feat: implement Tier 3 utility IRC commands

Implement all 7 utility IRC commands from issue #87:

User commands:
- USERHOST: quick lookup of user@host for up to 5 nicks (RPL 302)
- VERSION: server version string using globals.Version (RPL 351)
- ADMIN: server admin contact info (RPL 256-259)
- INFO: server software info text (RPL 371/374)
- TIME: server local time in RFC format (RPL 391)

Oper commands:
- KILL: forcibly disconnect a user (requires is_oper), broadcasts
  QUIT to all shared channels, cleans up sessions
- WALLOPS: broadcast message to all users with +w usermode
  (requires is_oper)

Supporting changes:
- Add is_wallops column to sessions table in 001_initial.sql
- Add user mode +w tracking via MODE nick +w/-w
- User mode queries now return actual modes (+o, +w)
- MODE -o allows de-opering yourself; MODE +o rejected
- MODE for other users returns ERR_USERSDONTMATCH (502)
- Extract dispatch helpers to reduce dispatchCommand complexity

Tests cover all commands including error cases, oper checks,
user mode set/unset, KILL broadcast, WALLOPS delivery, and
edge cases (self-kill, nonexistent users, missing params).

closes #87

internal/db/queries.go

@@ -2367,3 +2367,132 @@ func (database *Database) SetChannelUserLimit(
 
 	return nil
 }
+
+// SetSessionWallops sets the wallops (+w) flag on a
+// session.
+func (database *Database) SetSessionWallops(
+	ctx context.Context,
+	sessionID int64,
+	enabled bool,
+) error {
+	val := 0
+	if enabled {
+		val = 1
+	}
+
+	_, err := database.conn.ExecContext(
+		ctx,
+		`UPDATE sessions SET is_wallops = ? WHERE id = ?`,
+		val, sessionID,
+	)
+	if err != nil {
+		return fmt.Errorf("set session wallops: %w", err)
+	}
+
+	return nil
+}
+
+// IsSessionWallops returns whether the session has the
+// wallops (+w) usermode set.
+func (database *Database) IsSessionWallops(
+	ctx context.Context,
+	sessionID int64,
+) (bool, error) {
+	var isWallops int
+
+	err := database.conn.QueryRowContext(
+		ctx,
+		`SELECT is_wallops FROM sessions WHERE id = ?`,
+		sessionID,
+	).Scan(&isWallops)
+	if err != nil {
+		return false, fmt.Errorf(
+			"check session wallops: %w", err,
+		)
+	}
+
+	return isWallops != 0, nil
+}
+
+// GetWallopsSessionIDs returns all session IDs that have
+// the wallops (+w) usermode set.
+func (database *Database) GetWallopsSessionIDs(
+	ctx context.Context,
+) ([]int64, error) {
+	rows, err := database.conn.QueryContext(
+		ctx,
+		`SELECT id FROM sessions WHERE is_wallops = 1`,
+	)
+	if err != nil {
+		return nil, fmt.Errorf(
+			"get wallops sessions: %w", err,
+		)
+	}
+
+	defer func() { _ = rows.Close() }()
+
+	var ids []int64
+
+	for rows.Next() {
+		var sessionID int64
+		if scanErr := rows.Scan(&sessionID); scanErr != nil {
+			return nil, fmt.Errorf(
+				"scan wallops session: %w", scanErr,
+			)
+		}
+
+		ids = append(ids, sessionID)
+	}
+
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf(
+			"iterate wallops sessions: %w", err,
+		)
+	}
+
+	return ids, nil
+}
+
+// UserhostInfo holds the data needed for RPL_USERHOST.
+type UserhostInfo struct {
+	Nick        string
+	Username    string
+	Hostname    string
+	IsOper      bool
+	AwayMessage string
+}
+
+// GetUserhostInfo returns USERHOST info for the given
+// nicks. Only nicks that exist are returned.
+func (database *Database) GetUserhostInfo(
+	ctx context.Context,
+	nicks []string,
+) ([]UserhostInfo, error) {
+	if len(nicks) == 0 {
+		return nil, nil
+	}
+
+	results := make([]UserhostInfo, 0, len(nicks))
+
+	for _, nick := range nicks {
+		var info UserhostInfo
+
+		err := database.conn.QueryRowContext(
+			ctx,
+			`SELECT nick, username, hostname,
+			        is_oper, away_message
+			 FROM sessions WHERE nick = ?`,
+			nick,
+		).Scan(
+			&info.Nick, &info.Username, &info.Hostname,
+			&info.IsOper, &info.AwayMessage,
+		)
+		if err != nil {
+			continue // nick not found, skip
+		}
+
+		results = append(results, info)
+	}
+
+	return results, nil
+}

