/**
 * customerProfile — perfil del cliente para "lo de siempre".
 *
 * Lookup por teléfono (extraído del chat_id WhatsApp) en woo_orders_cache.
 * Agrupa items por woo_product_id en los últimos 6 meses, top 5 frequent_items.
 *
 * Cache 10 min por chat_id.
 */

import { pool } from "../../shared/db/pool.js";

const CACHE_TTL_MS = 10 * 60 * 1000;
const _cache = new Map();

function phoneFromChatId(chatId) {
  if (!chatId) return null;
  // chat_id típico: "5491133230322@s.whatsapp.net"
  const m = /^(\d+)/.exec(String(chatId));
  return m ? m[1] : null;
}

function normalizePhone(p) {
  return String(p || "").replace(/[^\d]/g, "");
}

/**
 * Devuelve perfil del cliente o null si no hay datos.
 */
export async function getCustomerProfile({ tenantId, chat_id }) {
  if (!tenantId || !chat_id) return null;
  const cacheKey = `${tenantId}:${chat_id}`;
  const cached = _cache.get(cacheKey);
  if (cached && Date.now() - cached.t < CACHE_TTL_MS) return cached.value;

  const phone = phoneFromChatId(chat_id);
  if (!phone) {
    _cache.set(cacheKey, { value: null, t: Date.now() });
    return null;
  }

  try {
    const profile = await fetchProfile({ tenantId, phone });
    _cache.set(cacheKey, { value: profile, t: Date.now() });
    return profile;
  } catch (err) {
    console.error("[customerProfile] error:", err?.message || err);
    return null;
  }
}

async function fetchProfile({ tenantId, phone }) {
  const phoneClean = normalizePhone(phone);
  if (!phoneClean) return null;

  // Match phones que terminen igual (los Woo a veces vienen con +54 o sin)
  const phoneSuffix = phoneClean.slice(-8);

  const orderSql = `
    SELECT id, woo_order_id, total, date_created,
           shipping_address_1, shipping_address_2, shipping_city, customer_name
    FROM woo_orders_cache
    WHERE tenant_id = $1
      AND regexp_replace(coalesce(customer_phone,''), '\\D', '', 'g') LIKE '%' || $2
      AND date_created > NOW() - INTERVAL '6 months'
    ORDER BY date_created DESC
    LIMIT 30
  `;
  const { rows: orders } = await pool.query(orderSql, [tenantId, phoneSuffix]);
  if (orders.length === 0) {
    return { is_returning: false, last_order_at: null, frequent_items: [], preferred_address: null };
  }

  const orderIds = orders.map((o) => o.woo_order_id);
  const itemsSql = `
    SELECT woo_product_id, product_name, sell_unit,
           COUNT(*) AS times,
           SUM(quantity) AS total_qty,
           AVG(quantity) AS avg_qty
    FROM woo_order_items
    WHERE tenant_id = $1 AND woo_order_id = ANY($2::bigint[]) AND woo_product_id IS NOT NULL
    GROUP BY woo_product_id, product_name, sell_unit
    ORDER BY times DESC, total_qty DESC
    LIMIT 5
  `;
  const { rows: items } = await pool.query(itemsSql, [tenantId, orderIds]);

  const frequent_items = items.map((it) => ({
    woo_id: Number(it.woo_product_id),
    name: it.product_name,
    times_ordered: Number(it.times),
    avg_qty: Number(it.avg_qty),
    avg_unit: it.sell_unit || null,
  }));

  const lastOrder = orders[0];
  const preferredAddress = [lastOrder.shipping_address_1, lastOrder.shipping_address_2, lastOrder.shipping_city]
    .filter(Boolean)
    .join(", ");

  return {
    is_returning: true,
    last_order_at: lastOrder.date_created,
    customer_name: lastOrder.customer_name || null,
    frequent_items,
    preferred_address: preferredAddress || null,
    total_orders_last_6m: orders.length,
  };
}

export function invalidateCustomerProfileCache(chat_id) {
  for (const k of _cache.keys()) if (k.endsWith(`:${chat_id}`)) _cache.delete(k);
}