turtle slave

-- Turtle Slaves
-- By Fenthis

slave_file = "/slave_id.txt"
slave_channel = 6969
status_channel = 2069

-- Set a reasonable name for a slave.
l = "Slave_" .. os.getComputerID()
print("Setting label to: " .. l)
os.setComputerLabel(l)

-- Assign to group
args = { ... }
if #args > 0 then
    group = args[1]
    f = fs.open(slave_file, "w")
    f.writeLine(group)
    f.close()
else
    if fs.exists(slave_file) then
        f = fs.open(slave_file, "r")
        group = f.readLine()
        f.close()
    else
        print("I don't know what slave group I am in.")
        exit()
    end
end
print("My group ID is: \""..group.."\"")

-- Connect to the model
local modem = peripheral.wrap("right")
modem.open(slave_channel)

-- Send a reply
local function send_status(message)
    x, y, z = gps.locate()
    if x then
        message.location = vector.new(x,y,z)
    end
    message.sender = os.getComputerLabel()
    message.group = group
    modem.transmit(status_channel, slave_channel,
        textutils.serialize(message))
end

-- The message handling
local function run_command(message)
    cmd = textutils.unserialize(message)
    if not cmd then return end
    if not cmd.group == group then return end

    if cmd.message_type == "slave_command" then
        print("Recieved command: \"" .. cmd.command .. "\" from " .. cmd.sender)
        send_status({["message_type"] = "running command",
            ["command"] = cmd.command})
        a = cmd.args or {}
        shell.run(cmd.command, unpack(a))
        send_status({["message_type"] = "finished command",
            ["command"] = cmd.command})
    end
end

-- Announce us
send_status({["message_type"] = "online"})

-- Main Loop
print("Waiting for commands, press Q to quit.")
while true do
    local event, modemSide, senderChannel,
        replyChannel, message, senderDistance = os.pullEvent()

    if event == "char" then
        if (modemSide == "Q" or modemSide == "q") then
            break
        end
    elseif event == "modem_message" then
        -- print("Message: " .. message)
        run_command(message)
    end
end

-- Exit!
modem.close(slave_channel)
send_status({["message_type"] = "offline"})
print("Done!")