Farming Program

local has_block, data = turtle.inspectDown()
local x = 0
local y = 0
local facing = "north"
local done = 0

local function updateY()
    if facing=="north" then
        y = y + 1
    elseif facing=="south" then
        y = y - 1
    end
end

while true do
    has_block, data = turtle.inspectDown()
    if turtle.getFuelLevel() < 50 then
        turtle.select(16)
        turtle.refuel()
        turtle.select(1)
    end
    if has_block then
        if data.state.age==7 then
            turtle.digDown()
            turtle.placeDown()
            turtle.forward()
            updateY()
        else
            turtle.forward()
            updateY()
        end
        done = 0
    elseif done < 1 then
        if facing=="north" then
            turtle.turnRight()
            turtle.forward()
            x = x + 1
            turtle.turnRight()
            turtle.forward()
            facing = "south"
        elseif facing=="south" then
            turtle.turnLeft()
            turtle.forward()
            x = x + 1
            turtle.turnLeft()
            turtle.forward()
            facing = "north"
        end
        done = done + 1
    else
        updateY()
        if facing=="south" then
            while y > 0 do
                turtle.forward()
                y = y - 1
                turtle.turnRight()
            end
        end
        if facing=="north" then
            turtle.turnLeft()
        end
        while x > 0 do
            turtle.forward()
            x = x - 1
        end
        turtle.turnLeft()
        turtle.forward()
        for i=1,15,1 do
            turtle.select(i)
            turtle.drop()
        end
        turtle.up()
        turtle.select(16)
        while turtle.getItemCount() < 64 do
            turtle.suck(1)
        end
        turtle.down()
        turtle.turnRight()
        turtle.turnRight()
        turtle.forward()
        turtle.select(1)
        facing = "north"
        done = 0
    end
end