'''
Live value for the web "Get Data" button (CCS811 air-quality sensor).
Prints {"eCO2": <ppm>, "TVOC": <ppb>, "timestamp": <str>} or {"error": "<msg>"}.

IMPORTANT: this does NOT read the I2C sensor. The CCS811 is owned by the
long-running daemon (CCS811/daemon.py); opening the bus here would collide with
it and corrupt the sensor. Instead we return the most recent row the daemon
stored in data_CCS811. TVOC is the primary measurement.

Usage: /usr/bin/python3 /var/www/nebuleair_pro_4g/CCS811/get_data.py
'''

import json
import sqlite3

DB_PATH = "/var/www/nebuleair_pro_4g/sqlite/sensors.db"


def main():
    try:
        conn = sqlite3.connect(DB_PATH, timeout=5)
        cursor = conn.cursor()
        cursor.execute(
            "SELECT timestamp, eCO2, TVOC FROM data_CCS811 ORDER BY timestamp DESC LIMIT 1"
        )
        row = cursor.fetchone()
        conn.close()
    except Exception as e:
        print(json.dumps({"error": f"DB read error: {e}"}))
        return

    if not row:
        print(json.dumps({"error": "No CCS811 data yet (daemon warming up?)"}))
        return

    print(json.dumps({"timestamp": row[0], "eCO2": int(row[1]), "TVOC": int(row[2])}))


if __name__ == "__main__":
    main()