"""
ServerClass DB Admin Dashboard
Flask + Socket.IO backend with background polling and real-time broadcasts.
"""
import os
import time
import threading
from typing import Dict, Any, Optional

import requests
from flask import Flask, render_template, request, jsonify
from flask_socketio import SocketIO, emit, disconnect

# -----------------------------------------------------------------------------
# Configuration
# -----------------------------------------------------------------------------
UPSTREAM_API = os.environ.get("UPSTREAM_API", "https://dooratre-db.hf.space")
POLL_INTERVAL = int(os.environ.get("POLL_INTERVAL", "10"))  # seconds
SECRET_KEY = os.environ.get("FLASK_SECRET_KEY", os.urandom(24).hex())

app = Flask(__name__)
app.config["SECRET_KEY"] = SECRET_KEY
socketio = SocketIO(app, cors_allowed_origins="*", async_mode="eventlet")

# -----------------------------------------------------------------------------
# Per-connection credential store (sid -> {admin_secret, api_key})
# -----------------------------------------------------------------------------
_sessions: Dict[str, Dict[str, str]] = {}
_sessions_lock = threading.Lock()


def get_session(sid: str) -> Optional[Dict[str, str]]:
    with _sessions_lock:
        return _sessions.get(sid)


def set_session(sid: str, creds: Dict[str, str]) -> None:
    with _sessions_lock:
        _sessions[sid] = creds


def drop_session(sid: str) -> None:
    with _sessions_lock:
        _sessions.pop(sid, None)


# -----------------------------------------------------------------------------
# Upstream API client
# -----------------------------------------------------------------------------
def fetch_upstream(creds: Dict[str, str]) -> Dict[str, Any]:
    """Fetch users + server status from upstream API using provided credentials."""
    result: Dict[str, Any] = {
        "ok": True,
        "users": [],
        "total": 0,
        "status": None,
        "errors": {},
        "timestamp": int(time.time()),
    }

    admin_secret = creds.get("admin_secret", "").strip()
    api_key = creds.get("api_key", "").strip()

    # Users (admin endpoint)
    try:
        r = requests.get(
            f"{UPSTREAM_API}/admin/users",
            headers={"X-Admin-Secret": admin_secret, "Content-Type": "application/json"},
            timeout=15,
        )
        if r.ok:
            data = r.json()
            result["users"] = data.get("users", [])
            result["total"] = data.get("total", len(result["users"]))
        else:
            result["errors"]["users"] = f"{r.status_code}: {r.text[:200]}"
    except Exception as e:
        result["errors"]["users"] = str(e)

    # Server status (API key)
    try:
        r = requests.get(
            f"{UPSTREAM_API}/api/server-status",
            headers={"X-API-Key": api_key, "Content-Type": "application/json"},
            timeout=15,
        )
        if r.ok:
            result["status"] = r.json()
        else:
            result["errors"]["status"] = f"{r.status_code}: {r.text[:200]}"
    except Exception as e:
        result["errors"]["status"] = str(e)

    if result["errors"] and not result["users"] and not result["status"]:
        result["ok"] = False

    return result


# -----------------------------------------------------------------------------
# Background poller
# -----------------------------------------------------------------------------
def background_poller():
    """Periodically fetches data for each connected session and pushes updates."""
    while True:
        socketio.sleep(POLL_INTERVAL)
        with _sessions_lock:
            sessions_snapshot = dict(_sessions)

        for sid, creds in sessions_snapshot.items():
            if not creds.get("admin_secret") and not creds.get("api_key"):
                continue
            try:
                payload = fetch_upstream(creds)
                payload["source"] = "auto"
                socketio.emit("data_update", payload, to=sid)
            except Exception as e:
                socketio.emit("error", {"message": str(e)}, to=sid)


# -----------------------------------------------------------------------------
# Routes
# -----------------------------------------------------------------------------
@app.route("/")
def index():
    return render_template("index.html", poll_interval=POLL_INTERVAL)


@app.route("/health")
def health():
    return jsonify({"status": "ok", "sessions": len(_sessions)})


# -----------------------------------------------------------------------------
# Socket.IO events
# -----------------------------------------------------------------------------
@socketio.on("connect")
def on_connect():
    set_session(request.sid, {"admin_secret": "", "api_key": ""})
    emit("connected", {"sid": request.sid, "poll_interval": POLL_INTERVAL})


@socketio.on("disconnect")
def on_disconnect():
    drop_session(request.sid)


@socketio.on("authenticate")
def on_authenticate(data):
    """Client sends credentials; server stores them and triggers immediate fetch."""
    creds = {
        "admin_secret": (data or {}).get("admin_secret", "").strip(),
        "api_key": (data or {}).get("api_key", "").strip(),
    }
    set_session(request.sid, creds)

    payload = fetch_upstream(creds)
    payload["source"] = "manual"
    emit("data_update", payload)


@socketio.on("refresh")
def on_refresh():
    """Manual refresh request."""
    creds = get_session(request.sid) or {}
    payload = fetch_upstream(creds)
    payload["source"] = "manual"
    emit("data_update", payload)


# -----------------------------------------------------------------------------
# Start background poller at import time (gunicorn-friendly)
# -----------------------------------------------------------------------------
_poller_started = False
_poller_lock = threading.Lock()

def _ensure_poller():
    global _poller_started
    with _poller_lock:
        if not _poller_started:
            socketio.start_background_task(background_poller)
            _poller_started = True

_ensure_poller()

# -----------------------------------------------------------------------------
# Entry point (only used for local `python app.py`)
# -----------------------------------------------------------------------------
if __name__ == "__main__":
    port = int(os.environ.get("PORT", 7860))
    socketio.run(app, host="0.0.0.0", port=port, debug=False)