diff --git a/go.mod b/go.mod
index cb65849..40aec41 100644
--- a/go.mod
+++ b/go.mod
@@ -6,7 +6,7 @@ go 1.20
 replace github.com/sandertv/gophertunnel => github.com/olebeck/gophertunnel v1.28.1-1
 
 //replace github.com/df-mc/dragonfly => ./dragonfly
-replace github.com/df-mc/dragonfly => github.com/olebeck/dragonfly v0.9.4-4
+replace github.com/df-mc/dragonfly => github.com/olebeck/dragonfly v0.9.4-5
 
 //replace gioui.org => ./gio
 replace gioui.org => github.com/olebeck/gio v0.0.0-20230321105529-d424f1a59af9
@@ -61,6 +61,7 @@ require (
 	github.com/mattn/go-isatty v0.0.17 // indirect
 	github.com/muhammadmuzzammil1998/jsonc v1.0.0 // indirect
 	github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c // indirect
+	github.com/repeale/fp-go v0.11.1 // indirect
 	github.com/tklauser/go-sysconf v0.3.11 // indirect
 	github.com/tklauser/numcpus v0.6.0 // indirect
 	github.com/yusufpapurcu/wmi v1.2.2 // indirect
diff --git a/go.sum b/go.sum
index ded041a..41f4706 100644
--- a/go.sum
+++ b/go.sum
@@ -10,6 +10,8 @@ git.wow.st/gmp/jni v0.0.0-20210610011705-34026c7e22d0 h1:bGG/g4ypjrCJoSvFrP5hafr
 git.wow.st/gmp/jni v0.0.0-20210610011705-34026c7e22d0/go.mod h1:+axXBRUTIDlCeE73IKeD/os7LoEnTKdkp8/gQOFjqyo=
 github.com/BurntSushi/toml v1.0.0 h1:dtDWrepsVPfW9H/4y7dDgFc2MBUSeJhlaDtK13CxFlU=
 github.com/BurntSushi/toml v1.0.0/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
+github.com/TeaEntityLab/fpGo/v2 v2.3.2 h1:qlGjFzXukp9IgVQl32cz4PosbiFEnwXa2EpDbwddHS8=
+github.com/TeaEntityLab/fpGo/v2 v2.3.2/go.mod h1:b06fRNLSnNiUwfSskBC3f3cocA4mAC2iySdtaP/T9uA=
 github.com/benoitkugler/pstokenizer v1.0.0/go.mod h1:l1G2Voirz0q/jj0TQfabNxVsa8HZXh/VMxFSRALWTiE=
 github.com/benoitkugler/textlayout v0.3.0 h1:2ehWXEkgb6RUokTjXh1LzdGwG4dRP6X3dqhYYDYhUVk=
 github.com/benoitkugler/textlayout v0.3.0/go.mod h1:o+1hFV+JSHBC9qNLIuwVoLedERU7sBPgEFcuSgfvi/w=
@@ -83,10 +85,8 @@ github.com/muhammadmuzzammil1998/jsonc v1.0.0 h1:8o5gBQn4ZA3NBA9DlTujCj2a4w0tqWr
 github.com/muhammadmuzzammil1998/jsonc v1.0.0/go.mod h1:saF2fIVw4banK0H4+/EuqfFLpRnoy5S+ECwTOCcRcSU=
 github.com/nicksnyder/go-i18n/v2 v2.2.1 h1:aOzRCdwsJuoExfZhoiXHy4bjruwCMdt5otbYojM/PaA=
 github.com/nicksnyder/go-i18n/v2 v2.2.1/go.mod h1:fF2++lPHlo+/kPaj3nB0uxtPwzlPm+BlgwGX7MkeGj0=
-github.com/olebeck/dragonfly v0.9.4-3 h1:zG6f7zBCM9HWx6eQ/O5VKUBxU6bjln+nDlfCF0vNZ/A=
-github.com/olebeck/dragonfly v0.9.4-3/go.mod h1:k8OQvjmfj+JbrwQf1qHfMETlFHOp0WJLjILN+QVqh+c=
-github.com/olebeck/dragonfly v0.9.4-4 h1:qe2pEasLpGdbOvz6DYE56AlxMCyidj60/i0ZbfdD+no=
-github.com/olebeck/dragonfly v0.9.4-4/go.mod h1:k8OQvjmfj+JbrwQf1qHfMETlFHOp0WJLjILN+QVqh+c=
+github.com/olebeck/dragonfly v0.9.4-5 h1:ixVX0Fe3wX8FryJiKC5gFVS4KDrKtd1dXJoBkzWhd1c=
+github.com/olebeck/dragonfly v0.9.4-5/go.mod h1:k8OQvjmfj+JbrwQf1qHfMETlFHOp0WJLjILN+QVqh+c=
 github.com/olebeck/gio v0.0.0-20230321105529-d424f1a59af9 h1:TqDsMHwjW5ZYfh+RE8ussT62m0qXqo+QjzSXb7BCVA4=
 github.com/olebeck/gio v0.0.0-20230321105529-d424f1a59af9/go.mod h1:+W1Kpf96YcfissZocFqIp6O42FDTuphkObbEybp+Ffc=
 github.com/olebeck/gophertunnel v1.28.1-1 h1:bw2jeMz94YHF5qQYhq1Yq/6fALkklGu7k26YbPI4DSs=
@@ -100,6 +100,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c h1:ncq/mPwQF4JjgDlrVEn3C11VoGHZN7m8qihwgMEtzYw=
 github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c/go.mod h1:OmDBASR4679mdNQnz2pUhc2G8CO2JrUAVFDRBDP/hJE=
+github.com/repeale/fp-go v0.11.1 h1:Q/e+gNyyHaxKAyfdbBqvip3DxhVWH453R+kthvSr9Mk=
+github.com/repeale/fp-go v0.11.1/go.mod h1:4KrwQJB1VRY+06CA+jTc4baZetr6o2PeuqnKr5ybQUc=
 github.com/sanbornm/go-selfupdate v0.0.0-20210106163404-c9b625feac49 h1:LuxslTBxJrrNeKfqoywIERWWhH43TgiVAiPEVlhgNBA=
 github.com/sanbornm/go-selfupdate v0.0.0-20210106163404-c9b625feac49/go.mod h1:fY313ZGG810aWruFYcyq3coFpHDrWJVoMfSRI81y1r4=
 github.com/sandertv/go-raknet v1.12.0 h1:olUzZlIJyX/pgj/mrsLCZYjKLNDsYiWdvQ4NIm3z0DA=
@@ -198,6 +200,7 @@ google.golang.org/protobuf v1.28.1 h1:d0NfwRgPtno5B1Wa6L2DAG+KivqkdutMf1UhdNx175
 google.golang.org/protobuf v1.28.1/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/fsnotify.v1 v1.4.7 h1:xOHLXZwVvI9hhs+cLKq5+I5onOuwQLhQwiu63xxlHs4=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
 gopkg.in/inconshreveable/go-update.v0 v0.0.0-20150814200126-d8b0b1d421aa h1:drvf2JoUL1fz3ttkGNkw+rf3kZa2//7XkYGpSO4NHNA=
diff --git a/subcommands/blind-proxy.go b/subcommands/blind-proxy.go
index 366ff42..50947ca 100644
--- a/subcommands/blind-proxy.go
+++ b/subcommands/blind-proxy.go
@@ -54,11 +54,6 @@ func (c *BlindProxyCMD) Execute(ctx context.Context, ui utils.UI) error {
 		listener.ID(), "Creative", 1, listener.Addr().(*net.UDPAddr).Port, listener.Addr().(*net.UDPAddr).Port,
 	)))
 
