package analyze

import (
	"sync"
	"testing"

	"github.com/dundee/gdu/v5/internal/testdir"
	"github.com/dundee/gdu/v5/pkg/fs"
	"github.com/stretchr/testify/assert"
)

// TestStoredDirUpdateStatsLockedAgainstReaders recomputes a StoredDir's stats
// while another goroutine reads them through the synchronized scalar accessors
// (GetSize, GetUsage, GetFlag, GetMtime, GetItemCount). Those readers take the
// embedded Dir mutex, so updateStats has to write the same fields under that
// mutex. Run with -race: without the locking the writes in updateStats race the
// reads here.
func TestStoredDirUpdateStatsLockedAgainstReaders(t *testing.T) {
	fin := testdir.CreateTestDir()
	defer fin()

	a := CreateStoredAnalyzer("/tmp/badger")
	dir := a.AnalyzeDir(
		"test_dir", func(_, _ string) bool { return false }, func(_ string) bool { return false },
	).(*StoredDir)
	a.GetDone().Wait()

	const rounds = 200

	stop := make(chan struct{})
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()
		for {
			select {
			case <-stop:
				return
			default:
			}
			_ = dir.GetSize()
			_ = dir.GetUsage()
			_ = dir.GetFlag()
			_ = dir.GetMtime()
			_ = dir.GetItemCount()
		}
	}()

	for range rounds {
		dir.UpdateStats(make(fs.HardLinkedItems))
	}
	close(stop)
	wg.Wait()

	// stats stay correct after the concurrent recomputation
	assert.Equal(t, int64(7+4096*3), dir.GetSize())
	assert.Equal(t, int64(5), dir.GetItemCount())
}