package main

import (
	"fmt"
	"time"
)

/*
	@Ref: https://livebook.manning.com/book/go-in-practice/chapter-3/65
*/

func main() {
	msg := make(chan string)
	done := make(chan bool)
	until := time.After(5 * time.Second)

	go send(msg, done)

	for {
		select {
		case m := <-msg:
			fmt.Println(m)
		case <-until:
			done <- true
			time.Sleep(500 * time.Millisecond)
			return
		}
	}
}

func send(ch chan<- string, done <-chan bool) {
	for {
		select {
		case <-done:
			fmt.Println("done")
			close(ch)
			return
		default:
			ch <- "Hello"
			time.Sleep(500 * time.Millisecond)

		}
	}
}

// Improper channel close
// func main() {
// 	msg := make(chan string)
// 	until := time.After(5 * time.Second)

// 	go send(msg)

// 	for {
// 		select {
// 		case m := <-msg:
// 			fmt.Println(m)
// 		case <-until:
// 			close(msg)
// 			time.Sleep(500 * time.Millisecond)
// 			return
// 		}
// 	}
// }

// func send(ch chan string) {
// 	for {
// 		ch <- "hello"
// 		time.Sleep(500 * time.Millisecond)
// 	}
// }