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.

README.md

@@ -13,6 +13,9 @@ It currently includes:
 - Twitch live notifications (per-guild `/config` setup)
 - Welcome messages, DMs, and default role assignment (per-guild `/config` setup)
 - Focused moderation tools (`/moderation purge|timeout|untimeout|kick|ban|unban|slowmode`)
+- Server logging system (edits/deletes/joins/leaves/roles/ban/kick/mod actions)
+
+When the bot is added to a new server for the first time, toggleable systems are defaulted to **disabled** and a setup DM is sent to the inviter (or server owner fallback) with enable instructions.
 
 ## Requirements
 
@@ -115,6 +118,10 @@ just down    # stop postgres
   - `/config setwelcomedm message:"..."` — DM welcome template (supports `{user}`, `{server}`)
   - `/config setwelcomegif url:<image-url>` — GIF/image used in welcome embed
   - `/config setdefaultrole role:@role` — Role automatically granted on join
+- **Logging** (**Manage Server**)
+  - `/config setlogchannel channel:#channel` — Set where logs are sent
+  - `/config enablelogging` — Enable event/moderation logs
+  - `/config disablelogging` — Disable event/moderation logs
 
 ## Notes
 

internal/bot/bot.go

@@ -34,8 +34,10 @@ func NewBot(token, appID, guildID, lavalinkHost, lavalinkPass string, cmds []*di
 	// - VoiceStateUpdate (meeting lobby): GuildVoiceStates
 	// - MessageReactionAdd (scheduling via reactions): GuildMessageReactions + DirectMessageReactions
 	session.Identify.Intents = discordgo.IntentsGuilds |
+		discordgo.IntentsGuildBans |
 		discordgo.IntentsGuildMembers |
 		discordgo.IntentsGuildMessages |
+		discordgo.IntentsMessageContent |
 		discordgo.IntentsGuildVoiceStates |
 		discordgo.IntentsGuildMessageReactions |
 		discordgo.IntentsDirectMessages |
@@ -76,7 +78,39 @@ func (b *Bot) Start() error {
 	})
 
 	b.Session.AddHandler(func(s *discordgo.Session, m *discordgo.GuildMemberAdd) {
+		events.HandleBotAddedOnGuild(s, m, b.Services)
+
+		// Ignore bot members for welcome/log onboarding of normal users.
+		if m != nil && m.Member != nil && m.User != nil && m.User.Bot {
+			return
+		}
+
 		events.HandleGuildMemberAdd(s, m, b.Services)
+		events.HandleGuildMemberAddLog(s, m, b.Services)
+	})
+
+	b.Session.AddHandler(func(s *discordgo.Session, m *discordgo.GuildMemberRemove) {
+		events.HandleGuildMemberRemoveLog(s, m, b.Services)
+	})
+
+	b.Session.AddHandler(func(s *discordgo.Session, m *discordgo.GuildMemberUpdate) {
+		events.HandleGuildMemberUpdateLog(s, m, b.Services)
+	})
+
+	b.Session.AddHandler(func(s *discordgo.Session, m *discordgo.MessageUpdate) {
+		events.HandleMessageUpdateLog(s, m, b.Services)
+	})
+
+	b.Session.AddHandler(func(s *discordgo.Session, m *discordgo.MessageDelete) {
+		events.HandleMessageDeleteLog(s, m, b.Services)
+	})
+
+	b.Session.AddHandler(func(s *discordgo.Session, m *discordgo.GuildBanAdd) {
+		events.HandleGuildBanAddLog(s, m, b.Services)
+	})
+
+	b.Session.AddHandler(func(s *discordgo.Session, m *discordgo.GuildBanRemove) {
+		events.HandleGuildBanRemoveLog(s, m, b.Services)
 	})
 
 	b.Session.AddHandler(func(s *discordgo.Session, vs *discordgo.VoiceStateUpdate) {

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,

internal/commands/help/help.go

@@ -133,6 +133,13 @@ func HelpHandler(s *discordgo.Session, i *discordgo.InteractionCreate) {
 					"`/config setwelcomegif url:<image-url>` — GIF/image used in welcome embed\n" +
 					"`/config setdefaultrole role:@role` — Role granted to new members",
 			},
+			{
+				Name: "Logging (**Manage Server**)",
+				Value: "" +
+					"`/config setlogchannel channel:#channel` — Set log output channel\n" +
+					"`/config enablelogging` — Enable event/moderation logging\n" +
+					"`/config disablelogging` — Disable event/moderation logging",
+			},
 			{
 				Name:  "Other",
 				Value: "`/help` — Show this help in DMs",

internal/commands/moderation/public/moderation.go

@@ -5,6 +5,9 @@ import (
 	"strings"
 	"time"
 
+	"velox-bot/internal/db/services"
+	"velox-bot/internal/modlog"
+
 	"github.com/bwmarrin/discordgo"
 )
 
