/**
 * ================================================================
 *  provisioner.js — сервис учёта и добавления устройств
 *  Егорин / ORBIT · Node.js 20+ · npm i mqtt pg express
 * ================================================================
 *  Делает:
 *   1. Слушает nodes/+/info  → неизвестный узел = запись в devices
 *      со status='pending' («Ожидают добавления» в UI)
 *   2. Слушает nodes/+/data  → телеметрия в Postgres, online-флаг,
 *      события смены реле
 *   3. Слушает nodes/+/status (LWT LAN-узлов) → online/offline
 *   4. LoRa-узлы: offline, если молчат > OFFLINE_AFTER_S
 *   5. REST API для интерфейса (см. README)
 *   6. При подтверждении устройства публикует MQTT Discovery
 *      для Home Assistant — сущности появляются в HA сами
 *
 *  Деплой: LXC/Docker на Proxmox, systemd unit или compose.
 *  ENV: MQTT_URL, PG_URL, PORT
 * ================================================================
 */

const mqtt = require("mqtt");
const { Pool } = require("pg");
const express = require("express");

const MQTT_URL = process.env.MQTT_URL || "mqtt://192.168.1.200:1883";
const PG_URL   = process.env.PG_URL   || "postgres://energy:energy@127.0.0.1:5432/energy";
const PORT     = process.env.PORT     || 8090;
const OFFLINE_AFTER_S = 120;           // 4 пропущенных периода LoRa-узла

const pg = new Pool({ connectionString: PG_URL });
const mq = mqtt.connect(MQTT_URL, { will: {
  topic: "services/provisioner/status", payload: "offline", retain: true
}});

const lastRelays = new Map(); // node_id -> [..] для детекта фронтов

// ---------------- MQTT ----------------
mq.on("connect", () => {
  mq.publish("services/provisioner/status", "online", { retain: true });
  mq.subscribe(["nodes/+/info", "nodes/+/data", "nodes/+/status"]);
  console.log("MQTT connected:", MQTT_URL);
});

mq.on("message", async (topic, payload) => {
  const [, nodeId, kind] = topic.split("/");
  try {
    if (kind === "info")   await onInfo(nodeId, JSON.parse(payload));
    if (kind === "data")   await onData(nodeId, JSON.parse(payload));
    if (kind === "status") await onStatus(nodeId, payload.toString());
  } catch (e) {
    console.error(`${topic}: ${e.message}`);
  }
});

// узел представился — регистрируем или обновляем паспорт
async function onInfo(id, m) {
  await pg.query(`
    INSERT INTO devices (node_id, transport, caps, fw, ip, mac, gw, last_seen, online)
    VALUES ($1,$2,$3,$4,$5,$6,$7,now(),TRUE)
    ON CONFLICT (node_id) DO UPDATE SET
      transport=$2, caps=$3, fw=$4,
      ip=COALESCE($5, devices.ip), mac=COALESCE($6, devices.mac),
      gw=COALESCE($7, devices.gw), last_seen=now(), online=TRUE`,
    [id, m.hw || "lora", m.caps || {}, m.fw || null,
     m.ip || null, m.mac || null, m.gw || null]);
  console.log(`info: ${id} (${m.hw})`);
}

// телеметрия
async function onData(id, m) {
  // авторегистрация, если data пришла раньше info
  await pg.query(`
    INSERT INTO devices (node_id, transport) VALUES ($1,$2)
    ON CONFLICT (node_id) DO NOTHING`, [id, m.rssi != null ? "lora" : "lan"]);

  await pg.query(`
    UPDATE devices SET last_seen=now(), online=TRUE,
      last_rssi=$2, last_snr=$3, gw=COALESCE($4, gw)
    WHERE node_id=$1`,
    [id, m.rssi ?? null, m.snr ?? null, m.gw ?? null]);

  await pg.query(`
    INSERT INTO telemetry (node_id, v, a, w, kwh, pf, hz, relays, rssi, snr)
    VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10)`,
    [id, m.v ?? null, m.a ?? null, m.w ?? null, m.kwh ?? null,
     m.pf ?? null, m.hz ?? null, JSON.stringify(m.r ?? []),
     m.rssi ?? null, m.snr ?? null]);

  // фронты реле → журнал
  const prev = lastRelays.get(id);
  if (Array.isArray(m.r)) {
    if (prev) {
      for (let i = 0; i < m.r.length; i++) {
        if (prev[i] !== m.r[i]) {
          await pg.query(
            `INSERT INTO relay_events (node_id, relay_n, state) VALUES ($1,$2,$3)`,
            [id, i, !!m.r[i]]);
        }
      }
    }
    lastRelays.set(id, m.r.slice());
  }
}

// LWT LAN-узлов
async function onStatus(id, s) {
  await pg.query(`UPDATE devices SET online=$2 WHERE node_id=$1`,
    [id, s === "online"]);
}

// LoRa-узлы без LWT: оффлайн по таймауту
setInterval(async () => {
  await pg.query(`
    UPDATE devices SET online=FALSE
    WHERE online AND transport='lora'
      AND last_seen < now() - make_interval(secs => $1)`, [OFFLINE_AFTER_S]);
}, 30000);

