crop_controller.lua

-- API --------------------------------------------------

function hasValue (tab, val)
    for index, value in ipairs(tab) do
        if value == val then
            return true
        end
    end

    return false
end

function printKeys(tab)
    -- Source - https://stackoverflow.com/a/12674376
    -- Posted by lhf
    -- Retrieved 2026-06-11, License - CC BY-SA 3.0

    local keyset={}
    local n=0

    for k,v in pairs(tab) do
        n=n+1
        keyset[n]=k
    end

    print(textutils.serialise(keyset))
end

---------------------------------------------------------

EXPECTED_CROP_MACHINES = 4
TIME_BETWEEN_HARVEST_SECONDS = 900

local function main()
    peripheral.find("modem", rednet.open)
    rednet.broadcast("crop_controller_ping")

    local timer_id = os.startTimer(1)

    -- Connect to crop workers
    local connected_crop_machines = {}
    repeat
        local event, p1, p2 = os.pullEvent()

        if event == "rednet_message" then
            local id = p1
            local message = p2

            if message == "crop_worker_pong" then
                connected_crop_machines[#connected_crop_machines + 1] = id
            end

        elseif event == "timer" and p1 == timer_id then
            rednet.broadcast("crop_controller_ping")
            timer_id = os.startTimer(1)
        end

    until #connected_crop_machines == EXPECTED_CROP_MACHINES

    os.cancelTimer(timer_id)

    -- Identify crop workers
    local name_response_count = 0
    local crop_machine_names = {}
    for i,v in ipairs(connected_crop_machines) do
        rednet.send(v, "crop_controller_identify")
    end

    repeat
        local id, message = rednet.receive()
        if hasValue(connected_crop_machines, id) then
            crop_machine_names[id] = message
            name_response_count = name_response_count + 1
        end
    until name_response_count == EXPECTED_CROP_MACHINES

    for i, v in pairs(crop_machine_names) do
        print(tostring(v) .. " has connected")
    end

    while true do
        -- Set off crop workers
        for i,v in ipairs(connected_crop_machines) do
            rednet.send(v, "crop_controller_harvest")
        end

        local finished_crop_machines = 0
        repeat
            local id, message = rednet.receive()
            if hasValue(connected_crop_machines, id) then
                if message == "crop_worker_finished" then
                    finished_crop_machines = finished_crop_machines + 1
                elseif message == "crop_worker_no_fuel" then
                    print(tostring(crop_machine_names[id]) .. " (" .. tostring(id) .. ") is out of fuel")
                elseif message == "crop_worker_no_seeds" then
                    print(tostring(crop_machine_names[id]) .. " (" .. tostring(id) .. ") doesn't have enough seeds")
                end
            end
        until finished_crop_machines == EXPECTED_CROP_MACHINES

        os.sleep(TIME_BETWEEN_HARVEST_SECONDS)
    end
end

main()