#!/usr/bin/python3

import socket
import threading

HOST = '0.0.0.0'
PORT = 12345

server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((HOST, PORT))
clients = []
lock = threading.Lock()


def send_to_all(conn, msg):
    with lock:
        for client, _ in clients:
            if client != conn:
                try:
                    client.sendall(msg.encode('utf-8'))
                except BrokenPipeError:
                    print("Verbindung verloren.")
                    with lock:
                        clients.remove((conn, nick))
                    conn.close()
                    break

def handle_client(conn, addr):
    nick = conn.recv(1024).decode('utf-8')
    print(f"Neuer Client verbunden: {addr} ({nick})")
    send_to_all(conn, f"{nick} hat den Chat betreten.")

    with lock:
        clients.append((conn, nick))

    while True:
        try:
            msg = conn.recv(1024).decode('utf-8')

            if not msg:
                break

            elif msg == "exit":
                print("Client getrennt:", addr)
                send_to_all(conn, f"{nick} hat den Chat verlassen")
                with lock:
                    clients.remove((conn, nick))
                conn.close()
                break

            print(clients)
            print(f"Nachricht von {addr} ({nick}): {msg}")

            if conn.fileno() != -1:
                send_to_all(conn, f"<{nick}>:{msg}")

        except ConnectionResetError:
            print("Client getrennt (Verbindungsreset):", addr)
            send_to_all(conn, f"{nick} hat den Chat verlassen.")

            with lock:
                clients.remove((conn, nick))
            conn.close()

            break


def start_server():
    server.listen()
    print(f'Server läuft auf {HOST}:{PORT}')

    while True:
        conn, addr = server.accept()
        threading.Thread(target=handle_client, args=(conn, addr)).start()


if __name__ == '__main__':
    try:
        start_server()
    except KeyboardInterrupt:
        print("Server wird heruntergefahren.")

        with lock:
            for client, nick in clients:
                send_to_all(client, f"{nick} hat den Chat verlassen.")
                client.close()

        server.close()