-	go func() {
-		<-ctx.Done()
-		listener.Close()
-	}()
-
 	clientConn, err := listener.Accept()
 	if err != nil {
 		return err
diff --git a/subcommands/capture.go b/subcommands/capture.go
index f24be93..c21a774 100644
--- a/subcommands/capture.go
+++ b/subcommands/capture.go
@@ -5,6 +5,7 @@ import (
 	"context"
 	"encoding/binary"
 	"flag"
+	"fmt"
 	"io"
 	"net"
 	"os"
@@ -15,7 +16,6 @@ import (
 	"github.com/bedrock-tool/bedrocktool/utils"
 
 	"github.com/sandertv/gophertunnel/minecraft/protocol/packet"
-	"github.com/sirupsen/logrus"
 )
 
 func init() {
@@ -32,13 +32,7 @@ func dumpPacket(f io.WriteCloser, toServer bool, payload []byte) {
 	binary.Write(f, binary.LittleEndian, packetSize)
 	binary.Write(f, binary.LittleEndian, toServer)
 	binary.Write(f, binary.LittleEndian, time.Now().UnixMilli())
-	n, err := f.Write(payload)
-	if err != nil {
-		logrus.Error(err)
-	}
-	if n < int(packetSize) {
-		f.Write(make([]byte, int(packetSize)-n))
-	}
+	f.Write(payload)
 	f.Write([]byte{0xBB, 0xBB, 0xBB, 0xBB})
 }
 
@@ -59,7 +53,7 @@ func (c *CaptureCMD) Execute(ctx context.Context, ui utils.UI) error {
 	}
 
 	os.Mkdir("captures", 0o775)
-	fio, err := os.Create("captures/" + hostname + "-" + time.Now().Format("2006-01-02_15-04-05") + ".pcap2")
+	fio, err := os.Create(fmt.Sprintf("captures/%s-%s.pcap2", hostname, time.Now().Format("2006-01-02_15-04-05")))
 	if err != nil {
 		return err
 	}
@@ -68,7 +62,7 @@ func (c *CaptureCMD) Execute(ctx context.Context, ui utils.UI) error {
 
 	proxy, err := utils.NewProxy()
 	if err != nil {
-		logrus.Fatal(err)
+		return err
 	}
 	proxy.PacketFunc = func(header packet.Header, payload []byte, src, dst net.Addr) {
 		IsfromClient := src.String() == proxy.Client.LocalAddr().String()
@@ -79,10 +73,5 @@ func (c *CaptureCMD) Execute(ctx context.Context, ui utils.UI) error {
 		dumpPacket(fio, IsfromClient, buf.Bytes())
 	}
 
