From d08d9dbddd6521079c6cbe007d9660aff69e7fed Mon Sep 17 00:00:00 2001
From: Mrs4s <mrs4sxiaoshi@gmail.com>
Date: Thu, 2 Dec 2021 01:03:10 +0800
Subject: [PATCH] feat: decode compressed guild event packet. close #207

---
 client/guild_eventflow.go | 13 +++++++++++++
 go.mod                    |  1 +
 go.sum                    |  2 ++
 3 files changed, 16 insertions(+)

diff --git a/client/guild_eventflow.go b/client/guild_eventflow.go
index 74f61f5e..771690ca 100644
--- a/client/guild_eventflow.go
+++ b/client/guild_eventflow.go
@@ -1,6 +1,7 @@
 package client
 
 import (
+	"github.com/pierrec/lz4/v4"
 	"sync"
 	"time"
 
@@ -32,6 +33,18 @@ func decodeGuildEventFlowPacket(c *QQClient, _ *incomingPacketInfo, payload []by
 	if err := proto.Unmarshal(payload, push); err != nil {
 		return nil, errors.Wrap(err, "failed to unmarshal protobuf message")
 	}
+	if push.GetCompressFlag() == 1 && len(push.CompressMsg) > 0 {
+		press := new(channel.PressMsg)
+		dst := make([]byte, len(push.CompressMsg)*2)
+		i, err := lz4.UncompressBlock(push.CompressMsg, dst)
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to decompress guild event packet")
+		}
+		if err = proto.Unmarshal(dst[:i], press); err != nil {
+			return nil, errors.Wrap(err, "failed to unmarshal protobuf message")
+		}
+		push.Msgs = press.Msgs
+	}
 	for _, m := range push.Msgs {
 		if m.Head.ContentHead.GetType() == 3841 {
 			// todo: 回头 event flow 的处理移出去重构下逻辑, 先暂时这样方便改
diff --git a/go.mod b/go.mod
index 4ea467a0..0adcf62b 100644
--- a/go.mod
+++ b/go.mod
@@ -14,6 +14,7 @@ require (
 
 require (
 	github.com/davecgh/go-spew v1.1.0 // indirect
+	github.com/pierrec/lz4/v4 v4.1.11 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.0 // indirect
diff --git a/go.sum b/go.sum
index d4774d9b..37187dd4 100644
--- a/go.sum
+++ b/go.sum
@@ -6,6 +6,8 @@ github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaS
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/klauspost/compress v1.13.6 h1:P76CopJELS0TiO2mebmnzgWaajssP/EszplttgQxcgc=
 github.com/klauspost/compress v1.13.6/go.mod h1:/3/Vjq9QcHkK5uEr5lBEmyoZ1iFhe47etQ6QUkpK6sk=
+github.com/pierrec/lz4/v4 v4.1.11 h1:LVs17FAZJFOjgmJXl9Tf13WfLUvZq7/RjfEJrnwZ9OE=
+github.com/pierrec/lz4/v4 v4.1.11/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=