package bps

import (
	"bytes"
	"io"
	"log"
	"testing"
	"time"
)

func init() {
	log.SetFlags(log.Ldate | log.Ltime | log.Lshortfile)
}

func TestSimple(t *testing.T) {
	bw, err := New(1*time.Second, 100)
	if err != nil {
		t.Fatalf("failure to make reasonable BPS: %v", err)
	}
	bw.Close()
}

func TestBadResolution(t *testing.T) {
	_, err := New(1*time.Hour, 1)
	if err == nil {
		t.Fatal("expected an error, got nil")
	}
}

func TestWriter(t *testing.T) {
	t.Parallel()
	bw, err := New(1*time.Second, 100)
	if err != nil {
		t.Fatalf("failure to make reasonable BPS: %v", err)
	}
	b := &bytes.Buffer{}
	b.Write([]byte("helloooooooooooooooooooooooooooooooooooooooooooooo"))
	for i := 0; i < 90; i++ {
		io.Copy(bw, b)
		last := bw.Rate()
		time.Sleep(10 * time.Millisecond)
		if last > bw.Rate() {
			t.Errorf("rate should be increasing, it isn't: last: %f > current: %f", last, bw.Rate())
		}
	}
	time.Sleep(2 * time.Second)
	for i := 0; i < 100; i++ {
		if bw.Rate() > 0 {
			t.Errorf("got high rate: got, want 0.0000", bw.Rate())
		}
		time.Sleep(9 * time.Millisecond)
	}
	bw.Close()
}

func TestAdd(t *testing.T) {
	t.Parallel()
	bw, err := New(1*time.Second, 100)
	if err != nil {
		t.Fatalf("failure to make reasonable BPS: %v", err)
	}
	for i := 0; i < 90; i++ {
		bw.Add(1024)
		last := bw.Rate()
		time.Sleep(10 * time.Millisecond)
		if last > bw.Rate() {
			t.Errorf("rate should be increasing, it isn't: last: %f > current: %f", last, bw.Rate())
		}
	}
	time.Sleep(2 * time.Second)
	for i := 0; i < 100; i++ {
		if bw.Rate() > 0 {
			t.Errorf("got high rate: got, want 0.0000", bw.Rate())
		}
		time.Sleep(9 * time.Millisecond)
	}
	bw.Close()
}

func TestHumanBytes(t *testing.T) {
	t.Parallel()
	bw, err := New(100*time.Second, 10)
	if err != nil {
		t.Fatalf("failure to make reasonable BPS: %v", err)
	}
	bw.Add(1000)
	got := bw.HumanRate()
	want := "10B/s"
	if got != want {
		t.Fatalf("did not get right human rate; got %v, want %v", got, want)
	}
}