[MM-38615] Permalink previews for DMs/GMs (#19765)

model/permalink.go

@@ -8,10 +8,12 @@ type Permalink struct {
 }
 
 type PreviewPost struct {
-	PostID             string `json:"post_id"`
-	Post               *Post  `json:"post"`
-	TeamName           string `json:"team_name"`
-	ChannelDisplayName string `json:"channel_display_name"`
+	PostID             string      `json:"post_id"`
+	Post               *Post       `json:"post"`
+	TeamName           string      `json:"team_name"`
+	ChannelDisplayName string      `json:"channel_display_name"`
+	ChannelType        ChannelType `json:"channel_type"`
+	ChannelID          string      `json:"channel_id"`
 }
 
 func NewPreviewPost(post *Post, team *Team, channel *Channel) *PreviewPost {
@@ -23,5 +25,7 @@ func NewPreviewPost(post *Post, team *Team, channel *Channel) *PreviewPost {
 		Post:               post,
 		TeamName:           team.Name,
 		ChannelDisplayName: channel.DisplayName,
+		ChannelType:        channel.Type,
+		ChannelID:          channel.Id,
 	}
 }