feat: implement server logging functionality

- Added a logging service to manage server event logs including message edits, deletions, member joins/leaves, and moderation actions.
- Introduced commands to configure logging settings, including setting the log channel and enabling/disabling logging.
- Updated the README to document the new logging features and commands.
- Enhanced moderation commands to log actions taken on members.

internal/commands/config/public/config.go

@@ -121,6 +121,30 @@ var Config = &discordgo.ApplicationCommand{
 				},
 			},
 		},
+		{
+			Type:        discordgo.ApplicationCommandOptionSubCommand,
+			Name:        "setlogchannel",
+			Description: "Set the moderation log channel",
+			Options: []*discordgo.ApplicationCommandOption{
+				{
+					Type:         discordgo.ApplicationCommandOptionChannel,
+					Name:         "channel",
+					Description:  "Text channel for logs",
+					Required:     true,
+					ChannelTypes: []discordgo.ChannelType{discordgo.ChannelTypeGuildText, discordgo.ChannelTypeGuildNews},
+				},
+			},
+		},
+		{
+			Type:        discordgo.ApplicationCommandOptionSubCommand,
+			Name:        "enablelogging",
+			Description: "Enable server logging events",
+		},
+		{
+			Type:        discordgo.ApplicationCommandOptionSubCommand,
+			Name:        "disablelogging",
+			Description: "Disable server logging events",
+		},
 	},
 }
 
@@ -169,6 +193,15 @@ func ConfigHandler(s *discordgo.Session, i *discordgo.InteractionCreate) {
 	case "setdefaultrole":
 		log.Printf("defaultrole: /config setdefaultrole invoked by %s in guild %s", i.Member.User.ID, i.GuildID)
 		handleSetDefaultRole(s, i)
+	case "setlogchannel":
+		log.Printf("log: /config setlogchannel invoked by %s in guild %s", i.Member.User.ID, i.GuildID)
+		handleSetLogChannel(s, i)
+	case "enablelogging":
+		log.Printf("log: /config enablelogging invoked by %s in guild %s", i.Member.User.ID, i.GuildID)
+		handleSetLoggingEnabled(s, i, true)
+	case "disablelogging":
+		log.Printf("log: /config disablelogging invoked by %s in guild %s", i.Member.User.ID, i.GuildID)
+		handleSetLoggingEnabled(s, i, false)
 	default:
 		respondEphemeral(s, i, "Unknown subcommand.")
 	}
@@ -460,6 +493,79 @@ func handleSetDefaultRole(s *discordgo.Session, i *discordgo.InteractionCreate)
 	respondEphemeral(s, i, "Default role set to "+role.Mention()+".")
 }
 
+func handleSetLogChannel(s *discordgo.Session, i *discordgo.InteractionCreate) {
+	if services.Global.LogSettings == nil {
+		respondEphemeral(s, i, "Log settings service is not available.")
+		return
+	}
+
+	guildID, err := strconv.ParseInt(i.GuildID, 10, 64)
+	if err != nil {
+		respondEphemeral(s, i, "Invalid guild ID.")
+		return
+	}
+
+	opt := i.ApplicationCommandData().Options[0]
+	var chOpt *discordgo.ApplicationCommandInteractionDataOption
+	for _, o := range opt.Options {
+		if o.Name == "channel" {
+			chOpt = o
+			break
+		}
+	}
+	if chOpt == nil {
+		respondEphemeral(s, i, "Missing channel option.")
+		return
+	}
+
+	ch := chOpt.ChannelValue(s)
+	if ch == nil {
+		respondEphemeral(s, i, "Invalid channel.")
+		return
+	}
+
+	channelID, err := strconv.ParseInt(ch.ID, 10, 64)
+	if err != nil {
+		respondEphemeral(s, i, "Invalid channel ID.")
+		return
+	}
+
+	if err := services.Global.LogSettings.SetChannel(context.Background(), guildID, channelID); err != nil {
+		respondEphemeral(s, i, "Failed to set log channel.")
+		return
+	}
+	if err := services.Global.LogSettings.SetEnabled(context.Background(), guildID, true); err != nil {
+		respondEphemeral(s, i, "Log channel set, but failed to enable logging.")
+		return
+	}
+
+	respondEphemeral(s, i, "Logging enabled in "+ch.Mention()+".")
+}
+
+func handleSetLoggingEnabled(s *discordgo.Session, i *discordgo.InteractionCreate, enabled bool) {
+	if services.Global.LogSettings == nil {
+		respondEphemeral(s, i, "Log settings service is not available.")
+		return
+	}
+
+	guildID, err := strconv.ParseInt(i.GuildID, 10, 64)
+	if err != nil {
+		respondEphemeral(s, i, "Invalid guild ID.")
+		return
+	}
+
+	if err := services.Global.LogSettings.SetEnabled(context.Background(), guildID, enabled); err != nil {
+		respondEphemeral(s, i, "Failed to update logging state.")
+		return
+	}
+
+	if enabled {
+		respondEphemeral(s, i, "Logging is now enabled.")
+		return
+	}
+	respondEphemeral(s, i, "Logging is now disabled.")
+}
+
 func respondEphemeral(s *discordgo.Session, i *discordgo.InteractionCreate, msg string) {
 	_ = s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
 		Type: discordgo.InteractionResponseChannelMessageWithSource,