-	err = proxy.Run(ctx, address)
-	time.Sleep(2 * time.Second)
-	if err != nil {
-		return err
-	}
-	return nil
+	return proxy.Run(ctx, address)
 }
diff --git a/subcommands/chat_log.go b/subcommands/chat_log.go
index f05fcf6..4e69c09 100644
--- a/subcommands/chat_log.go
+++ b/subcommands/chat_log.go
@@ -59,8 +59,7 @@ func (c *ChatLogCMD) Execute(ctx context.Context, ui utils.UI) error {
 		return pk, nil
 	}
 
-	err = proxy.Run(ctx, address)
-	return err
+	return proxy.Run(ctx, address)
 }
 
 func init() {
diff --git a/subcommands/resourcepack-d/resourcepack-d.go b/subcommands/resourcepack-d/resourcepack-d.go
index e3480d5..cc08f3a 100644
Binary files a/subcommands/resourcepack-d/resourcepack-d.go and b/subcommands/resourcepack-d/resourcepack-d.go differ
diff --git a/subcommands/skins/skins.go b/subcommands/skins/skins.go
index cf3832d..3a439dd 100644
--- a/subcommands/skins/skins.go
+++ b/subcommands/skins/skins.go
@@ -149,13 +149,13 @@ func (c *SkinCMD) Execute(ctx context.Context, ui utils.UI) error {
 	proxy, _ := utils.NewProxy()
 	proxy.WithClient = !c.NoProxy
 	proxy.OnClientConnect = func(hasClient bool) {
-		ui.Message(messages.SetUIState, messages.UIStateConnecting)
+		ui.Message(messages.SetUIState(messages.UIStateConnecting))
 	}
 	proxy.ConnectCB = func(err error) bool {
 		if err != nil {
 			return false
 		}
-		ui.Message(messages.SetUIState, messages.UIStateMain)
+		ui.Message(messages.SetUIState(messages.UIStateMain))
 		logrus.Info(locale.Loc("ctrl_c_to_exit", nil))
 		return true
 	}
@@ -168,7 +168,7 @@ func (c *SkinCMD) Execute(ctx context.Context, ui utils.UI) error {
 	proxy.PacketCB = func(pk packet.Packet, toServer bool, _ time.Time) (packet.Packet, error) {
 		if !toServer {
 			for _, s := range s.ProcessPacket(pk) {
-				ui.Message(messages.NewSkin, messages.NewSkinPayload{
+				ui.Message(messages.NewSkin{
 					PlayerName: s.PlayerName,
 					Skin:       s.Skin,
 				})
@@ -178,9 +178,9 @@ func (c *SkinCMD) Execute(ctx context.Context, ui utils.UI) error {
 	}
 
 	if proxy.WithClient {
-		ui.Message(messages.SetUIState, messages.UIStateConnect)
+		ui.Message(messages.SetUIState(messages.UIStateConnect))
 	} else {
-		ui.Message(messages.SetUIState, messages.UIStateConnecting)
+		ui.Message(messages.SetUIState(messages.UIStateConnecting))
 	}
 	err = proxy.Run(ctx, address)
 	return err
diff --git a/subcommands/world/chunk.go b/subcommands/world/chunk.go
index e39f1fc..b2d5ae7 100644
--- a/subcommands/world/chunk.go
+++ b/subcommands/world/chunk.go
@@ -4,6 +4,7 @@ import (
 	"github.com/bedrock-tool/bedrocktool/locale"
 	"github.com/df-mc/dragonfly/server/world"
 	"github.com/df-mc/dragonfly/server/world/chunk"
+	"github.com/repeale/fp-go"
 	"github.com/sandertv/gophertunnel/minecraft/protocol"
 	"github.com/sandertv/gophertunnel/minecraft/protocol/packet"
 	"github.com/sirupsen/logrus"
@@ -76,13 +77,9 @@ func (w *worldsServer) processLevelChunk(pk *packet.LevelChunk) {
 		})
 	default:
 		// legacy
-		empty := true
-		for _, sub := range ch.Sub() {
-			if !sub.Empty() {
-				empty = false
-				break
-			}
-		}
+		empty := fp.Every(func(sub *chunk.SubChunk) bool {
+			return sub.Empty()
+		})(ch.Sub())
 		if !empty {
 			w.mapUI.SetChunk(pk.Position, ch, true)
 		}
diff --git a/subcommands/world/chunk_render.go b/subcommands/world/chunk_render.go
index 28fced8..1dcdd50 100644
--- a/subcommands/world/chunk_render.go
+++ b/subcommands/world/chunk_render.go
@@ -29,37 +29,43 @@ func blockColorAt(c *chunk.Chunk, x uint8, y int16, z uint8) (blockColor color.R
 
