-- Initialize farm size variables
local width, height

-- Function to read farm size from user input
local function readFarmSize()
    print("Enter farm width: ")
    width = tonumber(read())
    print("Enter farm height: ")
    height = tonumber(read())
end

-- Function to check and refuel if needed
local function checkFuel()
    local fuelLevel = turtle.getFuelLevel()
    print("Current fuel level: " .. fuelLevel)
    if fuelLevel < 10 then
        print("Low fuel. Refueling...")
        turtle.select(1) -- Assume fuel is in slot 1
        if not turtle.refuel() then
            print("Failed to refuel. Check fuel source.")
            return false
        end
    end
    return true
end

-- Function to check if a crop below the turtle is fully grown
local function isCropGrown()
    local success, data = turtle.inspectDown()
    if success then
        return data.state and data.state.age == 7
    end
    return false
end

-- Function to get the seed type from a slot
local function getSeedType()
    for i = 1, 16 do
        local item = turtle.getItemDetail(i)
        if item and item.name:find("seed") then
            return i
        end
    end
    return nil
end

-- Function to replant a crop using the detected seed type
local function replantCrop()
    local seedSlot = getSeedType()
    if seedSlot then
        turtle.select(seedSlot)
        turtle.placeDown()
    else
        print("No seeds found in inventory.")
    end
end

-- Function to move the turtle forward a certain number of steps
local function moveForward(steps)
    for i = 1, steps do
        if not checkFuel() then
            return
        end
        if not turtle.forward() then
            print("Unable to move forward, possibly blocked")
            return
        end
    end
end

-- Function to move the turtle to the next row
local function moveToNextRow(isEvenRow)
    if isEvenRow then
        turtle.turnLeft()
        moveForward(1)
        turtle.turnLeft()
    else
        turtle.turnRight()
        moveForward(1)
        turtle.turnRight()
    end
end

-- Function to move the turtle back to its starting position (bottom-right corner)
local function returnToStart()
    -- Turn around to face the starting corner
    turtle.turnRight()
    turtle.turnRight()
    moveForward(height - 1) -- Move up the farm
    turtle.turnLeft()
    moveForward(width - 1)  -- Move to the bottom-right corner
    turtle.turnLeft()
end

-- Function to deposit items into a chest behind the turtle's starting position
local function depositItems()
    -- Turn to face the chest (which is behind the turtle's starting position)
    turtle.turnLeft()
    turtle.turnLeft()
    for i = 1, 16 do
        turtle.select(i)
        turtle.drop()
    end
    -- Return to the original orientation
    turtle.turnLeft()
    turtle.turnLeft()
end

-- Function to harvest and replant crops in a zigzag pattern
local function harvestAndReplant()
    for y = 1, height do
        for x = 1, width do
            if isCropGrown() then
                turtle.digDown()
                replantCrop() -- Replant the same type of seed detected in inventory
            end
            if x < width then
                moveForward(1) -- Move forward one block
            end
        end
        if y < height then
            moveToNextRow(y % 2 == 1)
        end
    end
end

-- Main program loop
print("Welcome to the Turtle Farm Program!")
print("Please place fuel in slot 1 of the turtle's inventory.")
readFarmSize()

while true do
    harvestAndReplant()
    returnToStart()
    depositItems()
    os.sleep(1800) -- Wait for 30 minutes before the next cycle
end