GPS Host Startup

-- GPS Host Startup Script
-- Place this as 'startup.lua' on each GPS host computer
-- The program will automatically determine its position and start broadcasting

local function startGPSHost()
    -- Find the ender modem
    local modem = peripheral.find("modem") or error("No modem attached!", 0)

    -- Check if it's a wireless modem (ender modem)
    if not modem.isWireless() then
        error("Modem is not wireless! GPS requires ender modems.", 0)
    end

    -- Get position from command line args, or try to detect
    local x, y, z = gps.locate(5)

    if not x then
        print("Cannot determine position automatically.")
        print("Please provide coordinates:")
        write("X: ")
        x = tonumber(read())
        write("Y: ")
        y = tonumber(read())
        write("Z: ")
        z = tonumber(read())
    end

    if not x or not y or not z then
        error("Invalid coordinates!", 0)
    end

    print("Starting GPS host at: " .. x .. ", " .. y .. ", " .. z)

    -- Run the GPS host program
    shell.run("gps", "host", tostring(x), tostring(y), tostring(z))
end

-- Run the GPS host
local success, err = pcall(startGPSHost)
if not success then
    printError("GPS Host Error: " .. err)
    sleep(5)
end