import express from "express";
import cors from "cors";
import bcrypt from "bcryptjs";
import jwt from "jsonwebtoken";
import pg from "pg";

const { Pool } = pg;

const app = express();
app.use(cors());
app.use(express.json());

// =========================
// ENV (Coolify variables)
// =========================
const {
  DATABASE_URL,
  JWT_SECRET,
  EVOLUTION_BASE_URL,
  EVOLUTION_API_KEY,
  EVOLUTION_INSTANCE,
  EVOLUTION_SENDER_NUMBER
} = process.env;

if (!DATABASE_URL) console.warn("⚠️ DATABASE_URL no definido");
if (!JWT_SECRET) console.warn("⚠️ JWT_SECRET no definido");

// =========================
// DB
// =========================
const pool = new Pool({
  connectionString: DATABASE_URL,
  ssl: DATABASE_URL?.includes("localhost") ? false : { rejectUnauthorized: false }
});

// =========================
// Helpers
// =========================
function normalizePhone(phone) {
  // Ajusta a tu gusto (E.164). Para España: +34XXXXXXXXX
  let p = String(phone || "").trim().replace(/\s+/g, "");
  if (!p) return "";
  if (!p.startsWith("+")) {
    // si meten 600..., asumimos España
    if (/^\d{9}$/.test(p)) p = "+34" + p;
  }
  return p;
}

function genCode6() {
  // 6 dígitos
  return String(Math.floor(100000 + Math.random() * 900000));
}

function signToken(user) {
  return jwt.sign(
    { sub: user.id, phone: user.phone, email: user.email },
    JWT_SECRET,
    { expiresIn: "30d" }
  );
}

function authMiddleware(req, res, next) {
  const h = req.headers.authorization || "";
  const token = h.startsWith("Bearer ") ? h.slice(7) : "";
  if (!token) return res.status(401).json({ ok: false, error: "No token" });

  try {
    const payload = jwt.verify(token, JWT_SECRET);
    req.user = payload;
    next();
  } catch {
    return res.status(401).json({ ok: false, error: "Token inválido" });
  }
}

// Rate-limit muy simple en memoria (para no freír el WhatsApp)
const lastSendByPhone = new Map();
function canSendCode(phone) {
  const now = Date.now();
  const last = lastSendByPhone.get(phone) || 0;
  // 1 envío cada 60s
  if (now - last < 60_000) return false;
  lastSendByPhone.set(phone, now);
  return true;
}

// =========================
// Evolution API (WhatsApp)
// =========================
async function sendWhatsAppCode(phone, code) {
  if (!EVOLUTION_BASE_URL || !EVOLUTION_API_KEY || !EVOLUTION_INSTANCE) {
    console.warn("⚠️ Evolution API env no configuradas, no envío WhatsApp.");
    return { ok: false, skipped: true };
  }

  // OJO: el endpoint exacto puede variar según tu Evolution.
  // Ajustamos a un patrón típico: /message/sendText/{instance}
  const url = `${EVOLUTION_BASE_URL.replace(/\/$/, "")}/message/sendText/${encodeURIComponent(EVOLUTION_INSTANCE)}`;

  const payload = {
    number: phone, // normalmente en formato +34...
    text: `Tu código de verificación es: ${code}\nCaduca en 10 minutos.`
  };

  const res = await fetch(url, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "apikey": EVOLUTION_API_KEY
    },
    body: JSON.stringify(payload)
  });

  const text = await res.text();
  let data;
  try { data = JSON.parse(text); } catch { data = text; }

  if (!res.ok) {
    console.error("❌ Evolution send failed:", res.status, data);
    return { ok: false, status: res.status, data };
  }
  return { ok: true, data };
}

// =========================
// Health
// =========================
app.get("/health", async (req, res) => {
  try {
    const r = await pool.query("select now() as now");
    res.json({ ok: true, db: true, now: r.rows[0].now });
  } catch (e) {
    res.json({ ok: false, db: false, error: String(e?.message || e) });
  }
});

app.get("/", (req, res) => res.send("IntegraRepara API OK"));

// =========================
// AUTH
// =========================

// Registro: crea user + manda código WhatsApp
app.post("/auth/register", async (req, res) => {
  try {
    const {
      fullName,
      phone,
      address,
      dni,
      email,
      password
    } = req.body || {};

    const p = normalizePhone(phone);

    if (!fullName || !p || !address || !dni || !email || !password) {
      return res.status(400).json({ ok: false, error: "Faltan campos obligatorios" });
    }

    if (!canSendCode(p)) {
      return res.status(429).json({ ok: false, error: "Espera 1 minuto antes de pedir otro código" });
    }

    const passwordHash = await bcrypt.hash(String(password), 10);

