snek/dashboard/app.py

"""SNEK Dashboard — Flask backend receiving SNEK callbacks."""

import json
import os
import queue
import sqlite3
import threading
import time
from pathlib import Path

from flask import Flask, jsonify, request, send_from_directory, stream_with_context, Response

from sensit_decoder import decode as sensit_decode

DB_PATH = os.environ.get("DB_PATH", "/data/messages.db")
Path(DB_PATH).parent.mkdir(parents=True, exist_ok=True)

app = Flask(__name__, static_folder="static", static_url_path="/static")

# --- SSE broadcast ---
_subscribers: list[queue.Queue] = []
_subscribers_lock = threading.Lock()


def _broadcast(event: dict) -> None:
    payload = json.dumps(event)
    with _subscribers_lock:
        dead = []
        for q in _subscribers:
            try:
                q.put_nowait(payload)
            except queue.Full:
                dead.append(q)
        for q in dead:
            _subscribers.remove(q)


# --- Database ---
def _init_db() -> None:
    with sqlite3.connect(DB_PATH) as conn:
        conn.execute(
            """CREATE TABLE IF NOT EXISTS messages (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                ts REAL NOT NULL,
                device TEXT NOT NULL,
                raw TEXT NOT NULL,
                decoded TEXT NOT NULL,
                rssi REAL,
                snr REAL,
                seq_number INTEGER
            )"""
        )
        conn.execute("CREATE INDEX IF NOT EXISTS idx_device_ts ON messages(device, ts DESC)")
        conn.commit()


_init_db()


# --- Routes ---
@app.route("/")
def index():
    return send_from_directory("static", "index.html")


@app.route("/webhook", methods=["POST"])
def webhook():
    """
    SNEK callback endpoint.
    SNEK sends JSON with: device, time, data, rssi, snr, seqNumber, etc.
    """
    body = request.get_json(force=True, silent=True) or {}
    device = (body.get("device") or "").lower()
    raw = (body.get("data") or "").lower()
    ts = float(body.get("time") or time.time())
    rssi = body.get("rssi")
    snr = body.get("snr")
    seq_number = body.get("seqNumber")

    if not device or not raw:
        return jsonify({"error": "missing device or data"}), 400

    decoded = sensit_decode(raw)

    with sqlite3.connect(DB_PATH) as conn:
        conn.execute(
            "INSERT INTO messages (ts, device, raw, decoded, rssi, snr, seq_number) "
            "VALUES (?,?,?,?,?,?,?)",
            (ts, device, raw, json.dumps(decoded), rssi, snr, seq_number),
        )
        conn.commit()

    _broadcast({
        "type": "message",
        "ts": ts,
        "device": device,
        "raw": raw,
        "decoded": decoded,
        "rssi": rssi,
        "snr": snr,
        "seqNumber": seq_number,
    })
    return jsonify({"status": "ok"})


@app.route("/api/devices")
def api_devices():
    with sqlite3.connect(DB_PATH) as conn:
        cur = conn.execute(
            "SELECT device, COUNT(*) c, MAX(ts) last_ts FROM messages GROUP BY device ORDER BY last_ts DESC"
        )
        rows = cur.fetchall()
    return jsonify([{"device": r[0], "count": r[1], "last_ts": r[2]} for r in rows])


@app.route("/api/messages")
def api_messages():
    device = (request.args.get("device") or "").lower()
    limit = int(request.args.get("limit") or 100)
    with sqlite3.connect(DB_PATH) as conn:
        if device:
            cur = conn.execute(
                "SELECT ts, device, raw, decoded, rssi, snr, seq_number FROM messages "
                "WHERE device = ? ORDER BY ts DESC LIMIT ?",
                (device, limit),
            )
        else:
            cur = conn.execute(
                "SELECT ts, device, raw, decoded, rssi, snr, seq_number FROM messages "
                "ORDER BY ts DESC LIMIT ?",
                (limit,),
            )
        rows = cur.fetchall()
    return jsonify([
        {
            "ts": r[0],
            "device": r[1],
            "raw": r[2],
            "decoded": json.loads(r[3]),
            "rssi": r[4],
            "snr": r[5],
            "seqNumber": r[6],
        }
        for r in rows
    ])


@app.route("/api/decode")
def api_decode():
    """Manual decode utility: /api/decode?hex=b60dc86e"""
    h = request.args.get("hex", "")
    return jsonify(sensit_decode(h))


@app.route("/events")
def events():
    """SSE stream of live messages."""
    def stream():
        q: queue.Queue = queue.Queue(maxsize=100)
        with _subscribers_lock:
            _subscribers.append(q)
        try:
            yield "event: ping\ndata: connected\n\n"
            while True:
                try:
                    payload = q.get(timeout=25)
                    yield f"data: {payload}\n\n"
                except queue.Empty:
                    yield ": keepalive\n\n"
        finally:
            with _subscribers_lock:
                if q in _subscribers:
                    _subscribers.remove(q)

    return Response(stream_with_context(stream()), mimetype="text/event-stream")


@app.route("/healthz")
def healthz():
    return jsonify({"status": "ok"})


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=3000)