@@ -238,6 +241,7 @@ func handlePurge(s *discordgo.Session, i *discordgo.InteractionCreate) {
 			return
 		}
 		respondEphemeral(s, i, "Deleted 1 message.")
+		sendModerationActionLog(s, i, "Purge", fmt.Sprintf("Deleted 1 message in <#%s>.", i.ChannelID), "")
 		return
 	}
 
@@ -247,6 +251,7 @@ func handlePurge(s *discordgo.Session, i *discordgo.InteractionCreate) {
 	}
 
 	respondEphemeral(s, i, fmt.Sprintf("Deleted %d messages.", len(ids)))
+	sendModerationActionLog(s, i, "Purge", fmt.Sprintf("Deleted %d messages in <#%s>.", len(ids), i.ChannelID), "")
 }
 
 func handleTimeout(s *discordgo.Session, i *discordgo.InteractionCreate) {
@@ -298,9 +303,11 @@ func handleTimeout(s *discordgo.Session, i *discordgo.InteractionCreate) {
 
 	if reason == "" {
 		respondEphemeral(s, i, fmt.Sprintf("Timed out %s for `%s`.", target.Mention(), dur.String()))
+		sendModerationActionLog(s, i, "Timeout", fmt.Sprintf("Target: %s\nDuration: `%s`", target.Mention(), dur.String()), "")
 		return
 	}
 	respondEphemeral(s, i, fmt.Sprintf("Timed out %s for `%s`. Reason: %s", target.Mention(), dur.String(), reason))
+	sendModerationActionLog(s, i, "Timeout", fmt.Sprintf("Target: %s\nDuration: `%s`", target.Mention(), dur.String()), reason)
 }
 
 func handleKick(s *discordgo.Session, i *discordgo.InteractionCreate) {
@@ -345,9 +352,11 @@ func handleKick(s *discordgo.Session, i *discordgo.InteractionCreate) {
 
 	if reason == "" {
 		respondEphemeral(s, i, "Kicked "+target.Mention()+".")
+		sendModerationActionLog(s, i, "Kick", "Target: "+target.Mention(), "")
 		return
 	}
 	respondEphemeral(s, i, "Kicked "+target.Mention()+". Reason: "+reason)
+	sendModerationActionLog(s, i, "Kick", "Target: "+target.Mention(), reason)
 }
 
 func handleBan(s *discordgo.Session, i *discordgo.InteractionCreate) {
@@ -399,9 +408,11 @@ func handleBan(s *discordgo.Session, i *discordgo.InteractionCreate) {
 
 	if reason == "" {
 		respondEphemeral(s, i, fmt.Sprintf("Banned %s (deleted %d days of messages).", target.Mention(), deleteDays))
+		sendModerationActionLog(s, i, "Ban", fmt.Sprintf("Target: %s\nDeleted message days: %d", target.Mention(), deleteDays), "")
 		return
 	}
 	respondEphemeral(s, i, fmt.Sprintf("Banned %s (deleted %d days of messages). Reason: %s", target.Mention(), deleteDays, reason))
+	sendModerationActionLog(s, i, "Ban", fmt.Sprintf("Target: %s\nDeleted message days: %d", target.Mention(), deleteDays), reason)
 }
 
 func handleUnban(s *discordgo.Session, i *discordgo.InteractionCreate) {
@@ -433,9 +444,11 @@ func handleUnban(s *discordgo.Session, i *discordgo.InteractionCreate) {
 
 	if reason == "" {
 		respondEphemeral(s, i, "Unbanned user ID `"+userID+"`.")
+		sendModerationActionLog(s, i, "Unban", "Target user ID: `"+userID+"`", "")
 		return
 	}
 	respondEphemeral(s, i, "Unbanned user ID `"+userID+"`. Reason: "+reason)
+	sendModerationActionLog(s, i, "Unban", "Target user ID: `"+userID+"`", reason)
 }
 
 func handleUntimeout(s *discordgo.Session, i *discordgo.InteractionCreate) {
@@ -472,9 +485,11 @@ func handleUntimeout(s *discordgo.Session, i *discordgo.InteractionCreate) {
 
 	if reason == "" {
 		respondEphemeral(s, i, "Removed timeout from "+target.Mention()+".")
+		sendModerationActionLog(s, i, "Timeout Removed", "Target: "+target.Mention(), "")
 		return
 	}
 	respondEphemeral(s, i, "Removed timeout from "+target.Mention()+". Reason: "+reason)
+	sendModerationActionLog(s, i, "Timeout Removed", "Target: "+target.Mention(), reason)
 }
 
 func handleSlowmode(s *discordgo.Session, i *discordgo.InteractionCreate) {
@@ -519,9 +534,11 @@ func handleSlowmode(s *discordgo.Session, i *discordgo.InteractionCreate) {
 
 	if seconds == 0 {
 		respondEphemeral(s, i, "Disabled slowmode in "+ch.Mention()+".")
+		sendModerationActionLog(s, i, "Slowmode", "Channel: "+ch.Mention()+"\nSet to: `0s`", "")
 		return
 	}
 	respondEphemeral(s, i, fmt.Sprintf("Set slowmode in %s to %d seconds.", ch.Mention(), seconds))
+	sendModerationActionLog(s, i, "Slowmode", fmt.Sprintf("Channel: %s\nSet to: `%ds`", ch.Mention(), seconds), "")
 }
 
 func hasPerm(i *discordgo.InteractionCreate, perm int64) bool {
@@ -538,3 +555,24 @@ func respondEphemeral(s *discordgo.Session, i *discordgo.InteractionCreate, msg
 	})
 }
 
