From 46874620886d075b63ca7e5884ab8f3a397c4957 Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Mon, 23 Dec 2024 13:47:58 +0200
Subject: [PATCH] msgconv/from-slack: bridge url preview thumbnail if no image
 is present

---
 go.mod                |  4 ++--
 go.sum                |  8 ++++----
 pkg/msgconv/blocks.go | 23 +++++++++++++++++------
 3 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/go.mod b/go.mod
index f0e7b73..cf2504f 100644
--- a/go.mod
+++ b/go.mod
@@ -13,7 +13,7 @@ require (
 	go.mau.fi/util v0.8.3
 	golang.org/x/net v0.32.0
 	gopkg.in/yaml.v3 v3.0.1
-	maunium.net/go/mautrix v0.22.1
+	maunium.net/go/mautrix v0.22.2-0.20241223114659-ba210a16b992
 )
 
 require (
@@ -43,4 +43,4 @@ require (
 	maunium.net/go/mauflag v1.0.0 // indirect
 )
 
-replace github.com/slack-go/slack => github.com/beeper/slackgo v0.0.0-20241211205744-f532856a1038
+replace github.com/slack-go/slack => github.com/beeper/slackgo v0.0.0-20241223114722-b8b7a4c49a18
diff --git a/go.sum b/go.sum
index df122c1..e95d07f 100644
--- a/go.sum
+++ b/go.sum
@@ -2,8 +2,8 @@ filippo.io/edwards25519 v1.1.0 h1:FNf4tywRC1HmFuKW5xopWpigGjJKiJSV0Cqo0cJWDaA=
 filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
 github.com/DATA-DOG/go-sqlmock v1.5.2 h1:OcvFkGmslmlZibjAjaHm3L//6LiuBgolP7OputlJIzU=
 github.com/DATA-DOG/go-sqlmock v1.5.2/go.mod h1:88MAG/4G7SMwSE3CeA0ZKzrT5CiOU3OJ+JlNzwDqpNU=
-github.com/beeper/slackgo v0.0.0-20241211205744-f532856a1038 h1:zP5Yl+MGAfNgbuyf1zP7YoXYIndra3iEknlILyUCPko=
-github.com/beeper/slackgo v0.0.0-20241211205744-f532856a1038/go.mod h1:axoegr/0xf8uWt4I+coY6x+CVKPbWGs4YqpoYbCBRr8=
+github.com/beeper/slackgo v0.0.0-20241223114722-b8b7a4c49a18 h1:s0gVLeb7pgYBIlwuUmFzMvDbxVWEWUvjDJaqurE5LI4=
+github.com/beeper/slackgo v0.0.0-20241223114722-b8b7a4c49a18/go.mod h1:axoegr/0xf8uWt4I+coY6x+CVKPbWGs4YqpoYbCBRr8=
 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=
@@ -78,5 +78,5 @@ gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 maunium.net/go/mauflag v1.0.0 h1:YiaRc0tEI3toYtJMRIfjP+jklH45uDHtT80nUamyD4M=
 maunium.net/go/mauflag v1.0.0/go.mod h1:nLivPOpTpHnpzEh8jEdSL9UqO9+/KBJFmNRlwKfkPeA=
-maunium.net/go/mautrix v0.22.1 h1:2lCM37vmVzZGE0tWD7UOySMtAuC5hq6Pw33KlY2VU/c=
-maunium.net/go/mautrix v0.22.1/go.mod h1:1rhqwH34Rz54ZqzdQYkmNW6rQUymNeTdaLA4l9LK6AI=
+maunium.net/go/mautrix v0.22.2-0.20241223114659-ba210a16b992 h1:7KLNq84HGVzpb7iBCtKTq5NhjDWh/r3Bj8Qmtv5gXy4=
+maunium.net/go/mautrix v0.22.2-0.20241223114659-ba210a16b992/go.mod h1:1rhqwH34Rz54ZqzdQYkmNW6rQUymNeTdaLA4l9LK6AI=
diff --git a/pkg/msgconv/blocks.go b/pkg/msgconv/blocks.go
index a519d03..7921997 100644
--- a/pkg/msgconv/blocks.go
+++ b/pkg/msgconv/blocks.go
@@ -92,13 +92,23 @@ func (mc *MessageConverter) attachmentToURLPreview(ctx context.Context, portal *
 	var mxc id.ContentURIString
 	var file *event.EncryptedFileInfo
 	var imageMime string
-	if attachment.ImageURL != "" {
-		bytes, err := mc.downloadExternalImage(ctx, attachment.ImageURL)
+	imageURL := attachment.ImageURL
+	imageSize := attachment.ImageBytes
+	imageWidth := attachment.ImageWidth
+	imageHeight := attachment.ImageHeight
+	if imageURL == "" {
+		imageURL = attachment.ThumbURL
+		imageSize = 0
+		imageWidth = attachment.ThumbWidth
+		imageHeight = attachment.ThumbHeight
+	}
+	if imageURL != "" {
+		bytes, err := mc.downloadExternalImage(ctx, imageURL)
 		if err != nil {
 			zerolog.Ctx(ctx).Err(err).Msg("Failed to download link preview image")
 		} else {
 			imageMime = http.DetectContentType(bytes)
-			mxc, file, err = intent.UploadMedia(ctx, portal.MXID, bytes, path.Base(attachment.ImageURL), imageMime)
+			mxc, file, err = intent.UploadMedia(ctx, portal.MXID, bytes, path.Base(imageURL), imageMime)
 			if err != nil {
 				zerolog.Ctx(ctx).Err(err).Msg("Failed to reupload link preview image")
 			}
@@ -109,12 +119,13 @@ func (mc *MessageConverter) attachmentToURLPreview(ctx context.Context, portal *
 		LinkPreview: event.LinkPreview{
 			CanonicalURL: attachment.FromURL,
 			Title:        attachment.Title,
+			SiteName:     attachment.ServiceName,
 			Type:         "website",
 			Description:  attachment.Text,
 			ImageURL:     mxc,
-			ImageSize:    attachment.ImageBytes,
-			ImageWidth:   attachment.ImageWidth,
-			ImageHeight:  attachment.ImageHeight,
+			ImageSize:    imageSize,
+			ImageWidth:   imageWidth,
+			ImageHeight:  imageHeight,
 		},
 		MatchedURL:      attachment.OriginalURL,
 		ImageEncryption: file,