import { getDecryptedTenantEcommerceConfig } from "../2-identity/db/repo.js";
import { debug as dbg } from "../shared/debug.js";
import { getSnapshotPriceByWooId } from "../shared/wooSnapshot.js";
import * as ordersRepo from "./ordersRepo.js";

// --- Simple in-memory lock to serialize work per key ---
const locks = new Map();

// --- Sync lock per tenant to prevent concurrent syncs ---
const syncLocks = new Map();
const syncInProgress = new Map();

async function withLock(key, fn) {
  const prev = locks.get(key) || Promise.resolve();
  let release;
  const next = new Promise((r) => (release = r));
  locks.set(key, prev.then(() => next));
  await prev;
  try {
    return await fn();
  } finally {
    release();
    if (locks.get(key) === next) locks.delete(key);
  }
}

async function fetchWoo({ url, method = "GET", body = null, timeout = 20000, headers = {} }) {
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(new Error("timeout")), timeout);
  const t0 = Date.now();
  try {
    const res = await fetch(url, {
      method,
      headers: {
        "Content-Type": "application/json",
        ...headers,
      },
      body: body ? JSON.stringify(body) : undefined,
      signal: controller.signal,
    });
    if (dbg.wooHttp) console.log("[wooOrders] http", method, res.status, Date.now() - t0, "ms");
    const text = await res.text();
    let parsed;
    try {
      parsed = text ? JSON.parse(text) : null;
    } catch {
      parsed = text;
    }
    if (!res.ok) {
      const err = new Error(`Woo HTTP ${res.status}`);
      err.status = res.status;
      err.body = parsed;
      err.url = url;
      err.method = method;
      throw err;
    }
    return parsed;
  } catch (e) {
    const err = new Error(`Woo request failed after ${Date.now() - t0}ms: ${e.message}`);
    err.cause = e;
    err.status = e?.status || null;
    err.body = e?.body || null;
    err.url = url;
    err.method = method;
    throw err;
  } finally {
    clearTimeout(timer);
  }
}

async function getWooClient({ tenantId }) {
  const encryptionKey = process.env.APP_ENCRYPTION_KEY;
  if (!encryptionKey) throw new Error("APP_ENCRYPTION_KEY is required to decrypt Woo credentials");
  const cfg = await getDecryptedTenantEcommerceConfig({
    tenant_id: tenantId,
    provider: "woo",
    encryption_key: encryptionKey,
  });
  if (!cfg) throw new Error("Woo config not found for tenant");
  const consumerKey =
    cfg.consumer_key ||
    process.env.WOO_CONSUMER_KEY ||
    (() => {
      throw new Error("consumer_key not set");
    })();
  const consumerSecret =
    cfg.consumer_secret ||
    process.env.WOO_CONSUMER_SECRET ||
    (() => {
      throw new Error("consumer_secret not set");
    })();
  const base = cfg.base_url.replace(/\/+$/, "");
  const auth = Buffer.from(`${consumerKey}:${consumerSecret}`).toString("base64");
  return {
    base,
    authHeader: { Authorization: `Basic ${auth}` },
    timeout: Math.max(cfg.timeout_ms ?? 60000, 60000),
  };
}

function parsePrice(p) {
  if (p == null) return null;
  const n = Number(String(p).replace(",", "."));
  return Number.isFinite(n) ? n : null;
}

async function getWooProductPrice({ tenantId, productId }) {
  if (!productId) return null;
  const snap = await getSnapshotPriceByWooId({ tenantId, wooId: productId });
  if (snap != null) return Number(snap);
  const client = await getWooClient({ tenantId });
  const url = `${client.base}/products/${encodeURIComponent(productId)}`;
  const data = await fetchWoo({ url, method: "GET", timeout: client.timeout, headers: client.authHeader });
  return parsePrice(data?.price ?? data?.regular_price ?? data?.sale_price);
}

function normalizeBasketItems(basket) {
  const items = Array.isArray(basket?.items) ? basket.items : [];
  return items.filter((it) => it && it.product_id && it.quantity && it.unit);
}