+func sendModerationActionLog(s *discordgo.Session, i *discordgo.InteractionCreate, action, details, reason string) {
+	if services.Global == nil {
+		return
+	}
+	moderator := "Unknown"
+	if i != nil && i.Member != nil && i.Member.User != nil {
+		moderator = i.Member.User.Mention()
+	}
+	desc := "Moderator: " + moderator + "\n" + details
+	if strings.TrimSpace(reason) != "" {
+		desc += "\nReason: " + reason
+	}
+	embed := &discordgo.MessageEmbed{
+		Title:       "Moderation Action: " + action,
+		Color:       0x5865F2,
+		Description: desc,
+		Timestamp:   time.Now().Format(time.RFC3339),
+	}
+	_ = modlog.Send(s, services.Global, i.GuildID, embed)
+}
+

internal/db/repos/settingsrepo/repo.go

@@ -15,6 +15,12 @@ type LevelReward struct {
 	RoleID  int64
 }
 
+type LogSettings struct {
+	GuildID   int64
+	ChannelID int64
+	IsEnabled bool
+}
+
 func NewRepo(db *sql.DB) *Repo {
 	return &Repo{db: db}
 }
@@ -240,6 +246,80 @@ func (r *Repo) SetLevelUpMessage(ctx context.Context, guildID int64, message str
 	return err
 }
 
+func (r *Repo) SetLogChannel(ctx context.Context, guildID int64, channelID int64) error {
+	const q = `
+		INSERT INTO logsettings (guild_id, log_channel_id, is_enabled)
+		VALUES ($1, $2, TRUE)
+		ON CONFLICT (guild_id)
+		DO UPDATE SET log_channel_id = EXCLUDED.log_channel_id
+	`
+	_, err := r.db.ExecContext(ctx, q, guildID, channelID)
+	return err
+}
+
+func (r *Repo) SetLogEnabled(ctx context.Context, guildID int64, enabled bool) error {
+	const q = `
+		INSERT INTO logsettings (guild_id, is_enabled)
+		VALUES ($1, $2)
+		ON CONFLICT (guild_id)
+		DO UPDATE SET is_enabled = EXCLUDED.is_enabled
+	`
+	_, err := r.db.ExecContext(ctx, q, guildID, enabled)
+	return err
+}
+
+func (r *Repo) GetLogSettings(ctx context.Context, guildID int64) (*LogSettings, error) {
+	const q = `
+		SELECT log_channel_id, is_enabled
+		FROM logsettings
+		WHERE guild_id = $1
+	`
+	row := r.db.QueryRowContext(ctx, q, guildID)
+	var channelID sql.NullInt64
+	var enabled sql.NullBool
+	switch err := row.Scan(&channelID, &enabled); err {
+	case nil:
+		out := &LogSettings{
+			GuildID:   guildID,
+			ChannelID: 0,
+			IsEnabled: false,
+		}
+		if channelID.Valid {
+			out.ChannelID = channelID.Int64
+		}
+		if enabled.Valid {
+			out.IsEnabled = enabled.Bool
+		}
+		return out, nil
+	case sql.ErrNoRows:
+		return &LogSettings{
+			GuildID:   guildID,
+			ChannelID: 0,
+			IsEnabled: false,
+		}, nil
+	default:
+		return nil, err
+	}
+}
+
+func (r *Repo) HasLogSettings(ctx context.Context, guildID int64) (bool, error) {
+	const q = `
+		SELECT 1
+		FROM logsettings
+		WHERE guild_id = $1
+	`
+	row := r.db.QueryRowContext(ctx, q, guildID)
+	var one int
+	switch err := row.Scan(&one); err {
+	case nil:
+		return true, nil
+	case sql.ErrNoRows:
+		return false, nil
+	default:
+		return false, err
+	}
+}
+
 func (r *Repo) GetLevelUpMessage(ctx context.Context, guildID int64) (string, error) {
 	const q = `
 		SELECT message

internal/db/services/logsettings/service.go

@@ -0,0 +1,32 @@
+package logsettings
+
+import (
+	"context"
+
+	"velox-bot/internal/db/repos/settingsrepo"
+)
+
+type Service struct {
+	settings *settingsrepo.Repo
+}
+
+func New(settings *settingsrepo.Repo) *Service {
+	return &Service{settings: settings}
+}
+
+func (s *Service) SetChannel(ctx context.Context, guildID, channelID int64) error {
+	return s.settings.SetLogChannel(ctx, guildID, channelID)
+}
+
+func (s *Service) SetEnabled(ctx context.Context, guildID int64, enabled bool) error {
+	return s.settings.SetLogEnabled(ctx, guildID, enabled)
+}
+
+func (s *Service) GetSettings(ctx context.Context, guildID int64) (*settingsrepo.LogSettings, error) {
+	return s.settings.GetLogSettings(ctx, guildID)
+}
+
+func (s *Service) HasSettings(ctx context.Context, guildID int64) (bool, error) {
+	return s.settings.HasLogSettings(ctx, guildID)
+}
+