internal/db/schema/001_initial.sql

@@ -10,6 +10,7 @@ CREATE TABLE IF NOT EXISTS sessions (
     hostname TEXT NOT NULL DEFAULT '',
     ip TEXT NOT NULL DEFAULT '',
     is_oper INTEGER NOT NULL DEFAULT 0,
+    is_wallops INTEGER NOT NULL DEFAULT 0,
     password_hash TEXT NOT NULL DEFAULT '',
     signing_key TEXT NOT NULL DEFAULT '',
     away_message TEXT NOT NULL DEFAULT '',

internal/handlers/api.go

@@ -1014,10 +1014,12 @@ func (hdlr *Handlers) dispatchCommand(
 	bodyLines func() []string,
 ) {
 	switch command {
-	case irc.CmdAway:
-		hdlr.handleAway(
+	case irc.CmdAway, irc.CmdNick,
+		irc.CmdPass, irc.CmdInvite:
+		hdlr.dispatchBodyOnlyCommand(
 			writer, request,
-			sessionID, clientID, nick, bodyLines,
+			sessionID, clientID, nick,
+			command, bodyLines,
 		)
 	case irc.CmdPrivmsg, irc.CmdNotice:
 		hdlr.handlePrivmsg(
@@ -1036,27 +1038,12 @@ func (hdlr *Handlers) dispatchCommand(
 			writer, request,
 			sessionID, clientID, nick, target, body,
 		)
-	case irc.CmdNick:
-		hdlr.handleNick(
-			writer, request,
-			sessionID, clientID, nick, bodyLines,
-		)
-	case irc.CmdPass:
-		hdlr.handlePass(
-			writer, request,
-			sessionID, clientID, nick, bodyLines,
-		)
 	case irc.CmdTopic:
 		hdlr.handleTopic(
 			writer, request,
 			sessionID, clientID, nick,
 			target, body, bodyLines,
 		)
-	case irc.CmdInvite:
-		hdlr.handleInvite(
-			writer, request,
-			sessionID, clientID, nick, bodyLines,
-		)
 	case irc.CmdKick:
 		hdlr.handleKick(
 			writer, request,
@@ -1067,12 +1054,15 @@ func (hdlr *Handlers) dispatchCommand(
 		hdlr.handleQuit(
 			writer, request, sessionID, nick, body,
 		)
-	case irc.CmdOper:
-		hdlr.handleOper(
+	case irc.CmdOper, irc.CmdKill, irc.CmdWallops:
+		hdlr.dispatchOperCommand(
 			writer, request,
-			sessionID, clientID, nick, bodyLines,
+			sessionID, clientID, nick,
+			command, bodyLines,
 		)
-	case irc.CmdMotd, irc.CmdPing:
+	case irc.CmdMotd, irc.CmdPing,
+		irc.CmdVersion, irc.CmdAdmin,
+		irc.CmdInfo, irc.CmdTime:
 		hdlr.dispatchInfoCommand(
 			writer, request,
 			sessionID, clientID, nick,
@@ -1127,6 +1117,11 @@ func (hdlr *Handlers) dispatchQueryCommand(
 			writer, request,
 			sessionID, clientID, nick,
 		)
+	case irc.CmdUserhost:
+		hdlr.handleUserhost(
+			writer, request,
+			sessionID, clientID, nick, bodyLines,
+		)
 	default:
 		hdlr.enqueueNumeric(
 			request.Context(), clientID,
@@ -2416,7 +2411,8 @@ func (hdlr *Handlers) executeTopic(
 }
 
 // dispatchInfoCommand handles informational IRC commands
-// that produce server-side numerics (MOTD, PING).
+// that produce server-side numerics (MOTD, PING,
+// VERSION, ADMIN, INFO, TIME).
 func (hdlr *Handlers) dispatchInfoCommand(
 	writer http.ResponseWriter,
 	request *http.Request,
@@ -2442,6 +2438,34 @@ func (hdlr *Handlers) dispatchInfoCommand(
 			},
 			http.StatusOK)
 
+		return
+	case irc.CmdVersion:
+		hdlr.handleVersion(
+			writer, request,
+			sessionID, clientID, nick,
+		)
+
+		return
+	case irc.CmdAdmin:
+		hdlr.handleAdmin(
+			writer, request,
+			sessionID, clientID, nick,
+		)
+
+		return
+	case irc.CmdInfo:
+		hdlr.handleInfo(
+			writer, request,
+			sessionID, clientID, nick,
+		)
+
+		return
+	case irc.CmdTime:
+		hdlr.handleTime(
+			writer, request,
+			sessionID, clientID, nick,
+		)
+
 		return
 	}
 