 	blockColor = color.RGBA{255, 0, 255, 255}
 	b, found := world.BlockByRuntimeID(rid)
-	if found {
-		if _, isWater := b.(block.Water); isWater {
-			// get the first non water block at the position
-			heightBlock := c.HeightMap().At(x, z)
-			depth := y - heightBlock
-			if depth > 0 {
-				blockColor = blockColorAt(c, x, heightBlock, z)
-			}
-
-			// blend that blocks color with water depending on depth
-			waterColor := (&block.Water{}).Color()
-			waterColor.A = uint8(utils.Clamp(int(150+depth*7), 255))
-			blockColor = utils.BlendColors(blockColor, waterColor)
-			blockColor.R -= uint8(depth * 2)
-			blockColor.G -= uint8(depth * 2)
-			blockColor.B -= uint8(depth * 2)
-			return blockColor
-		} else {
-			col := b.Color()
-			if col.A != 255 {
-				col = utils.BlendColors(blockColorAt(c, x, y-1, z), col)
-			}
-			return col
-		}
-	} else {
-		/*
-			name, nbt := b.EncodeBlock()
-			fmt.Printf("unknown color %d  %s %s %s\n", rid, reflect.TypeOf(b), name, nbt)
-		*/
+	if !found {
 		return blockColor
 	}
+
+	if _, isWater := b.(block.Water); isWater {
+		waterColor := block.Water{}.Color()
+
+		// get the first non water block at the position
+		heightBlock := c.HeightMap().At(x, z)
+		depth := y - heightBlock
+		if depth > 0 {
+			blockColor = blockColorAt(c, x, heightBlock, z)
+		}
+
+		// blend that blocks color with water depending on depth
+		waterColor.A = uint8(utils.Clamp(int(150+depth*7), 255))
+		blockColor = utils.BlendColors(blockColor, waterColor)
+		blockColor.R -= uint8(depth * 2)
+		blockColor.G -= uint8(depth * 2)
+		blockColor.B -= uint8(depth * 2)
+		return blockColor
+	} else {
+		col := b.Color()
+		if col.A != 255 {
+			col = utils.BlendColors(blockColorAt(c, x, y-1, z), col)
+		}
+
+		/*
+			a := color.RGBA{255, 0, 255, 255}
+			if col == a {
+				name, nbt := b.EncodeBlock()
+				fmt.Printf("unknown color %d  %s %s %s\n", rid, reflect.TypeOf(b), name, nbt)
+			}
+		*/
+
+		return col
+	}
 }
 
 func chunkGetColorAt(c *chunk.Chunk, x uint8, y int16, z uint8) color.RGBA {
diff --git a/subcommands/world/map_item.go b/subcommands/world/map_item.go
index ccf0800..b71cf60 100644
--- a/subcommands/world/map_item.go
+++ b/subcommands/world/map_item.go
@@ -95,7 +95,7 @@ func NewMapUI(w *worldsServer) *MapUI {
 }
 
 func (m *MapUI) Start() {
-	r := m.w.gui.Message("can_show_images", nil)
+	r := m.w.gui.Message(messages.CanShowImages{})
 	if r.Ok {
 		m.showOnGui = true
 	}
@@ -182,7 +182,7 @@ func (m *MapUI) SchedRedraw() {
 // Redraw draws chunk images to the map image
 func (m *MapUI) Redraw() {
 	m.l.Lock()
-	updatedChunks := []protocol.ChunkPos{}
+	updatedChunks := make([]protocol.ChunkPos, 0, m.renderQueue.Length())
 	for {
 		r, ok := m.renderQueue.Dequeue().(*RenderElem)
 		if !ok {
@@ -225,7 +225,7 @@ func (m *MapUI) Redraw() {
 	}
 	if m.showOnGui {
 		min, max := m.GetBounds()
-		m.w.gui.Message(messages.UpdateMap, messages.UpdateMapPayload{
+		m.w.gui.Message(messages.UpdateMap{
 			ChunkCount:   len(m.renderedChunks),
 			Rotation:     m.w.serverState.PlayerPos.Yaw,
 			UpdatedTiles: updatedChunks,
diff --git a/subcommands/world/world.go b/subcommands/world/world.go
index dcdaa5d..d4988a4 100644
--- a/subcommands/world/world.go
+++ b/subcommands/world/world.go
@@ -25,6 +25,7 @@ import (
 	"github.com/df-mc/dragonfly/server/world/mcdb"
 	"github.com/df-mc/goleveldb/leveldb/opt"
 	"github.com/go-gl/mathgl/mgl32"
+	"github.com/repeale/fp-go"
 	"github.com/sandertv/gophertunnel/minecraft"
 	"github.com/sandertv/gophertunnel/minecraft/protocol"
 	"github.com/sandertv/gophertunnel/minecraft/protocol/packet"
@@ -104,8 +105,8 @@ func NewWorldsServer(ctx context.Context, proxy *utils.ProxyContext, ServerName
 	w.mapUI = NewMapUI(w)
 	w.Reset(w.CurrentName())
 