    // intenta crear usuario
    let user;
    try {
      const q = await pool.query(
        `insert into users (full_name, phone, address, dni, email, password_hash, is_verified)
         values ($1,$2,$3,$4,$5,$6,false)
         returning id, full_name, phone, email, is_verified`,
        [String(fullName).trim(), p, String(address).trim(), String(dni).trim(), String(email).trim().toLowerCase(), passwordHash]
      );
      user = q.rows[0];
    } catch (e) {
      // si ya existe por email o phone
      return res.status(409).json({ ok: false, error: "Ya existe un usuario con ese teléfono o email" });
    }

    const code = genCode6();
    const codeHash = await bcrypt.hash(code, 10);
    const expiresAt = new Date(Date.now() + 10 * 60 * 1000); // 10 min

    await pool.query(
      `insert into login_codes (user_id, phone, code_hash, purpose, expires_at)
       values ($1,$2,$3,'register_verify',$4)`,
      [user.id, p, codeHash, expiresAt]
    );

    await sendWhatsAppCode(p, code);

    res.json({ ok: true, needsVerify: true, phone: p });
  } catch (e) {
    res.status(500).json({ ok: false, error: String(e?.message || e) });
  }
});

// Verificar código de registro: activa user + devuelve token
app.post("/auth/verify", async (req, res) => {
  try {
    const { phone, code } = req.body || {};
    const p = normalizePhone(phone);

    if (!p || !code) return res.status(400).json({ ok: false, error: "Faltan phone o code" });

    const u = await pool.query(`select * from users where phone=$1`, [p]);
    if (!u.rowCount) return res.status(404).json({ ok: false, error: "Usuario no existe" });
    const user = u.rows[0];

    // busca último código válido no consumido
    const c = await pool.query(
      `select * from login_codes
       where phone=$1 and purpose='register_verify' and consumed_at is null and expires_at > now()
       order by created_at desc
       limit 1`,
      [p]
    );

    if (!c.rowCount) return res.status(400).json({ ok: false, error: "Código inválido o caducado" });

    const row = c.rows[0];
    const ok = await bcrypt.compare(String(code).trim(), row.code_hash);
    if (!ok) return res.status(400).json({ ok: false, error: "Código incorrecto" });

    await pool.query(`update login_codes set consumed_at=now() where id=$1`, [row.id]);
    await pool.query(`update users set is_verified=true where id=$1`, [user.id]);

    // settings por defecto
    await pool.query(
      `insert into user_settings (user_id, company_name)
       values ($1,$2)
       on conflict (user_id) do nothing`,
      [user.id, user.full_name]
    );

    const token = signToken(user);
    res.json({ ok: true, token });
  } catch (e) {
    res.status(500).json({ ok: false, error: String(e?.message || e) });
  }
});

// Login normal (email+password). Si quieres 2FA por WhatsApp también, lo hacemos luego.
app.post("/auth/login", async (req, res) => {
  try {
    const { email, password } = req.body || {};
    if (!email || !password) return res.status(400).json({ ok: false, error: "Faltan email o password" });

    const q = await pool.query(`select * from users where email=$1`, [String(email).trim().toLowerCase()]);
    if (!q.rowCount) return res.status(401).json({ ok: false, error: "Credenciales incorrectas" });

    const user = q.rows[0];

    const ok = await bcrypt.compare(String(password), user.password_hash);
    if (!ok) return res.status(401).json({ ok: false, error: "Credenciales incorrectas" });

    if (!user.is_verified) return res.status(403).json({ ok: false, error: "Cuenta no verificada por WhatsApp" });

    const token = signToken(user);
    res.json({ ok: true, token });
  } catch (e) {
    res.status(500).json({ ok: false, error: String(e?.message || e) });
  }
});

// =========================
// SERVICES (multi-tenant)
// =========================
app.get("/services", authMiddleware, async (req, res) => {
  try {
    const userId = req.user.sub;
    const q = await pool.query(
      `select * from services where user_id=$1 order by created_at desc`,
      [userId]
    );
    res.json({ ok: true, count: q.rowCount, services: q.rows });
  } catch (e) {
    res.status(500).json({ ok: false, error: String(e?.message || e) });
  }
});

app.post("/services", authMiddleware, async (req, res) => {
  try {
    const userId = req.user.sub;
    const body = req.body || {};
    const title = body.title;
    const clientName = body.clientName ?? body.client ?? "";

    if (!title) return res.status(400).json({ ok: false, error: "Falta title" });

    const q = await pool.query(
      `insert into services (user_id, title, client_name, phone, address, notes)
       values ($1,$2,$3,$4,$5,$6)
       returning *`,
      [
        userId,
        String(title).trim(),
        clientName ? String(clientName).trim() : null,
        body.phone ? String(body.phone).trim() : null,
        body.address ? String(body.address).trim() : null,
        body.notes ? String(body.notes).trim() : null
      ]
    );

    res.status(201).json({ ok: true, service: q.rows[0] });
  } catch (e) {
    res.status(500).json({ ok: false, error: String(e?.message || e) });
  }
});

// =========================
// STATIC (HTML)
// =========================
app.use(express.static("public"));

const port = process.env.PORT || 3000;
app.listen(port, () => console.log(`🚀 API listening on :${port}`));