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());

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 de entorno");
  process.exit(1);
}

const pool = new Pool({
  connectionString: DATABASE_URL,
  ssl: false 
});

// ==========================================
// 🧠 AUTO-ACTUALIZACIÓN DE BASE DE DATOS (AISLAMIENTO DE DATOS)
// ==========================================
async function autoUpdateDB() {
  const client = await pool.connect();
  try {
    console.log("🔄 Revisando estructura de base de datos...");

    // 1. Crear tablas básicas
    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 guilds (
        id SERIAL PRIMARY KEY,
        name TEXT NOT NULL, 
        created_at TIMESTAMP DEFAULT NOW()
      );
      CREATE TABLE IF NOT EXISTS user_guilds (
        user_id INT REFERENCES users(id) ON DELETE CASCADE,
        guild_id INT REFERENCES guilds(id) ON DELETE CASCADE,
        PRIMARY KEY (user_id, guild_id)
      );
      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()
      );
    `);

    // 2. AÑADIR COLUMNAS FALTANTES (PARCHES)
    
    // Parche A: Roles
    await client.query(`
      DO $$ BEGIN 
        IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name='users' AND column_name='role') THEN 
          ALTER TABLE users ADD COLUMN role TEXT DEFAULT 'operario'; 
        END IF; 
      END $$;
    `);

    // Parche B: DUEÑO (owner_id) en Usuarios
    await client.query(`
      DO $$ BEGIN 
        IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name='users' AND column_name='owner_id') THEN 
          ALTER TABLE users ADD COLUMN owner_id INT; 
        END IF; 
      END $$;
    `);

    // Parche C: DUEÑO en Gremios
    await client.query(`
      DO $$ BEGIN 
        IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name='guilds' AND column_name='owner_id') THEN 
          ALTER TABLE guilds ADD COLUMN owner_id INT REFERENCES users(id) ON DELETE CASCADE; 
        END IF; 
      END $$;
    `);

    // Parche D: DUEÑO en Servicios
    await client.query(`
      DO $$ BEGIN 
        IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name='services' AND column_name='owner_id') THEN 
          ALTER TABLE services ADD COLUMN owner_id INT REFERENCES users(id) ON DELETE CASCADE; 
        END IF; 
      END $$;
    `);

    // 3. LIMPIEZA DE RESTRICCIONES VIEJAS
    try {
        await client.query(`ALTER TABLE guilds DROP CONSTRAINT IF EXISTS guilds_name_key`);
    } catch (e) {}

    console.log("✅ DB Sincronizada: Aislamiento de datos activado.");
  } catch (e) {
    console.error("❌ Error DB:", e);
  } finally {
    client.release();
  }
}

// =========================
// 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) {
  // LÓGICA DE AISLAMIENTO:
  const accountId = user.owner_id || user.id;

  return jwt.sign(
    { 
      sub: user.id, 
      email: user.email, 
      phone: user.phone, 
      role: user.role || 'operario',
      accountId: accountId 
    },
    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 {
    req.user = jwt.verify(token, JWT_SECRET);
    next();
  } catch {
    return res.status(401).json({ ok: false, error: "Token inválido" });
  }
}

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

// 1. REGISTRO (Crea un DUEÑO / JEFE)
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" });
    
    const passwordHash = await bcrypt.hash(password, 10);
    
    await client.query('BEGIN');
    
    // Verificamos duplicados
    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." });
      }
      // Actualizamos reintento
      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 {
      // Insertamos nuevo. owner_id se deja NULL porque ÉL es el jefe.
      const insert = await client.query(
        "INSERT INTO users (full_name, phone, address, dni, email, password_hash, role, owner_id) VALUES ($1, $2, $3, $4, $5, $6, 'admin', NULL) 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]);

    // Enviar WhatsApp
    if (EVOLUTION_BASE_URL && EVOLUTION_API_KEY) {
        const url = `${EVOLUTION_BASE_URL.replace(/\/$/, "")}/message/sendText/${EVOLUTION_INSTANCE}`;
        await fetch(url, {
             method: "POST", 
             headers: { "Content-Type": "application/json", "apikey": EVOLUTION_API_KEY },
             body: JSON.stringify({ number: p.replace("+", ""), text: `🔐 Código IntegraRepara: *${code}*` })
        }).catch(console.error);
    } else {
        console.log("📨 Código simulado:", code);
    }
    
    await client.query('COMMIT');
    res.json({ ok: true, phone: p });
  } catch (e) {
    await client.query('ROLLBACK');
    console.error(e);
    res.status(500).json({ ok: false, error: "Error server" });
  } finally {
    client.release();
  }
});

