term.write("Please place ladders in slot 1")
read()
term.write("Please place chests in slot 2")
read()
term.write("Please place torches in slot 3")
read()
term.write("Enter Current Turtle height!")
height = read()
term.write("Enter Tunnel length!")
length = read()
startFuelLevel = turtle.getFuelLevel()
blockMovedForward = 0

function moveForward()
    turtle.forward();
end

function moveBackward()
    turtle.back();
end

function moveUp()
    turtle.up();
end

function moveDown()
    turtle.down();
end

function digFront()
    while turtle.detect() do
        turtle.dig()
        sleep(1)
    end
end

function digUp()
    while turtle.detectUp() do
        turtle.digUp()
        sleep(1)
    end
end

function digDown()
    while turtle.detectDown() do
        turtle.digDown()
        sleep(1)
    end
end

function getFuelLevel()
    return turtle.getFuelLevel()
end

function placeTorch()
    turtle.turnLeft()
    turtle.select(3)
    turtle.place()
    turtle.turnRight()
end

function placeChest()
    turtle.select(2)
    turtle.placeDown()
    for i=4, 17 do
        turtle.select(i)
        turtle.dropDown()
    end
end

function placeLadder()
    turtle.select(1)
    turtle.placeDown()
end

function main()
    for i=14,height do
        digDown()
        moveDown()
        sleep(1)
    end
    ran = 0
    print("Used "..startFuelLevel-getFuelLevel())
    while getFuelLevel() > startFuelLevel/2 do
        turtle.select(2)
        for i=0, 2 do
            digFront()
            moveForward()
            digUp()
            digDown()
            if ran >= 10 then
                ran = 0
                placeTorch()
                placeChest()
            end
        end
        blockMovedForward = blockMovedForward + 2
        turtle.turnLeft()
        for i=0, length do
            digFront()
            moveForward()
            digUp()
            digDown()
        end
        turtle.turnLeft()
        turtle.turnLeft()
        for i=0, length do
            moveForward()
        end
        for i=0, length do
            digFront()
            moveForward()
            digUp()
            digDown()
        end
        turtle.turnLeft()
        turtle.turnLeft()
        for i=0, length do
            moveForward()
        end
        turtle.turnRight()
        term.write(getFuelLevel()/2.." Fuel Units left")
        ran = ran+1
    end
    term.write("Returning Home!")
    turtle.turnLeft()
    turtle.turnLeft()
    for i=0, blockMovedForward do
        digFront()
        moveForward()
    end
    for i=14, height do
        moveUp()
        placeLadder()
    end
    term.write("Used a total of "..startFuelLevel-getFuelLevel().." Fuel Units")
end
main()