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)
	if err != nil {
		t.Fatalf("failure to make reasonable BPS: %v", err)
	}
	bw.Close()
}

func TestBadResolution(t *testing.T) {
	var i uint
	for i = 0; i < minResolution; i++ {
		_, err := NewPrecise(1*time.Second, i)
		if err == nil {
			t.Fatalf("expected an error, got nil for %d", i)
		}
	}
}

func TestWriter(t *testing.T) {
	t.Parallel()
	bw, err := New(1 * time.Second)
	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)
	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 := NewPrecise(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)
	}
}

// TestSparkBadBucketCounts just makes sure that bad inputs are reported
func TestSparkBadBucketCounts(t *testing.T) {
	bw := BPS{
		buckets: make([]int64, 10),
	}
	sizes := []int{-10, -1, 0, 11, 12, 100, 1000}
	for _, size := range sizes {
		got := bw.Sparkline(size)
		want := "bucket count inappropriate"
		if got != want {
			t.Fatalf("got: %v, want: %v", got, want)
		}
	}
}

// TestSparkline just creates a simple BPS and traverses all reasonable count
// sizes. It's primarily a test for panics which plagued us early on.
func TestSparkline(t *testing.T) {
	buckets := 20
	bw := BPS{
		buckets: make([]int64, buckets),
	}

	t.Logf("all 0")
	for i := 0; i < buckets; i++ {
		bw.buckets[i] = 0
	}
	for i := 1; i < buckets; i++ {
		line := bw.Sparkline(i)
		t.Logf("count: %d, len %d: %+v", i, len([]rune(line)), line)
	}

	t.Logf("increasing")
	for i := 0; i < buckets; i++ {
		bw.buckets[i] = int64(i * buckets)
	}
	for i := 1; i < buckets; i++ {
		line := bw.Sparkline(i)
		t.Logf("count: %d, len %d: %+v", i, len([]rune(line)), line)
	}

	t.Logf("decreasing")
	for i := 0; i < buckets; i++ {
		bw.buckets[i] = int64((buckets - i) * buckets)
	}
	for i := 1; i < buckets; i++ {
		line := bw.Sparkline(i)
		t.Logf("count: %d, len %d: %+v", i, len([]rune(line)), line)
	}
}

func TestSparkRandom(t *testing.T) {
	buckets := 20
	bw := BPS{
		buckets: make([]int64, buckets),
	}
	bw.buckets[3] = 100
	t.Logf("%+v", bw.Sparkline(10))
	bw.buckets[7] = 300
	for i := 1; i < buckets; i++ {
		line := bw.Sparkline(i)
		t.Logf("count: %d, len: %d: %+v", i, len([]rune(line)), line)
	}
}