import Maybe from '../tsutils/Maybe';
import { Location, DocumentNode, StringValueNode } from '../language/ast';
import {
  GraphQLSchemaValidationOptions,
  GraphQLSchema,
  GraphQLSchemaNormalizedConfig,
} from '../type/schema';

interface Options extends GraphQLSchemaValidationOptions {
  /**
   * Descriptions are defined as preceding string literals, however an older
   * experimental version of the SDL supported preceding comments as
   * descriptions. Set to true to enable this deprecated behavior.
   * This option is provided to ease adoption and will be removed in v16.
   *
   * Default: false
   */
  commentDescriptions?: boolean;

  /**
   * Set to true to assume the SDL is valid.
   *
   * Default: false
   */
  assumeValidSDL?: boolean;
}

/**
 * Produces a new schema given an existing schema and a document which may
 * contain GraphQL type extensions and definitions. The original schema will
 * remain unaltered.
 *
 * Because a schema represents a graph of references, a schema cannot be
 * extended without effectively making an entire copy. We do not know until it's
 * too late if subgraphs remain unchanged.
 *
 * This algorithm copies the provided schema, applying extensions while
 * producing the copy. The original schema remains unaltered.
 *
 * Accepts options as a third argument:
 *
 *    - commentDescriptions:
 *        Provide true to use preceding comments as the description.
 *
 */
export function extendSchema(
  schema: GraphQLSchema,
  documentAST: DocumentNode,
  options?: Options,
): GraphQLSchema;

/**
 * @internal
 */
export function extendSchemaImpl(
  schemaConfig: GraphQLSchemaNormalizedConfig,
  documentAST: DocumentNode,
  options?: Options,
): GraphQLSchemaNormalizedConfig;

/**
 * Given an ast node, returns its string description.
 * @deprecated: provided to ease adoption and will be removed in v16.
 *
 * Accepts options as a second argument:
 *
 *    - commentDescriptions:
 *        Provide true to use preceding comments as the description.
 *
 */
export function getDescription(
  node: { readonly description?: StringValueNode; readonly loc?: Location },
  options?: Maybe<{ commentDescriptions?: boolean }>,
): string | undefined;