import socket
import sys
import threading
import json
from datetime import datetime, timezone

def listen_to_server(sock):
    buffer = ""
    try:
        while True:
            data = sock.recv(4096)
            if not data:
                print("🔌 Connection closed by server.")
                break
            buffer += data.decode()
            while '\n' in buffer:
                line, buffer = buffer.split('\n', 1)
                try:
                    msg = json.loads(line)
                    ts = msg.get("timestamp", "?")
                    sender = msg.get("sender", "?")
                    content = msg.get("content", "")
                    level = msg.get("level", "local")
                    print(f"[Received @ {ts}] {sender} ({level}): {content}")
                except json.JSONDecodeError:
                    print("⚠Received invalid JSON.")
    except Exception as e:
        print("⚠Error receiving from server:", e)
    finally:
        sock.close()
        print("Disconnected.")
        sys.exit(0)

if __name__ == "__main__":
    if len(sys.argv) != 5:
        print("Usage: python client.py <username> <region> <host> <port>")
        sys.exit(1)

    username = sys.argv[1]
    region = sys.argv[2]
    host = sys.argv[3]
    port = int(sys.argv[4])

    try:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.connect((host, port))
    except ConnectionRefusedError:
        print(f"Connection refused to {host}:{port}. Is the server running?")
        sys.exit(1)
    except Exception as e:
        print(f"Connection error: {e}")
        sys.exit(1)
    
    print(f"Connected to server {host}:{port} as {username}")
    print("Type messages. Use `::level=local|national|global` (default: local)")
    
    threading.Thread(target=listen_to_server, args=(sock,), daemon=True).start()
    
    try:
        while True:
            line = input()
            if "::level=" in line:
                parts = line.split("::level=")
                content = parts[0].strip()
                level = parts[1].strip().lower()
            else:
                content = line.strip()
                level = "local"
            
            if not content:
                continue
            
            timestamp = datetime.now(timezone.utc).isoformat()
            message = {
                "id": f"{username}-{timestamp}",
                "sender": username,
                "content": content,
                "level": level,
                "timestamp": timestamp,
                "region": region
            }
            
            try:
                sock.sendall((json.dumps(message) + "\n").encode())
            except Exception:
                print("Failed to send message. Disconnected?")
                break
    except KeyboardInterrupt:
        print("\nClient closed.")
    finally:
        sock.close()
        sys.exit(0)