@@ -2532,15 +2556,11 @@ func (hdlr *Handlers) handleMode(
 
 	channel := target
 	if !strings.HasPrefix(channel, "#") {
-		// User mode query — return empty modes.
-		hdlr.enqueueNumeric(
-			request.Context(), clientID,
-			irc.RplUmodeIs, nick, nil, "+",
+		hdlr.handleUserMode(
+			writer, request,
+			sessionID, clientID, nick, target,
+			bodyLines,
 		)
-		hdlr.broker.Notify(sessionID)
-		hdlr.respondJSON(writer, request,
-			map[string]string{"status": "ok"},
-			http.StatusOK)
 
 		return
 	}

internal/handlers/utility.go

@@ -0,0 +1,727 @@
+package handlers
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"git.eeqj.de/sneak/neoirc/internal/db"
+	"git.eeqj.de/sneak/neoirc/pkg/irc"
+)
+
+// maxUserhostNicks is the maximum number of nicks allowed
+// in a single USERHOST query (RFC 2812).
+const maxUserhostNicks = 5
+
+// dispatchBodyOnlyCommand routes commands that take
+// (writer, request, sessionID, clientID, nick, bodyLines).
+func (hdlr *Handlers) dispatchBodyOnlyCommand(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, command string,
+	bodyLines func() []string,
+) {
+	switch command {
+	case irc.CmdAway:
+		hdlr.handleAway(
+			writer, request,
+			sessionID, clientID, nick, bodyLines,
+		)
+	case irc.CmdNick:
+		hdlr.handleNick(
+			writer, request,
+			sessionID, clientID, nick, bodyLines,
+		)
+	case irc.CmdPass:
+		hdlr.handlePass(
+			writer, request,
+			sessionID, clientID, nick, bodyLines,
+		)
+	case irc.CmdInvite:
+		hdlr.handleInvite(
+			writer, request,
+			sessionID, clientID, nick, bodyLines,
+		)
+	}
+}
+
+// dispatchOperCommand routes oper-related commands (OPER,
+// KILL, WALLOPS) to their handlers.
+func (hdlr *Handlers) dispatchOperCommand(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, command string,
+	bodyLines func() []string,
+) {
+	switch command {
+	case irc.CmdOper:
+		hdlr.handleOper(
+			writer, request,
+			sessionID, clientID, nick, bodyLines,
+		)
+	case irc.CmdKill:
+		hdlr.handleKill(
+			writer, request,
+			sessionID, clientID, nick, bodyLines,
+		)
+	case irc.CmdWallops:
+		hdlr.handleWallops(
+			writer, request,
+			sessionID, clientID, nick, bodyLines,
+		)
+	}
+}
+
+// handleUserhost handles the USERHOST command.
+// Returns user@host info for up to 5 nicks.
+func (hdlr *Handlers) handleUserhost(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick string,
+	bodyLines func() []string,
+) {
+	ctx := request.Context()
+
+	lines := bodyLines()
+	if len(lines) == 0 {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			irc.ErrNeedMoreParams, nick,
+			[]string{irc.CmdUserhost},
+			"Not enough parameters",
+		)
+
+		return
+	}
+
+	// Limit to 5 nicks per RFC 2812.
+	nicks := lines
+	if len(nicks) > maxUserhostNicks {
+		nicks = nicks[:maxUserhostNicks]
+	}
+
+	infos, err := hdlr.params.Database.GetUserhostInfo(
+		ctx, nicks,
+	)
+	if err != nil {
+		hdlr.log.Error(
+			"userhost query failed", "error", err,
+		)
+		hdlr.respondError(
+			writer, request,
+			"internal error",
+			http.StatusInternalServerError,
+		)
+
+		return
+	}
+
+	replyStr := hdlr.buildUserhostReply(infos)
+
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplUserHost, nick, nil,
+		replyStr,
+	)
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// buildUserhostReply builds the RPL_USERHOST reply
+// string per RFC 2812.
+func (hdlr *Handlers) buildUserhostReply(
+	infos []db.UserhostInfo,
+) string {
+	replies := make([]string, 0, len(infos))
+
+	for idx := range infos {
+		info := &infos[idx]
+
+		username := info.Username
+		if username == "" {
+			username = info.Nick
+		}
+
+		hostname := info.Hostname
+		if hostname == "" {
+			hostname = hdlr.serverName()
+		}
+
+		operStar := ""
+		if info.IsOper {
+			operStar = "*"
+		}
+
+		awayPrefix := "+"
+		if info.AwayMessage != "" {
+			awayPrefix = "-"
+		}
+
+		replies = append(replies,
+			info.Nick+operStar+"="+
+				awayPrefix+username+"@"+hostname,
+		)
+	}
+
+	return strings.Join(replies, " ")
+}
+
+// handleVersion handles the VERSION command.
+// Returns the server version string.
+func (hdlr *Handlers) handleVersion(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick string,
+) {
+	ctx := request.Context()
+	srvName := hdlr.serverName()
+	version := hdlr.serverVersion()
+
+	// 351 RPL_VERSION
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplVersion, nick,
+		[]string{version + ".", srvName},
+		"",
+	)
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// handleAdmin handles the ADMIN command.
+// Returns server admin contact info.
+func (hdlr *Handlers) handleAdmin(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick string,
+) {
+	ctx := request.Context()
+	srvName := hdlr.serverName()
+
+	// 256 RPL_ADMINME
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplAdminMe, nick,
+		[]string{srvName},
+		"Administrative info",
+	)
+
+	// 257 RPL_ADMINLOC1
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplAdminLoc1, nick, nil,
+		"neoirc server",
+	)
+
+	// 258 RPL_ADMINLOC2