function toMoney(value) {
  const n = Number(value);
  if (!Number.isFinite(n)) return null;
  return (Math.round(n * 100) / 100).toFixed(2);
}

async function buildLineItems({ tenantId, basket }) {
  const items = normalizeBasketItems(basket);
  const lineItems = [];
  for (const it of items) {
    const productId = Number(it.product_id);
    const unit = String(it.unit).toLowerCase();
    const qty = Number(it.quantity);
    if (!productId || !Number.isFinite(qty) || qty <= 0) continue;
    const pricePerKg = await getWooProductPrice({ tenantId, productId });

    if (unit === "unit") {
      const total = pricePerKg != null ? toMoney(pricePerKg * qty) : null;
      lineItems.push({
        product_id: productId,
        ...(it.variation_id ? { variation_id: it.variation_id } : {}),
        quantity: Math.round(qty),
        ...(total ? { subtotal: total, total } : {}),
        meta_data: [
          { key: "unit", value: "unit" },
        ],
      });
      continue;
    }

    // Carne por peso: convertir a gramos
    // Si qty < 100, asumir que viene en kg (ej: 1.5 kg)
    // Si qty >= 100, asumir que ya viene en gramos (ej: 1500 g)
    const grams = qty < 100 ? Math.round(qty * 1000) : Math.round(qty);
    const kilos = grams / 1000;
    const total = pricePerKg != null ? toMoney(pricePerKg * kilos) : null;
    lineItems.push({
      product_id: productId,
      ...(it.variation_id ? { variation_id: it.variation_id } : {}),
      quantity: 1,
      ...(total ? { subtotal: total, total } : {}),
      meta_data: [
        { key: "unit", value: "g" },
        { key: "weight_g", value: grams },
        { key: "unit_price_per_kg", value: pricePerKg },
      ],
    });
  }
  return lineItems;
}

function mapAddress(address) {
  if (!address || typeof address !== "object") return null;
  // Generar email fallback si no hay uno válido (usa formato wa_chat_id)
  let email = address.email || "";
  if (!email || !email.includes("@")) {
    const phone = address.phone || "";
    // Formato: {phone}@s.whatsapp.net (igual que wa_chat_id)
    email = phone ? `${phone.replace(/[^0-9]/g, "")}@s.whatsapp.net` : `anon-${Date.now()}@s.whatsapp.net`;
  }
  return {
    first_name: address.first_name || "",
    last_name: address.last_name || "",
    address_1: address.address_1 || address.text || "",
    address_2: address.address_2 || "",
    city: address.city || "",
    state: address.state || "",
    postcode: address.postcode || "",
    country: address.country || "AR",
    phone: address.phone || "",
    email,
  };
}

export async function createOrder({ tenantId, wooCustomerId, basket, address, shippingMethod, run_id }) {
  const lockKey = `${tenantId}:${wooCustomerId || "anon"}`;
  return withLock(lockKey, async () => {
    const client = await getWooClient({ tenantId });
    const lineItems = await buildLineItems({ tenantId, basket });
    if (!lineItems.length) throw new Error("order_empty_basket");
    const addr = mapAddress(address);
    // Estado "pending" en Woo = el pago/cobro lo gestiona el comercio offline.
    const payload = {
      status: "pending",
      customer_id: wooCustomerId || undefined,
      line_items: lineItems,
      ...(addr ? { billing: addr, shipping: addr } : {}),
      meta_data: [
        { key: "source", value: "whatsapp" },
        ...(run_id ? [{ key: "run_id", value: run_id }] : []),
        ...(shippingMethod ? [{ key: "shipping_method", value: shippingMethod }] : []),
      ],
    };
    const url = `${client.base}/orders`;
    const data = await fetchWoo({ url, method: "POST", body: payload, timeout: client.timeout, headers: client.authHeader });
    return { id: data?.id || null, raw: data, line_items: lineItems };
  });
}

