chat message parsing

Author: BuckarooBanzay

client_handler.go

@@ -178,7 +178,7 @@ func (ch *ClientHandler) handleCommand(o interface{}) error {
 	case *commands.ServerTimeOfDay:
 		fmt.Printf("Time of day: %d\n", cmd.TimeOfDay)
 	case *commands.ServerChatMessage:
-		fmt.Printf("Chat: '%s'\n", cmd.Message)
+		fmt.Printf("Chat: %s\n", cmd)
 	case *commands.ServerMovePlayer:
 		fmt.Printf("Move player: '%s'\n", cmd)
 

commands/server_chat_message.go

@@ -1,10 +1,18 @@
 package commands
 
 import (
+	"encoding/binary"
 	"fmt"
+
+	"golang.org/x/text/encoding/unicode"
 )
 
+type ServerChatMessageType int
+
 type ServerChatMessage struct {
+	Version int
+	Type    ServerChatMessageType
+	Sender  string
 	Message string
 }
 
@@ -17,11 +25,38 @@ func (p *ServerChatMessage) MarshalPacket() ([]byte, error) {
 }
 
 func (p *ServerChatMessage) UnmarshalPacket(payload []byte) error {
-	size := payload[5]
-	p.Message = string(payload[6 : (size*2)+6])
+	offset := 0
+	p.Version = int(payload[offset])
+	offset++
+	p.Type = ServerChatMessageType(payload[offset])
+	offset++
+
+	sender_len := binary.BigEndian.Uint16(payload[offset:])
+	offset += 2
+
+	utf16 := unicode.UTF16(unicode.BigEndian, unicode.IgnoreBOM)
+	sender_bytes, err := utf16.NewDecoder().Bytes(payload[offset : offset+int(sender_len*2)])
+	if err != nil {
+		return err
+	}
+
+	p.Sender = string(sender_bytes)
+	offset += int(sender_len * 2)
+
+	message_len := binary.BigEndian.Uint16(payload[offset:])
+	offset += 2
+
+	message_bytes, err := utf16.NewDecoder().Bytes(payload[offset : offset+int(message_len*2)])
+	if err != nil {
+		return err
+	}
+
+	p.Message = string(message_bytes)
+
 	return nil
 }
 
 func (p *ServerChatMessage) String() string {
-	return fmt.Sprintf("{ServerChatMessage Message='%s'}", p.Message)
+	return fmt.Sprintf("{ServerChatMessage Version=%d, Type=%d, Sender='%s', Message='%s'}",
+		p.Version, p.Type, p.Sender, p.Message)
 }

go.mod

@@ -8,5 +8,6 @@ require (
 	github.com/davecgh/go-spew v1.1.0 // indirect
 	github.com/gorilla/mux v1.8.0
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	golang.org/x/text v0.3.7
 	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
 )

go.sum

@@ -9,6 +9,8 @@ github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5Cc
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=