package channel

import (
	"sync"
	"testing"
	"time"
)

func TestChan(t *testing.T) {
	t.Run("close", func(t *testing.T) {
		ch := NewSingle()
		wg := sync.WaitGroup{}
		wg.Add(2)
		go func() {
			ch.Send()
			//ch.Send()
			close(ch)
			tmp, ok := <-ch
			t.Log("after close", tmp, ok)
			wg.Done()
		}()

		go func() {
			time.Sleep(time.Second)
			tmp, ok := <-ch
			t.Log(tmp, ok)
			wg.Done()
		}()

		wg.Wait()
	})
}

func TestChClose(t *testing.T) {
	const (
		buffer = 10
	)
	t.Run("send-finish-read-after", func(t *testing.T) {
		t.Run("for", func(t *testing.T) {
			ch := NewBufferSingle(buffer)
			wg := new(sync.WaitGroup)
			wg.Add(2)
			go func() {
				for i := 0; i < buffer; i++ {
					ch.Send()
				}
				close(ch)
				wg.Done()
				t.Log("send fin, close. ")
			}()

			go func() {
				time.Sleep(time.Second)
				for i := 0; i < buffer+1; i++ {
					s, ok := <-ch
					t.Log(s, ok)
				}
				wg.Done()
			}()

			wg.Wait()
		})

		t.Run("for-range", func(t *testing.T) {
			ch := NewBufferSingle(buffer)
			wg := new(sync.WaitGroup)
			wg.Add(2)
			go func() {
				for i := 0; i < buffer; i++ {
					ch.Send()
				}
				close(ch)
				t.Log("send fin, close. ")
				wg.Done()
			}()

			go func() {
				time.Sleep(time.Second)
				for s := range ch {
					t.Log(s)
				}
				wg.Done()
			}()

			wg.Wait()
		})

	})
}

func TestIntChan(t *testing.T) {
	wg := sync.WaitGroup{}
	wg.Add(2)
	buf := 5

	ch := NewBufferInt(buf)
	go func() {
		defer wg.Done()
		for cnt := buf; cnt > 0; cnt-- {
			ch.Send(1)
		}
		// 不 close ranger read 会永久阻塞
		close(ch)
	}()

	go func() {
		defer wg.Done()
		<-time.After(time.Second)
		t.Logf("channel len:%d cap: %d\n", len(ch), cap(ch))
		for i := range ch {
			_ = i
		}
	}()
	wg.Wait()
	t.Logf("channel len:%d cap: %d\n", len(ch), cap(ch))
}