export async function updateOrder({ tenantId, wooOrderId, basket, address, run_id }) {
  if (!wooOrderId) throw new Error("missing_woo_order_id");
  const lockKey = `${tenantId}:order:${wooOrderId}`;
  return withLock(lockKey, async () => {
    const client = await getWooClient({ tenantId });
    const lineItems = await buildLineItems({ tenantId, basket });
    if (!lineItems.length) throw new Error("order_empty_basket");
    const addr = mapAddress(address);
    const payload = {
      line_items: lineItems,
      ...(addr ? { billing: addr, shipping: addr } : {}),
      meta_data: [
        { key: "source", value: "whatsapp" },
        ...(run_id ? [{ key: "run_id", value: run_id }] : []),
      ],
    };
    const url = `${client.base}/orders/${encodeURIComponent(wooOrderId)}`;
    const data = await fetchWoo({ url, method: "PUT", body: payload, timeout: client.timeout, headers: client.authHeader });
    return { id: data?.id || wooOrderId, raw: data, line_items: lineItems };
  });
}

function isRetryableNetworkError(err) {
  const e0 = err;
  const e1 = err?.cause;
  const e2 = err?.cause?.cause;
  const candidates = [e0, e1, e2].filter(Boolean);
  const codes = new Set(candidates.map((e) => e.code).filter(Boolean));
  const names = new Set(candidates.map((e) => e.name).filter(Boolean));
  const messages = candidates.map((e) => String(e.message || "")).join(" | ").toLowerCase();

  const aborted =
    names.has("AbortError") ||
    messages.includes("aborted") ||
    messages.includes("timeout") ||
    messages.includes("timed out");

  const retryCodes = new Set(["ECONNRESET", "ETIMEDOUT", "UND_ERR_CONNECT_TIMEOUT", "UND_ERR_SOCKET"]);
  const byCode = [...codes].some((c) => retryCodes.has(c));

  return aborted || byCode;
}

async function getOrderStatus({ client, wooOrderId }) {
  const url = `${client.base}/orders/${encodeURIComponent(wooOrderId)}`;
  const data = await fetchWoo({ url, method: "GET", timeout: client.timeout, headers: client.authHeader });
  return { id: data?.id, status: data?.status, raw: data };
}

export async function updateOrderStatus({ tenantId, wooOrderId, status }) {
  if (!wooOrderId) throw new Error("missing_woo_order_id");
  const lockKey = `${tenantId}:order:${wooOrderId}:status`;
  return withLock(lockKey, async () => {
    const client = await getWooClient({ tenantId });
    const payload = { status };
    const url = `${client.base}/orders/${encodeURIComponent(wooOrderId)}`;
    
    // Timeout corto para el PUT (Woo procesa pero tarda en responder)
    const putTimeout = 3000;
    
    try {
      const data = await fetchWoo({ url, method: "PUT", body: payload, timeout: putTimeout, headers: client.authHeader });
      return { id: data?.id || wooOrderId, raw: data };
    } catch (err) {
      // Si es timeout, verificar si el status cambió con un GET
      if (isRetryableNetworkError(err)) {
        if (dbg.wooHttp) console.log("[wooOrders] updateOrderStatus timeout, checking with GET...");
        
        try {
          const current = await getOrderStatus({ client, wooOrderId });
          // Si el status ya es el deseado, la operación fue exitosa
          if (current.status === status) {
            if (dbg.wooHttp) console.log("[wooOrders] updateOrderStatus confirmed via GET", { wooOrderId, status });
            return { id: current.id || wooOrderId, raw: current.raw, recovered: true };
          }
        } catch (getErr) {
          // Si falla el GET también, propagar el error original
          if (dbg.wooHttp) console.log("[wooOrders] updateOrderStatus GET also failed:", getErr.message);
        }
      }
      throw err;
    }
  });
}

export async function listRecentOrders({ tenantId, limit = 20 }) {
  const client = await getWooClient({ tenantId });
  const url = `${client.base}/orders?per_page=${limit}&orderby=date&order=desc`;
  const data = await fetchWoo({ url, method: "GET", timeout: client.timeout, headers: client.authHeader });
  
  if (!Array.isArray(data)) return [];
  