internal/db/services/services.go

@@ -1,8 +1,10 @@
 package services
 
 import (
+	"velox-bot/internal/db/services/defaultrole"
 	"velox-bot/internal/db/services/level"
 	"velox-bot/internal/db/services/levelsettings"
+	"velox-bot/internal/db/services/logsettings"
 	"velox-bot/internal/db/services/meeting"
 	"velox-bot/internal/db/services/projects"
 	"velox-bot/internal/db/services/rps"
@@ -10,7 +12,6 @@ import (
 	"velox-bot/internal/db/services/twitch"
 	"velox-bot/internal/db/services/usersettings"
 	"velox-bot/internal/db/services/welcome"
-	"velox-bot/internal/db/services/defaultrole"
 )
 
 type Services struct {
@@ -24,11 +25,12 @@ type Services struct {
 	Twitch        *twitch.Service
 	Welcome       *welcome.Service
 	DefaultRole   *defaultrole.Service
+	LogSettings   *logsettings.Service
 }
 
 var Global *Services
 
-func NewServices(level *level.Service, levelSettings *levelsettings.Service, meeting *meeting.Service, schedule *schedule.Service, userSettings *usersettings.Service, projects *projects.Service, rps *rps.Service, twitchSvc *twitch.Service, welcomeSvc *welcome.Service, defaultRoleSvc *defaultrole.Service) *Services {
+func NewServices(level *level.Service, levelSettings *levelsettings.Service, meeting *meeting.Service, schedule *schedule.Service, userSettings *usersettings.Service, projects *projects.Service, rps *rps.Service, twitchSvc *twitch.Service, welcomeSvc *welcome.Service, defaultRoleSvc *defaultrole.Service, logSettingsSvc *logsettings.Service) *Services {
 	s := &Services{
 		Level:         level,
 		LevelSettings: levelSettings,
@@ -40,6 +42,7 @@ func NewServices(level *level.Service, levelSettings *levelsettings.Service, mee
 		Twitch:        twitchSvc,
 		Welcome:       welcomeSvc,
 		DefaultRole:   defaultRoleSvc,
+		LogSettings:   logSettingsSvc,
 	}
 	Global = s
 	return s

internal/events/event_handlers.go

@@ -11,6 +11,8 @@ import (
 )
 
 func HandleMessageCreate(s *discordgo.Session, m *discordgo.MessageCreate, services *services.Services) {
+	CacheMessageFromCreate(m)
+
 	if m.Author.Bot || m.GuildID == "" {
 		return
 	}

