minetorch2.lua

MaxTorchDistance = 14

function getIndexOf(item)
    for i = 1, 16 do
        local current = turtle.getItemDetail(i, false)
        if current ~= nil then
            print(current["name"])
            if current["name"] == item then
                return i
            end
        end
    end

    return -1
end

function refuel()
    if turtle.getFuelLevel() == 0 then
        for i = 1, 16 do
            turtle.select(i)
            if turtle.refuel(0) then
                return true
            end
        end

        print("No fuel found!")
        return false
    else
        return true
    end
end

function goBack(distance)
    turtle.turnLeft()
    turtle.turnLeft()

    for _ = 1, distance do
        turtle.forward()
    end
end

function mineVerticalStrip()
    turtle.dig()
    turtle.forward()
    turtle.digDown()
    turtle.digUp()
end

function main()
    local distance = 0
    local torchDistance = 0
    local indexOfTorches = getIndexOf("minecraft:torch")

    if indexOfTorches == -1 then
        print("No torches found!")
        return
    end

    if indexOfTorches ~= 1 then
        turtle.select(indexOfTorches)
        turtle.transferTo(1)
    end

    while true do
        if refuel() then
            indexOfTorches = getIndexOf("minecraft:torch")
            if indexOfTorches == -1 then
                print("Ran out of torches!")
                break
            end

            mineVerticalStrip()
            distance = distance + 1

            torchDistance = torchDistance + 1
            if torchDistance == MaxTorchDistance then
                turtle.placeDown()
                torchDistance = 0
            end

            turtle.turnRight()
            mineVerticalStrip()

            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()

            mineVerticalStrip()
            turtle.turnRight()
            turtle.turnRight()
            turtle.forward()
            turtle.turnLeft()
        else
            print("Ran out of fuel!")
            break
        end
    end

    if distance ~= 0 then
        goBack()
    end
end

main()