  // Mapear a formato simplificado
  return data.map(order => normalizeWooOrder(order));
}

/**
 * Normaliza un pedido de WooCommerce a formato interno
 */
function normalizeWooOrder(order) {
  // Detectar si es orden de test (run_id empieza con "test-")
  const runIdMeta = order.meta_data?.find(m => m.key === "run_id");
  const runId = runIdMeta?.value || null;
  const isTest = runId?.startsWith("test-") || false;
  const sourceMeta = order.meta_data?.find(m => m.key === "source");
  const source = sourceMeta?.value || "web";
  
  // Método de envío (shipping)
  const metaShippingMethod = order.meta_data?.find(m => m.key === "shipping_method")?.value || null;
  const shippingLines = order.shipping_lines || [];
  const wooShippingMethod = shippingLines[0]?.method_title || shippingLines[0]?.method_id || null;
  const shippingMethod = metaShippingMethod || wooShippingMethod;
  
  let isDelivery = false;
  if (metaShippingMethod) {
    isDelivery = metaShippingMethod === "delivery";
  } else if (wooShippingMethod) {
    isDelivery = !wooShippingMethod.toLowerCase().includes("retiro") && 
                 !wooShippingMethod.toLowerCase().includes("pickup") &&
                 !wooShippingMethod.toLowerCase().includes("local");
  }
  
  return {
    id: order.id,
    status: order.status,
    total: order.total,
    currency: order.currency,
    date_created: order.date_created,
    billing: {
      first_name: order.billing?.first_name || "",
      last_name: order.billing?.last_name || "",
      phone: order.billing?.phone || "",
      email: order.billing?.email || "",
      address_1: order.billing?.address_1 || "",
      address_2: order.billing?.address_2 || "",
      city: order.billing?.city || "",
      state: order.billing?.state || "",
      postcode: order.billing?.postcode || "",
    },
    shipping: {
      first_name: order.shipping?.first_name || "",
      last_name: order.shipping?.last_name || "",
      address_1: order.shipping?.address_1 || "",
      address_2: order.shipping?.address_2 || "",
      city: order.shipping?.city || "",
      state: order.shipping?.state || "",
      postcode: order.shipping?.postcode || "",
    },
    line_items: (order.line_items || []).map(li => ({
      id: li.id,
      name: li.name,
      product_id: li.product_id,
      variation_id: li.variation_id,
      quantity: li.quantity,
      total: li.total,
      subtotal: li.subtotal,
      sku: li.sku,
      meta_data: li.meta_data,
    })),
    source,
    run_id: runId,
    is_test: isTest,
    shipping_method: shippingMethod,
    is_delivery: isDelivery,
    raw: order,
  };
}

/**
 * Detecta la unidad de venta de un line item
 */
function detectSellUnit(lineItem) {
  // 1. Buscar en meta_data
  const unitMeta = lineItem.meta_data?.find(m => m.key === "unit");
  if (unitMeta?.value === "g" || unitMeta?.value === "kg") return "kg";
  if (unitMeta?.value === "unit") return "unit";
  
  // 2. Detectar por nombre del producto
  const name = (lineItem.name || "").toLowerCase();
  if (name.includes("kg") || name.includes("kilo")) return "kg";
  
  // 3. Default a unit
  return "unit";
}

/**
 * Sincroniza pedidos de WooCommerce a la cache local (incremental)
 * Usa un lock por tenant para evitar syncs concurrentes
 */
export async function syncOrdersIncremental({ tenantId }) {
  // Si ya hay un sync en progreso para este tenant, esperar a que termine
  const existingPromise = syncInProgress.get(tenantId);
  if (existingPromise) {
    console.log(`[wooOrders] syncOrdersIncremental already in progress for tenant ${tenantId}, waiting...`);
    return existingPromise;
  }
  