internal/events/logging.go

@@ -0,0 +1,376 @@
+package events
+
+import (
+	"fmt"
+	"log"
+	"slices"
+	"strings"
+	"sync"
+	"time"
+
+	"velox-bot/internal/db/services"
+	"velox-bot/internal/modlog"
+
+	"github.com/bwmarrin/discordgo"
+)
+
+type cachedMessage struct {
+	Content  string
+	AuthorID string
+}
+
+var messageCache sync.Map // map[messageID]cachedMessage
+
+func HandleMessageUpdateLog(s *discordgo.Session, m *discordgo.MessageUpdate, svc *services.Services) {
+	if s == nil || m == nil || m.Message == nil || m.GuildID == "" || svc == nil {
+		return
+	}
+	if m.Author != nil && m.Author.Bot {
+		return
+	}
+
+	before := ""
+	if m.BeforeUpdate != nil {
+		before = strings.TrimSpace(m.BeforeUpdate.Content)
+	}
+	if before == "" {
+		if prev, ok := getCachedMessage(m.ID); ok {
+			before = strings.TrimSpace(prev.Content)
+		}
+	}
+	after := strings.TrimSpace(m.Content)
+	if before == after {
+		return
+	}
+
+	jumpURL := fmt.Sprintf("https://discord.com/channels/%s/%s/%s", m.GuildID, m.ChannelID, m.ID)
+	authorMention := "Unknown"
+	if m.Author != nil {
+		authorMention = m.Author.Mention()
+	}
+
+	embed := &discordgo.MessageEmbed{
+		Title:       "Message Edited",
+		Color:       0xF1C40F,
+		Description: fmt.Sprintf("Author: %s\nChannel: <#%s>\n[Jump to message](%s)", authorMention, m.ChannelID, jumpURL),
+		Fields: []*discordgo.MessageEmbedField{
+			{Name: "Before", Value: truncateOrPlaceholder(before), Inline: false},
+			{Name: "After", Value: truncateOrPlaceholder(after), Inline: false},
+		},
+		Timestamp: time.Now().Format(time.RFC3339),
+	}
+	if err := modlog.Send(s, svc, m.GuildID, embed); err != nil {
+		log.Printf("log: failed to send message edit log: %v", err)
+	}
+
+	cacheMessage(m.ID, after, authorIDOrEmpty(m.Author))
+}
+
+func HandleMessageDeleteLog(s *discordgo.Session, m *discordgo.MessageDelete, svc *services.Services) {
+	if s == nil || m == nil || m.Message == nil || m.GuildID == "" || svc == nil {
+		return
+	}
+
+	authorID := ""
+	authorLabel := "Unknown"
+	content := ""
+	if m.BeforeDelete != nil {
+		if m.BeforeDelete.Author != nil {
+			authorID = m.BeforeDelete.Author.ID
+			authorLabel = m.BeforeDelete.Author.Mention()
+		}
+		content = strings.TrimSpace(m.BeforeDelete.Content)
+	}
+	if content == "" {
+		if prev, ok := getCachedMessage(m.ID); ok {
+			content = strings.TrimSpace(prev.Content)
+			if authorID == "" && prev.AuthorID != "" {
+				authorID = prev.AuthorID
+				authorLabel = "<@" + prev.AuthorID + ">"
+			}
+		}
+	}
+	if authorID == "" && m.Author != nil {
+		authorID = m.Author.ID
+		authorLabel = m.Author.Mention()
+	}
+	if authorID == "" {
+		authorLabel = "Unknown"
+	}
+
+	embed := &discordgo.MessageEmbed{
+		Title:       "Message Deleted",
+		Color:       0xE74C3C,
+		Description: fmt.Sprintf("Author: %s\nChannel: <#%s>\nMessage ID: `%s`", authorLabel, m.ChannelID, m.ID),
+		Fields: []*discordgo.MessageEmbedField{
+			{Name: "Content", Value: truncateOrPlaceholder(content), Inline: false},
+		},
+		Timestamp: time.Now().Format(time.RFC3339),
+	}
+	if err := modlog.Send(s, svc, m.GuildID, embed); err != nil {
+		log.Printf("log: failed to send message delete log: %v", err)
+	}
+	deleteCachedMessage(m.ID)
+}
+
+func HandleGuildMemberAddLog(s *discordgo.Session, m *discordgo.GuildMemberAdd, svc *services.Services) {
+	if s == nil || m == nil || m.Member == nil || m.User == nil || m.GuildID == "" || svc == nil {
+		return
+	}
+	embed := &discordgo.MessageEmbed{
+		Title:       "Member Joined",
+		Color:       0x2ECC71,
+		Description: fmt.Sprintf("%s joined the server.\nUser ID: `%s`", m.User.Mention(), m.User.ID),
+		Timestamp:   time.Now().Format(time.RFC3339),
+	}
+	if err := modlog.Send(s, svc, m.GuildID, embed); err != nil {
+		log.Printf("log: failed to send member join log: %v", err)
+	}
+}
+
+func HandleGuildMemberRemoveLog(s *discordgo.Session, m *discordgo.GuildMemberRemove, svc *services.Services) {
+	if s == nil || m == nil || m.Member == nil || m.User == nil || m.GuildID == "" || svc == nil {
+		return
+	}
+
+	// Try to classify this leave as a kick via recent audit log.
+	kickEntry, kickMod := findRecentAuditEntryForTarget(s, m.GuildID, m.User.ID, discordgo.AuditLogActionMemberKick)
+	title := "Member Left"
+	color := 0x95A5A6
+	description := fmt.Sprintf("%s left the server.\nUser ID: `%s`", m.User.Mention(), m.User.ID)
+	if kickEntry != nil {
+		title = "Member Kicked"
+		color = 0xE67E22
+		description = fmt.Sprintf("%s was kicked.\nUser ID: `%s`", m.User.Mention(), m.User.ID)
+		if kickMod != nil {
+			description += "\nModerator: " + kickMod.Mention()
+		}
+		if strings.TrimSpace(kickEntry.Reason) != "" {
+			description += "\nReason: " + kickEntry.Reason
+		}
+	}
+
+	embed := &discordgo.MessageEmbed{
+		Title:       title,
+		Color:       color,
+		Description: description,
+		Timestamp:   time.Now().Format(time.RFC3339),
+	}
+	if err := modlog.Send(s, svc, m.GuildID, embed); err != nil {
+		log.Printf("log: failed to send member remove log: %v", err)
+	}
+}
+
+func HandleGuildMemberUpdateLog(s *discordgo.Session, m *discordgo.GuildMemberUpdate, svc *services.Services) {
+	if s == nil || m == nil || m.Member == nil || m.User == nil || m.GuildID == "" || svc == nil || m.BeforeUpdate == nil {
+		return
+	}
+
+	added := diffRoleIDs(m.BeforeUpdate.Roles, m.Roles)
+	removed := diffRoleIDs(m.Roles, m.BeforeUpdate.Roles)