-	w.gui.Message(messages.Init, messages.InitPayload{
-		Handler: w.uiMessage,
+	w.gui.Message(messages.Init{
+		Handler: nil,
 	})
 
 	return w
@@ -173,7 +174,7 @@ func (c *WorldCMD) Execute(ctx context.Context, ui utils.UI) error {
 	}
 	proxy.ConnectCB = w.OnConnect
 	proxy.OnClientConnect = func(hasClient bool) {
-		w.gui.Message(messages.SetUIState, messages.UIStateConnecting)
+		w.gui.Message(messages.SetUIState(messages.UIStateConnecting))
 	}
 	proxy.PacketCB = func(pk packet.Packet, toServer bool, _ time.Time) (packet.Packet, error) {
 		forward := true
@@ -200,32 +201,16 @@ func (c *WorldCMD) Execute(ctx context.Context, ui utils.UI) error {
 		return pk, nil
 	}
 
-	w.gui.Message(messages.SetUIState, messages.UIStateConnect)
+	w.gui.Message(messages.SetUIState(messages.UIStateConnect))
 	err = w.proxy.Run(ctx, serverAddress)
 	if err != nil {
 		return err
 	}
 	w.SaveAndReset()
-	ui.Message(messages.SetUIState, messages.UIStateFinished)
+	ui.Message(messages.SetUIState(messages.UIStateFinished))
 	return nil
 }
 
-func (w *worldsServer) uiMessage(name string, data interface{}) messages.MessageResponse {
-	r := messages.MessageResponse{
-		Ok:   false,
-		Data: nil,
-	}
-	switch name {
-	case messages.SetVoidGen:
-		set_void_gen := data.(messages.SetVoidGenPayload)
-		r.Ok = w.setVoidGen(set_void_gen.Value, true)
-	case messages.SetWorldName:
-		set_world_name := data.(messages.SetWorldNamePayload)
-		r.Ok = w.setWorldName(set_world_name.WorldName, true)
-	}
-	return r
-}
-
 func (w *worldsServer) SetPlayerPos(Position mgl32.Vec3, Pitch, Yaw, HeadYaw float32) {
 	last := w.serverState.PlayerPos
 	current := TPlayerPos{
@@ -243,16 +228,14 @@ func (w *worldsServer) SetPlayerPos(Position mgl32.Vec3, Pitch, Yaw, HeadYaw flo
 
 func (w *worldsServer) setVoidGen(val bool, fromUI bool) bool {
 	w.settings.voidGen = val
-	var s string
+	var s = locale.Loc("void_generator_false", nil)
 	if w.settings.voidGen {
 		s = locale.Loc("void_generator_true", nil)
-	} else {
-		s = locale.Loc("void_generator_false", nil)
 	}
 	w.proxy.SendMessage(s)
 
 	if !fromUI {
-		w.gui.Message(messages.SetVoidGen, messages.SetVoidGenPayload{
+		w.gui.Message(messages.SetVoidGen{
 			Value: w.settings.voidGen,
 		})
 	}
@@ -265,7 +248,7 @@ func (w *worldsServer) setWorldName(val string, fromUI bool) bool {
 	w.proxy.SendMessage(locale.Loc("worldname_set", locale.Strmap{"Name": w.worldState.Name}))
 
 	if !fromUI {
-		w.gui.Message(messages.SetWorldName, messages.SetWorldNamePayload{
+		w.gui.Message(messages.SetWorldName{
 			WorldName: w.worldState.Name,
 		})
 	}
@@ -301,25 +284,22 @@ func (w *worldsServer) SaveAndReset() {
 	for cp := range w.worldState.chunks {
 		keys = append(keys, cp)
 	}
-	for _, cp := range keys {
-		has_any := false
-		for _, sc := range w.worldState.chunks[cp].Sub() {
-			has_any = !sc.Empty()
-			if has_any {
-				break
-			}
-		}
-		if !has_any {
-			delete(w.worldState.chunks, cp)
-		}
+
+	for _, cp := range fp.Filter(func(cp protocol.ChunkPos) bool {
+		return fp.Some(func(sc *chunk.SubChunk) bool {
+			return !sc.Empty()
+		})(w.worldState.chunks[cp].Sub())
+	})(keys) {
+		delete(w.worldState.chunks, cp)
 	}
+
 	if len(w.worldState.chunks) == 0 {
 		w.Reset(w.CurrentName())
 		return
 	}
 
 	logrus.Infof(locale.Loc("saving_world", locale.Strmap{"Name": w.worldState.Name, "Count": len(w.worldState.chunks)}))
-	w.gui.Message(messages.SavingWorld, messages.SavingWorldPayload{
+	w.gui.Message(messages.SavingWorld{
 		Name:   w.worldState.Name,
 		Chunks: len(w.worldState.chunks),
 	})
@@ -558,11 +538,11 @@ func (w *worldsServer) SaveAndReset() {
 	logrus.Info(locale.Loc("saved", locale.Strmap{"Name": filename}))
 	//os.RemoveAll(folder)
 	w.Reset(w.CurrentName())
-	w.gui.Message(messages.SetUIState, messages.UIStateMain)
+	w.gui.Message(messages.SetUIState(messages.UIStateMain))
 }
 
 func (w *worldsServer) OnConnect(err error) bool {
-	w.gui.Message(messages.SetUIState, messages.UIStateMain)
+	w.gui.Message(messages.SetUIState(messages.UIStateMain))
 
 	if err != nil {
 		return false
diff --git a/ui/gui.go b/ui/gui.go
index 583baff..776678d 100644
--- a/ui/gui.go
+++ b/ui/gui.go
@@ -114,8 +114,8 @@ func (g *GUI) run(w *app.Window) error {
 	}
 }
 
