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 DB
// ==========================================
async function autoUpdateDB() {
  const client = await pool.connect();
  try {
    console.log("🔄 Revisando estructura de base de datos...");

    await client.query(`
      CREATE TABLE IF NOT EXISTS users (
        id SERIAL PRIMARY KEY,
        full_name TEXT NOT NULL,
        phone TEXT NOT NULL, -- ELIMINADO 'UNIQUE' EN DEFINICIÓN (Se gestiona abajo)
        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()
      );
    `);

    // --- CORRECCIÓN MULTITENANT ---
    // Eliminamos la restricción global de teléfono único si existe para permitir 
    // que el mismo teléfono esté en varias empresas.
    try {
        await client.query(`ALTER TABLE users DROP CONSTRAINT IF EXISTS users_phone_key`);
    } catch (e) {
        // Ignoramos si no existe o hay error menor
    }

    // Parches
    await client.query(`
      DO $$ BEGIN 
        IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name='users' AND column_name='role') THEN 
          ALTER TABLE users ADD COLUMN role TEXT DEFAULT 'operario'; 
        END IF; 
        IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name='users' AND column_name='owner_id') THEN 
          ALTER TABLE users ADD COLUMN owner_id INT; 
        END IF; 
        IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name='guilds' AND column_name='owner_id') THEN 
          ALTER TABLE guilds ADD COLUMN owner_id INT REFERENCES users(id) ON DELETE CASCADE; 
        END IF; 
        IF NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name='services' AND column_name='owner_id') THEN 
          ALTER TABLE services ADD COLUMN owner_id INT REFERENCES users(id) ON DELETE CASCADE; 
        END IF; 
      END $$;
    `);

    try { await client.query(`ALTER TABLE guilds DROP CONSTRAINT IF EXISTS guilds_name_key`); } catch (e) {}
    console.log("✅ DB Sincronizada.");
  } 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) {
  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" }); }
}

async function sendWhatsAppCode(phone, code) {
    if (!EVOLUTION_BASE_URL || !EVOLUTION_API_KEY) {
        console.log("⚠️ Evolution no configurado. Código:", code);
        return;
    }
    const url = `${EVOLUTION_BASE_URL.replace(/\/$/, "")}/message/sendText/${EVOLUTION_INSTANCE}`;
    await fetch(url, { 
         method: "POST", 
         headers: { "Content-Type": "application/json", "apikey": EVOLUTION_API_KEY },
         body: JSON.stringify({ number: phone.replace("+", ""), text: `🔐 Código IntegraRepara: *${code}*` })
    }).catch(console.error);
}

// =========================
// RUTAS DE AUTENTICACIÓN
// =========================

// 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" });
    
    const passwordHash = await bcrypt.hash(password, 10);
    await client.query('BEGIN');
    
    // Verificamos Email (Que debe ser único globalmente para login)
    const checkUser = await client.query("SELECT * FROM users WHERE email = $1", [email]);
    let userId;

    if (checkUser.rowCount > 0) {
      const existing = checkUser.rows[0];
      // Si existe y ya está verificado, error.
      if (existing.is_verified) {
        await client.query('ROLLBACK');
        return res.status(409).json({ ok: false, error: "El email ya está registrado." });
      }
      await client.query("UPDATE users SET full_name=$1, address=$2, dni=$3, password_hash=$4, phone=$5 WHERE id=$6", [fullName, address, dni, passwordHash, p, existing.id]);
      userId = existing.id;
    } else {
      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]);
    await sendWhatsAppCode(p, code);
    
    await client.query('COMMIT');
    res.json({ ok: true, phone: p });
  } catch (e) {
    await client.query('ROLLBACK');
    res.status(500).json({ ok: false, error: "Error server" });
  } finally { client.release(); }
});

// 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: "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" }); }
});

// RECUPERAR CONTRASEÑA
app.post("/auth/forgot-password", async (req, res) => {
  try {
    const { dni, phone } = req.body;
    const p = normalizePhone(phone);
    const userQuery = await pool.query("SELECT id FROM users WHERE dni = $1 AND phone = $2", [dni, p]);
    
    if (userQuery.rowCount === 0) {
        return res.status(404).json({ ok: false, error: "No coinciden los datos." });
    }

    const userId = userQuery.rows[0].id;
    const code = genCode6();
    const codeHash = await bcrypt.hash(code, 10);
    const expiresAt = new Date(Date.now() + 10 * 60 * 1000);

    await pool.query("INSERT INTO login_codes (user_id, phone, code_hash, purpose, expires_at) VALUES ($1, $2, $3, 'password_reset', $4)", 
    [userId, p, codeHash, expiresAt]);

    await sendWhatsAppCode(p, code);
    res.json({ ok: true, msg: "Código enviado" });

