client.py

import socket
import threading
from prompt_toolkit import Application
from prompt_toolkit.buffer import Buffer
from prompt_toolkit.layout.containers import HSplit, VSplit, Window, WindowAlign
from prompt_toolkit.layout.controls import BufferControl, FormattedTextControl
from prompt_toolkit.layout.layout import Layout
from prompt_toolkit.key_binding import KeyBindings
from prompt_toolkit.styles import Style
from prompt_toolkit.application.current import get_app

HOST = input("Enter server IP: ")
PORT = 5555
nickname = input("Choose your nickname: ").strip() or "Anonymous"

# ─── socket setup ───────────────────────────────────────────
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
    sock.connect((HOST, PORT))
except ConnectionRefusedError:
    print("Server is not reachable.")
    exit(1)

sock.sendall(nickname.encode('utf-8'))

# ─── global state ───────────────────────────────────────────
messages = []          # each element: (text, is_system)
users = []             # list of nicknames
stop_event = threading.Event()

def add_message(text, is_system=False):
    """Append a message to the history and refresh UI."""
    messages.append((text, is_system))
    if len(messages) > 1000:
        messages.pop(0)
    get_app().invalidate()

def update_users(new_list):
    global users
    users = new_list
    get_app().invalidate()

# ─── receiving thread ───────────────────────────────────────
def receiver():
    while not stop_event.is_set():
        try:
            data = sock.recv(1024)
            if not data:
                add_message("[Connection lost]", is_system=True)
                stop_event.set()
                break
            text = data.decode('utf-8')
            if text.startswith("##users##"):
                # update user list
                userlist = text[9:].split(",") if len(text) > 9 else []
                update_users([u for u in userlist if u])  # filter empty
            else:
                add_message(text)
        except (ConnectionResetError, BrokenPipeError, OSError):
            add_message("[Connection lost]", is_system=True)
            stop_event.set()
            break

threading.Thread(target=receiver, daemon=True).start()

# ─── TUI layout ─────────────────────────────────────────────

# Message history pane (top left)
class MessageHistory:
    def __pt_formatted_text__(self):
        fragments = []
        for text, is_system in messages:
            if is_system:
                fragments.append(("class:system", f"• {text}\n"))
            else:
                fragments.append(("", f"{text}\n"))
        return fragments

message_control = FormattedTextControl(MessageHistory())
message_window = Window(
    content=message_control,
    wrap_lines=True,
    style="bg:#222222 #ffffff",
)

# User list pane (right side)
def get_user_list_text():
    if not users:
        return [("class:userlist", "   (no one)\n")]
    lines = []
    for u in users:
        lines.append(("class:userlist", f"   {u}\n"))
    return lines

user_list_control = FormattedTextControl(get_user_list_text)
user_list_window = Window(
    content=user_list_control,
    width=20,
    style="bg:#333333 #aaaaaa",
    align=WindowAlign.LEFT,
)

# Input field (bottom)
input_buffer = Buffer()
input_window = Window(
    height=1,
    content=BufferControl(buffer=input_buffer),
    style="bg:#444444 #ffffff",
)

# Combine everything
root_container = HSplit([
    VSplit([
        message_window,
        user_list_window,
    ]),
    input_window,
])

# ─── key bindings ───────────────────────────────────────────
kb = KeyBindings()

@kb.add("enter")
def _(event):
    text = input_buffer.text
    if text:
        if text == "/quit":
            stop_event.set()
            sock.close()
            event.app.exit()
        else:
            try:
                sock.sendall(text.encode('utf-8'))
            except (BrokenPipeError, ConnectionResetError):
                add_message("Cannot send message – disconnected", is_system=True)
            input_buffer.text = ""

@kb.add("c-c")
def _(event):
    stop_event.set()
    sock.close()
    event.app.exit()

# ─── styling ────────────────────────────────────────────────
style = Style([
    ("system", "fg:#888888 italic"),
    ("userlist", "fg:#88ff88"),
])

# ─── build the application ──────────────────────────────────
app = Application(
    layout=Layout(root_container, focused_element=input_window),
    key_bindings=kb,
    style=style,
    full_screen=True,
)

def run_tui():
    try:
        app.run()
    except KeyboardInterrupt:
        pass
    finally:
        stop_event.set()
        sock.close()

if __name__ == "__main__":
    run_tui()