-- Configuration
local saplingSlot = 1
local fuelSlot = 2 -- (use stick)
local woodSlot = 3
local farmlenght = 10 -- must be even
local farmwidth = 10
local fuelScannedItem = ""
local woodScannedItem = ""
local sapplingScannedItem = ""

local function findItem(itemName)
    for slot = 1, 16 do
        local itemDetail = turtle.getItemDetail(slot)
        if itemDetail and itemDetail.name == itemName then
            return slot
        end
    end
    return -1
end

-- Function to refuel the turtle
local function refuel()
    if turtle.getFuelLevel() == "unlimited" or turtle.getFuelLevel() > 100 then
        return
    end
    repeat
        local slotNumber = findItem(fuelScannedItem)
        if slotNumber ~= -1 then
            turtle.select(slotNumber)
            if turtle.refuel(0) then
                turtle.refuel(1)
            else
                print("the sample provided is not fuel")
            end
        else
            print("no fuel")
            print("insert required fuel then press any key to start...")
            os.pullEvent("key")
        end
    until slotNumber ~= -1
end

-- Function to check if the block in front is wood
local function isWoodAhead()
    local success, data = turtle.inspect()
    if success then
        -- Check if the block in front matches the wood slot item
        if data.name == woodScannedItem then
            return true
        end
    end
    return false
end


-- Function to check if the block on top is wood
local function isWoodUp()
    local success, data = turtle.inspectUp()
    if success then
        -- Check if the block in front matches the wood slot item
        if data.name == woodScannedItem then
            return true
        end
    end
    return false
end

-- Function to go up until there is no more wood
local function goUpUntilNoWood()
    while isWoodUp() do
        turtle.digUp()
        turtle.up()
        refuel()
    end
    while not turtle.detectDown() do
        turtle.down()
    end
    turtle.digDown()
end

-- Function to plant sapling
local function plantSapling()
    local slotNumber = findItem(sapplingScannedItem)
    if slotNumber ~= -1 then
        turtle.select(slotNumber)
        turtle.placeDown()
    else
        print("no sappling, skipping")
    end
end

-- Function to unload inventory
local function unloadInventory()
    for i = 4, 16 do
        turtle.select(i)
        turtle.drop()
    end
end

-- Function to ensure the path is clear of wood or leaves
local function clearpath()
    if isWoodAhead() then
        turtle.dig()
        turtle.forward()
        goUpUntilNoWood()
        plantSapling()
    else
        turtle.dig()
        turtle.forward()
    end
    turtle.suckDown()
end

-- Main function
local function main()
    print("Slot    | 1              | 2           | 3           |  4   |")
    print("Content | Sapling sample | Fuel sample | Wood sample | Fuel |")
    print("Press any key to start...")
    os.pullEvent("key")
    fuelScannedItem = turtle.getItemDetail(fuelSlot).name
    woodScannedItem = turtle.getItemDetail(woodSlot).name
    sapplingScannedItem = turtle.getItemDetail(saplingSlot).name
    print("fuel : "..fuelScannedItem)
    print("wood : "..woodScannedItem)
    print("sappling : "..sapplingScannedItem)
    print("Running")
    while true do
        -- Start zigzag pattern
        for i = 1, (farmlenght) do
            for j = 1, (farmwidth-1) do
                refuel()
                clearpath()
            end
            -- Turn at end of row
            if i < farmlenght then
                if i % 2 == 1 then
                    turtle.turnRight()
                    clearpath()
                    turtle.turnRight()
                else
                    turtle.turnLeft()
                    clearpath()
                    turtle.turnLeft()
                end
            end
        end
        -- Return to start
        turtle.turnRight()
        for i = 1, (farmlenght-1) do
            clearpath()
        end
        -- Unload inventory
        unloadInventory() -- face the hopper
        turtle.turnRight()
    end
end

main()