apps-registry/workloads/commerce-backend/src/api/admin/inventory-panel/route.ts

import type { MedusaRequest, MedusaResponse } from "@medusajs/framework";
import { ContainerRegistrationKeys } from "@medusajs/framework/utils";
import {
  createInventoryItemsWorkflow,
  updateInventoryLevelsWorkflow,
  updateProductVariantsWorkflow,
} from "@medusajs/medusa/core-flows";
import { attachInventoryItemToVariantWorkflow } from "../../../workflows/attach-inventory-item-to-variant";

// Panel simplificado de inventario (pensado para un usuario no tecnico,
// no reemplaza la vista nativa de Medusa Admin -- ver ADR/memoria del
// bug de Firefox Android, tema aparte). Un producto = una variante en
// este catalogo real (confirmado en vivo contra /store/products antes
// de asumirlo), asi que la tabla trabaja a nivel de producto.

const PRODUCT_FIELDS = [
  "id",
  "title",
  "thumbnail",
  "status",
  "variants.id",
  "variants.sku",
  "variants.manage_inventory",
  "variants.inventory_items.inventory_item_id",
  "variants.inventory_items.inventory.location_levels.id",
  "variants.inventory_items.inventory.location_levels.location_id",
  "variants.inventory_items.inventory.location_levels.stocked_quantity",
];

async function defaultLocationId(req: MedusaRequest): Promise<string | null> {
  const query = req.scope.resolve(ContainerRegistrationKeys.QUERY);
  const { data: locations = [] } = await query.graph({
    entity: "stock_location",
    fields: ["id"],
  });
  return locations[0]?.id ?? null;
}

export async function GET(req: MedusaRequest, res: MedusaResponse) {
  const query = req.scope.resolve(ContainerRegistrationKeys.QUERY);
  const locationId = await defaultLocationId(req);

  const { data: products = [] } = await query.graph({
    entity: "product",
    fields: PRODUCT_FIELDS,
  });

  const rows = products.map((product) => {
    const variant = product.variants?.[0];
    const inventoryItem = variant?.inventory_items?.[0];
    const level = inventoryItem?.inventory?.location_levels?.find(
      (candidate) => candidate?.location_id === locationId,
    );
    return {
      productId: product.id,
      variantId: variant?.id ?? null,
      title: product.title,
      thumbnail: product.thumbnail,
      status: product.status,
      sku: variant?.sku ?? null,
      managed: variant?.manage_inventory ?? false,
      quantity: level?.stocked_quantity ?? 0,
    };
  });

  res.json({ rows, locationId });
}

type PanelUpdateBody = {
  productId: string;
  variantId: string;
  managed?: boolean;
  quantity?: number;
};

export async function POST(req: MedusaRequest<PanelUpdateBody>, res: MedusaResponse) {
  const { productId, variantId, managed, quantity } = req.body;
  if (!productId || !variantId) {
    res.status(400).json({ error: "productId y variantId son obligatorios" });
    return;
  }

  const query = req.scope.resolve(ContainerRegistrationKeys.QUERY);
  const locationId = await defaultLocationId(req);
  if (!locationId) {
    res.status(400).json({ error: "No hay una bodega (stock location) configurada" });
    return;
  }

  const { data: products = [] } = await query.graph({
    entity: "product",
    fields: PRODUCT_FIELDS,
    filters: { id: productId },
  });
  const variant = products[0]?.variants?.find((v: { id: string }) => v.id === variantId);
  const inventoryItem = variant?.inventory_items?.[0];
  let inventoryItemId: string | undefined = inventoryItem?.inventory_item_id;

  if (managed === true && !inventoryItemId) {
    // Primera vez que se activa el seguimiento para esta variante -- no
    // trae InventoryItem todavia (confirmado en vivo: togglear
    // manage_inventory=true en una variante existente NO crea uno solo,
    // a diferencia de crear un producto nuevo con manage_inventory
    // desde el inicio). Se crea con el nivel de stock inicial y se
    // vincula aparte.
    const { result: items } = await createInventoryItemsWorkflow(req.scope).run({
      input: {
        items: [
          {
            title: variant?.sku ? undefined : products[0]?.title,
            sku: variant?.sku ?? undefined,
            location_levels: [{ location_id: locationId, stocked_quantity: quantity ?? 0 }],
          },
        ],
      },
    });
    inventoryItemId = items[0]?.id;
    if (inventoryItemId) {
      await attachInventoryItemToVariantWorkflow(req.scope).run({
        input: { inventoryItemId, variantId },
      });
    }
    await updateProductVariantsWorkflow(req.scope).run({
      input: { product_variants: [{ id: variantId, manage_inventory: true }] },
    });
  } else {
    if (typeof managed === "boolean") {
      await updateProductVariantsWorkflow(req.scope).run({
        input: { product_variants: [{ id: variantId, manage_inventory: managed }] },
      });
    }
    if (typeof quantity === "number" && inventoryItemId) {
      const level = inventoryItem?.inventory?.location_levels?.find(
        (candidate) => candidate?.location_id === locationId,
      );
      await updateInventoryLevelsWorkflow(req.scope).run({
        input: {
          updates: [
            {
              id: level?.id,
              inventory_item_id: inventoryItemId,
              location_id: locationId,
              stocked_quantity: quantity,
            },
          ],
        },
      });
    }
  }

  res.json({ ok: true });
}