# scopes.core.actor

import asyncio
from collections.abc import Awaitable, Callable
from typing import Any, Optional

from scopes.util import keywords as k, Symbol
k('full quit')

type Behavior = Callable[[Any], Awaitable[Behavior | None]]
type Mailbox = asyncio.Queue

async def loop(q: asyncio.Queue, bhv: Behavior) -> None:
    while True:
        msg = await q.get()
        if msg is k.quit: 
            break
        bhv = await bhv(msg) or bhv
        q.task_done()

def create(bhv: Behavior, maxsize: int = 0, 
           group: Optional[asyncio.TaskGroup] = None) -> asyncio.Queue:
    q: asyncio.Queue = asyncio.Queue(maxsize)
    if group is None:
        asyncio.create_task(loop(q, bhv))
    else:
        group.create_task(loop(q, bhv))
    return q

async def try_send(rcvr: Mailbox, msg: Any) -> Symbol | None:
    if rcvr.full():
        return k.full
    await rcvr.put(msg)
    return None