/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow strict
 */

import invariant from '../jsutils/invariant';
import { getIntrospectionQuery } from './introspectionQuery';
import type { GraphQLSchema } from '../type/schema';
import { execute } from '../execution/execute';
import { parse } from '../language/parser';
import type {
  IntrospectionQuery,
  IntrospectionOptions,
} from './introspectionQuery';

/**
 * Build an IntrospectionQuery from a GraphQLSchema
 *
 * IntrospectionQuery is useful for utilities that care about type and field
 * relationships, but do not need to traverse through those relationships.
 *
 * This is the inverse of buildClientSchema. The primary use case is outside
 * of the server context, for instance when doing schema comparisons.
 */
export function introspectionFromSchema(
  schema: GraphQLSchema,
  options?: IntrospectionOptions,
): IntrospectionQuery {
  const queryAST = parse(getIntrospectionQuery(options));
  const result = execute(schema, queryAST);
  invariant(!result.then && !result.errors && result.data);
  return (result.data: any);
}