CC - Fuel

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-- BY UPZONE --
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os.loadAPI("builder\\apis\\Colors")

UNLIMITED_FUEL = -1

function getFuelLevel()
    level = turtle.getFuelLevel()
    if level == "unlimited" then
        return UNLIMITED_FUEL
    else
        return level
    end
end

function getFuelLimit()
    limit = turtle.getFuelLimit()
    if limit == "unlimited" then
        return UNLIMITED_FUEL
    else
        return limit
    end
end

function requestFuel(to, startX, startY)
    -- already enough fuel
    if getFuelLevel() > to then
        return
    end

    -- over limit
    if getFuelLimit() ~= UNLIMITED_FUEL and getFuelLimit() < to then
        to = getFuelLimit()
    end

    term.setCursorPos(startX, startY)
    term.write("You need to refuel your turtle.")
    term.setCursorPos(startX, startY + 1)
    term.write("Place any fuel source into")
    term.setCursorPos(startX, startY + 2)
    term.write("the inventory to refuel ...")

    -- for string formatting
    toFuelStringSize = string.len(tostring(to))

    while getFuelLevel() < to do
        term.setCursorPos(startX, startY + 4)
        text = string.format("Fuel: [%0" .. toFuelStringSize .. "d/" .. to .. "]", getFuelLevel())
        term.blit(text, string.rep(Colors.red, string.len(text)), string.rep(Colors.black, string.len(text)))

        for i = 1, 16 do
            if turtle.getItemCount(i) > 0 then
                turtle.select(i)
                if turtle.refuel(0) then
                    turtle.refuel()
                    break
                end
            end
        end
    end
    term.setCursorPos(startX, startY + 4)
    text = string.format("Fuel: [%0" .. toFuelStringSize .. "d/" .. to .. "]", getFuelLevel())
    term.blit(text, string.rep(Colors.lime, string.len(text)), string.rep(Colors.black, string.len(text)))
    print("")
end