import can
import socket
import threading
import time


class TCPServer:
    def __init__(self, host='0.0.0.0', port=3169): 
        self.host = host
        self.port = port 
        self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.is_running = False
        self.clients = [] # List of connected clients
        self.lock = threading.Lock() # Lock for thread-safe client list
        self.no_clients_logged = False

    def _log(self, message):
        """ Custom logging with a dynamic header. """
        timestamp = time.strftime('%H:%M:%S')
        client_count = len(self.clients)
        header_state = 'BROADCASTING' if client_count > 0 else 'WAITING FOR CLIENTS' if client_count == 0 else 'UNKNOWN'
        header = f'[{timestamp}] ||| Connected clients: {client_count} ||| {header_state}'
        print(f'{header}\n{message}\n')

    def setup(self):
        """ Set up the server by binding to the host and port and start to listen """
        self.server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.server_socket.bind((self.host, self.port))
        self.server_socket.listen(5)
        self.is_running = True
        self._log(f'The server is set up and listening on {self.host}:{self.port}')

    def shutdown(self):
        """ Shut down the server and disconnect all clients. """
        self.is_running = False 
        for client_socket in self.clients:
            try:
                client_socket.close()
            except Exception:
                pass
        self.clients.clear()
        self.server_socket.close()
        self._log(f'The server that was running on {self.host}:{self.port} has been shut down.', 'SHUTDOWN')

    def run(self):
        """ Run the server and accept clients. """
        self._log('The server is running. Press CTRL+C to stop.')
        try:
            while self.is_running:
                client_socket, client_address = self.server_socket.accept()
                client_thread = threading.Thread(
                    target = self.handle_client,
                    args = (client_socket, client_address),
                    daemon = True
                )
                client_thread.start()
        except KeyboardInterrupt:
            self._log('The server is shutting down...', 'SHUTDOWN')
        finally:
            self.shutdown()

    def handle_client(self, client_socket, client_address):
        """ Handle new client connections and add them to the client list. """
        with self.lock:
            client_socket.settimeout(30)
            self.clients.append(client_socket)
        self._log(f'Client connected: {client_address}')
        try:
            while self.is_running:
                data = client_socket.recv(1024)
                if not data:
                    break
                message = data.decode().strip()
                self._log(f'Received message from {client_address}: {message}')
                if message.lower() == 'ping':
                    response = 'pong'
                    client_socket.sendall('pong'.encode())
                    self._log(f'Sent response to {client_address}: {response}')
        except Exception as e:
            self._log(f'Error with client {client_address}: {e}')
        finally:
            self._log(f'Client disconnected: {client_address}')
            with self.lock:
                self.clients.remove(client_socket)
            client_socket.close()

    def broadcast_data(self, data):
        """Send the {data} to all connected clients, disconnecting those that are inactive."""
        with self.lock:
            if not self.clients:
                if not self.no_clients_logged:  # Log the message once
                    self._log('No connected clients, pausing data broadcast.')
                    self.no_clients_logged = True
                return  # Skip broadcasting if no clients are connected
            
            self.no_clients_logged = False
            self._log(f'Sending data to {len(self.clients)} clients.')
            
            for client_socket in list(self.clients):
                try:
                    # Set a 100ms timeout for the socket, attempt to send the data and reset timeout after successful send
                    #client_socket.settimeout(0.1)
                    client_socket.sendall(data.encode())
                    self._log(f'Data sent to client: {client_socket.getpeername()} -- {data}')
                    #client_socket.settimeout(None)
                except (socket.timeout, BrokenPipeError, ConnectionResetError) as e:
                    self._log(f'Disconnecting client due to inactivity or error: {e}')
                    self.clients.remove(client_socket)
                    try:
                        client_socket.close()
                    except Exception:
                        pass


def dump_can_messages(interface: str, server: TCPServer):
    """
    Reads and dumps CAN messages from the specified interface.

    :param interface: The name of the CAN interface (e.g., 'can0').
    """
    bus = None
    try:
        bus = can.interface.Bus(channel=interface, interface='socketcan')
        print(f"Listening for messages on {interface}...")
        while True:
            message = bus.recv()  # Blocks until a message is received
            if message:
                msg = f"Timestamp: {message.timestamp:.6f}, ID: {message.arbitration_id:03X}, Data: {message.data.hex()}\n"
                server.broadcast_data(msg)
    except KeyboardInterrupt:
        print("\nExiting...")

    except can.CanError as e:
        print(f"CAN Error: {e}")

    finally:
        if bus is not None:
            bus.shutdown()
            print("CAN bus shut down cleanly.")


if __name__ == "__main__":
    server = TCPServer()
    server.setup()

    server_thread = threading.Thread(target = server.run, daemon = True)
    server_thread.start()
    
    dump_can_messages("can1", server)