import { EncryptedMetadataManager, MetadataEntry, SettingsManager } from "@saleor/app-sdk/settings-manager";

import { FetchAppDetailsDocument, FetchAppDetailsQuery, UpdateAppMetadataDocument } from "../../generated/graphql";
import { settingsManagerSecretKey } from "../../saleor-app";
import { SimpleGraphqlClient } from "./graphql";


/*
 * Function is using urql graphql client to fetch all available metadata.
 * Before returning query result, we are transforming response to list of objects with key and value fields
 * which can be used by the manager.
 * Result of this query is cached by the manager.
 */
export async function fetchAllMetadata(client: SimpleGraphqlClient): Promise<MetadataEntry[]> {
  const { error, data } = await client
    .query<FetchAppDetailsQuery>(FetchAppDetailsDocument, {})
    .toPromise();

  if (error) {
    console.debug("Error during fetching the metadata: ", error);
    return [];
  }

  return data?.app?.privateMetadata.map((md) => ({ key: md.key, value: md.value })) || [];
}

/*
 * Mutate function takes urql client and metadata entries, and construct mutation to the API.
 * Before data are send, additional query for required App ID is made.
 * The manager will use updated entries returned by this mutation to update it's cache.
 */
export async function mutateMetadata(client: SimpleGraphqlClient, metadata: MetadataEntry[]) {
  // to update the metadata, ID is required
  const { error: idQueryError, data: idQueryData } = await client
    .query(FetchAppDetailsDocument, {})
    .toPromise();

  if (idQueryError) {
    console.debug("Could not fetch the app id: ", idQueryError);
    throw new Error(
      "Could not fetch the app id. Please check if auth data for the client are valid."
    );
  }

  const appId = idQueryData?.app?.id;

  if (!appId) {
    console.debug("Missing app id");
    throw new Error("Could not fetch the app ID");
  }

  const { error: mutationError, data: mutationData } = await client
    .mutation(UpdateAppMetadataDocument, {
      id: appId,
      input: metadata,
    })
    .toPromise();

  if (mutationError) {
    console.debug("Mutation error: ", mutationError);
    throw new Error(`Mutation error: ${mutationError.message}`);
  }

  return (
    mutationData?.updatePrivateMetadata?.item?.privateMetadata.map((md) => ({
      key: md.key,
      value: md.value,
    })) || []
  );
}

export const createSettingsManager = (client: SimpleGraphqlClient): SettingsManager => {
  /*
   * EncryptedMetadataManager gives you interface to manipulate metadata and cache values in memory.
   * We recommend it for production, because all values are encrypted.
   * If your use case require plain text values, you can use MetadataManager.
   */
  return new EncryptedMetadataManager({
    // Secret key should be randomly created for production and set as environment variable
    encryptionKey: settingsManagerSecretKey,
    fetchMetadata: () => fetchAllMetadata(client),
    mutateMetadata: (metadata) => mutateMetadata(client, metadata),
  });
};