-func (g *GUI) Message(name string, data interface{}) messages.MessageResponse {
-	r := g.router.Handler(name, data)
+func (g *GUI) Message(data interface{}) messages.MessageResponse {
+	r := g.router.Handler(data)
 	if r.Ok || r.Data != nil {
 		return r
 	}
@@ -125,8 +125,8 @@ func (g *GUI) Message(name string, data interface{}) messages.MessageResponse {
 		Data: nil,
 	}
 
-	switch name {
-	case "can_show_images":
+	switch data.(type) {
+	case messages.CanShowImages:
 		r.Ok = true
 	}
 
diff --git a/ui/gui/pages/page.go b/ui/gui/pages/page.go
index 8b10711..d1046d1 100644
--- a/ui/gui/pages/page.go
+++ b/ui/gui/pages/page.go
@@ -13,7 +13,7 @@ import (
 	"github.com/bedrock-tool/bedrocktool/ui/messages"
 )
 
-type HandlerFunc = func(name string, data interface{}) messages.MessageResponse
+type HandlerFunc = func(data interface{}) messages.MessageResponse
 
 type Page interface {
 	Actions() []component.AppBarAction
@@ -133,10 +133,10 @@ func (r *Router) Layout(gtx layout.Context, th *material.Theme) layout.Dimension
 	return layout.Dimensions{Size: gtx.Constraints.Max}
 }
 
-func (r *Router) Handler(name string, data interface{}) messages.MessageResponse {
+func (r *Router) Handler(data interface{}) messages.MessageResponse {
 	page, ok := r.pages[r.current]
 	if ok {
-		return page.Handler()(name, data)
+		return page.Handler()(data)
 	}
 	return messages.MessageResponse{}
 }
diff --git a/ui/gui/pages/settings/settings.go b/ui/gui/pages/settings/settings.go
index 1c1c17f..5420967 100644
--- a/ui/gui/pages/settings/settings.go
+++ b/ui/gui/pages/settings/settings.go
@@ -176,7 +176,7 @@ func (p *Page) Layout(gtx C, th *material.Theme) D {
 }
 
 func (p *Page) Handler() pages.HandlerFunc {
-	return func(name string, data interface{}) messages.MessageResponse {
+	return func(data interface{}) messages.MessageResponse {
 		return messages.MessageResponse{
 			Ok:   false,
 			Data: nil,
diff --git a/ui/gui/pages/skins/skins.go b/ui/gui/pages/skins/skins.go
index da24edd..0eed53c 100644
--- a/ui/gui/pages/skins/skins.go
+++ b/ui/gui/pages/skins/skins.go
@@ -24,7 +24,7 @@ type Page struct {
 	State     messages.UIState
 	SkinsList widget.List
 	l         sync.Mutex
-	Skins     []messages.NewSkinPayload
+	Skins     []messages.NewSkin
 }
 
 func New(router *pages.Router) *Page {
@@ -96,28 +96,20 @@ func (p *Page) Layout(gtx C, th *material.Theme) D {
 	return layout.Flex{}.Layout(gtx)
 }
 
-func (p *Page) handler(name string, data interface{}) messages.MessageResponse {
+func (p *Page) handler(data interface{}) messages.MessageResponse {
 	r := messages.MessageResponse{
 		Ok:   false,
 		Data: nil,
 	}
 
-	switch name {
+	switch m := data.(type) {
 	case messages.SetUIState:
-		state := data.(messages.UIState)
-		p.State = state
+		p.State = m
 		p.Router.Invalidate()
 		r.Ok = true
-
-	case messages.Init:
-		init := data.(messages.InitPayload)
-		_ = init
-		r.Ok = true
-
 	case messages.NewSkin:
 		p.l.Lock()
-		new_skin := data.(messages.NewSkinPayload)
-		p.Skins = append(p.Skins, new_skin)
+		p.Skins = append(p.Skins, m)
 		p.l.Unlock()
 		p.Router.Invalidate()
 		r.Ok = true
diff --git a/ui/gui/pages/worlds/map.go b/ui/gui/pages/worlds/map.go
index 4f25341..b24bb62 100644
--- a/ui/gui/pages/worlds/map.go
+++ b/ui/gui/pages/worlds/map.go
@@ -90,7 +90,7 @@ func drawTile(img *image.RGBA, min, pos protocol.ChunkPos, tile *image.RGBA) {
 	), tile, image.Point{}, draw.Src)
 }
 