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplAdminLoc2, nick, nil,
+		"IRC over HTTP",
+	)
+
+	// 259 RPL_ADMINEMAIL
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplAdminEmail, nick, nil,
+		"admin@"+srvName,
+	)
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// handleInfo handles the INFO command.
+// Returns server software information.
+func (hdlr *Handlers) handleInfo(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick string,
+) {
+	ctx := request.Context()
+	version := hdlr.serverVersion()
+
+	infoLines := []string{
+		"neoirc — IRC semantics over HTTP",
+		"Version: " + version,
+		"Written in Go",
+		"Started: " +
+			hdlr.params.Globals.StartTime.
+				Format(time.RFC1123),
+	}
+
+	for _, line := range infoLines {
+		// 371 RPL_INFO
+		hdlr.enqueueNumeric(
+			ctx, clientID, irc.RplInfo, nick, nil,
+			line,
+		)
+	}
+
+	// 374 RPL_ENDOFINFO
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplEndOfInfo, nick, nil,
+		"End of /INFO list",
+	)
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// handleTime handles the TIME command.
+// Returns the server's local time in RFC format.
+func (hdlr *Handlers) handleTime(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick string,
+) {
+	ctx := request.Context()
+	srvName := hdlr.serverName()
+
+	// 391 RPL_TIME
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplTime, nick,
+		[]string{srvName},
+		time.Now().Format(time.RFC1123),
+	)
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// handleKill handles the KILL command.
+// Forcibly disconnects a user (oper only).
+func (hdlr *Handlers) handleKill(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick string,
+	bodyLines func() []string,
+) {
+	ctx := request.Context()
+
+	// Check oper status.
+	isOper, err := hdlr.params.Database.IsSessionOper(
+		ctx, sessionID,
+	)
+	if err != nil || !isOper {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			irc.ErrNoPrivileges, nick, nil,
+			"Permission Denied- You're not an IRC operator",
+		)
+
+		return
+	}
+
+	lines := bodyLines()
+	if len(lines) == 0 {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			irc.ErrNeedMoreParams, nick,
+			[]string{irc.CmdKill},
+			"Not enough parameters",
+		)
+
+		return
+	}
+
+	targetNick := strings.TrimSpace(lines[0])
+	if targetNick == "" {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			irc.ErrNeedMoreParams, nick,
+			[]string{irc.CmdKill},
+			"Not enough parameters",
+		)
+
+		return
+	}
+
+	reason := "KILLed"
+	if len(lines) > 1 {
+		reason = lines[1]
+	}
+
+	targetSID, lookupErr := hdlr.params.Database.
+		GetSessionByNick(ctx, targetNick)
+	if lookupErr != nil {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			irc.ErrNoSuchNick, nick,
+			[]string{targetNick},
+			"No such nick/channel",
+		)
+
+		return
+	}
+
+	// Do not allow killing yourself.
+	if targetSID == sessionID {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			irc.ErrCantKillServer, nick, nil,
+			"You cannot KILL yourself",
+		)
+
+		return
+	}
+
+	hdlr.executeKillUser(
+		request, targetSID, targetNick, nick, reason,
+	)
+
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// executeKillUser forcibly disconnects a user: broadcasts
+// QUIT to their channels, parts all channels, and deletes
+// the session.
+func (hdlr *Handlers) executeKillUser(
+	request *http.Request,
+	targetSID int64,
+	targetNick, killerNick, reason string,
+) {
+	ctx := request.Context()
+
+	quitMsg := "Killed (" + killerNick + " (" + reason + "))"
+
+	quitBody, err := json.Marshal([]string{quitMsg})
+	if err != nil {
+		hdlr.log.Error(
+			"marshal kill quit body", "error", err,
+		)
+
+		return
+	}
+
+	channels, _ := hdlr.params.Database.
+		GetSessionChannels(ctx, targetSID)
+
+	notified := map[int64]bool{}
+
+	var dbID int64
+
+	if len(channels) > 0 {
+		dbID, _, _ = hdlr.params.Database.InsertMessage(
+			ctx, irc.CmdQuit, targetNick, "",
+			nil, json.RawMessage(quitBody), nil,
+		)
+	}
+
+	for _, chanInfo := range channels {
+		memberIDs, _ := hdlr.params.Database.
+			GetChannelMemberIDs(ctx, chanInfo.ID)
+
+		for _, mid := range memberIDs {
+			if mid != targetSID && !notified[mid] {
+				notified[mid] = true
+
+				_ = hdlr.params.Database.EnqueueToSession(
+					ctx, mid, dbID,
+				)
+
+				hdlr.broker.Notify(mid)
+			}
+		}
+
+		_ = hdlr.params.Database.PartChannel(
+			ctx, chanInfo.ID, targetSID,
+		)
+
+		_ = hdlr.params.Database.DeleteChannelIfEmpty(
+			ctx, chanInfo.ID,
+		)
+	}
+
+	_ = hdlr.params.Database.DeleteSession(
+		ctx, targetSID,
+	)
+}
+
+// handleWallops handles the WALLOPS command.
+// Broadcasts a message to all users with +w usermode
+// (oper only).
+func (hdlr *Handlers) handleWallops(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick string,
+	bodyLines func() []string,
+) {
+	ctx := request.Context()
+
+	// Check oper status.
+	isOper, err := hdlr.params.Database.IsSessionOper(
+		ctx, sessionID,
+	)
+	if err != nil || !isOper {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			irc.ErrNoPrivileges, nick, nil,
