const amqp = require("amqplib");
const express = require("express");

const HOST = process.env.RABBIT_HOST || "localhost";
const PORT = parseInt(process.env.RABBIT_PORT || "5672");
const USER = process.env.RABBIT_USER || "guest";
const PASS = process.env.RABBIT_PASS || "guest";
const QUEUE = process.env.RABBIT_QUEUE || "iot-events";
const INTERVAL = parseInt(process.env.PRODUCE_INTERVAL || "3") * 1000;

const SENSORS = [
  { id: "temp_living", type: "temperature", location: "living_room", unit: "°C", min: 18, max: 28 },
  { id: "temp_bedroom", type: "temperature", location: "bedroom", unit: "°C", min: 16, max: 26 },
  { id: "temp_office", type: "temperature", location: "office", unit: "°C", min: 19, max: 27 },
  { id: "humidity_living", type: "humidity", location: "living_room", unit: "%", min: 30, max: 70 },
  { id: "humidity_bed", type: "humidity", location: "bedroom", unit: "%", min: 35, max: 65 },
  { id: "power_kitchen", type: "power_meter", location: "kitchen", unit: "kW", min: 0.1, max: 3.5 },
  { id: "power_living", type: "power_meter", location: "living_room", unit: "kW", min: 0.2, max: 2 },
  { id: "power_office", type: "power_meter", location: "office", unit: "kW", min: 0.3, max: 4 },
];

let channel = null;
let eventsSent = 0;
let errors = 0;

async function connect() {
  const conn = await amqp.connect(`amqp://${USER}:${PASS}@${HOST}:${PORT}`);
  channel = await conn.createChannel();
  await channel.assertQueue(QUEUE, { durable: true });
  console.log(`Producer connected to RabbitMQ, queue: ${QUEUE}`);
}

async function produce() {
  while (true) {
    try {
      if (!channel) await connect();
      const s = SENSORS[Math.floor(Math.random() * SENSORS.length)];
      const event = {
        event_id: crypto.randomUUID(),
        sensor_id: s.id, device_type: s.type, location: s.location,
        value: +(s.min + Math.random() * (s.max - s.min)).toFixed(2),
        unit: s.unit,
        timestamp: new Date().toISOString(),
      };
      channel.sendToQueue(QUEUE, Buffer.from(JSON.stringify(event)), { persistent: true });
      eventsSent++;
      if (eventsSent % 10 === 0) console.log(`Sent ${eventsSent} events`);
    } catch (e) {
      errors++;
      console.error("Error:", e.message);
    }
    await new Promise(r => setTimeout(r, INTERVAL));
  }
}

const app = express();
app.get("/", (req, res) => res.json({ service: "iot-producer", status: "running", queue: QUEUE, events_sent: eventsSent, errors }));
app.get("/health", (req, res) => res.json({ status: "ok" }));
app.listen(process.env.PORT || 3000, () => { console.log("Producer started"); produce(); });