import { parse } from 'graphql';

import { SubstitutionMap, DefinitionParser } from './ast';
import { TypeExpression } from '../type-expression/TypeExpression';
import { TypeArg } from '../type-expression/types';


const SUBSTITUTION_PREFIX = '__GIRIN__SUBS__';

export function gql(strings: TemplateStringsArray, ...interpolated: Array<string | TypeExpression | TypeArg>): DefinitionParser[] {
  const result = [strings[0]];
  const subsMap: SubstitutionMap = {};

  for (let i = 0; i < interpolated.length; i++) {
    const item = interpolated[i];
    let name: string;
    if (typeof item === 'string') {
      name = item;
    } else {
      name = `${SUBSTITUTION_PREFIX}${i}`;
      subsMap[name] = item;
    }
    result.push(name);
    result.push(strings[i + 1]);
  }

  const ast = parse(result.join(''));

  return ast.definitions.map(rootNode => new DefinitionParser(rootNode, subsMap));
}