Add support for forwarded messages

Fixes #170
Closes #182

formatter.go

@@ -74,7 +74,7 @@ var discordRendererWithInlineLinks = goldmark.New(
 	fixIndentedParagraphs, format.HTMLOptions, discordExtensions,
 )
 
-func (portal *Portal) renderDiscordMarkdownOnlyHTML(text string, allowInlineLinks bool) string {
+func (portal *Portal) renderDiscordMarkdownOnlyHTMLNoUnwrap(text string, allowInlineLinks bool) string {
 	text = escapeFixer.ReplaceAllStringFunc(text, escapeReplacement)
 
 	var buf strings.Builder
@@ -88,7 +88,11 @@ func (portal *Portal) renderDiscordMarkdownOnlyHTML(text string, allowInlineLink
 	if err != nil {
 		panic(fmt.Errorf("markdown parser errored: %w", err))
 	}
-	return format.UnwrapSingleParagraph(buf.String())
+	return buf.String()
+}
+
+func (portal *Portal) renderDiscordMarkdownOnlyHTML(text string, allowInlineLinks bool) string {
+	return format.UnwrapSingleParagraph(portal.renderDiscordMarkdownOnlyHTMLNoUnwrap(text, allowInlineLinks))
 }
 
 const formatterContextPortalKey = "fi.mau.discord.portal"

go.mod

@@ -42,4 +42,4 @@ require (
 	maunium.net/go/mauflag v1.0.0 // indirect
 )
 
-replace github.com/bwmarrin/discordgo => github.com/beeper/discordgo v0.0.0-20250320154217-0d7f942e6b38
+replace github.com/bwmarrin/discordgo => github.com/beeper/discordgo v0.0.0-20250607214857-f23a8518ece2

go.sum

@@ -1,7 +1,7 @@
 github.com/DATA-DOG/go-sqlmock v1.5.0 h1:Shsta01QNfFxHCfpW6YH2STWB0MudeXXEWMr20OEh60=
 github.com/DATA-DOG/go-sqlmock v1.5.0/go.mod h1:f/Ixk793poVmq4qj/V1dPUg2JEAKC73Q5eFN3EC/SaM=
-github.com/beeper/discordgo v0.0.0-20250320154217-0d7f942e6b38 h1:1WoSvVGM1pI9f+x7EGD2QPaXSUQeF3B7Lox7bmVe//s=
+github.com/beeper/discordgo v0.0.0-20250607214857-f23a8518ece2 h1:8lgTjYGSIlS90f0jiFfEC4UwxCq9FiUo4dKwjknbupQ=
-github.com/beeper/discordgo v0.0.0-20250320154217-0d7f942e6b38/go.mod h1:59+AOzzjmL6onAh62nuLXmn7dJCaC/owDLWbGtjTcFA=
+github.com/beeper/discordgo v0.0.0-20250607214857-f23a8518ece2/go.mod h1:59+AOzzjmL6onAh62nuLXmn7dJCaC/owDLWbGtjTcFA=
 github.com/coreos/go-systemd/v22 v22.5.0 h1:RrqgGjYQKalulkV8NGVIfkXQf6YYmOyiJKk8iXXhfZs=
 github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=

portal_convert.go

@@ -34,6 +34,8 @@ import (
 	"maunium.net/go/mautrix/event"
 	"maunium.net/go/mautrix/format"
 	"maunium.net/go/mautrix/id"
+
+	"go.mau.fi/mautrix-discord/database"
 )
 
 type ConvertedMessage struct {
@@ -664,6 +666,12 @@ func (portal *Portal) convertDiscordMentions(msg *discordgo.Message, syncGhosts
 	return &matrixMentions
 }
 
+const forwardTemplateHTML = `<blockquote>
+<p>↷ Forwarded</p>
+%s
+<p>%s</p>
+</blockquote>`
+
 func (portal *Portal) convertDiscordTextMessage(ctx context.Context, intent *appservice.IntentAPI, msg *discordgo.Message) *ConvertedMessage {
 	log := zerolog.Ctx(ctx)
 	if msg.Type == discordgo.MessageTypeCall {
@@ -685,6 +693,36 @@ func (portal *Portal) convertDiscordTextMessage(ctx context.Context, intent *app
 	}
 	if msg.Content != "" && !isPlainGifMessage(msg) {
 		htmlParts = append(htmlParts, portal.renderDiscordMarkdownOnlyHTML(msg.Content, true))
+	} else if msg.MessageReference != nil &&
+		msg.MessageReference.Type == discordgo.MessageReferenceTypeForward &&
+		len(msg.MessageSnapshots) > 0 &&
+		msg.MessageSnapshots[0].Message != nil {
+		forwardedHTML := portal.renderDiscordMarkdownOnlyHTMLNoUnwrap(msg.MessageSnapshots[0].Message.Content, true)
+		msgTSText := msg.MessageSnapshots[0].Message.Timestamp.Format("2006-01-02 15:04 MST")
+		origLink := fmt.Sprintf("unknown channel • %s", msgTSText)
+		forwardedFromPortal := portal.bridge.GetExistingPortalByID(database.NewPortalKey(msg.MessageReference.ChannelID, ""))
+		if forwardedFromPortal != nil {
+			origMessage := portal.bridge.DB.Message.GetFirstByDiscordID(forwardedFromPortal.Key, msg.MessageReference.MessageID)
+			if origMessage != nil {
+				origLink = fmt.Sprintf(
+					`<a href="%s">#%s • %s</a>`,
+					forwardedFromPortal.MXID.EventURI(origMessage.MXID, portal.bridge.AS.HomeserverDomain),
+					forwardedFromPortal.PlainName,
+					msgTSText,
+				)
+			} else if forwardedFromPortal.MXID != "" {
+				origLink = fmt.Sprintf(
+					`<a href="%s">#%s</a> • %s`,
+					forwardedFromPortal.MXID.URI(portal.bridge.AS.HomeserverDomain),
+					forwardedFromPortal.PlainName,
+					msgTSText,
+				)
+			} else if forwardedFromPortal.PlainName != "" {
+				origLink = fmt.Sprintf("%s • %s", forwardedFromPortal.PlainName, msgTSText)
+			}
+		}
+
+		htmlParts = append(htmlParts, fmt.Sprintf(forwardTemplateHTML, forwardedHTML, origLink))
 	}
 	previews := make([]*BeeperLinkPreview, 0)
 	for i, embed := range msg.Embeds {