+			"Permission Denied- You're not an IRC operator",
+		)
+
+		return
+	}
+
+	lines := bodyLines()
+	if len(lines) == 0 {
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			irc.ErrNeedMoreParams, nick,
+			[]string{irc.CmdWallops},
+			"Not enough parameters",
+		)
+
+		return
+	}
+
+	message := strings.Join(lines, " ")
+
+	wallopsSIDs, err := hdlr.params.Database.
+		GetWallopsSessionIDs(ctx)
+	if err != nil {
+		hdlr.log.Error(
+			"get wallops sessions failed", "error", err,
+		)
+		hdlr.respondError(
+			writer, request,
+			"internal error",
+			http.StatusInternalServerError,
+		)
+
+		return
+	}
+
+	if len(wallopsSIDs) > 0 {
+		body, mErr := json.Marshal([]string{message})
+		if mErr != nil {
+			hdlr.log.Error(
+				"marshal wallops body", "error", mErr,
+			)
+			hdlr.respondError(
+				writer, request,
+				"internal error",
+				http.StatusInternalServerError,
+			)
+
+			return
+		}
+
+		_ = hdlr.fanOutSilent(
+			request, irc.CmdWallops, nick, "*",
+			json.RawMessage(body), wallopsSIDs,
+		)
+	}
+
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// handleUserMode handles user mode queries and changes
+// (e.g., MODE nick, MODE nick +w).
+func (hdlr *Handlers) handleUserMode(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, target string,
+	bodyLines func() []string,
+) {
+	ctx := request.Context()
+
+	lines := bodyLines()
+
+	// Mode change requested.
+	if len(lines) > 0 {
+		// Users can only change their own modes.
+		if target != nick && target != "" {
+			hdlr.respondIRCError(
+				writer, request, clientID, sessionID,
+				irc.ErrUsersDoNotMatch, nick, nil,
+				"Can't change mode for other users",
+			)
+
+			return
+		}
+
+		hdlr.applyUserModeChange(
+			writer, request,
+			sessionID, clientID, nick, lines[0],
+		)
+
+		return
+	}
+
+	// Mode query — build the current mode string.
+	modeStr := hdlr.buildUserModeString(ctx, sessionID)
+
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplUmodeIs, nick, nil,
+		modeStr,
+	)
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// buildUserModeString constructs the mode string for a
+// user (e.g., "+ow" for oper+wallops).
+func (hdlr *Handlers) buildUserModeString(
+	ctx context.Context,
+	sessionID int64,
+) string {
+	modes := "+"
+
+	isOper, err := hdlr.params.Database.IsSessionOper(
+		ctx, sessionID,
+	)
+	if err == nil && isOper {
+		modes += "o"
+	}
+
+	isWallops, err := hdlr.params.Database.IsSessionWallops(
+		ctx, sessionID,
+	)
+	if err == nil && isWallops {
+		modes += "w"
+	}
+
+	return modes
+}
+
+// applyUserModeChange applies a user mode change string
+// (e.g., "+w", "-w").
+func (hdlr *Handlers) applyUserModeChange(
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, modeStr string,
+) {
+	ctx := request.Context()
+
+	if len(modeStr) < 2 { //nolint:mnd // +/- and mode char
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			irc.ErrUmodeUnknownFlag, nick, nil,
+			"Unknown MODE flag",
+		)
+
+		return
+	}
+
+	adding := modeStr[0] == '+'
+	modeChar := modeStr[1:]
+
+	applied, err := hdlr.applyModeChar(
+		ctx, writer, request,
+		sessionID, clientID, nick,
+		modeChar, adding,
+	)
+	if err != nil || !applied {
+		return
+	}
+
+	newModes := hdlr.buildUserModeString(ctx, sessionID)
+
+	hdlr.enqueueNumeric(
+		ctx, clientID, irc.RplUmodeIs, nick, nil,
+		newModes,
+	)
+
+	hdlr.broker.Notify(sessionID)
+	hdlr.respondJSON(writer, request,
+		map[string]string{"status": "ok"},
+		http.StatusOK)
+}
+
+// applyModeChar applies a single user mode character.
+// Returns (applied, error).
+func (hdlr *Handlers) applyModeChar(
+	ctx context.Context,
+	writer http.ResponseWriter,
+	request *http.Request,
+	sessionID, clientID int64,
+	nick, modeChar string,
+	adding bool,
+) (bool, error) {
+	switch modeChar {
+	case "w":
+		err := hdlr.params.Database.SetSessionWallops(
+			ctx, sessionID, adding,
+		)
+		if err != nil {
+			hdlr.log.Error(
+				"set wallops mode failed", "error", err,
+			)
+			hdlr.respondError(
+				writer, request,
+				"internal error",
+				http.StatusInternalServerError,
+			)
+
+			return false, fmt.Errorf(
+				"set wallops: %w", err,
+			)
+		}
+	case "o":
+		// +o cannot be set via MODE, only via OPER.
+		if adding {
+			hdlr.respondIRCError(
+				writer, request, clientID, sessionID,
+				irc.ErrUmodeUnknownFlag, nick, nil,
+				"Unknown MODE flag",
+			)
+
+			return false, nil
+		}
+
+		err := hdlr.params.Database.SetSessionOper(
+			ctx, sessionID, false,
+		)
+		if err != nil {
+			hdlr.log.Error(
+				"clear oper mode failed", "error", err,
+			)
+			hdlr.respondError(
+				writer, request,
+				"internal error",
+				http.StatusInternalServerError,
+			)
+
+			return false, fmt.Errorf(
+				"clear oper: %w", err,
+			)
+		}
+	default:
+		hdlr.respondIRCError(
+			writer, request, clientID, sessionID,
+			irc.ErrUmodeUnknownFlag, nick, nil,
+			"Unknown MODE flag",
+		)
+
+		return false, nil
+	}
+
+	return true, nil
+}