// ---------------- HA MQTT Discovery ----------------
// вызывается при approve: сущности появляются в HA автоматически
async function publishHaDiscovery(d) {
  const dev = {
    identifiers: [`energy_${d.node_id}`],
    name: d.name || d.node_id,
    manufacturer: "МПО-Информ",
    model: d.transport === "lan" ? "Energy Node LAN" : "Energy Node LoRa",
    sw_version: d.fw || "",
  };
  const base = `nodes/${d.node_id}`;
  const pub = (t, cfg) =>
    mq.publish(t, JSON.stringify(cfg), { retain: true });

  const sensors = [
    ["v",   "Напряжение", "voltage", "V",   null],
    ["a",   "Ток",        "current", "A",   null],
    ["w",   "Мощность",   "power",   "W",   null],
    ["kwh", "Энергия",    "energy",  "kWh", "total_increasing"],
  ];
  for (const [key, name, cls, unit, stateClass] of sensors) {
    const cfg = {
      name, unique_id: `${d.node_id}_${key}`,
      state_topic: `${base}/data`,
      value_template: `{{ value_json.${key} }}`,
      device_class: cls, unit_of_measurement: unit, device: dev,
    };
    if (stateClass) cfg.state_class = stateClass;
    pub(`homeassistant/sensor/${d.node_id}_${key}/config`, cfg);
  }

  const nRelays = d.caps?.relays || 0;
  const names = d.relay_names || [];
  for (let i = 0; i < nRelays; i++) {
    pub(`homeassistant/switch/${d.node_id}_r${i}/config`, {
      name: names[i] || `Реле ${i + 1}`,
      unique_id: `${d.node_id}_r${i}`,
      state_topic: `${base}/data`,
      value_template: `{{ 'ON' if value_json.r[${i}] == 1 else 'OFF' }}`,
      command_topic: `${base}/cmd`,
      payload_on:  JSON.stringify({ cmd: "relay", n: i, s: 1 }),
      payload_off: JSON.stringify({ cmd: "relay", n: i, s: 0 }),
      device: dev,
    });
  }
}

// ---------------- REST API для интерфейса ----------------
const app = express();
app.use(express.json());

// список устройств (+ последняя телеметрия); ?status=pending|active
app.get("/api/devices", async (req, res) => {
  const { status, project } = req.query;
  const cond = [], args = [];
  if (status)  { args.push(status);  cond.push(`status=$${args.length}`); }
  if (project) { args.push(project); cond.push(`project=$${args.length}`); }
  const where = cond.length ? "WHERE " + cond.join(" AND ") : "";
  const { rows } = await pg.query(
    `SELECT * FROM v_devices_board ${where} ORDER BY project, name NULLS LAST, node_id`, args);
  res.json(rows);
});

// подтвердить устройство (добавить на сервер)
app.post("/api/devices/:id/approve", async (req, res) => {
  const { name, project, object, relay_names, approved_by } = req.body || {};
  const { rows } = await pg.query(`
    UPDATE devices SET status='active', name=$2, project=$3, object=$4,
      relay_names=$5, approved_at=now(), approved_by=$6
    WHERE node_id=$1 RETURNING *`,
    [req.params.id, name || req.params.id, project || null, object || null,
     JSON.stringify(relay_names || []), approved_by || "ui"]);
  if (!rows.length) return res.status(404).json({ error: "not found" });
  await publishHaDiscovery(rows[0]);
  res.json(rows[0]);
});

// отклонить / отключить
app.post("/api/devices/:id/disable", async (req, res) => {
  await pg.query(`UPDATE devices SET status='disabled' WHERE node_id=$1`,
    [req.params.id]);
  res.json({ ok: true });
});

// команда узлу (реле, poll) + журнал
app.post("/api/devices/:id/cmd", async (req, res) => {
  const payload = req.body || {};
  mq.publish(`nodes/${req.params.id}/cmd`, JSON.stringify(payload));
  await pg.query(
    `INSERT INTO commands (node_id, payload, source) VALUES ($1,$2,'ui')`,
    [req.params.id, JSON.stringify(payload)]);
  res.json({ ok: true });
});

// история для графиков: ?hours=24
app.get("/api/devices/:id/history", async (req, res) => {
  const hours = Math.min(parseInt(req.query.hours || "24", 10), 720);
  const { rows } = await pg.query(`
    SELECT ts, v, a, w, kwh FROM telemetry
    WHERE node_id=$1 AND ts > now() - make_interval(hours => $2)
    ORDER BY ts`, [req.params.id, hours]);
  res.json(rows);
});

// журнал реле
app.get("/api/devices/:id/relay-events", async (req, res) => {
  const { rows } = await pg.query(`
    SELECT ts, relay_n, state FROM relay_events
    WHERE node_id=$1 ORDER BY ts DESC LIMIT 100`, [req.params.id]);
  res.json(rows);
});

app.listen(PORT, () => console.log(`API on :${PORT}`));