import { makeExecutableSchema } from '@graphql-tools/schema';
import { introspectSchema, RenameTypes } from '@graphql-tools/wrap';
import { stitchSchemas } from '@graphql-tools/stitch';
import { GraphQLUpload } from 'graphql-upload-minimal';
//import GraphQLUpload from 'graphql-upload/GraphQLUpload.mjs';

import makeRemoteExecutor from './make-remote-executor';
import { Config } from '../app';

export default async function gatewaySchema(services: Config) {

    const localSchema = makeExecutableSchema({
        typeDefs: /* GraphQL */ `
            scalar Upload
        `,
        resolvers: {
            Upload: GraphQLUpload,
        },
    });

    const schemaList = [];

    const list = services.list;

    for await(const service of list) {

        try {
            const executor = await makeRemoteExecutor(service.url);
            const subschema = {
                schema: await introspectSchema(executor),
                executor: executor,
                transforms: [
                    new RenameTypes((name) => {
                        if (name === 'Upload') {
                            return name;
                        }
                        return `${service.prefix}${name}`;
                    }),
                ],
            };
            schemaList.push(subschema);
        } catch (err) {
            service._version = null;
            process.env.TEST !== 'true' && console.log('Could not connect to service: ' + service.name, err);
        }

    }

    return stitchSchemas({
        subschemas: [
            localSchema,
            schemaList
        ]
    });

}