package gc

import (
	"fmt"
	"s1d3sw1ped/SteamCache2/vfs"
	"s1d3sw1ped/SteamCache2/vfs/memory"
	"sort"
	"testing"
	"time"

	"golang.org/x/exp/rand"
)

func TestGCSmallRandom(t *testing.T) {
	t.Parallel()

	m := memory.New(1024 * 1024 * 16)
	gc := New(m, 10, func(vfs vfs.VFS, size int) {
		tstart := time.Now()
		deletions := 0
		targetreclaim := int64(size)
		var reclaimed int64

		t.Logf("GC starting to reclaim %d bytes", targetreclaim)

		stats := vfs.StatAll()
		sort.Slice(stats, func(i, j int) bool {
			// Sort by access time so we can remove the oldest files first.
			return stats[i].AccessTime().Before(stats[j].AccessTime())
		})

		// Delete the oldest files until we've reclaimed enough space.
		for _, s := range stats {
			sz := s.Size() // Get the size of the file
			err := vfs.Delete(s.Name())
			if err != nil {
				panic(err)
			}
			reclaimed += sz // Track how much space we've reclaimed
			deletions++     // Track how many files we've deleted

			// t.Logf("GC deleting %s, %v", s.Name(), s.AccessTime().Format(time.RFC3339Nano))

			if reclaimed >= targetreclaim { // We've reclaimed enough space
				break
			}
		}

		t.Logf("GC took %v to reclaim %d bytes by deleting %d files", time.Since(tstart), reclaimed, deletions)
	})

	for i := 0; i < 10000; i++ {
		if err := gc.Set(fmt.Sprintf("key:%d", i), genRandomData(1024*1, 1024*4)); err != nil {
			t.Errorf("Set failed: %v", err)
		}
	}

	if gc.Size() > 1024*1024*16 {
		t.Errorf("MemoryFS size is %d, want <= 1024", m.Size())
	}
}

func genRandomData(min int, max int) []byte {
	data := make([]byte, rand.Intn(max-min)+min)
	rand.Read(data)
	return data
}

func TestGCLargeRandom(t *testing.T) {
	t.Parallel()

	m := memory.New(1024 * 1024 * 16) // 16MB
	gc := New(m, 10, func(vfs vfs.VFS, size int) {
		tstart := time.Now()
		deletions := 0
		targetreclaim := int64(size)
		var reclaimed int64

		t.Logf("GC starting to reclaim %d bytes", targetreclaim)

		stats := vfs.StatAll()
		sort.Slice(stats, func(i, j int) bool {
			// Sort by access time so we can remove the oldest files first.
			return stats[i].AccessTime().Before(stats[j].AccessTime())
		})

		// Delete the oldest files until we've reclaimed enough space.
		for _, s := range stats {
			sz := s.Size() // Get the size of the file
			vfs.Delete(s.Name())
			reclaimed += sz // Track how much space we've reclaimed
			deletions++     // Track how many files we've deleted

			if reclaimed >= targetreclaim { // We've reclaimed enough space
				break
			}
		}

		t.Logf("GC took %v to reclaim %d bytes by deleting %d files", time.Since(tstart), reclaimed, deletions)
	})

	for i := 0; i < 10000; i++ {
		if err := gc.Set(fmt.Sprintf("key:%d", i), genRandomData(1024, 1024*1024)); err != nil {
			t.Errorf("Set failed: %v", err)
		}
	}

	if gc.Size() > 1024*1024*16 {
		t.Errorf("MemoryFS size is %d, want <= 1024", m.Size())
	}
}