  } catch (e) {
    console.error(e);
    res.status(500).json({ ok: false, error: "Error interno" });
  }
});

app.post("/auth/reset-password", async (req, res) => {
  const client = await pool.connect();
  try {
    const { phone, code, newPassword } = req.body;
    const p = normalizePhone(phone);

    const codeQuery = await client.query(`
        SELECT lc.*, u.id as uid 
        FROM login_codes lc
        JOIN users u ON lc.user_id = u.id
        WHERE lc.phone=$1 
          AND lc.purpose='password_reset' 
          AND lc.consumed_at IS NULL 
          AND lc.expires_at > NOW()
        ORDER BY lc.created_at DESC LIMIT 1
    `, [p]);

    if (codeQuery.rowCount === 0) return res.status(400).json({ ok: false, error: "Código inválido o expirado" });

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

    const newHash = await bcrypt.hash(newPassword, 10);
    
    await client.query('BEGIN');
    await client.query("UPDATE users SET password_hash=$1 WHERE id=$2", [newHash, row.uid]);
    await client.query("UPDATE login_codes SET consumed_at=NOW() WHERE id=$1", [row.id]);
    await client.query('COMMIT');

    res.json({ ok: true, msg: "Contraseña actualizada" });

  } catch (e) {
    await client.query('ROLLBACK');
    console.error(e);
    res.status(500).json({ ok: false, error: "Error al cambiar contraseña" });
  } finally { client.release(); }
});


// =========================
// RUTAS PROTEGIDAS
// =========================

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" }); }
});

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 }); }
});

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 }); }
});

// ADMIN USERS
app.get("/admin/users", authMiddleware, async (req, res) => {
  try {
    const q = await pool.query(`
      SELECT u.id, u.full_name, u.email, u.phone, u.role, COALESCE(json_agg(g.id) FILTER (WHERE g.id IS NOT NULL), '[]') as guilds
      FROM users u LEFT JOIN user_guilds ug ON u.id = ug.user_id LEFT JOIN guilds g ON ug.guild_id = g.id
      WHERE u.owner_id = $1 GROUP BY u.id ORDER BY u.id DESC
    `, [req.user.accountId]);
    res.json({ ok: true, users: q.rows });
  } catch (e) { res.status(500).json({ ok: false, error: "Error listar users" }); }
});

// CREAR USUARIO (CORREGIDO MULTITENANT)
app.post("/admin/users", authMiddleware, async (req, res) => {
  const client = await pool.connect();
  try {
    const { fullName, email, password, role, guilds, phone } = req.body;
    if (!email || !password || !fullName || !phone) return res.status(400).json({ ok: false, error: "Faltan datos" });
    const p = normalizePhone(phone);
    const passwordHash = await bcrypt.hash(password, 10);

    // NUEVO: Verificamos duplicado SOLO dentro de mi empresa
    const checkDup = await client.query(
        "SELECT id FROM users WHERE (phone=$1 OR email=$2) AND owner_id=$3",
        [p, email, req.user.accountId]
    );
    if (checkDup.rowCount > 0) {
        return res.status(400).json({ ok: false, error: "❌ Este empleado ya existe en tu empresa (Email o Teléfono)." });
    }

    await client.query('BEGIN');
    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', p, 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');
    // Mantenemos el check global de email único, pero permitimos teléfonos duplicados en distintas empresas
    if (e.code === '23505' && e.constraint.includes('email')) {
        return res.status(400).json({ ok: false, error: "❌ El Email ya está usado en el sistema." });
    }
    res.status(500).json({ ok: false, error: "Error creando usuario" });
  } finally { client.release(); }
});

app.put("/admin/users/:id", authMiddleware, async (req, res) => {
    const client = await pool.connect();
    try {
        const userId = req.params.id;
        const { fullName, email, phone, role, guilds, password } = req.body;
        const p = normalizePhone(phone);
        await client.query('BEGIN');
        const check = await client.query("SELECT id FROM users WHERE id=$1 AND owner_id=$2", [userId, req.user.accountId]);
        if(check.rowCount === 0) throw new Error("No encontrado");
        if(password) {
            const hash = await bcrypt.hash(password, 10);
            await client.query("UPDATE users SET full_name=$1, email=$2, phone=$3, role=$4, password_hash=$5 WHERE id=$6", [fullName, email, p, role, hash, userId]);
        } else {
            await client.query("UPDATE users SET full_name=$1, email=$2, phone=$3, role=$4 WHERE id=$5", [fullName, email, p, role, userId]);
        }
        if (guilds && Array.isArray(guilds)) {
            await client.query("DELETE FROM user_guilds WHERE user_id=$1", [userId]);
            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: "Actualizado" });
    } catch (e) { await client.query('ROLLBACK'); res.status(500).json({ ok: false, error: "Error updating" }); } finally { client.release(); }
});

app.delete("/admin/users/:id", authMiddleware, async (req, res) => {
    try {
        const result = await pool.query("DELETE FROM users WHERE id=$1 AND owner_id=$2", [req.params.id, req.user.accountId]);
        if (result.rowCount === 0) return res.status(404).json({ ok: false, error: "No encontrado" });
        res.json({ ok: true });
    } catch (e) { res.status(500).json({ ok: false, error: "Error deleting" }); }
});

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