Help: show it in the channel when the DM can't be sent, and log where the command came from

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

internal/commands/help/help.go

@@ -185,39 +185,67 @@ func embeds(author *discordgo.MessageEmbedAuthor) []*discordgo.MessageEmbed {
 	return append(out, cur)
 }
 
+// HelpHandler sends the help by direct message. If that isn't possible (the
+// member has DMs off, or shares no server with the bot), it shows the help to
+// them in the channel instead, as a message only they can see.
 func HelpHandler(s *discordgo.Session, i *discordgo.InteractionCreate) {
-	s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
-		Type: discordgo.InteractionResponseChannelMessageWithSource,
-		Data: &discordgo.InteractionResponseData{
-			Content: "Check your DMs for help.",
-			Flags:   discordgo.MessageFlagsEphemeral,
-		},
-	})
-
-	userID := ""
-
-	// check if command is run in a guild
-	if i.Member != nil {
-		userID = i.Member.User.ID
-	} else {
-		userID = i.Interaction.User.ID
-	}
-
-	dmChannel, err := s.UserChannelCreate(userID)
-	if err != nil {
-		log.Printf("Error creating DM channel: %v", err)
-		return
-	}
-
 	author := discordgo.MessageEmbedAuthor{
 		Name: "Velox Bot",
 		URL:  "https://gitea.fernandovideira.com/FernandoJVideira/velox-bot",
 	}
+	list := embeds(&author)
 
-	for _, e := range embeds(&author) {
-		if _, err := s.ChannelMessageSendEmbed(dmChannel.ID, e); err != nil {
-			log.Printf("Error sending help: %v", err)
-			return
+	// Used in a DM with the bot, there is nowhere else to send it.
+	if i.GuildID == "" {
+		_ = s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+			Type: discordgo.InteractionResponseChannelMessageWithSource,
+			Data: &discordgo.InteractionResponseData{Embeds: list},
+		})
+		return
+	}
+
+	// Answer first (sending the DM can take a moment), and edit the answer
+	// once we know where the help went.
+	if err := s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+		Type: discordgo.InteractionResponseDeferredChannelMessageWithSource,
+		Data: &discordgo.InteractionResponseData{Flags: discordgo.MessageFlagsEphemeral},
+	}); err != nil {
+		log.Printf("help: cannot answer: %v", err)
+		return
+	}
+
+	userID := ""
+	if i.Member != nil && i.Member.User != nil {
+		userID = i.Member.User.ID
+	} else if i.User != nil {
+		userID = i.User.ID
+	}
+
+	if err := sendByDM(s, userID, list); err != nil {
+		// Typically "Cannot send messages to this user": DMs are off.
+		// The context says where the command came from, which is what to look at
+		// when "no mutual guilds" appears for someone who is in a server with
+		// the bot: a command run through a user install, or in a server the bot
+		// isn't actually a member of, has no shared server for Discord to see.
+		log.Printf("help: DM not possible, showing it here (guild %q, context %d, installs %v): %v",
+			i.GuildID, i.Context, i.AuthorizingIntegrationOwners, err)
+		note := "I couldn't DM you (your DMs may be off), so here it is."
+		_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{Content: &note, Embeds: &list})
+		return
+	}
+	done := "Check your DMs for help."
+	_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{Content: &done})
+}
+
+func sendByDM(s *discordgo.Session, userID string, list []*discordgo.MessageEmbed) error {
+	dm, err := s.UserChannelCreate(userID)
+	if err != nil {
+		return err
+	}
+	for _, e := range list {
+		if _, err := s.ChannelMessageSendEmbed(dm.ID, e); err != nil {
+			return err
 		}
 	}
+	return nil
 }