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();

// =========================
// MIDDLEWARES
// =========================
app.use(cors());
app.use(express.json());

// =========================
// VARIABLES DE ENTORNO
// =========================
const {
  DATABASE_URL,
  JWT_SECRET,
  EVOLUTION_BASE_URL,
  EVOLUTION_API_KEY,
  EVOLUTION_INSTANCE,
} = process.env;

if (!DATABASE_URL || !JWT_SECRET) {
  console.error("❌ ERROR FATAL: Faltan variables DATABASE_URL o JWT_SECRET");
  process.exit(1);
}

// =========================
// CONEXIÓN DB
// =========================
const pool = new Pool({
  connectionString: DATABASE_URL,
  ssl: false // Correcto para Coolify interno
});

// ==========================================
// 🛠️ RUTA DE INSTALACIÓN (Ejecutar una vez)
// ==========================================
// Esta ruta crea las tablas si no existen.
// Úsala entrando a: https://tu-api.com/setup-db
app.get("/setup-db", async (req, res) => {
  try {
    const client = await pool.connect();
    await client.query(`
      CREATE TABLE IF NOT EXISTS users (
        id SERIAL PRIMARY KEY,
        full_name TEXT NOT NULL,
        phone TEXT UNIQUE NOT NULL,
        email TEXT UNIQUE NOT NULL,
        dni TEXT,
        address TEXT,
        password_hash TEXT NOT NULL,
        is_verified BOOLEAN DEFAULT FALSE,
        created_at TIMESTAMP DEFAULT NOW()
      );

      CREATE TABLE IF NOT EXISTS login_codes (
        id SERIAL PRIMARY KEY,
        user_id INT REFERENCES users(id) ON DELETE CASCADE,
        phone TEXT NOT NULL,
        code_hash TEXT NOT NULL,
        purpose TEXT DEFAULT 'register_verify',
        consumed_at TIMESTAMP,
        expires_at TIMESTAMP NOT NULL,
        created_at TIMESTAMP DEFAULT NOW()
      );

      CREATE TABLE IF NOT EXISTS services (
        id SERIAL PRIMARY KEY,
        user_id INT REFERENCES users(id) ON DELETE CASCADE,
        title TEXT NOT NULL,
        client_name TEXT,
        phone TEXT,
        address TEXT,
        notes TEXT,
        created_at TIMESTAMP DEFAULT NOW()
      );
    `);
    client.release();
    res.send("✅ ¡Base de datos configurada correctamente! Tablas creadas.");
  } catch (e) {
    console.error(e);
    res.status(500).send("❌ Error creando tablas: " + e.message);
  }
});

// =========================
// RUTA DE "ESTOY VIVO"
// =========================
app.get("/", (req, res) => {
  res.status(200).send("🚀 IntegraRepara API v1.0 - Online");
});

// =========================
// HELPERS
// =========================
function normalizePhone(phone) {
  let p = String(phone || "").trim().replace(/\s+/g, "").replace(/-/g, "");
  if (!p) return "";
  if (!p.startsWith("+") && /^[6789]\d{8}$/.test(p)) {
    return "+34" + p;
  }
  return p;
}

function genCode6() {
  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" });
  }
}

// =========================
// WHATSAPP
// =========================
async function sendWhatsAppCode(phone, code) {
  if (!EVOLUTION_BASE_URL || !EVOLUTION_API_KEY) {
    console.log("⚠️ Evolution no configurado. Código simulado:", code);
    return { ok: true, skipped: true };
  }
  try {
    const baseUrl = EVOLUTION_BASE_URL.replace(/\/$/, "");
    const url = `${baseUrl}/message/sendText/${EVOLUTION_INSTANCE}`;
    
    const body = {
      number: phone.replace("+", ""), 
      text: `🔐 Tu código IntegraRepara es: *${code}*\n\nNo lo compartas.`
    };

    const res = await fetch(url, {
      method: "POST",
      headers: { "Content-Type": "application/json", "apikey": EVOLUTION_API_KEY },
      body: JSON.stringify(body)
    });
    
    if (!res.ok) {
        const txt = await res.text();
        console.error("❌ Error Evolution:", txt);
        return { ok: false };
    }
    return { ok: true };
  } catch (e) {
    console.error("❌ Error enviando WhatsApp:", e);
    return { ok: false };
  }
}

