import { useCallback } from "react";
import useSWR from "swr";
import { useClient } from "./AppConfig/AppConfig.tsx";
import { Failure, Success } from "./async-op.ts";
import { swrResponseToResult } from "./result/swr.ts";
import { useCurrentUser } from "./store/index.tsx";
import type { FailurePayload } from "./types.ts";

function useGetOwnedProduct(productCode: string) {
  const client = useClient();

  const swr = useSWR(
    `getOwnedProduct:${productCode}`,
    useCallback(() => {
      return client.getOwnedProduct(productCode);
    }, [productCode]),
  );

  return swrResponseToResult(swr);
}

export type ProductStatusSuccessPayload =
  /**
   * The user should authenticate before proceeding to checkout.
   */
  | { type: "AUTHENTICATE" }

  /**
   * The user can proceed to checkout.
   */
  | { type: "PURCHASE" }

  /**
   * The user already owns this product. The `downloadUrl` property should be
   * used to let the user download their files.
   */
  | { type: "DOWNLOAD"; downloadUrl: string };

/**
 * Wraps ITC client's getOwnedProduct call and maps it's responses into
 * {@link ProductStatusSuccessPayload} which is more appropriate for product
 * purchase pages.
 */
export function useGetProductStatus(productCode: string) {
  const result = useGetOwnedProduct(productCode);
  const currentUser = useCurrentUser();

  if (result.isPending) {
    return result;
  }

  if (result.isFailure) {
    const { failure } = result;

    if (failure.type === "API_ERROR") {
      // The no currentUser case is possible in case the user is logged into ITC
      // via a domain-wide cookie, but they have not yet logged in this app.
      if (failure.code === 401 || !currentUser) {
        return new Success<ProductStatusSuccessPayload>({
          type: "AUTHENTICATE",
        });
      }

      if (failure.code === 403) {
        return new Success<ProductStatusSuccessPayload>({
          type: "PURCHASE",
        });
      }
    }

    // Other errors should be handled by the default error handling
    return result;
  }

  // This shouldn't happen in practice, as this particular endpoint errors out
  // if a product link fails to generate.
  const { downloadUrl } = result.value;
  if (!downloadUrl) {
    return new Failure<FailurePayload>({
      type: "UNKNOWN_ERROR",
    });
  }

  return new Success<ProductStatusSuccessPayload>({
    type: "DOWNLOAD",
    downloadUrl,
  });
}