+	if len(added) == 0 && len(removed) == 0 {
+		return
+	}
+
+	fields := make([]*discordgo.MessageEmbedField, 0, 2)
+	if len(added) > 0 {
+		fields = append(fields, &discordgo.MessageEmbedField{
+			Name:   "Roles Added",
+			Value:  joinRoleMentions(added),
+			Inline: false,
+		})
+	}
+	if len(removed) > 0 {
+		fields = append(fields, &discordgo.MessageEmbedField{
+			Name:   "Roles Removed",
+			Value:  joinRoleMentions(removed),
+			Inline: false,
+		})
+	}
+
+	embed := &discordgo.MessageEmbed{
+		Title:       "Member Roles Updated",
+		Color:       0x3498DB,
+		Description: fmt.Sprintf("Member: %s (`%s`)", m.User.Mention(), m.User.ID),
+		Fields:      fields,
+		Timestamp:   time.Now().Format(time.RFC3339),
+	}
+	if err := modlog.Send(s, svc, m.GuildID, embed); err != nil {
+		log.Printf("log: failed to send member update log: %v", err)
+	}
+}
+
+func HandleGuildBanAddLog(s *discordgo.Session, m *discordgo.GuildBanAdd, svc *services.Services) {
+	if s == nil || m == nil || m.User == nil || m.GuildID == "" || svc == nil {
+		return
+	}
+
+	entry, moderator := findRecentAuditEntryForTarget(s, m.GuildID, m.User.ID, discordgo.AuditLogActionMemberBanAdd)
+	desc := fmt.Sprintf("%s was banned.\nUser ID: `%s`", m.User.Mention(), m.User.ID)
+	if moderator != nil {
+		desc += "\nModerator: " + moderator.Mention()
+	}
+	if entry != nil && strings.TrimSpace(entry.Reason) != "" {
+		desc += "\nReason: " + entry.Reason
+	}
+
+	embed := &discordgo.MessageEmbed{
+		Title:       "Member Banned",
+		Color:       0xC0392B,
+		Description: desc,
+		Timestamp:   time.Now().Format(time.RFC3339),
+	}
+	if err := modlog.Send(s, svc, m.GuildID, embed); err != nil {
+		log.Printf("log: failed to send ban add log: %v", err)
+	}
+}
+
+func HandleGuildBanRemoveLog(s *discordgo.Session, m *discordgo.GuildBanRemove, svc *services.Services) {
+	if s == nil || m == nil || m.User == nil || m.GuildID == "" || svc == nil {
+		return
+	}
+
+	entry, moderator := findRecentAuditEntryForTarget(s, m.GuildID, m.User.ID, discordgo.AuditLogActionMemberBanRemove)
+	desc := fmt.Sprintf("%s was unbanned.\nUser ID: `%s`", m.User.Mention(), m.User.ID)
+	if moderator != nil {
+		desc += "\nModerator: " + moderator.Mention()
+	}
+	if entry != nil && strings.TrimSpace(entry.Reason) != "" {
+		desc += "\nReason: " + entry.Reason
+	}
+
+	embed := &discordgo.MessageEmbed{
+		Title:       "Member Unbanned",
+		Color:       0x27AE60,
+		Description: desc,
+		Timestamp:   time.Now().Format(time.RFC3339),
+	}
+	if err := modlog.Send(s, svc, m.GuildID, embed); err != nil {
+		log.Printf("log: failed to send ban remove log: %v", err)
+	}
+}
+
+func findRecentAuditEntryForTarget(s *discordgo.Session, guildID, targetID string, action discordgo.AuditLogAction) (*discordgo.AuditLogEntry, *discordgo.User) {
+	if s == nil || guildID == "" || targetID == "" {
+		return nil, nil
+	}
+	logs, err := s.GuildAuditLog(guildID, "", "", int(action), 10)
+	if err != nil || logs == nil {
+		return nil, nil
+	}
+
+	var chosen *discordgo.AuditLogEntry
+	now := time.Now().UTC()
+	for _, e := range logs.AuditLogEntries {
+		if e == nil || e.TargetID != targetID || e.ActionType == nil || *e.ActionType != action {
+			continue
+		}
+		ts, err := discordgo.SnowflakeTimestamp(e.ID)
+		if err != nil {
+			continue
+		}
+		// Keep only very recent entries to reduce false positives.
+		if now.Sub(ts) > 2*time.Minute {
+			continue
+		}
+		chosen = e
+		break
+	}
+	if chosen == nil {
+		return nil, nil
+	}
+
+	for _, u := range logs.Users {
+		if u != nil && u.ID == chosen.UserID {
+			return chosen, u
+		}
+	}
+	return chosen, nil
+}
+
+func truncateOrPlaceholder(s string) string {
+	v := strings.TrimSpace(s)
+	if v == "" {
+		return "*empty*"
+	}
+	if len(v) <= 1000 {
+		return v
+	}
+	return v[:997] + "..."
+}
+
+func diffRoleIDs(base, compare []string) []string {
+	out := make([]string, 0)
+	for _, id := range base {
+		if id == "" {
+			continue
+		}
+		if !slices.Contains(compare, id) {
+			out = append(out, id)
+		}
+	}
+	return out
+}
+
+func joinRoleMentions(roleIDs []string) string {
+	if len(roleIDs) == 0 {
+		return "*none*"
+	}
+	const max = 12
+	parts := make([]string, 0, len(roleIDs))
+	for idx, id := range roleIDs {
+		if idx >= max {
+			parts = append(parts, fmt.Sprintf("... and %d more", len(roleIDs)-max))
+			break
+		}
+		parts = append(parts, "<@&"+id+">")
+	}
+	return strings.Join(parts, ", ")
+}
+
+func CacheMessageFromCreate(m *discordgo.MessageCreate) {
+	if m == nil || m.Message == nil || m.ID == "" {
+		return
+	}
+	cacheMessage(m.ID, strings.TrimSpace(m.Content), authorIDOrEmpty(m.Author))
+}
+
+func cacheMessage(messageID, content, authorID string) {
+	if messageID == "" {
+		return
+	}
+	messageCache.Store(messageID, cachedMessage{
+		Content:  content,
+		AuthorID: authorID,
+	})
+}
+
+func getCachedMessage(messageID string) (cachedMessage, bool) {
+	if messageID == "" {
+		return cachedMessage{}, false
+	}
+	raw, ok := messageCache.Load(messageID)
+	if !ok {
+		return cachedMessage{}, false
+	}
+	msg, ok := raw.(cachedMessage)
+	if !ok {
+		return cachedMessage{}, false
+	}
+	return msg, true
+}
+
+func deleteCachedMessage(messageID string) {
+	if messageID == "" {
+		return
+	}
+	messageCache.Delete(messageID)
+}
+
+func authorIDOrEmpty(u *discordgo.User) string {
+	if u == nil {
+		return ""
+	}
+	return u.ID
+}
+

