package common

import (
	"testing"
)

func TestFIFO(t *testing.T) {
	fifo := NewFifo(5)
	if fifo.MaxLen() != 5 {
		t.Fatal("unexpected fifo max_len:", fifo.MaxLen())
	}
	if fifo.Len() != 0 {
		t.Fatal("unexpected fifo len:", fifo.Len())
	}

	fifo.Push(1)
	fifo.Push(2)
	fifo.Push(3)
	fifo.Push(4)
	fifo.Push(5)
	fifo.Push(6)
	t.Log("fifo:", fifo.List())
	if fifo.Len() != 5 {
		t.Fatal("unexpected fifo len:", fifo.Len())
	}
	if fifo.Front().Value.(int) != 2 {
		t.Fatalf("unexpected front:%v", fifo.Front().Value.(int))
	}
	if fifo.Back().Value.(int) != 6 {
		t.Fatalf("unexpected back:%v", fifo.Back().Value.(int))
	}

	pop := fifo.Pop().(int)
	if pop != 2 {
		t.Fatalf("unexpected pop:%v", pop)
	}
	fifo.Pop()
	fifo.Pop()
	fifo.Pop()
	fifo.Pop()
	if fifo.Len() != 0 {
		t.Fatal("unexpected fifo len:", fifo.Len())
	}
	if fifo.Pop() != nil {
		t.Fatal("fifo pop empty should return nil")
	}
}