#!/usr/bin/python3
import socket
import threading
import select

def forward(source, destination):
    try:
        while True:
            ready, _, _ = select.select([source], [], [], 1)
            if ready:
                data = source.recv(4096)
                if not data:
                    break
                destination.sendall(data)
    except (OSError, socket.error) as e:
        print(f"Connection error: {e}")
    finally:
        try:
            source.shutdown(socket.SHUT_RD)
        except OSError:
            pass
        try:
            destination.shutdown(socket.SHUT_WR)
        except OSError:
            pass

def handle(client_socket, remote_host, remote_port):
    try:
        remote_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        remote_socket.connect((remote_host, remote_port))
        
        thread1 = threading.Thread(target=forward, args=(client_socket, remote_socket))
        thread2 = threading.Thread(target=forward, args=(remote_socket, client_socket))
        
        thread1.start()
        thread2.start()

        thread1.join()
        thread2.join()
    except Exception as e:
        print(f"Error in handle: {e}")
    finally:
        client_socket.close()
        remote_socket.close()

def create_forwarder(local_host, local_port, remote_host, remote_port):
    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    server_socket.bind((local_host, local_port))
    server_socket.listen(5)
    
    print(f"Forwarding {local_host}:{local_port} to {remote_host}:{remote_port}")

    while True:
        try:
            client_socket, address = server_socket.accept()
            print(f"Received connection from {address}")
            threading.Thread(target=handle, args=(client_socket, remote_host, remote_port)).start()
        except Exception as e:
            print(f"Error accepting connection: {e}")

def main():
    listen_ip = '0.0.0.0'
    
    imap_thread = threading.Thread(target=create_forwarder, args=(listen_ip, 1143, '127.0.0.1', 1142))
    imap_thread.start()

    smtp_thread = threading.Thread(target=create_forwarder, args=(listen_ip, 1025, '127.0.0.1', 1024))
    smtp_thread.start()

    imap_thread.join()
    smtp_thread.join()

if __name__ == "__main__":
    main()