-- Locals Variables
local noFuelNeeded = 0 -- Check if turtle is using no fuel config
local itemFuel = turtle.getItemCount(1) -- Fuel Slot 1
local itemFuel1 = turtle.getItemCount(2) -- Fuel Slot 2
local chest = turtle.getItemCount(3) -- Chest Slot 3
local distance = 0 -- Distance will dig
local distanceCount = 0 -- Count the distance
local missingFuel = 0 -- If there is missing fuel this will be 1
local missingChest = 0 -- If there is missing chest this will be 1

-- Checking On Items
local function checking()
    if noFuelNeeded == 0 then
        if itemFuel == 0 then
            missingFuel = 1
        else
            missingFuel = 0
        end
    end
    if chest == 0 then
        missingChest = 1
    else
        missingChest = 0
    end
    if missingFuel == 1 then
        print("Missing Fuel in Slot 1")
    end
    if missingChest == 1 then
        print("Missing Chest in Slot 3")
    end
end

local function recheck()
    itemFuel = turtle.getItemCount(1)
    itemFuel1 = turtle.getItemCount(2)
    chest = turtle.getItemCount(3)
end

local function reFuel()
    if noFuelNeeded == 0 then
        repeat
            if turtle.getFuelLevel() < 120 then
                if itemFuel > 1 then
                    turtle.select(1)
                    turtle.refuel(1)
                    itemFuel = itemFuel - 1
                    turtle.select(4)
                elseif itemFuel1 > 1 then
                    turtle.select(2)
                    turtle.refuel(1)
                    itemFuel1 = itemFuel1 - 1
                    turtle.select(4)
                else
                    print("out of fuel")
                    os.shutdown()
                end
            end
        until turtle.getFuelLevel() >= 120
    end
end

local function dig()
    turtle.dig()
    turtle.forward()
    turtle.turnLeft()
    turtle.dig()
    turtle.turnRight()
    turtle.turnRight()
    turtle.dig()
    turtle.digUp()
    turtle.up()
    turtle.dig()
    turtle.turnRight()
    turtle.turnRight()
    turtle.dig()
    turtle.digUp()
    turtle.up()
    turtle.dig()
    turtle.turnRight()
    turtle.turnRight()
    turtle.dig()
    turtle.down()
    turtle.down()
    turtle.turnLeft()
end

local function chestDump()
    if turtle.getItemCount(16)> 0 then -- If slot 16 in turtle has item slot 4 to 16 will go to chest
        if Chest ~= 0 then
            turtle.select(3)
            turtle.digDown()
            turtle.placeDown()
            for slot = 4, 16 do
                turtle.select(slot)
                sleep(0.6) -- Small fix for slow pc because i had people problem with this
                turtle.dropDown()
            end
        turtle.select(4)
        else
            print("Out Of Chest")
            os.shutdown()
        end
    end
end

function main()
    repeat
        reFuel()
        dig()
        distanceCount = distanceCount + 1
        chestDump()
    until distance == distanceCount
end

function start()
    print("Welcome!")
    print("This 3x3 Tunnel Program 4x4 is coming soon after this one is done")
    print("Please input your fuel in slot 1 and optionally also in slot 2 and chests in Slot 3")
    print("Please Input Your Distance You Want Turtle To Dig")
    input = io.read()
    distance = tonumber(input)
    print("Turtle Will Dig " .. distance .. " Long")
    if turtle.getFuelLevel() == "unlimited" then -- just check if config of fuel is to unlimited
    noFuelNeeded = 1
    end
    checking()
    if missingFuel == 1 or missingChest == 1 then
        repeat
            print("Please Put In Items That Are Missing")
            sleep(10)
            recheck()
            checking()
        until missingFuel == 0 and missingChest == 0
    end
    main()
end

start()