import { ASTNode, GraphQLError, GraphQLScalarType } from 'graphql';

import { Upload } from './Upload';

export const GraphQLUpload = new GraphQLScalarType({
  name: 'Upload',
  description: 'The `Upload` scalar type represents a file upload.',
  parseValue(value: { promise: Promise<Upload> }) {
    if (value instanceof Upload) return value.promise;
    throw new GraphQLError('Upload value invalid.');
  },
  parseLiteral(node: ASTNode | ASTNode[]) {
    throw new GraphQLError('Upload literal unsupported.', { nodes: node });
  },
  serialize() {
    throw new GraphQLError('Upload serialization unsupported.');
  },
});