import { readFileFromPath } from '../helpers/files';
import { RenderContext } from '../render/common/RenderContext';
import {
  buildClientSchema,
  buildSchema,
  getIntrospectionQuery,
  graphql,
  GraphQLNamedType,
  GraphQLSchema,
} from 'graphql';
import { BuiltInParserName } from 'prettier';

export interface TypeRenderer {
  (type: GraphQLNamedType, ctx: RenderContext): void;
}

export interface SchemaRenderer {
  (schema: GraphQLSchema, ctx: RenderContext): void;
}

export async function toClientSchema(schemaGql: string) {
  const schema = buildSchema(schemaGql);

  const introspectionResponse = await graphql({ schema, source: getIntrospectionQuery() });

  if (!introspectionResponse.data) {
    throw new Error(JSON.stringify(introspectionResponse.errors));
  }

  return buildClientSchema(introspectionResponse.data as any);
}

export async function schemaRenderTest(schemaGql: string, renderer: SchemaRenderer, parser?: BuiltInParserName) {
  const schema = await toClientSchema(schemaGql);

  const ctx = new RenderContext(schema);

  renderer(schema, ctx);

  return ctx.toCode(parser, true);
}

export async function typeRenderTest(
  schemaGql: string,
  renderer: TypeRenderer,
  typeNames: string[],
  parser?: BuiltInParserName,
) {
  const schema = await toClientSchema(schemaGql);

  const ctx = new RenderContext(schema);

  typeNames.forEach((typeName) => {
    const type = schema.getType(typeName);

    if (!type) {
      throw new Error(`type ${typeName} is not defined in the schema`);
    }

    renderer(type, ctx);
  });

  return ctx.toCode(parser, true);
}

export async function typeRenderTestCase(
  dirName: string,
  file: string,
  renderer: TypeRenderer,
  typeNames: string[],
  output = false,
) {
  const [gql, ts] = await Promise.all([
    readFileFromPath([dirName, `cases/${file}.graphql`]),
    readFileFromPath([dirName, `cases/${file}.case.ts`]),
  ]);

  const actualTs = await typeRenderTest(gql, renderer, typeNames, 'typescript');

  if (output) {
    console.log(actualTs);
    throw new Error('test case did not run');
  } else {
    expect(actualTs).toBe(ts);
  }
}