-func (m *Map) Update(u *messages.UpdateMapPayload) {
+func (m *Map) Update(u *messages.UpdateMap) {
 	if m.MapImage == nil {
 		m.scaleFactor = 1
 	}
diff --git a/ui/gui/pages/worlds/worlds.go b/ui/gui/pages/worlds/worlds.go
index 46933f1..ee96ee0 100644
--- a/ui/gui/pages/worlds/worlds.go
+++ b/ui/gui/pages/worlds/worlds.go
@@ -30,7 +30,7 @@ type Page struct {
 	worldName  string
 
 	worldsList widget.List
-	worlds     []messages.SavingWorldPayload
+	worlds     []messages.SavingWorld
 	l          sync.Mutex
 }
 
@@ -115,47 +115,33 @@ func (p *Page) Layout(gtx C, th *material.Theme) D {
 	return layout.Dimensions{}
 }
 
-func (u *Page) handler(name string, data interface{}) messages.MessageResponse {
+func (u *Page) handler(data interface{}) messages.MessageResponse {
 	r := messages.MessageResponse{
 		Ok:   false,
 		Data: nil,
 	}
 
-	switch name {
+	switch m := data.(type) {
 	case messages.SetUIState:
-		state := data.(messages.UIState)
-		u.State = state
+		u.State = m
 		u.Router.Invalidate()
 		r.Ok = true
-
-	case messages.Init:
-		init := data.(messages.InitPayload)
-		_ = init
-		r.Ok = true
-
 	case messages.UpdateMap:
-		update_map := data.(messages.UpdateMapPayload)
-		u.chunkCount = update_map.ChunkCount
-		u.worldMap.Update(&update_map)
+		u.chunkCount = m.ChunkCount
+		u.worldMap.Update(&m)
 		u.Router.Invalidate()
 		r.Ok = true
-
 	case messages.SetVoidGen:
-		set_void_gen := data.(messages.SetVoidGenPayload)
-		u.voidGen = set_void_gen.Value
+		u.voidGen = m.Value
 		u.Router.Invalidate()
 		r.Ok = true
-
 	case messages.SetWorldName:
-		set_world_name := data.(messages.SetWorldNamePayload)
-		u.worldName = set_world_name.WorldName
+		u.worldName = m.WorldName
 		u.Router.Invalidate()
 		r.Ok = true
-
 	case messages.SavingWorld:
 		u.l.Lock()
-		saving_world := data.(messages.SavingWorldPayload)
-		u.worlds = append(u.worlds, saving_world)
+		u.worlds = append(u.worlds, m)
 		u.l.Unlock()
 		u.Router.Invalidate()
 		r.Ok = true
diff --git a/ui/gui/uis.go b/ui/gui/uis.go
index 3ab5f81..207d499 100644
--- a/ui/gui/uis.go
+++ b/ui/gui/uis.go
@@ -8,4 +8,4 @@ import (
 type C = layout.Context
 type D = layout.Dimensions
 
-type HandlerFunc = func(name string, data interface{}) messages.MessageResponse
+type HandlerFunc = func(data interface{}) messages.MessageResponse
diff --git a/ui/messages/messages.go b/ui/messages/messages.go
index ae0fd65..8e24995 100644
--- a/ui/messages/messages.go
+++ b/ui/messages/messages.go
@@ -11,7 +11,7 @@ type MessageResponse struct {
 	Data interface{}
 }
 
-type UIState = int
+type UIState int
 
 const (
 	UIStateConnect = iota
@@ -24,39 +24,29 @@ type HandlerFunc = func(name string, data interface{}) MessageResponse
 
 //
 
-const SetUIState = "set_ui_state"
-
-type SetUIStatePayload = UIState
+type SetUIState = UIState
 
 //
 
-const SetVoidGen = "set_void_gen"
-
-type SetVoidGenPayload struct {
+type SetVoidGen struct {
 	Value bool
 }
 
 //
 
-const SetWorldName = "set_world_name"
-
-type SetWorldNamePayload struct {
+type SetWorldName struct {
 	WorldName string
 }
 
 //
 
-var Init = "init"
-
-type InitPayload struct {
+type Init struct {
 	Handler HandlerFunc
 }
 
 //
 
-var UpdateMap = "update_map"
-
-type UpdateMapPayload struct {
+type UpdateMap struct {
 	ChunkCount   int
 	Rotation     float32
 	UpdatedTiles []protocol.ChunkPos
@@ -67,16 +57,14 @@ type UpdateMapPayload struct {
 
 //
 
-var NewSkin = "new_skin"
-
-type NewSkinPayload struct {
+type NewSkin struct {
 	PlayerName string
 	Skin       *protocol.Skin
 }
 