internal/events/onboarding.go

@@ -0,0 +1,163 @@
+package events
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"strconv"
+	"strings"
+	"time"
+
+	"velox-bot/internal/db/services"
+
+	"github.com/bwmarrin/discordgo"
+)
+
+// HandleBotAddedOnGuild applies safe defaults when this bot is added to a guild
+// and DMs setup instructions to the inviter (or guild owner fallback).
+func HandleBotAddedOnGuild(s *discordgo.Session, m *discordgo.GuildMemberAdd, svc *services.Services) {
+	if s == nil || m == nil || m.Member == nil || m.User == nil || svc == nil {
+		return
+	}
+	if s.State == nil || s.State.User == nil {
+		return
+	}
+	if m.User.ID != s.State.User.ID {
+		return
+	}
+
+	guildID64, err := strconv.ParseInt(m.GuildID, 10, 64)
+	if err != nil {
+		return
+	}
+
+	// Treat an existing logsettings row as "already onboarded once".
+	alreadyOnboarded := false
+	if svc.LogSettings != nil {
+		exists, err := svc.LogSettings.HasSettings(context.Background(), guildID64)
+		if err == nil {
+			alreadyOnboarded = exists
+		}
+	}
+	if alreadyOnboarded {
+		return
+	}
+
+	// Explicitly disable toggleable systems by default.
+	if svc.LevelSettings != nil {
+		if err := svc.LevelSettings.SetLevelSystemEnabled(context.Background(), guildID64, false); err != nil {
+			log.Printf("onboarding: failed to set default level state for guild %s: %v", m.GuildID, err)
+		}
+	}
+	if svc.LogSettings != nil {
+		if err := svc.LogSettings.SetEnabled(context.Background(), guildID64, false); err != nil {
+			log.Printf("onboarding: failed to set default log state for guild %s: %v", m.GuildID, err)
+		}
+	}
+
+	recipientID := findRecentBotAdderID(s, m.GuildID)
+	if recipientID == "" {
+		recipientID = guildOwnerID(s, m.GuildID)
+	}
+	if recipientID == "" {
+		log.Printf("onboarding: unable to resolve DM recipient for guild %s", m.GuildID)
+		return
+	}
+
+	dmCh, err := s.UserChannelCreate(recipientID)
+	if err != nil {
+		log.Printf("onboarding: failed creating DM for user %s: %v", recipientID, err)
+		return
+	}
+
+	guildName := m.GuildID
+	if g, err := s.State.Guild(m.GuildID); err == nil && g != nil && strings.TrimSpace(g.Name) != "" {
+		guildName = g.Name
+	} else if g, err := s.Guild(m.GuildID); err == nil && g != nil && strings.TrimSpace(g.Name) != "" {
+		guildName = g.Name
+	}
+
+	embed := &discordgo.MessageEmbed{
+		Title: "Thanks for adding Velox Bot!",
+		Color: 0x5865F2,
+		Description: fmt.Sprintf(
+			"Server: **%s**\n\nFor safety, toggleable systems start **disabled by default**.\nUse these commands in your server to enable features:",
+			guildName,
+		),
+		Fields: []*discordgo.MessageEmbedField{
+			{
+				Name: "Level System",
+				Value: "`/slvl toggle`",
+				Inline: false,
+			},
+			{
+				Name: "Logging System",
+				Value: "" +
+					"`/config setlogchannel channel:#channel`\n" +
+					"`/config enablelogging`",
+				Inline: false,
+			},
+			{
+				Name: "Welcome System",
+				Value: "" +
+					"`/config setwelcomechannel channel:#channel`\n" +
+					"`/config setwelcomemessage message:\"...\"`\n" +
+					"`/config setwelcomedm message:\"...\"`",
+				Inline: false,
+			},
+		},
+		Footer: &discordgo.MessageEmbedFooter{
+			Text: "Tip: run /help in any server channel for the full command reference.",
+		},
+		Timestamp: time.Now().Format(time.RFC3339),
+	}
+
+	if _, err := s.ChannelMessageSendEmbed(dmCh.ID, embed); err != nil {
+		log.Printf("onboarding: failed sending setup DM to user %s: %v", recipientID, err)
+	}
+}
+
+func findRecentBotAdderID(s *discordgo.Session, guildID string) string {
+	if s == nil || s.State == nil || s.State.User == nil {
+		return ""
+	}
+	logs, err := s.GuildAuditLog(guildID, "", "", int(discordgo.AuditLogActionBotAdd), 10)
+	if err != nil || logs == nil {
+		return ""
+	}
+
+	botID := s.State.User.ID
+	now := time.Now().UTC()
+	for _, entry := range logs.AuditLogEntries {
+		if entry == nil || entry.TargetID != botID || entry.ActionType == nil || *entry.ActionType != discordgo.AuditLogActionBotAdd {
+			continue
+		}
+		ts, err := discordgo.SnowflakeTimestamp(entry.ID)
+		if err != nil {
+			continue
+		}
+		if now.Sub(ts) > 10*time.Minute {
+			continue
+		}
+		if entry.UserID != "" {
+			return entry.UserID
+		}
+	}
+	return ""
+}
+
+func guildOwnerID(s *discordgo.Session, guildID string) string {
+	if s == nil || guildID == "" {
+		return ""
+	}
+	if s.State != nil {
+		if g, err := s.State.Guild(guildID); err == nil && g != nil && g.OwnerID != "" {
+			return g.OwnerID
+		}
+	}
+	if g, err := s.Guild(guildID); err == nil && g != nil {
+		return g.OwnerID
+	}
+	return ""
+}
+

