Kelp farm auto-smelter

local version = 20240122.1500
-- https://www.youtube.com/watch?v=i-eBj0qLmRU
--[[
    |S|T|C|     S = smoker, T = turtle, C = chest/barrel (for crafted dried kelp blocks)
    |H|C|       H = hopper, C= single or double chest (could also use barrel
    Script for turtle placed next to a smoker / furnace
    SuckDown output from smoker which is a chest below
    Craft dried kelp into dried kelp blocks
    if fuel required place into smoker on the right
    else rotate 180 and place in chest on the left
]]
local storage = 0
local backup = false
local totalStored = 0
local slots = {1,2,3,5,6,7,9,10,11}

local function isItemOfType(direction, itemTable)
    -- check if item in front of turtle is a specific type
    local success, data = false, nil
    if direction == "up" then
        success, data= turtle.inspectUp()
    elseif direction == "down" then
        success, data= turtle.inspectDown()
    else
        success, data= turtle.inspect()                 -- check if anything in front
    end
    if success then                                     -- a block is in front
        if type(itemTable) == "table" then              -- Are we checking for multiple items eg {"chest", "barrel"} ?
            for _, item in ipairs(itemTable) do         -- iterate items
                if data.name:find(item) ~= nil then     -- match found
                    return true
                end
            end
        elseif type(itemTable) == "string" then         -- checking for single item
            if data.name:find(itemTable) ~= nil then    -- match found
                return true
            end
        end
    end
    return false                                        -- no match
end

local function getStorage()
    -- turtle has already been aligned with smoker/furnace. Now find chest/barrel
    -- use no. of turns to base future rotations to face storage
    print("Locating storage")
    backup = isItemOfType("up", {"chest", "barrel"})    -- check for fuel backup storage
    if backup then
        print("Found backup fuel supply above")
    end

    local turns = 0
    repeat
        if isItemOfType("forward", {"chest", "barrel"}) then    -- look for chest or barrel
            storage = turns                             -- storage = current no of turns
        else
            turtle.turnRight()
            turns = turns + 1
        end
    until storage > 0 or turns == 4                     -- limit to 4 in case no storage present

    if storage > 0 then                                 -- has the turtle rotated?
        for i = 1, storage do                           -- rotate in opposite direction until facing smelter
            turtle.turnLeft()
        end
    end
end

local function orientate()
    print("Checking position")
    while not isItemOfType("forward", {"smoker", "furnace"}) do -- true if facing a smoker or furnace
        turtle.turnRight()                              -- not facing smoker so turn
    end
end

local function craftKelp()
    turtle.select(16)                                   -- select a slot out of crafting area
    turtle.suckDown()                                   -- remove items from chest below (dried kelp)
    local quantity = turtle.getItemCount(16)            -- count items obtained
    print(quantity.. " dried kelp found")
    if quantity >= 9 then                               -- need min 9 to craft
        local amount = math.floor(quantity / 9)         -- calculate how many to put in each of 9 slots
        for slot = 1, 9 do
            turtle.transferTo(slots[slot], amount)      -- fill slots with same amount each
        end
        turtle.dropDown()                               -- drop remaining back into chest
        turtle.select(1)                                -- put crafted items in slot 1
        if turtle.craft() then
            return true
        end
    end
    return false
end

local function needsFuel()
    -- check if smelter is in 'lit' state.
    -- attempt to remove fuel from smelter if not lit
    local success, data = turtle.inspect()
    if success then                                         -- smelter found
        if data.name:find("smoker") ~= nil or data.name:find("furnace") ~= nil then
            if not data.state.lit then                      -- if not lit, check for unused fuel
                turtle.select(2)                            -- use spare slot
                if turtle.suck() then                       -- fuel present
                    turtle.drop(1)                          -- replace fuel
                    turtle.select(1)                        -- reset selected slot to 1
                    return false
                end
                turtle.select(1)                            -- not lit, no fuel = refuel
                return true
            end
        end
    end
    turtle.select(1)
    return false
end

local function addFuelBackup()
    -- make sure backup fuel store has 3 blocks in it
    local retValue = false
    turtle.select(2)                                        -- select empty slot
    turtle.suckUp()                                         -- remove any stored fuel
    print("Checking fuel backup")
    if turtle.getItemCount(2) < 3 then                      -- check how much fuel was in storage
        turtle.select(1)                                    -- add 1 more block from recently crafted
        turtle.dropUp(1)
    end
    turtle.select(2)                                        -- replace blocks removed for counting
    turtle.dropUp()

    return turtle.getItemCount(1)                           -- return any remaining blocks
end

local function run()
    -- infinite loop to constantly attend to kelp farm smelter
    local slots = {1, 2, 3, 5, 6, 7, 9, 10, 11}             -- translate turtle 16 slots into equivalent crafting slots
    while true do                                           -- infinite loop
        if craftKelp() then                                 -- try crafting kelp block
            -- at least 1 block crafted
            if needsFuel() then                             -- check if needs fuel
                print("Refuelling smelter")
                turtle.select(1)
                turtle.drop(1)                              -- drop crafted blocks into smoker fuel slot
            end
            local count = turtle.getItemCount(1)
            if count > 0 then                               -- spare dried kelp blocks available
                count = addFuelBackup()
                if count > 0 then                           -- still some kelp left
                    for turns = 1, storage do
                        turtle.turnRight()                  -- face storage
                    end
                    print("Storing "..count.." excess dried kelp blocks")
                    totalStored = totalStored + count
                    turtle.select(1)
                    turtle.drop()                           -- drop into storage
                    for turns = 1, storage do
                        turtle.turnLeft()                   -- face smelter
                    end
                end
            end
        else                                                -- not crafted: could be insufficient kelp or out of fuel
            print("Waiting 10 seconds for further smelting")
            sleep(10)
            if craftKelp() then
                print("Refuelling smelter 2nd attempt")
                turtle.drop(1)                              -- drop crafted blocks into smoker fuel slot
            else
                if backup then
                    print("Refuelling smelter from backup")
                    turtle.select(1)
                    turtle.suckUp(1)
                    turtle.drop()
                end
            end
        end

        for time = 60, 1, -1 do                         -- wait 1 minute
            term.clear()
            term.setCursorPos(1, 1)
            print("Stored so far: "..totalStored.." blocks")
            print("Next kelp craft cycle: "..time.." secs")
            sleep(1)
        end
    end
end

local function main()
    orientate()
    getStorage()
    run()
end

main()