ComputerCraft StripMining Turtle

--Strip Mining Turtle Program v1.0
local Steps = 0
local Idle = true
local Returning = false

function Dig()
    turtle.dig()
    turtle.digUp()
    turtle.digDown()
end

function Refuel()
    for i=1,16 do
        turtle.select(i)
        if turtle.refuel(i) then
            turtle.refuel(i)
        end
    end
    turtle.select(1)
end

function canContinue()
    if turtle.getFuelLevel() > Steps then
        return true
    else
        Refuel()
        if turtle.getFuelLevel() > Steps then
            return true
        else
            return false
        end
    end
    return false
end

function Return()
    Returning = true
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.forward(Steps)
end

while true do
    if Idle == true then
        while turtle.getFuelLevel < 5 do
            Refuel()
        end
        Idle = false
    else
        if canContinue() then
            if turtle.detect() == false then
                turtle.forward()
                Steps = Steps + 1
            else
                Dig()
            end
        else
            Return()
            Idle = true
        end
    end
end