internal/modlog/modlog.go

@@ -0,0 +1,30 @@
+package modlog
+
+import (
+	"context"
+	"strconv"
+
+	"velox-bot/internal/db/services"
+
+	"github.com/bwmarrin/discordgo"
+)
+
+func Send(s *discordgo.Session, svc *services.Services, guildID string, embed *discordgo.MessageEmbed) error {
+	if s == nil || svc == nil || svc.LogSettings == nil || embed == nil || guildID == "" {
+		return nil
+	}
+
+	gid, err := strconv.ParseInt(guildID, 10, 64)
+	if err != nil {
+		return nil
+	}
+
+	cfg, err := svc.LogSettings.GetSettings(context.Background(), gid)
+	if err != nil || cfg == nil || !cfg.IsEnabled || cfg.ChannelID == 0 {
+		return err
+	}
+
+	_, err = s.ChannelMessageSendEmbed(strconv.FormatInt(cfg.ChannelID, 10), embed)
+	return err
+}
+

main.go

@@ -22,6 +22,7 @@ import (
 	"velox-bot/internal/db/services"
 	"velox-bot/internal/db/services/level"
 	"velox-bot/internal/db/services/levelsettings"
+	"velox-bot/internal/db/services/logsettings"
 	"velox-bot/internal/db/services/meeting"
 	"velox-bot/internal/db/services/projects"
 	"velox-bot/internal/db/services/rps"
@@ -57,6 +58,7 @@ func main() {
 	defaultRoleRepo := defaultrolerepo.NewRepo(db)
 	levelService := level.New(levelRepo, settingsRepo)
 	levelSettingsService := levelsettings.New(settingsRepo)
+	logSettingsService := logsettings.New(settingsRepo)
 	meetingService := meeting.New(settingsRepo)
 	scheduleService := schedule.New(scheduleRepo)
 	userSettingsService := usersettings.New(userSettingsRepo)
@@ -65,7 +67,7 @@ func main() {
 	twitchService := twitch.New(twitchRepo, config.TwitchClientID)
 	welcomeService := welcome.New(welcomeRepo)
 	defaultRoleService := defaultrole.New(defaultRoleRepo)
-	services := services.NewServices(levelService, levelSettingsService, meetingService, scheduleService, userSettingsService, projectsService, rpsService, twitchService, welcomeService, defaultRoleService)
+	services := services.NewServices(levelService, levelSettingsService, meetingService, scheduleService, userSettingsService, projectsService, rpsService, twitchService, welcomeService, defaultRoleService, logSettingsService)
 
 	bot, err := bot.NewBot(config.BotToken, config.AppID, config.GuildID, config.LavalinkHost, config.LavalinkPass, commands.AllCommands, services)
 	if err != nil {