import { TokenResult } from '@axinom/mosaic-id-utils';
import { MosaicError, MosaicErrors } from '@axinom/mosaic-service-common';
import { getGqlClient } from '../common/gql-client';
import { IdLinkBeErrors } from '../common/id-link-be-errors';
import {
  GenerateLongLivedTokenDocument,
  GenerateLongLivedTokenMutation,
  GenerateLongLivedTokenMutationVariables,
} from '../generated/graphql.types';
import { getWellKnownEndpoints } from '../well-known-endpoints';

/**
 * This function generates a long lived access token for a user token. It can be used to invoke long running processes.
 * @param authEndpoint URL for id-service authEndpoint.
 * @param serviceAccountToken A valid service account token with permission GENERATE_LONG_LIVED_TOKEN granted.
 * @param userAccessToken User access token to extend the validity period for.
 * @param validityDurationInSeconds Token expiration time in seconds. If not given, it will be defaulted to 2592000 (30 days).
 * @returns {TokenResult} Long lived access token.
 */
export const generateLongLivedToken = async (
  authEndpoint: string,
  serviceAccountToken: string,
  userAccessToken: string,
  validityDurationInSeconds?: number,
): Promise<TokenResult> => {
  const client = getGqlClient(
    (await getWellKnownEndpoints(authEndpoint)).authGraphQlEndpoint,
    serviceAccountToken,
  );

  const result = await client.mutate<
    GenerateLongLivedTokenMutation,
    GenerateLongLivedTokenMutationVariables
  >({
    mutation: GenerateLongLivedTokenDocument,
    variables: {
      input: {
        userToken: userAccessToken,
        validityDurationInSeconds,
      },
    },
    errorPolicy: 'all',
    fetchPolicy: 'no-cache',
  });

  if (!result.errors) {
    if (!result.data) {
      throw new MosaicError({
        code: MosaicErrors.UnexpectedNullUndefined.code,
        message: `Unexpected null or undefined value received for 'generateLongLivedToken' result.`,
      });
    }
    const tokenResponse = result.data.generateLongLivedToken;

    const longLivedToken = {
      accessToken: tokenResponse.accessToken,
      tokenType: tokenResponse.tokenType,
      expiresInSeconds: tokenResponse.expiresInSeconds,
    };

    return longLivedToken;
  } else {
    const aggregatedErrorMessage = result.errors.reduce(
      (aggregatedError, gqlError) => {
        return (aggregatedError += gqlError.message);
      },
      '',
    );

    throw new MosaicError({
      ...IdLinkBeErrors.LongLivedTokenGenerationError,
      details: {
        originalError: aggregatedErrorMessage,
      },
    });
  }
};