cc-wheat-farm

local function findInInventory(itemName)
    local item = turtle.getItemDetail()
    if item and item.name == itemName then
        return
    end

    for i=1,16 do
        turtle.select(i)
        local item = turtle.getItemDetail()
        if item and item.name == itemName then
            return
        end
    end
end

local function replant()
    local success, data = turtle.inspectDown()
    if not success then return end
    if data.name ~= "minecraft:wheat" then return end
    if data.state.age ~= 7 then return end
    turtle.digDown()
    findInInventory("minecraft:wheat_seeds")
    turtle.placeDown()
end

local function harvestLayer()
    -- Turtle should be over belt facing towards the farm.
    for i=1,2 do
        turtle.forward()
    end

    for i=1,4 do
        replant()
        for i=1,8 do
            turtle.forward()
            replant()
        end
        turtle.turnRight()
        turtle.forward()
        turtle.turnRight()

        replant()
        for i=1,8 do
            turtle.forward()
            replant()
        end
        turtle.turnLeft()
        turtle.forward()
        turtle.turnLeft()
    end
    replant()
    for i=1,8 do
        turtle.forward()
        replant()
    end

    turtle.turnLeft()
    for i=1,8 do
        turtle.forward()
    end
    turtle.turnLeft()
    for i=1,10 do
        turtle.forward()
    end
    for i=1,2 do
        turtle.turnLeft()
    end
end

local function dropAll(itemName)
    for i=1,16 do
        turtle.select(i)
        local item = turtle.getItemDetail()
        if item and item.name == itemName then
            turtle.dropDown()
        end
    end
end

local function harvestAll()
    harvestLayer()
    for i=1,2 do
        for i=1,4 do
            turtle.up()
        end
        harvestLayer()
    end
    for i=1,8 do
        turtle.down()
    end
    dropAll("minecraft:wheat")
    turtle.turnLeft()
    for i=1,2 do turtle.forward() end
    dropAll("minecraft:wheat_seeds")
    for i=1,2 do turtle.turnRight() end
    for i=1,2 do turtle.forward() end
    turtle.turnLeft()
end

turtle.select(1)

while true do
    harvestAll()
end