package main

import (
	"encoding/gob"
	"fmt"
	"net"
	"time"
	"os"
	"sync"
)

const (
	dataStr string = "This is my string.  There are many like it.  But this one is mine."
	rounds int = 1
)

type tester struct {
	T time.Time
	X net.IP
	D []byte
	M map[string]([]byte)
}

type testa struct {
	X, Y, Z uint64
	Msg []byte
}

func main() {
	var wg sync.WaitGroup
	lst, err := net.Listen("unix", "/tmp/comms")
	if err != nil {
		fmt.Printf("listen error: %v\n", err)
		os.Exit(-1)
	}
	defer lst.Close()
	conn, err := net.Dial("unix", "/tmp/comms")
	if err != nil {
		fmt.Printf("connect error: %v\n", err)
		os.Exit(-1)
	}
	defer conn.Close()

	wg.Add(2)
	go reader(lst, &wg)
	go writer(conn, &wg)
	wg.Wait()
}


func writer(conn net.Conn, wg *sync.WaitGroup) {
	var err error
	var i int
	genc := gob.NewEncoder(conn)
	ip := net.ParseIP("BE::EF")
	for i = 0; i < rounds; i++ {
		err = genc.Encode(tester{time.Now(), ip, []byte(dataStr), nil})
		if err != nil {
			fmt.Printf("Encode error: %v\n", err)
			os.Exit(-1)
		}
	}
	err = genc.Encode(tester{time.Now(), nil, nil, nil})
	if err != nil {
		fmt.Printf("Failed to encode the nil message\n")
		os.Exit(-1)
	}
	fmt.Printf("Threw nil entry after %d rounds\n", i)
	err = genc.Encode(testa{1, 2, 3, []byte("HERE IS YOUR MESSAGE")})
	if err != nil {
		fmt.Printf("Failed to encode testa message\n")
		os.Exit(-1)
	}
	wg.Done()
}

func reader(lst net.Listener, wg *sync.WaitGroup) {
	var t tester
	var ta testa

	conn, err := lst.Accept()
	if err != nil {
		fmt.Printf("Accept error: %v\n", err)
		os.Exit(-1)
	}
	defer conn.Close()
	gdec := gob.NewDecoder(conn)

	for i := 0; ; i++{
		err := gdec.Decode(&t)
		if err != nil {
			fmt.Printf("Decode error on #%d: %v\n", i, err)
			os.Exit(-1)
		}
		if t.D == nil || len(t.D) == 0 {
			fmt.Printf("Got the nil message\n")
			break
		}
	}
	err = gdec.Decode(&ta)
	if err != nil {
		fmt.Printf("She is dead jim...\n")
		os.Exit(-1)
	}
	if string(ta.Msg) != "HERE IS YOUR MESSAGE" {
		fmt.Printf("Failed to get the message out\n")
		os.Exit(-1)
	}
	wg.Done()
}