package main

import (
	"context"
	"log"
	"net"
	"net/http"
	"sync"

	"krwu.top/krpc.v1"
)

func startServer(addr chan string) {
	var foo Foo
	if err := krpc.Register(&foo); err != nil {
		log.Fatal("register error: ", err)
	}
	krpc.HandleHTTP()
	// pick a free port
	l, err := net.Listen("tcp", ":0")
	if err != nil {
		log.Fatal("network error:", err)
	}
	log.Println("start rpc server on", l.Addr())
	addr <- l.Addr().String()
	_ = http.Serve(l, nil)
	//krpc.Accept(l)
}

func main() {
	log.SetFlags(0)
	addr := make(chan string)
	go startServer(addr)

	cli, _ := krpc.DialHTTP("tcp", <-addr)
	defer func() { _ = cli.Close() }()

	// send options
	var wg sync.WaitGroup
	// send request & receive response
	for i := 0; i < 5; i++ {
		wg.Add(1)
		go func(i int) {
			defer wg.Done()
			args := &Args{Num1: i, Num2: i * i}
			var reply int
			if err := cli.Call(context.TODO(), "Foo.Sum", args, &reply); err != nil {
				log.Fatal("call Foo.Sum error: ", err)
			}
			log.Printf("%d + %d = %d\n", args.Num1, args.Num2, reply)
		}(i)
	}
	wg.Wait()
}