
print("Coal/Charcoal/Peat = 1")
print("Coal Coke = 2")
print("Biofuel Can = 3 **")
print("Coalfuel Can = 4 **")
print("** Ensure these work in your version")
fueltype = read()

function fueltypeset()
if fueltype == "1" then
fueltype = 80
elseif fueltype == "2" then
fueltype = 160
elseif fueltype == "3" then
fueltype = 520
elseif fueltype == "4" then
fueltype = 1520
end
end
fueltypeset()
term.clear()
term.setCursorPos(1, 1)

print("Drop mined cobblestone? 0=No, 1=Yes")
cobblesetting = read()
term.clear()
term.setCursorPos(1, 1)
if cobblesetting == "1" then
if turtle.getItemCount(2) < 1 then
print("Place 1 cobblestone in Slot 2")
print("")
end
end

print("Place torches? 0=No, 1=Yes")
print("Place torches in Slot 3")
torchsetting = read()
term.clear()
term.setCursorPos(1, 1)
if torchsetting == "1" then
if turtle.getItemCount(3) < tunnellength/4 then
print("Warning: You will not have enough torches for entire tunnel length.")
print("")
print("")
end
end


print("Return and deposit items to chest if inventory nears full?")
print("0=No, 1=Yes")
returnsetting  = read()
term.clear()
term.setCursorPos(1, 1)
if returnsetting == "1" then
print("Place chest immediately behind turtle.")
print("")
end

print("Deposit inventory into chest upon completion?")
print("0=No, 1=Yes")
dcomplete  = read()
term.clear()
term.setCursorPos(1, 1)
if dcomplete == "1" then
print("Place chest immediately behind turtle.")
print("")
end

print("Terminate program once length is reached?")
print("Note: This will prevent the turtle from depositing items into a chest upon completion.")
print("0=No, 1=Yes")
tcomplete  = read()
term.clear()
term.setCursorPos(1, 1)
if tcomplete == "1" then
        if dcomplete == "1" then
        print("Turtle will NOT deposit items upon completion.")
 print("")
end
end

print("")
print("Begin mining?")
print("0=Cancel Program, Any Key=Yes")
beginmine = read()
if beginmine == "0" then
os.reboot()
end

term.clear()
term.setCursorPos(1,1)
if tcomplete == "1" then
  print("Tunneling " .. tunnellength .. " blocks, then terminating.")
  elseif tcomplete == "0" then
  print("Tunneling " .. tunnellength .. " blocks, then returning.")
end
sleep(2)

torchpos = 0

function progress()
term.setCursorPos(1,3)
print("Progress: " .. torchpos .. " of " .. tunnellength)
end

function fuelcheck()
        if turtle.getFuelLevel() ~= "unlimited" then
                if turtle.getFuelLevel()/fueltype < 0.26 then
                turtle.select(1)
                turtle.refuel(1)
                end
        end
end

function dropcobble()
    local stackSize = turtle.getItemCount(2)
        if cobblesetting == "1" then
                if turtle.getFuelLevel() ~= "unlimited" then
                        if stackSize > 2 then
                        stackSize = stackSize-1
                        turtle.select(2)
                        turtle.drop(stackSize)
                        end
                elseif turtle.getFuelLevel() == "unlimited" then
                        if stackSize > 2 then
                                stackSize = stackSize-1
                                turtle.select(2)
                                turtle.drop(stackSize)
                                end
                        turtle.select(1)
                        if turtle.compareTo(2) then
                                turtle.drop()
                                end

                        end
                end
end


function minewallRight()
fuelcheck()
turtle.select(1)
turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()
turtle.turnRight()
moveforward()
turtle.digDown()
turtle.digUp()
moveforward()
turtle.digDown()
turtle.digUp()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.turnLeft()
torchpos = torchpos + 1
progress()
end

function minewallLeft()
fuelcheck()
turtle.select(1)
turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()
turtle.turnLeft()
moveforward()
turtle.digDown()
turtle.digUp()
moveforward()
turtle.digDown()
turtle.digUp()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()

turtle.dig()
moveforward()
turtle.digUp()
turtle.digDown()


turtle.turnRight()
torchpos = torchpos + 1
progress()
end

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

function placetorch()
        if torchsetting == "1" then
                if torchpos % 4 == 0 then
                turtle.turnLeft()
                turtle.dig()
                turtle.select(3)
                turtle.place()
                turtle.turnRight()
                dropcobble()
                fuelcheck()
                fullinventory()
                turtle.select(1)
                end
        else
                if torchpos % 4 == 0 then
                dropcobble()
                fuelcheck()
                fullinventory()
                turtle.select(1)
                end
        end
end

function moveforward()
while not turtle.forward() do
sleep(0.25)
turtle.dig()
end
end

function turtlehome()
for y = 1, tunnellength do
fuelcheck()
moveforward()
end
end


function fullinventory()
local invcount = 0
        if returnsetting == "1" then
                for c = 4, 16 do
                        if turtle.getItemCount(c) > 0 then
                        invcount = invcount+1
                        end
                end
                if invcount > 12 then
                        turtle.turnLeft()
                        turtle.turnLeft()
                        fuelcheck()
                        for f = 1, torchpos+1 do
                        moveforward()
                        fuelcheck()
                        end
                        for d = 4, 16 do
                        turtle.select(d)
                        turtle.dropDown()
                        end
                        turtle.turnLeft()
                        turtle.turnLeft()
                        fuelcheck()
                        for f = 1, torchpos+1 do
                        moveforward()
                        fuelcheck()
                        end
                        invcount = 0
                else
                        invcount = 0
                end
        end
end

function depositcomplete()
        if dcomplete == "1" then
                for d = 1, 16 do
                        turtle.select(d)
                        turtle.drop()
                end
        end
end

function terminatecomplete()
        if tcomplete =="1" then
                turtle.down()
                os.reboot()
  sleep(3)
        end
end

fuelcheck()
turtle.digUp()
turtle.up()
minecycle()
terminatecomplete()
turtle.turnLeft()
turtle.turnLeft()
fuelcheck()
turtlehome()
turtle.down()
depositcomplete()
turtle.turnRight()
turtle.turnRight()
term.setCursorPos(1,5)
print("Mining Successful")
term.setCursorPos(1,7)