package main

import (
	"context"
	"fmt"

	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
	"google.golang.org/grpc/health/grpc_health_v1"
	"google.golang.org/grpc/resolver"
)

// testResolver is a dummy resolver that always resolves to a static address.
type testResolver struct{}

func (testResolver) Scheme() string {
	return "test"
}

func (r testResolver) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
	cc.UpdateState(resolver.State{
		Addresses: []resolver.Address{
			{Addr: "10.1.1.1:1234"},
		},
	})
	return r, nil
}

func (testResolver) ResolveNow(_ resolver.ResolveNowOptions) {}

func (testResolver) Close() {}

func init() {
	resolver.Register(testResolver{})
}

func main() {
	cc, err := grpc.NewClient("test://",
		grpc.WithTransportCredentials(insecure.NewCredentials()),
	)
	if err != nil {
		panic(err)
	}
	defer cc.Close()

	c := grpc_health_v1.NewHealthClient(cc)

	res, err := c.Check(context.Background(), &grpc_health_v1.HealthCheckRequest{})
	if err != nil {
		panic(err)
	}

	fmt.Println(res)
}