import json
import os
from typing import Any, Dict

from flask import Flask, jsonify, render_template, request
import paho.mqtt.client as mqtt


MQTT_HOST = os.getenv("MQTT_HOST", "127.0.0.1")
MQTT_PORT = int(os.getenv("MQTT_PORT", "1883"))
MQTT_USER = os.getenv("MQTT_USER", "")
MQTT_PASSWORD = os.getenv("MQTT_PASSWORD", "")
MQTT_BASE_TOPIC = os.getenv("MQTT_BASE_TOPIC", "evs")
PORTAL_BIND_HOST = os.getenv("PORTAL_BIND_HOST", "0.0.0.0")
PORTAL_BIND_PORT = int(os.getenv("PORTAL_BIND_PORT", "8088"))


app = Flask(__name__)
mqtt_client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION2, client_id="evs-control-portal")
if MQTT_USER:
    mqtt_client.username_pw_set(MQTT_USER, MQTT_PASSWORD)
mqtt_client.connect(MQTT_HOST, MQTT_PORT, keepalive=30)
mqtt_client.loop_start()


def _topic_for_device(device_id: str) -> str:
    return f"{MQTT_BASE_TOPIC}/{device_id}/command"


def _publish(device_id: str, payload: Dict[str, Any]) -> Dict[str, Any]:
    topic = _topic_for_device(device_id)
    encoded = json.dumps(payload, separators=(",", ":"))
    info = mqtt_client.publish(topic, encoded, qos=0, retain=False)
    return {
        "ok": info.rc == mqtt.MQTT_ERR_SUCCESS,
        "topic": topic,
        "payload": payload,
        "mqtt_rc": info.rc,
    }


@app.get("/")
def index():
    return render_template("index.html", mqtt_host=MQTT_HOST, mqtt_port=MQTT_PORT, base_topic=MQTT_BASE_TOPIC)


@app.post("/api/publish")
def api_publish():
    body = request.get_json(force=True, silent=True) or {}
    device_id = str(body.get("device_id", "")).strip()
    payload = body.get("payload")
    if not device_id:
        return jsonify({"ok": False, "error": "device_id is required"}), 400
    if not isinstance(payload, dict):
        return jsonify({"ok": False, "error": "payload must be a JSON object"}), 400
    return jsonify(_publish(device_id, payload))


if __name__ == "__main__":
    app.run(host=PORTAL_BIND_HOST, port=PORTAL_BIND_PORT, debug=False)