import { ok, err, type CommandContext } from "@tailor-platform/erp-kit/core";
import type { Transaction, Updateable } from "../generated/kysely-tailordb";
import { StorageLocationNotFoundError, DuplicateLocationNameError } from "../lib/errors.generated";

export type UpdateStorageLocationInput = {
  id: string;
  name?: string;
  storageCondition?: string | null;
  capacity?: number | null;
};
/**
 * Function: updateStorageLocation
 *
 * Modifies the mutable fields of a storage location, including name,
 * storageCondition, and capacity. siteId and code are immutable after creation.
 */
export async function run(
  db: Transaction,
  input: UpdateStorageLocationInput,
  _ctx: CommandContext,
) {
  const { name, storageCondition, capacity } = input;

  // 1. Check storage location exists
  const location = await db
    .selectFrom("StorageLocation")
    .selectAll()
    .where("id", "=", input.id)
    .forUpdate()
    .executeTakeFirst();

  if (!location) {
    return err(new StorageLocationNotFoundError(input.id));
  }

  // 2. If name changed, check uniqueness within site
  const nameChanged = name !== undefined && name !== location.name;

  if (nameChanged) {
    const checkName = name ?? location.name;

    const duplicate = await db
      .selectFrom("StorageLocation")
      .selectAll()
      .where("siteId", "=", location.siteId)
      .where("id", "!=", location.id)
      .where("name", "=", checkName)
      .forUpdate()
      .executeTakeFirst();

    if (duplicate) {
      return err(new DuplicateLocationNameError(checkName));
    }
  }

  // 3. Build update set
  const updates: Updateable<"StorageLocation"> = {};
  if (name !== undefined) updates.name = name;
  if (storageCondition !== undefined) updates.storageCondition = storageCondition;
  if (capacity !== undefined) updates.capacity = capacity !== null ? String(capacity) : null;

  if (Object.keys(updates).length === 0) {
    return ok({ storageLocation: location });
  }

  // 4. Update location
  const updatedLocation = await db
    .updateTable("StorageLocation")
    .set(updates)
    .where("id", "=", location.id)
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({ storageLocation: updatedLocation });
}