From d9b6a90afc8aeac8b5c97cf96ead05a56da473ea Mon Sep 17 00:00:00 2001
From: Tnze <cjd001113@outlook.com>
Date: Sun, 4 Jul 2021 00:44:42 +0800
Subject: [PATCH] Handle screen open/send content

---
 bot/basic/info.go                     |  5 +++--
 bot/screen/inventory.go               | 12 ++++++++++--
 bot/screen/screen.go                  |  6 ++++--
 data/inv/inv.go => bot/screen/type.go |  3 +--
 examples/daze/daze.go                 |  4 ++--
 net/packet/types.go                   |  9 ++++++---
 6 files changed, 26 insertions(+), 13 deletions(-)
 rename data/inv/inv.go => bot/screen/type.go (91%)

diff --git a/bot/basic/info.go b/bot/basic/info.go
index 70a00fd..9679592 100644
--- a/bot/basic/info.go
+++ b/bot/basic/info.go
@@ -4,6 +4,7 @@ import (
 	"unsafe"
 
 	"github.com/Tnze/go-mc/data/packetid"
+	"github.com/Tnze/go-mc/nbt"
 	pk "github.com/Tnze/go-mc/net/packet"
 )
 
@@ -47,8 +48,8 @@ func (p *Player) handleJoinGamePacket(packet pk.Packet) error {
 		(*pk.Byte)(&p.PrevGamemode),
 		&WorldCount,
 		pk.Ary{Len: &WorldCount, Ary: &WorldNames},
-		pk.NBT(new(interface{})),
-		pk.NBT(new(interface{})),
+		pk.NBT(new(nbt.RawMessage)),
+		pk.NBT(new(nbt.RawMessage)),
 		(*pk.Identifier)(&p.WorldName),
 		(*pk.Long)(&p.HashedSeed),
 		(*pk.VarInt)(&p.MaxPlayers),
diff --git a/bot/screen/inventory.go b/bot/screen/inventory.go
index 8da3e2b..67f11f1 100644
--- a/bot/screen/inventory.go
+++ b/bot/screen/inventory.go
@@ -1,8 +1,16 @@
 package screen
 
+import (
+	"fmt"
+
+	"github.com/Tnze/go-mc/data/item"
+	"github.com/Tnze/go-mc/nbt"
+)
+
 type Inventory struct {
 }
 
-func (inv Inventory) SetSlot(i int, id int32, count byte, NBT interface{}) {
-	panic("implement me")
+func (inv Inventory) SetSlot(i int, id int32, count byte, NBT nbt.RawMessage) {
+	// TODO: accept inv data
+	fmt.Printf("Inventory[%d] = minecraft:%v * %d\n", i, item.ByID[item.ID(id)].Name, count)
 }
diff --git a/bot/screen/screen.go b/bot/screen/screen.go
index d03689b..375c89a 100644
--- a/bot/screen/screen.go
+++ b/bot/screen/screen.go
@@ -6,6 +6,7 @@ import (
 	"github.com/Tnze/go-mc/bot"
 	"github.com/Tnze/go-mc/chat"
 	"github.com/Tnze/go-mc/data/packetid"
+	"github.com/Tnze/go-mc/nbt"
 	pk "github.com/Tnze/go-mc/net/packet"
 )
 
@@ -18,6 +19,7 @@ func NewManager(c *bot.Client) *Manager {
 	m.Screens[0] = &Inventory{}
 	c.Events.AddListener(
 		bot.PacketHandler{Priority: 64, ID: packetid.OpenWindow, F: m.onOpenScreen},
+		bot.PacketHandler{Priority: 64, ID: packetid.WindowItems, F: m.onSetContentPacket},
 	)
 	return m
 }
@@ -60,7 +62,7 @@ type slot struct {
 	present pk.Boolean
 	id      pk.VarInt
 	count   pk.Byte
-	nbt     interface{}
+	nbt     nbt.RawMessage
 }
 
 func (s *slot) ReadFrom(r io.Reader) (n int64, err error) {
@@ -74,7 +76,7 @@ func (s *slot) ReadFrom(r io.Reader) (n int64, err error) {
 }
 
 type Container interface {
-	SetSlot(i int, id int32, count byte, NBT interface{})
+	SetSlot(i int, id int32, count byte, NBT nbt.RawMessage)
 }
 
 type Error struct {
diff --git a/data/inv/inv.go b/bot/screen/type.go
similarity index 91%
rename from data/inv/inv.go
rename to bot/screen/type.go
index cfa2ba1..de435d7 100644
--- a/data/inv/inv.go
+++ b/bot/screen/type.go
@@ -1,5 +1,4 @@
-// Package inv maps window types to inventory slot information.
-package inv
+package screen
 
 type Info struct {
 	Name       string
diff --git a/examples/daze/daze.go b/examples/daze/daze.go
index d7f8a32..f3facd4 100644
--- a/examples/daze/daze.go
+++ b/examples/daze/daze.go
@@ -1,7 +1,5 @@
 // Daze could join an offline-mode server as client.
 // Just standing there and do nothing. Automatically reborn after five seconds of death.
-//
-// BUG(Tnze): Kick by Disconnect: Time Out
 package main
 
 import (
@@ -14,6 +12,7 @@ import (
 
 	"github.com/Tnze/go-mc/bot"
 	"github.com/Tnze/go-mc/bot/basic"
+	"github.com/Tnze/go-mc/bot/screen"
 	"github.com/Tnze/go-mc/chat"
 	_ "github.com/Tnze/go-mc/data/lang/zh-cn"
 )
@@ -33,6 +32,7 @@ func main() {
 		Disconnect: onDisconnect,
 		Death:      onDeath,
 	}.Attach(client)
+	_ = screen.NewManager(client)
 
 	//Login
 	err := client.JoinServer(*address)
diff --git a/net/packet/types.go b/net/packet/types.go
index 6ae25d4..bc78c7f 100644
--- a/net/packet/types.go
+++ b/net/packet/types.go
@@ -441,20 +441,23 @@ type nbtField struct {
 	FieldName string
 }
 
-// Encode a nbtField
 func (n nbtField) WriteTo(w io.Writer) (int64, error) {
 	var buf bytes.Buffer
-	if err := nbt.NewEncoder(&buf).Encode(n.V, n.FieldName); err != nil {
+	if n.V == nil {
+		buf.WriteByte(nbt.TagEnd)
+	} else if err := nbt.NewEncoder(&buf).Encode(n.V, n.FieldName); err != nil {
 		return 0, err
 	}
 	return buf.WriteTo(w)
 }
 
-// Decode a nbtField
 func (n nbtField) ReadFrom(r io.Reader) (int64, error) {
 	// LimitReader is used to count reader length
 	lr := &io.LimitedReader{R: r, N: math.MaxInt64}
 	err := nbt.NewDecoder(lr).Decode(n.V)
+	if err != nil && errors.Is(err, nbt.ErrEND) {
+		err = nil
+	}
 	return math.MaxInt64 - lr.N, err
 }