from pywebio import *
from pywebio.input import *
from pywebio.output import *
from pywebio.session import *

import asyncio

chat_msgs = []
online_users = set()

MAX_MESSAGES_COUNT = 100


async def main():
    global chat_msgs

    put_markdown("##  Welcome to online chat")

    msg_box = output()
    put_scrollable(msg_box, height=300, keep_bottom=True)

    nickname = await input("Log in chat", required=True, placeholder="Your name", validate=lambda
        n: "This nickname is already in use" if n in online_users or n == '' else None)
    online_users.add(nickname)

    chat_msgs.append(f"`{nickname}` joined the chat!")
    msg_box.append(put_markdown(f"`{nickname}` joined the chat!"))

    refresh_task = run_async(refresh_msg(nickname, msg_box))

    while True:
        data = await input_group(" New message", [
            input(placeholder="Message text", name="msg"),
            actions(name="cmd", buttons=["Send", {'label': "Leave the chat", 'type': 'cancel'}])
        ], validate=lambda m: ('msg', "Enter your message!") if m["cmd"] == "Send" and not m["msg"] else None)

        if data is None:
            break

        msg_box.append(put_markdown(f"`{nickname}`: {data['msg']}"))
        chat_msgs.append((nickname, data['msg']))

    # exit chat
    refresh_task.close()

    online_users.remove(nickname)
    toast("You left chat!")
    msg_box.append(put_markdown(f" User `{nickname}` leave the chat!"))
    chat_msgs.append(('', f"User `{nickname}` leave the chat!"))

    put_buttons(['Back to chat'], onclick=lambda btn:run_js('window.location.reload()'))


async def refresh_msg(nickname, msg_box):
    global chat_msgs
    last_idx = len(chat_msgs)

    while True:
        await asyncio.sleep(1)

        for m in chat_msgs[last_idx:]:
            if m[0] != nickname:
                msg_box.append(put_markdown(f"`{m[0]}`: {m[1]}"))

        # remove expired
        if len(chat_msgs) > MAX_MESSAGES_COUNT:
            chat_msgs = chat_msgs[len(chat_msgs) // 2:]

        last_idx = len(chat_msgs)


if __name__ == "__main__":
    start_server(main, debug=True, port=8080, cdn=False, host="192.168.0.14")