  // Crear promise para este sync y registrarla
  const syncPromise = doSyncOrdersIncremental({ tenantId });
  syncInProgress.set(tenantId, syncPromise);
  
  try {
    const result = await syncPromise;
    return result;
  } finally {
    syncInProgress.delete(tenantId);
  }
}

/**
 * Implementación interna del sync (sin lock)
 * Procesa e inserta página por página para:
 * - Bajo consumo de RAM (solo ~100 pedidos en memoria a la vez)
 * - Resiliencia a cortes (progreso se guarda en DB)
 * - Sync incremental real (puede resumir desde donde quedó)
 */
async function doSyncOrdersIncremental({ tenantId }) {
  const client = await getWooClient({ tenantId });
  const latestDate = await ordersRepo.getLatestOrderDate({ tenantId });
  
  let synced = 0;
  let page = 1;
  const perPage = 100; // Máximo permitido por Woo
  
  console.log(`[wooOrders] syncOrdersIncremental starting, latestDate: ${latestDate || 'none (full sync)'}`);
  
  while (true) {
    // Construir URL con paginación
    let url = `${client.base}/orders?per_page=${perPage}&page=${page}&orderby=date&order=desc`;
    
    // Si tenemos fecha, filtrar solo los más recientes
    if (latestDate) {
      const afterDate = new Date(latestDate);
      afterDate.setMinutes(afterDate.getMinutes() - 1);
      url += `&after=${afterDate.toISOString()}`;
    }
    
    const data = await fetchWoo({ url, method: "GET", timeout: client.timeout, headers: client.authHeader });
    
    if (!Array.isArray(data) || data.length === 0) {
      break;
    }
    
    // Procesar e insertar INMEDIATAMENTE esta página
    for (const rawOrder of data) {
      const order = normalizeWooOrder(rawOrder);
      
      const cacheOrder = {
        woo_order_id: order.id,
        status: order.status,
        total: parseFloat(order.total) || 0,
        currency: order.currency,
        date_created: order.date_created,
        date_paid: order.date_paid,
        source: order.source,
        is_delivery: order.is_delivery,
        is_cash: order.is_cash,
        customer_name: `${order.billing.first_name} ${order.billing.last_name}`.trim(),
        customer_phone: order.billing.phone,
        customer_email: order.billing.email,
        shipping_address_1: order.shipping.address_1,
        shipping_address_2: order.shipping.address_2,
        shipping_city: order.shipping.city,
        shipping_state: order.shipping.state,
        shipping_postcode: order.shipping.postcode,
        shipping_country: "AR",
        billing_address_1: order.billing.address_1,
        billing_city: order.billing.city,
        billing_state: order.billing.state,
        billing_postcode: order.billing.postcode,
        raw: order.raw,
      };
      
      await ordersRepo.upsertOrder({ tenantId, order: cacheOrder });
      
      const items = order.line_items.map(li => ({
        woo_product_id: li.product_id || li.variation_id,
        product_name: li.name,
        sku: li.sku,
        quantity: parseFloat(li.quantity) || 0,
        unit_price: li.subtotal ? parseFloat(li.subtotal) / (parseFloat(li.quantity) || 1) : null,
        line_total: parseFloat(li.total) || 0,
        sell_unit: detectSellUnit(li),
      }));
      
      await ordersRepo.upsertOrderItems({ tenantId, wooOrderId: order.id, items });
      synced++;
    }
    
    // Log de progreso después de insertar
    const totalInCache = await ordersRepo.countOrders({ tenantId });
    console.log(`[wooOrders] syncOrdersIncremental page ${page}: +${data.length} orders (${totalInCache} total in DB)`);
    
    // Si es última página
    if (data.length < perPage) {
      break;
    }
    
    page++;
  }
  
  const totalInCache = await ordersRepo.countOrders({ tenantId });
  console.log(`[wooOrders] syncOrdersIncremental completed: ${synced} synced, ${totalInCache} total in cache`);
  
  return { synced, total: totalInCache };
}