"""
Skill : MQTT_PUBLISH / MQTT_SUBSCRIBE
Permet à l'agent de communiquer avec d'autres agents via MQTT.

Commandes :
    MQTT_PUBLISH: <topic> | <message>
        → Publie un message sur un topic MQTT

    MQTT_SUBSCRIBE: <topic>
        → Lit le dernier message reçu sur un topic (via fichier cache)
"""
import json
import paho.mqtt.publish as publish
import paho.mqtt.client as mqtt
from pathlib import Path

SKILL_NAME = "mqtt"
TRIGGER    = None
TRIGGERS   = {
    "MQTT_PUBLISH:":   "mqtt_publish",
    "MQTT_SUBSCRIBE:": "mqtt_subscribe",
}

CONFIG_FILE = Path("/opt/agent/config/config.json")
CACHE_DIR   = Path("/opt/agent/mqtt_cache")

def _get_cfg():
    with open(CONFIG_FILE) as f:
        cfg = json.load(f)
    return (
        cfg.get("mqtt_host",      "localhost"),
        int(cfg.get("mqtt_port",  1883)),
        cfg.get("mqtt_client_id", "agent1"),
    )

def mqtt_publish(args: str) -> str:
    if "|" not in args:
        return "Erreur : format attendu → MQTT_PUBLISH: <topic> | <message>"
    topic, _, message = args.partition("|")
    topic, message = topic.strip(), message.strip()
    if not topic or not message:
        return "Erreur : topic ou message vide."
    try:
        host, port, _ = _get_cfg()
        publish.single(topic, payload=message, hostname=host, port=port)
        return "Message publié sur «{}» : {}".format(topic, message)
    except Exception as e:
        return "Erreur MQTT_PUBLISH : {}".format(e)

def mqtt_subscribe(args: str) -> str:
    topic = args.strip()
    if not topic:
        return "Erreur : topic vide."
    try:
        host, port, client_id = _get_cfg()
        received = []

        def on_message(client, userdata, msg):
            received.append(msg.payload.decode(errors="replace"))

        client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION2,
                             client_id=client_id + "_sub")
        client.on_message = on_message
        client.connect(host, port, keepalive=5)
        client.subscribe(topic)
        client.loop_start()

        import time
        time.sleep(2)
        client.loop_stop()
        client.disconnect()

        if received:
            return "Message reçu sur «{}» :\n{}".format(topic, "\n".join(received))
        return "Aucun message reçu sur «{}» (2s d'attente).".format(topic)

    except Exception as e:
        return "Erreur MQTT_SUBSCRIBE : {}".format(e)