import os
import os.cmdline
import net

fn main() {
    println('Usage: net_udp_server_and_client [-l] [-p 5000]')
    println('     -l      - act as a server and listen')
    println('     -p XXXX - custom port number')
    println('------------------------------------------')
    is_server := '-l' in os.args
    port := cmdline.option(os.args, '-p', '40001').int()
    mut buf := []u8{len: 100}
    if is_server {
        println('UDP echo server, listening for udp packets on port: ${port}')
        mut c := net.listen_udp(':${port}')!
        for {
            read, addr := c.read(mut buf) or { continue }
            println('received ${read} bytes from ${addr}')
            c.write_to(addr, buf[..read]) or {
                println('Server: connection dropped')
                continue
            }
        }
    } else {
        println('UDP client, sending packets to port: ${port}.\nType `exit` to exit.')
        mut c := net.dial_udp('localhost:${port}')!
        for {
            mut line := os.input('client > ')
            match line {
                '' {
                    line = '\n'
                }
                'exit' {
                    println('goodbye.')
                    exit(0)
                }
                else {}
            }
            c.write_string(line)!
            read, _ := c.read(mut buf)!
            println('server : ' + buf[0..read].bytestr())
        }
    }
}