internal/handlers/utility_test.go

@@ -0,0 +1,982 @@
+// Tests for Tier 3 utility IRC commands: USERHOST,
+// VERSION, ADMIN, INFO, TIME, KILL, WALLOPS.
+//
+//nolint:paralleltest
+package handlers_test
+
+import (
+	"strings"
+	"testing"
+)
+
+// --- USERHOST ---
+
+func TestUserhostSingleNick(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("alice")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "USERHOST",
+		bodyKey:    []string{"alice"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 302 RPL_USERHOST.
+	msg := findNumericWithParams(msgs, "302")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_USERHOST (302), got %v",
+			msgs,
+		)
+	}
+
+	// Body should contain "alice" with the
+	// nick=+user@host format.
+	body := getNumericBody(msg)
+	if !strings.Contains(body, "alice") {
+		t.Fatalf(
+			"expected body to contain 'alice', got %q",
+			body,
+		)
+	}
+
+	// '+' means not away.
+	if !strings.Contains(body, "=+") {
+		t.Fatalf(
+			"expected not-away prefix '=+', got %q",
+			body,
+		)
+	}
+}
+
+func TestUserhostMultipleNicks(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token1 := tserver.createSession("bob")
+	token2 := tserver.createSession("carol")
+
+	_ = token2
+
+	_, lastID := tserver.pollMessages(token1, 0)
+
+	tserver.sendCommand(token1, map[string]any{
+		commandKey: "USERHOST",
+		bodyKey:    []string{"bob", "carol"},
+	})
+
+	msgs, _ := tserver.pollMessages(token1, lastID)
+
+	msg := findNumericWithParams(msgs, "302")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_USERHOST (302), got %v",
+			msgs,
+		)
+	}
+
+	body := getNumericBody(msg)
+	if !strings.Contains(body, "bob") {
+		t.Fatalf(
+			"expected body to contain 'bob', got %q",
+			body,
+		)
+	}
+
+	if !strings.Contains(body, "carol") {
+		t.Fatalf(
+			"expected body to contain 'carol', got %q",
+			body,
+		)
+	}
+}
+
+func TestUserhostNonexistentNick(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("dave")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "USERHOST",
+		bodyKey:    []string{"nobody"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Should still get 302 but with empty body.
+	msg := findNumericWithParams(msgs, "302")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_USERHOST (302), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestUserhostNoParams(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("eve")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "USERHOST",
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 461 ERR_NEEDMOREPARAMS.
+	if !findNumeric(msgs, "461") {
+		t.Fatalf(
+			"expected ERR_NEEDMOREPARAMS (461), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestUserhostShowsOper(t *testing.T) {
+	tserver := newTestServerWithOper(t)
+
+	token := tserver.createSession("opernick")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	// Authenticate as oper.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "OPER",
+		bodyKey:    []string{testOperName, testOperPassword},
+	})
+
+	_, lastID = tserver.pollMessages(token, lastID)
+
+	// USERHOST should show '*' for oper.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "USERHOST",
+		bodyKey:    []string{"opernick"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	msg := findNumericWithParams(msgs, "302")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_USERHOST (302), got %v",
+			msgs,
+		)
+	}
+
+	body := getNumericBody(msg)
+	if !strings.Contains(body, "opernick*=") {
+		t.Fatalf(
+			"expected oper '*' in reply, got %q",
+			body,
+		)
+	}
+}
+
+func TestUserhostShowsAway(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("awaynick")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	// Set away.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "AWAY",
+		bodyKey:    []string{"gone fishing"},
+	})
+
+	_, lastID = tserver.pollMessages(token, lastID)
+
+	// USERHOST should show '-' for away.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "USERHOST",
+		bodyKey:    []string{"awaynick"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	msg := findNumericWithParams(msgs, "302")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_USERHOST (302), got %v",
+			msgs,
+		)
+	}
