package webapp

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestLogBufferAppendTail(t *testing.T) {
	buf := NewLogBuffer(5)
	for i := 0; i < 12; i++ {
		buf.Append("line " + itoa(i))
	}
	// capacity 5, should hold the last 5 lines: 7..11
	got := buf.Tail(5)
	require.Len(t, got, 5)
	assert.Equal(t, "line 7", got[0])
	assert.Equal(t, "line 11", got[4])
	assert.Equal(t, 5, buf.Cap())
	assert.Equal(t, 5, buf.Size())
}

func TestLogBufferTailSmall(t *testing.T) {
	buf := NewLogBuffer(100)
	for i := 0; i < 3; i++ {
		buf.Append("x" + itoa(i))
	}
	got := buf.Tail(2)
	require.Len(t, got, 2)
	assert.Equal(t, "x1", got[0])
	assert.Equal(t, "x2", got[1])
}

func TestLogBufferTailEmpty(t *testing.T) {
	buf := NewLogBuffer(10)
	assert.Nil(t, buf.Tail(5))
	assert.Equal(t, 0, buf.Size())
}

func TestLogBufferTailZero(t *testing.T) {
	buf := NewLogBuffer(10)
	buf.Append("hello")
	assert.Nil(t, buf.Tail(0))
}

func TestLogBufferAppendStripsNewline(t *testing.T) {
	buf := NewLogBuffer(10)
	buf.Append("hello\n")
	got := buf.Tail(1)
	require.Len(t, got, 1)
	assert.Equal(t, "hello", got[0])
}

func TestFormatBytes(t *testing.T) {
	assert.Equal(t, "0 B", fmtBytes(0))
	assert.Equal(t, "1023 B", fmtBytes(1023))
	assert.Equal(t, "1.00 KiB", fmtBytes(1024))
	assert.Equal(t, "1.50 KiB", fmtBytes(1536))
	assert.Equal(t, "1.00 MiB", fmtBytes(1024*1024))
	assert.Equal(t, "4.00 GiB", fmtBytes(4*1024*1024*1024))
}

func TestFormatPercent(t *testing.T) {
	assert.Equal(t, "0.00%", fmtPercent(0))
	assert.Equal(t, "50.00%", fmtPercent(50))
	assert.Equal(t, "100.00%", fmtPercent(100))
}

func TestFormatDuration(t *testing.T) {
	assert.Equal(t, "0s", fmtDuration(0))
	assert.Equal(t, "59s", fmtDuration(59*1_000_000_000))
	assert.Equal(t, "1m 0s", fmtDuration(60*1_000_000_000))
	assert.Equal(t, "1h 0m 0s", fmtDuration(60*60*1_000_000_000))
	assert.Equal(t, "1d 0h 0m 0s", fmtDuration(24*60*60*1_000_000_000))
	assert.Equal(t, "2d 3h 4m 5s", fmtDuration((2*24+3)*3600*1_000_000_000+(4*60+5)*1_000_000_000))
}

func TestParseTail(t *testing.T) {
	assert.Equal(t, 200, parseTail(""))
	assert.Equal(t, 200, parseTail("garbage"))
	assert.Equal(t, 200, parseTail("199")) // not in the allowed set
	assert.Equal(t, 200, parseTail("200"))
	assert.Equal(t, 500, parseTail("500"))
	assert.Equal(t, 1000, parseTail("1000"))
	assert.Equal(t, 5000, parseTail("5000"))
	assert.Equal(t, 200, parseTail("5001"))
}