// multiple producers, single consumer
package main

import (
	"fmt"
	"sync"
)

// producers sends the value to the channel
func producers(id int, ch chan<- int, wg *sync.WaitGroup) {
	defer wg.Done()
	for i:=1; i <= 100; i++ {
		fmt.Printf("goroutine %d sent the value %d\n", id, i)
		ch <- i
	}
}

// consumers consumes the values
func consumers(id int, ch <-chan int, wg *sync.WaitGroup) {
	defer wg.Done()
	for val := range ch {
		fmt.Printf("value received by goroutine %d: %d\n",id, val)
	}
}

func main() {
	ch := make(chan int)
	var wg sync.WaitGroup
	var prowg sync.WaitGroup // separate waitgroup for producers
	numProducers := 2
	
	for i:=1; i <= numProducers; i++ {
		prowg.Add(1)
		go producers(i, ch, &wg)
	}

	go func ()  {
		prowg.Wait()
		close(ch)	
	}()

	wg.Add(1)
	go consumers(i, ch, &wg)
	
	wg.Wait()
}