import { ApolloServer } from '@apollo/server';

import { expressMiddleware } from '@apollo/server/express4';

import { ApolloServerPluginDrainHttpServer } from '@apollo/server/plugin/drainHttpServer'

import { ApolloServerPluginCacheControl } from '@apollo/server/plugin/cacheControl';

import express from 'express';

import http from 'http';

import cors from 'cors';

import bodyParser from 'body-parser';

const typeDefs = `#graphql

type Query {

hello: String

"""

Chosen by fair dice roll

**Guaranteed** to be [random](https://xkcd.com/221/)!

"""

rollDice(

"Amount of sides of the die"

numSides: Int

): Int

}

`;

const resolvers = {

Query: {

hello: () => 'Apollo, touchdown',

rollDice: (parent, args, contextValue, info) => {

console.log('Roll Dice:');

console.log('parent', parent);

console.log('args', args);

console.log('context', contextValue);

// The info object can be parsed to select only those fields from mongo:

// https://github.com/robrichard/graphql-fields

// https://github.com/du5rte/graphql-mongodb-projection

console.log('info', info);

return 4;

}

},

};

const app = express();

const httpServer = http.createServer(app);

const server = new ApolloServer({

typeDefs,

resolvers,

plugins: [

ApolloServerPluginDrainHttpServer({ httpServer }),

ApolloServerPluginCacheControl({

// Cache everything for 1 second by default.

defaultMaxAge: 1,

// Don't send the `cache-control` response header.

calculateHttpHeaders: false,

}),

// Custom Plugin

{

// More server lifecycle events:

// https://www.apollographql.com/docs/apollo-server/v2/integrations/plugins/#apollo-server-event-reference

// requestDidStart, parsingDidStart, willSendResponse, didEncounterErrors, ...

async serverWillStart() {

console.log('Starting server!');

return {

async serverWillStop() {

console.log('Stopping server!');

},

};

},

},

],

});

await server.start();

app.use(

cors(),

bodyParser.json(),

expressMiddleware(server, {

context: async ({ req, res }) => {

return {lang: req.headers['accept-language'] || 'nl'}

},

}),

);

await new Promise(resolve => httpServer.listen({ port: 4000 }, resolve));

console.log('🚀 GraphQL Apollo server listening to port 4000');

console.log('Check http://localhost:4000 for the Apollo GUI');