mutation Say {
  greet(greeting: "hi!")
}

subscription Listen {
  greetings {
    greeting
  }
}

subscription ListenToHi {
  greetings(greeting: "hi!") {
    greeting
  }
}

export const schema = makeExecutableSchema({
  typeDefs: /* GraphQL */ `
    type Greeting {
      greeting: String
    }
    type Subscription {
      greetings(greeting: String): Greeting
    }
    type Mutation {
      greet(greeting: String!): String
    }
  `,
  resolvers: {
    Mutation: {
      greet: async (root, args, context, info) => {
        context.publish("GREETINGS", {
          greetings: { greeting: args.greeting },
        });
        return "ok";
      },
    },
    Subscription: {
      greetings: {
        subscribe: subscribe("GREETINGS", {
          filter: (root, args, context, info) => {
            return args.greeting
              ? { greetings: { greeting: args.greeting } }
              : {};
          },
        }),
      },
    },
  },
});