+
+	body := getNumericBody(msg)
+	if !strings.Contains(body, "=-") {
+		t.Fatalf(
+			"expected away prefix '=-' in reply, got %q",
+			body,
+		)
+	}
+}
+
+// --- VERSION ---
+
+func TestVersion(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("frank")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "VERSION",
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 351 RPL_VERSION.
+	msg := findNumericWithParams(msgs, "351")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_VERSION (351), got %v",
+			msgs,
+		)
+	}
+
+	params := getNumericParams(msg)
+	if len(params) == 0 {
+		t.Fatal("expected VERSION params, got none")
+	}
+
+	// First param should contain version string.
+	if !strings.Contains(params[0], "test") {
+		t.Fatalf(
+			"expected version to contain 'test', got %q",
+			params[0],
+		)
+	}
+}
+
+// --- ADMIN ---
+
+func TestAdmin(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("grace")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "ADMIN",
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 256 RPL_ADMINME.
+	if !findNumeric(msgs, "256") {
+		t.Fatalf(
+			"expected RPL_ADMINME (256), got %v",
+			msgs,
+		)
+	}
+
+	// Expect 257 RPL_ADMINLOC1.
+	if !findNumeric(msgs, "257") {
+		t.Fatalf(
+			"expected RPL_ADMINLOC1 (257), got %v",
+			msgs,
+		)
+	}
+
+	// Expect 258 RPL_ADMINLOC2.
+	if !findNumeric(msgs, "258") {
+		t.Fatalf(
+			"expected RPL_ADMINLOC2 (258), got %v",
+			msgs,
+		)
+	}
+
+	// Expect 259 RPL_ADMINEMAIL.
+	if !findNumeric(msgs, "259") {
+		t.Fatalf(
+			"expected RPL_ADMINEMAIL (259), got %v",
+			msgs,
+		)
+	}
+}
+
+// --- INFO ---
+
+func TestInfo(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("hank")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "INFO",
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 371 RPL_INFO (at least one).
+	if !findNumeric(msgs, "371") {
+		t.Fatalf(
+			"expected RPL_INFO (371), got %v",
+			msgs,
+		)
+	}
+
+	// Expect 374 RPL_ENDOFINFO.
+	if !findNumeric(msgs, "374") {
+		t.Fatalf(
+			"expected RPL_ENDOFINFO (374), got %v",
+			msgs,
+		)
+	}
+}
+
+// --- TIME ---
+
+func TestTime(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("iris")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "TIME",
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 391 RPL_TIME.
+	msg := findNumericWithParams(msgs, "391")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_TIME (391), got %v",
+			msgs,
+		)
+	}
+}
+
+// --- KILL ---
+
+func TestKillSuccess(t *testing.T) {
+	tserver := newTestServerWithOper(t)
+
+	// Create the victim first.
+	victimToken := tserver.createSession("victim")
+	_ = victimToken
+
+	// Create oper user.
+	operToken := tserver.createSession("killer")
+	_, lastID := tserver.pollMessages(operToken, 0)
+
+	// Authenticate as oper.
+	tserver.sendCommand(operToken, map[string]any{
+		commandKey: "OPER",
+		bodyKey:    []string{testOperName, testOperPassword},
+	})
+
+	_, lastID = tserver.pollMessages(operToken, lastID)
+
+	// Kill the victim.
+	status, result := tserver.sendCommand(
+		operToken, map[string]any{
+			commandKey: "KILL",
+			bodyKey:    []string{"victim", "go away"},
+		},
+	)
+
+	if status != 200 {
+		t.Fatalf("expected 200, got %d: %v", status, result)
+	}
+
+	resultStatus, _ := result[statusKey].(string)
+	if resultStatus != "ok" {
+		t.Fatalf(
+			"expected status ok, got %v",
+			result,
+		)
+	}
+
+	// Verify the victim's session is gone by trying
+	// to WHOIS them.
+	tserver.sendCommand(operToken, map[string]any{
+		commandKey: "WHOIS",
+		toKey:      "victim",
+	})
+
+	msgs, _ := tserver.pollMessages(operToken, lastID)
+
+	// Should get 401 ERR_NOSUCHNICK.
+	if !findNumeric(msgs, "401") {
+		t.Fatalf(
+			"expected victim to be gone (401), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestKillNotOper(t *testing.T) {
+	tserver := newTestServer(t)
+
+	_ = tserver.createSession("target")
+
+	token := tserver.createSession("notoper")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "KILL",
+		bodyKey:    []string{"target", "no reason"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 481 ERR_NOPRIVILEGES.
+	if !findNumeric(msgs, "481") {
+		t.Fatalf(
