import paho.mqtt.client as mqtt
import psycopg2
import logging
import sys
import json
import os
import time

MQTT_HOST = os.getenv("MQTT_HOST", "mosquitto")
MQTT_PORT = int(os.getenv("MQTT_PORT", 1883))
PG_DSN = os.getenv("DATABASE_URL", "postgresql://simugaz:simugaz@db/simugaz")

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(message)s",
    datefmt="%Y-%m-%dT%H:%M:%S",
    stream=sys.stdout,
    force=True,
)
log = logging.getLogger(__name__)


def get_db():
    for _ in range(10):
        try:
            conn = psycopg2.connect(PG_DSN)
            conn.autocommit = True
            log.info("PostgreSQL connecté")
            return conn
        except Exception as e:
            log.warning(f"Attente PostgreSQL... ({e})")
            time.sleep(3)
    raise RuntimeError("Impossible de se connecter à PostgreSQL")


def get_device_id(conn, dev_eui: str) -> str:
    """
    Insère le device si inconnu
    Retourne le device_id correspondant au dev_eui
    """
    with conn.cursor() as cur:
        cur.execute(
            """
            INSERT INTO device (device_eui)
            VALUES (%s)
            ON CONFLICT (device_eui) DO NOTHING
        """,
            (dev_eui,),
        )

        cur.execute("SELECT device_id FROM device WHERE device_eui = %s", (dev_eui,))
        row = cur.fetchone()
        return str(row[0])


def insert_reading(conn, device_id: str, pulses: int):
    """Insère une télérelève liée au device"""
    with conn.cursor() as cur:
        cur.execute(
            """
            INSERT INTO reading (device_id, date, pulses)
            VALUES (%s, NOW(), %s)
        """,
            (device_id, pulses),
        )


db_conn = None


def on_connect(client, userdata, flags, reason_code, properties):
    log.info(f"MQTT connecté (code={reason_code})")
    client.subscribe("application/+/device/+/event/up", qos=1)


def on_message(client, userdata, msg):
    try:
        body = json.loads(msg.payload)
        dev_eui = body["deviceInfo"]["devEui"]
        pulses = int(body["object"]["pulse_count"])

        device_id = get_device_id(db_conn, dev_eui)
        insert_reading(db_conn, device_id, pulses)

        log.info(
            f"[UP] dev_eui={dev_eui} | device_id={device_id} | pulses={pulses}| relevé inséré"
        )

    except Exception as e:
        log.exception(f"Erreur traitement message : {e}")


# ── Main ─────────────────────────────────────────────────────────
if __name__ == "__main__":
    db_conn = get_db()

    mqttc = mqtt.Client(mqtt.CallbackAPIVersion.VERSION2)
    mqttc.on_connect = on_connect
    mqttc.on_message = on_message
    mqttc.reconnect_delay_set(min_delay=1, max_delay=30)

    mqttc.connect(MQTT_HOST, MQTT_PORT, 60)
    mqttc.loop_forever()