'''
Script to get CO2 values from Senseair S88 sensor and write to database
/usr/bin/python3 /var/www/nebuleair_pro_4g/S88/write_data.py

Port and protocol details come from config_table (key S88_port).
The actual sensor read protocol is implemented in read_co2() below.
'''

import serial
import sqlite3
import sys

DB_PATH = "/var/www/nebuleair_pro_4g/sqlite/sensors.db"
DEFAULT_PORT = "/dev/ttyAMA5"
BAUDRATE = 9600


def get_config(cursor, key, default):
    cursor.execute("SELECT value FROM config_table WHERE key = ?", (key,))
    row = cursor.fetchone()
    return row[0] if row else default


def read_co2(ser):
    # TODO: implement the Senseair S88 read protocol once the datasheet is provided.
    # Expected return: integer CO2 concentration in ppm, or None on failure.
    raise NotImplementedError("Senseair S88 read protocol not implemented yet")


def main():
    conn = sqlite3.connect(DB_PATH)
    cursor = conn.cursor()

    port = get_config(cursor, "S88_port", DEFAULT_PORT)

    try:
        ser = serial.Serial(
            port=port,
            baudrate=BAUDRATE,
            parity=serial.PARITY_NONE,
            stopbits=serial.STOPBITS_ONE,
            bytesize=serial.EIGHTBITS,
            timeout=1,
        )
    except Exception as e:
        print(f"Error opening serial port {port}: {e}")
        conn.close()
        sys.exit(1)

    try:
        co2 = read_co2(ser)
        if co2 is None:
            print("Failed to read CO2 from S88.")
            return

        co2_ppm = int(round(co2))

        cursor.execute("SELECT last_updated FROM timestamp_table LIMIT 1")
        row = cursor.fetchone()
        rtc_time_str = row[0]

        cursor.execute(
            "INSERT INTO data_S88 (timestamp, CO2) VALUES (?, ?)",
            (rtc_time_str, co2_ppm),
        )
        conn.commit()
        print(f"CO2: {co2_ppm} ppm (saved at {rtc_time_str})")
    except NotImplementedError as e:
        print(f"S88 not ready: {e}")
    except Exception as e:
        print(f"S88 error: {e}")
    finally:
        try:
            ser.close()
        except Exception:
            pass
        conn.close()


if __name__ == "__main__":
    main()