"""WebSocket handler and broadcast helpers for hbd.

WebSocket connections are served through the regular HTTP port via the
/ws route registered in http.py (aiohttp WebSocketResponse upgrade).
The separate standalone WebSocket server on ws_port is no longer used.
"""

import asyncio
import json
import logging
from typing import Callable, Iterable, Optional
from . import data

logger = logging.getLogger(__name__)

# Map of WebSocket → User object (or None when auth is disabled)
_connections: dict = {}
_loop: Optional[asyncio.AbstractEventLoop] = None
_get_hosts: Optional[Callable[[], Iterable]] = None
_verbose: bool = False


def setup(
    loop: asyncio.AbstractEventLoop,
    get_hosts: Optional[Callable[[], Iterable]] = None,
    verbose: bool = False,
):
    """Register the running loop and initial-state callback.

    Call this once from _run_async before starting the HTTP server.
    """
    global _loop, _get_hosts, _verbose
    _loop = loop
    _get_hosts = get_hosts
    _verbose = verbose


def _user_can_see_host(user, host_name: str) -> bool:
    """Return True if *user* may see updates for *host_name* (manager or higher)."""
    from . import hbdclass, users as users_mod
    if user is None or not users_mod.users_enabled():
        return True
    if user.admin:
        return True
    host = hbdclass.Host.hosts.get(host_name)
    if host is None:
        return False
    return host.is_manager(user.username)


def _get_token(request) -> str:
    """Extract session token from request (mirrors logic in http.py)."""
    auth = request.headers.get("Authorization", "")
    if auth.startswith("Bearer "):
        return auth[7:].strip()
    token = request.headers.get("X-Auth-Token", "")
    if token:
        return token
    return request.cookies.get("hbd_session", "")


async def handler(request):
    """aiohttp WebSocket upgrade handler — register as GET /ws."""
    from aiohttp import web
    from . import users as users_mod

    ws = web.WebSocketResponse()
    await ws.prepare(request)

    token = _get_token(request)
    user = users_mod.get_session_user(token) if token else None

    _connections[ws] = user
    remote = request.remote
    logger.info("WebSocket connected from %s", remote)

    try:
        # Send current host state, filtered to hosts this user may see
        if _get_hosts:
            try:
                for h in list(_get_hosts()):
                    host_name = h.get("raw_name") or h.get("name", "")
                    if _user_can_see_host(user, host_name):
                        await ws.send_str(json.dumps({"type": "host", "data": h}))
            except Exception as e:
                logger.error("Error sending initial hosts: %s", e)

        # Send recent messages
        if data.msgs:
            try:
                for m in data.msgs:
                    await ws.send_str(json.dumps({"type": "message", "data": m}))
            except Exception as e:
                logger.error("Error sending initial messages: %s", e)

        # Keep connection open, ignore incoming frames
        async for msg in ws:
            from aiohttp import WSMsgType
            if msg.type == WSMsgType.TEXT:
                if _verbose:
                    logger.debug("ws recv from %s: %s", remote, msg.data)
            elif msg.type in (WSMsgType.ERROR, WSMsgType.CLOSE):
                break

    except Exception as e:
        logger.exception("WebSocket handler error from %s: %s", remote, e)
    finally:
        _connections.pop(ws, None)
        logger.info("WebSocket disconnected from %s", remote)

    return ws


def broadcast(typ: str, payload) -> bool:
    """Thread-safe broadcast to all connected WebSocket clients.

    For host and plugin updates, only sends to clients whose user has
    manager-or-higher access to that host.  Other message types are
    broadcast to all clients.

    Can be called from any thread; schedules sends on the event loop.
    Returns False if the loop is not running yet.
    """
    if not _loop:
        return False

    # Determine the host name for access-filtered message types
    host_name: Optional[str] = None
    if typ in ("host", "plugin"):
        host_name = payload.get("raw_name") or payload.get("host") or payload.get("name")

    jmsg = json.dumps({"type": typ, "data": payload})

    async def _send_all():
        dead = set()
        for ws, user in list(_connections.items()):
            try:
                if ws.closed:
                    dead.add(ws)
                    continue
                if host_name is not None and not _user_can_see_host(user, host_name):
                    continue
                await ws.send_str(jmsg)
            except Exception:
                dead.add(ws)
        for ws in dead:
            _connections.pop(ws, None)

    asyncio.run_coroutine_threadsafe(_send_all(), _loop)
    return True


def connection_count() -> int:
    return len(_connections)