import { SpecifyError, specifyErrors } from '../errors/index.js';

export const SPECIFY_HTTP_API_AUTHORIZATION_HEADER_NAME = 'Authorization';

export function makePersonalAccessTokenHeaderValue(personalAccessToken: unknown) {
  if (typeof personalAccessToken !== 'string' || personalAccessToken.length === 0) {
    throw new SpecifyError({
      publicMessage: 'Personal access token must be a string',
      errorKey: specifyErrors.UNEXPECTED_ERROR.errorKey,
    });
  }
  return `PAT ${personalAccessToken}`;
}

export function generatePersonalAccessTokenHeader(personalAccessToken: string | undefined):
  | {}
  | {
      Authorization: string;
    } {
  if (!personalAccessToken) return {};
  return {
    [SPECIFY_HTTP_API_AUTHORIZATION_HEADER_NAME]:
      makePersonalAccessTokenHeaderValue(personalAccessToken),
  };
}

export function extractPersonalAccessTokenFromHeaderValue(headerValue: string) {
  if (headerValue.startsWith('PAT ')) {
    return headerValue.slice(4);
  }
}

const lowercase_SPECIFY_HTTP_API_AUTHORIZATION_HEADER_NAME =
  SPECIFY_HTTP_API_AUTHORIZATION_HEADER_NAME.toLowerCase();
export function extractPersonalAccessTokenFromHeaders(
  headers: Record<string, string | string[] | undefined>,
) {
  const assertedHeaders = headers ?? {};

  let authorizationHeader;
  if (assertedHeaders.hasOwnProperty(lowercase_SPECIFY_HTTP_API_AUTHORIZATION_HEADER_NAME)) {
    authorizationHeader = assertedHeaders[lowercase_SPECIFY_HTTP_API_AUTHORIZATION_HEADER_NAME];
  } else if (assertedHeaders.hasOwnProperty(SPECIFY_HTTP_API_AUTHORIZATION_HEADER_NAME)) {
    authorizationHeader = assertedHeaders[SPECIFY_HTTP_API_AUTHORIZATION_HEADER_NAME];
  }

  if (authorizationHeader) {
    if (Array.isArray(authorizationHeader)) {
      return extractPersonalAccessTokenFromHeaderValue(authorizationHeader[0]);
    }
    return extractPersonalAccessTokenFromHeaderValue(authorizationHeader);
  }
}