// =========================
// RUTAS
// =========================

// 1. REGISTRO
app.post("/auth/register", async (req, res) => {
  const client = await pool.connect();
  try {
    const { fullName, phone, address, dni, email, password } = req.body;
    const p = normalizePhone(phone);
    if (!fullName || !p || !email || !password) {
      return res.status(400).json({ ok: false, error: "Faltan datos obligatorios" });
    }
    
    const passwordHash = await bcrypt.hash(password, 10);
    
    await client.query('BEGIN');
    
    const checkUser = await client.query("SELECT * FROM users WHERE email = $1 OR phone = $2", [email, p]);
    let userId;

    if (checkUser.rowCount > 0) {
      const existing = checkUser.rows[0];
      if (existing.is_verified) {
        await client.query('ROLLBACK');
        return res.status(409).json({ ok: false, error: "Usuario ya registrado y verificado." });
      }
      await client.query(
        "UPDATE users SET full_name=$1, address=$2, dni=$3, password_hash=$4 WHERE id=$5",
        [fullName, address, dni, passwordHash, existing.id]
      );
      userId = existing.id;
    } else {
      const insert = await client.query(
        "INSERT INTO users (full_name, phone, address, dni, email, password_hash) VALUES ($1, $2, $3, $4, $5, $6) RETURNING id",
        [fullName, p, address, dni, email, passwordHash]
      );
      userId = insert.rows[0].id;
    }

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

    await client.query("DELETE FROM login_codes WHERE user_id = $1", [userId]);
    await client.query(
      "INSERT INTO login_codes (user_id, phone, code_hash, expires_at) VALUES ($1, $2, $3, $4)",
      [userId, p, codeHash, expiresAt]
    );

    await sendWhatsAppCode(p, code);
    
    await client.query('COMMIT');
    res.json({ ok: true, phone: p, msg: "Código enviado" });
  } catch (e) {
    await client.query('ROLLBACK');
    console.error("Error en Registro:", e);
    res.status(500).json({ ok: false, error: "Error interno del servidor" });
  } finally {
    client.release();
  }
});

// 2. VERIFICACIÓN
app.post("/auth/verify", async (req, res) => {
  try {
    const { phone, code } = req.body;
    const p = normalizePhone(phone);
    
    const q = await pool.query(`
      SELECT lc.*, u.id as uid, u.email 
      FROM login_codes lc 
      JOIN users u ON lc.user_id = u.id
      WHERE lc.phone=$1 AND lc.consumed_at IS NULL AND lc.expires_at > NOW()
      ORDER BY lc.created_at DESC LIMIT 1`, 
      [p]
    );

    if (q.rowCount === 0) return res.status(400).json({ ok: false, error: "Código inválido o expirado" });
    
    const row = q.rows[0];
    const valid = await bcrypt.compare(String(code), row.code_hash);
    
    if (!valid) 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", [row.uid]);
    
    const token = signToken({ id: row.uid, email: row.email, phone: p });
    res.json({ ok: true, token });
  } catch (e) {
    console.error("Error Verify:", e);
    res.status(500).json({ ok: false, error: "Error verificando código" });
  }
});

// 3. LOGIN
app.post("/auth/login", async (req, res) => {
  try {
    const { email, password } = req.body;
    const q = await pool.query("SELECT * FROM users WHERE email=$1", [email]);
    
    if (q.rowCount === 0) return res.status(401).json({ ok: false, error: "Credenciales inválidas" });
    
    const u = q.rows[0];
    const match = await bcrypt.compare(password, u.password_hash);
    
    if (!match) return res.status(401).json({ ok: false, error: "Credenciales inválidas" });
    if (!u.is_verified) return res.status(403).json({ ok: false, error: "Cuenta no verificada" });
    
    res.json({ ok: true, token: signToken(u) });
  } catch(e) {
    console.error("Error Login:", e);
    res.status(500).json({ ok: false, error: "Error en login" });
  }
});

// 4. SERVICIOS (PROTEGIDO)
app.get("/services", authMiddleware, async (req, res) => {
    try {
        const q = await pool.query("SELECT * FROM services WHERE user_id=$1 ORDER BY created_at DESC", [req.user.sub]);
        res.json({ ok: true, services: q.rows });
    } catch (e) {
        res.status(500).json({ ok: false, error: "Error al obtener servicios" });
    }
});

// ARRANCAR
const port = process.env.PORT || 3000;
app.listen(port, "0.0.0.0", () => console.log(`🚀 Server OK en puerto ${port}`));