/**
 * select_candidate — resuelve un pending NEEDS_TYPE eligiendo woo_id.
 *
 * Si el pending tenía `requested_qty` ya, lo promueve directo a READY → cart.
 * Sino lo deja en NEEDS_QUANTITY esperando set_quantity.
 */

import {
  updatePendingItem,
  moveReadyToCart,
  PendingStatus,
} from "../../orderModel.js";
import { getSnapshotItemsByIds } from "../../../shared/wooSnapshot.js";

export async function selectCandidateTool(args, ctx) {
  const { pending_id, woo_id } = args;
  const pending = (ctx.order.pending || []).find((p) => p.id === pending_id);
  if (!pending) {
    return { ok: false, error: "pending_not_found" };
  }

  // Buscar el producto seleccionado en el snapshot para nombre/unit/precio
  const lookup = await getSnapshotItemsByIds({
    tenantId: ctx.tenantId,
    wooProductIds: [woo_id],
  });
  const found = (lookup?.items || [])[0];
  if (!found) {
    return {
      ok: false,
      error: "woo_id_unknown",
      hint: "El woo_id no existe en el catálogo. Probá con search_catalog.",
    };
  }

  const sellsByWeight =
    !found.sell_unit || !["unit", "unidad"].includes(found.sell_unit);
  const displayUnit = found.sell_unit === "unit" ? "unit" : sellsByWeight ? "kg" : "unit";

  const hasRequestedQty =
    pending.requested_qty != null && Number.isFinite(pending.requested_qty) && pending.requested_qty > 0;
  const finalQty = hasRequestedQty ? pending.requested_qty : null;
  const finalUnit = pending.requested_unit || displayUnit;
  const needsQty = sellsByWeight && !hasRequestedQty;

  const updated = updatePendingItem(ctx.order, pending_id, {
    selected_woo_id: woo_id,
    selected_name: found.name,
    selected_price: found.price ?? null,
    selected_unit: displayUnit,
    candidates: [],
    qty: needsQty ? null : finalQty,
    unit: finalUnit,
    status: needsQty ? PendingStatus.NEEDS_QUANTITY : PendingStatus.READY,
  });
  ctx.order = moveReadyToCart(updated);

  if (!needsQty) {
    ctx.pending_actions.push({
      type: "add_to_cart",
      payload: { woo_id, qty: finalQty, unit: finalUnit },
    });
    ctx.last_shown_options = [];
  }

  return {
    ok: true,
    selected: { woo_id, name: found.name, unit: displayUnit, sells_by_weight: sellsByWeight },
    needs_quantity: needsQty,
    cart_size: (ctx.order.cart || []).length,
  };
}