// 2. VERIFICACIÓN & LOGIN
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, u.role, u.owner_id 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" });
    
    const row = q.rows[0];
    if (!(await bcrypt.compare(String(code), row.code_hash))) 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]);
    
    res.json({ ok: true, token: signToken({ id: row.uid, email: row.email, phone: p, role: row.role, owner_id: row.owner_id }) });
  } catch (e) { res.status(500).json({ ok: false, error: "Error verify" }); }
});

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: "Datos incorrectos" });
    const u = q.rows[0];
    if (!(await bcrypt.compare(password, u.password_hash))) return res.status(401).json({ ok: false, error: "Datos incorrectos" });
    
    res.json({ ok: true, token: signToken(u) });
  } catch(e) { res.status(500).json({ ok: false, error: "Error login" }); }
});

// ==========================================
// 🔒 RUTAS PROTEGIDAS (DATOS AISLADOS)
// ==========================================

// GET SERVICIOS (Solo los de MI empresa)
app.get("/services", authMiddleware, async (req, res) => {
    try {
        const q = await pool.query("SELECT * FROM services WHERE owner_id=$1 ORDER BY created_at DESC", [req.user.accountId]);
        res.json({ ok: true, services: q.rows });
    } catch (e) { res.status(500).json({ ok: false, error: "Error servicios" }); }
});

// GET GREMIOS
app.get("/guilds", authMiddleware, async (req, res) => {
  try {
    const q = await pool.query("SELECT * FROM guilds WHERE owner_id=$1 ORDER BY name ASC", [req.user.accountId]);
    res.json({ ok: true, guilds: q.rows });
  } catch (e) { res.status(500).json({ ok: false, error: e.message }); }
});

// POST GREMIOS
app.post("/guilds", authMiddleware, async (req, res) => {
  try {
    const { name } = req.body;
    if (!name) return res.status(400).json({ ok: false, error: "Falta nombre" });
    
    const q = await pool.query("INSERT INTO guilds (name, owner_id) VALUES ($1, $2) RETURNING *", [name.toUpperCase(), req.user.accountId]);
    res.json({ ok: true, guild: q.rows[0] });
  } catch (e) { res.status(500).json({ ok: false, error: "Gremio duplicado" }); }
});

app.delete("/guilds/:id", authMiddleware, async (req, res) => {
  try {
    await pool.query("DELETE FROM guilds WHERE id = $1 AND owner_id = $2", [req.params.id, req.user.accountId]);
    res.json({ ok: true });
  } catch (e) { res.status(500).json({ ok: false, error: e.message }); }
});

// CREAR USUARIO (Se vincula a MI empresa)
app.post("/admin/users", authMiddleware, async (req, res) => {
  const client = await pool.connect();
  try {
    const { fullName, email, password, role, guilds } = req.body;
    if (!email || !password || !fullName) return res.status(400).json({ ok: false, error: "Faltan datos" });

    const passwordHash = await bcrypt.hash(password, 10);
    const dummyPhone = `manual_${Date.now()}_${Math.floor(Math.random()*1000)}`; 

    await client.query('BEGIN');

    // AQUÍ ESTÁ LA MAGIA: owner_id = req.user.accountId
    const insert = await client.query(
      `INSERT INTO users (full_name, email, password_hash, role, phone, is_verified, owner_id) 
       VALUES ($1, $2, $3, $4, $5, TRUE, $6) RETURNING id`,
      [fullName, email, passwordHash, role || 'operario', dummyPhone, req.user.accountId]
    );
    const userId = insert.rows[0].id;

    if (guilds && Array.isArray(guilds)) {
      for (const guildId of guilds) {
        await client.query("INSERT INTO user_guilds (user_id, guild_id) VALUES ($1, $2)", [userId, guildId]);
      }
    }

    await client.query('COMMIT');
    res.json({ ok: true, msg: "Usuario creado" });
  } catch (e) {
    await client.query('ROLLBACK');
    
    // --- NUEVO: GESTIÓN DE ERRORES MEJORADA ---
    if (e.code === '23505') { // Código de clave duplicada
        if (e.constraint && e.constraint.includes('email')) {
            return res.status(400).json({ ok: false, error: "❌ El email ya está registrado." });
        }
    }
    // -------------------------------------------
    
    console.error(e);
    res.status(500).json({ ok: false, error: "Error creando usuario" });
  } finally {
    client.release();
  }
});

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