From c2e1c35dca41cd61d51a5b58d1aa2925fbf3f7d4 Mon Sep 17 00:00:00 2001
From: Gary Kramlich <grim@reaperworld.com>
Date: Fri, 11 Feb 2022 02:43:54 -0600
Subject: [PATCH] Add support for edited messages from discord

---
 bridge/portal.go    | 43 ++++++++++++++++++++++++++++++++++++++++++-
 bridge/user.go      | 19 +++++++++++++++++++
 database/message.go |  2 +-
 3 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/bridge/portal.go b/bridge/portal.go
index 1f522fe..e6328f5 100644
--- a/bridge/portal.go
+++ b/bridge/portal.go
@@ -270,6 +270,8 @@ func (p *Portal) handleDiscordMessages(msg portalDiscordMessage) {
 	switch msg.msg.(type) {
 	case *discordgo.MessageCreate:
 		p.handleDiscordMessageCreate(msg.user, msg.msg.(*discordgo.MessageCreate).Message)
+	case *discordgo.MessageUpdate:
+		p.handleDiscordMessagesUpdate(msg.user, msg.msg.(*discordgo.MessageUpdate).Message)
 	case *discordgo.MessageDelete:
 		p.handleDiscordMessageDelete(msg.user, msg.msg.(*discordgo.MessageDelete).Message)
 	case *discordgo.MessageReactionAdd:
@@ -329,11 +331,50 @@ func (p *Portal) handleDiscordMessageCreate(user *User, msg *discordgo.Message)
 	resp, err := intent.SendMessageEvent(p.MXID, event.EventMessage, content)
 	if err != nil {
 		p.log.Warnfln("failed to send message %q to matrix: %v", msg.ID, err)
+
 		return
 	}
 
 	ts, _ := msg.Timestamp.Parse()
-	p.markMessageHandled(nil, msg.ID, resp.EventID, msg.Author.ID, ts)
+	p.markMessageHandled(existing, msg.ID, resp.EventID, msg.Author.ID, ts)
+}
+
+func (p *Portal) handleDiscordMessagesUpdate(user *User, msg *discordgo.Message) {
+	if user.ID == msg.Author.ID {
+		return
+	}
+
+	if p.MXID == "" {
+		p.log.Warnln("handle message called without a valid portal")
+
+		return
+	}
+
+	existing := p.bridge.db.Message.GetByDiscordID(p.Key, msg.ID)
+	if existing == nil {
+		p.log.Debugln("failed to find previous message to update", msg.ID)
+	}
+
+	content := &event.MessageEventContent{
+		Body:    msg.Content,
+		MsgType: event.MsgText,
+	}
+
+	content.SetEdit(existing.MatrixID)
+
+	intent := p.bridge.GetPuppetByID(msg.Author.ID).IntentFor(p)
+
+	_, err := intent.SendMessageEvent(p.MXID, event.EventMessage, content)
+	if err != nil {
+		p.log.Warnfln("failed to send message %q to matrix: %v", msg.ID, err)
+
+		return
+	}
+
+	// It appears that matrix updates only work against the original event id
+	// so updating it to the new one from an edit makes it so you can't update
+	// it anyways. So we just don't update anything and we can keep updating
+	// the message.
 }
 
 func (p *Portal) handleDiscordMessageDelete(user *User, msg *discordgo.Message) {
diff --git a/bridge/user.go b/bridge/user.go
index a38b54e..72218dd 100644
--- a/bridge/user.go
+++ b/bridge/user.go
@@ -214,6 +214,7 @@ func (u *User) Connect() error {
 
 	u.User.Session.AddHandler(u.messageCreateHandler)
 	u.User.Session.AddHandler(u.messageDeleteHandler)
+	u.User.Session.AddHandler(u.messageUpdateHandler)
 	u.User.Session.AddHandler(u.reactionAddHandler)
 	u.User.Session.AddHandler(u.reactionRemoveHandler)
 
@@ -321,6 +322,24 @@ func (u *User) messageDeleteHandler(s *discordgo.Session, m *discordgo.MessageDe
 	portal.discordMessages <- msg
 }
 
+func (u *User) messageUpdateHandler(s *discordgo.Session, m *discordgo.MessageUpdate) {
+	if m.GuildID != "" {
+		u.log.Debugln("ignoring message update for guild message")
+
+		return
+	}
+
+	key := database.NewPortalKey(m.ChannelID, u.ID)
+	portal := u.bridge.GetPortalByID(key)
+
+	msg := portalDiscordMessage{
+		msg:  m,
+		user: u,
+	}
+
+	portal.discordMessages <- msg
+}
+
 func (u *User) reactionAddHandler(s *discordgo.Session, m *discordgo.MessageReactionAdd) {
 	if m.GuildID != "" {
 		u.log.Debugln("ignoring reaction for guild message")
diff --git a/database/message.go b/database/message.go
index 044b555..59dde3e 100644
--- a/database/message.go
+++ b/database/message.go
@@ -69,7 +69,7 @@ func (m *Message) Delete() {
 
 func (m *Message) UpdateMatrixID(mxid id.EventID) {
 	query := "UPDATE message SET matrix_message_id=$1 WHERE channel_id=$2" +
-		"AND receiver=$3 AND discord_message_id=$4"
+		" AND receiver=$3 AND discord_message_id=$4"
 	m.MatrixID = mxid
 
 	_, err := m.db.Exec(query, m.MatrixID, m.Channel.ChannelID, m.Channel.Receiver, m.DiscordID)