-var SavingWorld = "saving_world"
-
-type SavingWorldPayload struct {
+type SavingWorld struct {
 	Name   string
 	Chunks int
 }
+
+type CanShowImages struct{}
diff --git a/utils/behaviourpack/bp.go b/utils/behaviourpack/bp.go
index c2a3c1b..b8621e5 100644
--- a/utils/behaviourpack/bp.go
+++ b/utils/behaviourpack/bp.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/bedrock-tool/bedrocktool/utils"
+	"github.com/repeale/fp-go"
 	"github.com/sandertv/gophertunnel/minecraft/resource"
 	"github.com/sirupsen/logrus"
 )
@@ -73,22 +74,16 @@ func (bp *BehaviourPack) CheckAddLink(pack utils.Pack) {
 
 	hasEntitiesFolder := false
 	if bp.HasEntities() {
-		for _, f := range z.File {
-			if f.Name == "entity" && f.FileInfo().IsDir() {
-				hasEntitiesFolder = true
-				break
-			}
-		}
+		hasEntitiesFolder = fp.Some(func(f *zip.File) bool {
+			return f.Name == "entity" && f.FileInfo().IsDir()
+		})(z.File)
 	}
 
 	hasItemsFolder := false
 	if bp.HasItems() {
-		for _, f := range z.File {
-			if f.Name == "items" && f.FileInfo().IsDir() {
-				hasItemsFolder = true
-				break
-			}
-		}
+		hasItemsFolder = fp.Some(func(f *zip.File) bool {
+			return f.Name == "items" && f.FileInfo().IsDir()
+		})(z.File)
 	}
 
 	// has no assets needed
@@ -139,7 +134,7 @@ func (bp *BehaviourPack) Save(fpath string) error {
 		return e.Encode(thing)
 	}
 
-	if len(bp.blocks) > 0 { // blocks
+	if bp.HasBlocks() { // blocks
 		blocks_dir := path.Join(fpath, "blocks")
 		os.Mkdir(blocks_dir, 0o755)
 		for _, be := range bp.blocks {
@@ -149,7 +144,7 @@ func (bp *BehaviourPack) Save(fpath string) error {
 			}
 		}
 	}
-	if len(bp.items) > 0 { // items
+	if bp.HasItems() { // items
 		items_dir := path.Join(fpath, "items")
 		os.Mkdir(items_dir, 0o755)
 		for _, ib := range bp.items {
@@ -159,7 +154,7 @@ func (bp *BehaviourPack) Save(fpath string) error {
 			}
 		}
 	}
-	if len(bp.entities) > 0 { // items
+	if bp.HasEntities() { // entities
 		items_dir := path.Join(fpath, "entities")
 		os.Mkdir(items_dir, 0o755)
 		for _, eb := range bp.entities {
diff --git a/utils/iui.go b/utils/iui.go
index 49b37ad..ebd034e 100644
--- a/utils/iui.go
+++ b/utils/iui.go
@@ -17,7 +17,7 @@ import (
 type UI interface {
 	Init() bool
 	Start(context.Context, context.CancelFunc) error
-	Message(name string, data interface{}) messages.MessageResponse
+	Message(data interface{}) messages.MessageResponse
 	ServerInput(context.Context, string) (string, string, error)
 }
 
@@ -25,7 +25,7 @@ type BaseUI struct {
 	UI
 }
 
-func (u *BaseUI) Message(name string, data interface{}) messages.MessageResponse {
+func (u *BaseUI) Message(data interface{}) messages.MessageResponse {
 	return messages.MessageResponse{
 		Ok:   false,
 		Data: nil,
diff --git a/utils/net.go b/utils/net.go
index 4622344..351b289 100644
--- a/utils/net.go
+++ b/utils/net.go
@@ -1,8 +1,12 @@
 package utils
 
-import "net"
+import (
+	"net"
 
-var PrivateIPNetworks = []net.IPNet{
+	"github.com/repeale/fp-go"
+)
+
+var privateIPNetworks = []net.IPNet{
 	{
 		IP:   net.ParseIP("10.0.0.0"),
 		Mask: net.CIDRMask(8, 32),
@@ -19,12 +23,9 @@ var PrivateIPNetworks = []net.IPNet{
 
 // IPPrivate checks if ip is private
 func IPPrivate(ip net.IP) bool {
-	for _, ipNet := range PrivateIPNetworks {
-		if ipNet.Contains(ip) {
-			return true
-		}
-	}
-	return false
+	return fp.Some(func(ipNet net.IPNet) bool {
+		return ipNet.Contains(ip)
+	})(privateIPNetworks)
 }
 
 // GetLocalIP returns the non loopback local IP of the host
diff --git a/utils/utils.go b/utils/utils.go
index 9cf90c6..fe6ec65 100644
--- a/utils/utils.go
+++ b/utils/utils.go
@@ -120,30 +120,6 @@ func spawnConn(ctx context.Context, clientConn *minecraft.Conn, serverConn *mine
 	return nil
 }
 
-// get longest line length
-func maxLen(lines []string) int {
-	o := 0
-	for _, line := range lines {
-		if o < len(line) {
-			o = len(line)
-		}
-	}
-	return o
-}
-
-// MarginLines makes text centered
-func MarginLines(lines []string) string {
-	ret := ""
-	max := maxLen(lines)
-	for _, line := range lines {
-		if len(line) != max {
-			ret += strings.Repeat(" ", max/2-len(line)/4)
-		}
-		ret += line + "\n"
-	}
-	return ret
-}
-
 // SplitExt splits path to filename and extension
 func SplitExt(filename string) (name, ext string) {
 	name, ext = path.Base(filename), path.Ext(filename)