+			"expected ERR_NOPRIVILEGES (481), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestKillNoParams(t *testing.T) {
+	tserver := newTestServerWithOper(t)
+
+	token := tserver.createSession("opertest")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "OPER",
+		bodyKey:    []string{testOperName, testOperPassword},
+	})
+
+	_, lastID = tserver.pollMessages(token, lastID)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "KILL",
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 461 ERR_NEEDMOREPARAMS.
+	if !findNumeric(msgs, "461") {
+		t.Fatalf(
+			"expected ERR_NEEDMOREPARAMS (461), got %v",
+			msgs,
+		)
+	}
+}
+
+// sendOperKillCommand is a helper that creates an oper
+// session, authenticates, then sends KILL with the given
+// target nick, and returns the resulting messages.
+func sendOperKillCommand(
+	t *testing.T,
+	tserver *testServer,
+	operNick, targetNick string,
+) []map[string]any {
+	t.Helper()
+
+	token := tserver.createSession(operNick)
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "OPER",
+		bodyKey:    []string{testOperName, testOperPassword},
+	})
+
+	_, lastID = tserver.pollMessages(token, lastID)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "KILL",
+		bodyKey:    []string{targetNick},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	return msgs
+}
+
+func TestKillNonexistentUser(t *testing.T) {
+	tserver := newTestServerWithOper(t)
+
+	msgs := sendOperKillCommand(
+		t, tserver, "opertest2", "ghost",
+	)
+
+	// Expect 401 ERR_NOSUCHNICK.
+	if !findNumeric(msgs, "401") {
+		t.Fatalf(
+			"expected ERR_NOSUCHNICK (401), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestKillSelf(t *testing.T) {
+	tserver := newTestServerWithOper(t)
+
+	msgs := sendOperKillCommand(
+		t, tserver, "selfkiller", "selfkiller",
+	)
+
+	// Expect 483 ERR_CANTKILLSERVER.
+	if !findNumeric(msgs, "483") {
+		t.Fatalf(
+			"expected ERR_CANTKILLSERVER (483), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestKillBroadcastsQuit(t *testing.T) {
+	tserver := newTestServerWithOper(t)
+
+	// Create victim and join a channel.
+	victimToken := tserver.createSession("vuser")
+
+	tserver.sendCommand(victimToken, map[string]any{
+		commandKey: joinCmd,
+		toKey:      "#killtest",
+	})
+
+	// Create observer and join same channel.
+	observerToken := tserver.createSession("observer")
+
+	tserver.sendCommand(observerToken, map[string]any{
+		commandKey: joinCmd,
+		toKey:      "#killtest",
+	})
+
+	_, lastObs := tserver.pollMessages(observerToken, 0)
+
+	// Create oper.
+	operToken := tserver.createSession("theoper2")
+
+	tserver.pollMessages(operToken, 0)
+
+	tserver.sendCommand(operToken, map[string]any{
+		commandKey: "OPER",
+		bodyKey:    []string{testOperName, testOperPassword},
+	})
+
+	tserver.pollMessages(operToken, 0)
+
+	// Kill the victim.
+	tserver.sendCommand(operToken, map[string]any{
+		commandKey: "KILL",
+		bodyKey:    []string{"vuser", "testing kill"},
+	})
+
+	// Observer should see a QUIT message.
+	msgs, _ := tserver.pollMessages(observerToken, lastObs)
+
+	foundQuit := false
+
+	for _, msg := range msgs {
+		cmd, _ := msg["command"].(string)
+		if cmd == "QUIT" {
+			from, _ := msg["from"].(string)
+			if from == "vuser" {
+				foundQuit = true
+
+				break
+			}
+		}
+	}
+
+	if !foundQuit {
+		t.Fatalf(
+			"expected QUIT from vuser, got %v",
+			msgs,
+		)
+	}
+}
+
+// --- WALLOPS ---
+
+func TestWallopsSuccess(t *testing.T) {
+	tserver := newTestServerWithOper(t)
+
+	// Create receiver with +w.
+	receiverToken := tserver.createSession("receiver")
+
+	tserver.sendCommand(receiverToken, map[string]any{
+		commandKey: "MODE",
+		toKey:      "receiver",
+		bodyKey:    []string{"+w"},
+	})
+
+	_, lastRecv := tserver.pollMessages(receiverToken, 0)
+
+	// Create oper.
+	operToken := tserver.createSession("walloper")
+
+	tserver.pollMessages(operToken, 0)
+
+	tserver.sendCommand(operToken, map[string]any{
+		commandKey: "OPER",
+		bodyKey:    []string{testOperName, testOperPassword},
+	})
+
+	tserver.pollMessages(operToken, 0)
+
+	// Also set +w on oper so they receive it too.
+	tserver.sendCommand(operToken, map[string]any{
+		commandKey: "MODE",
+		toKey:      "walloper",
+		bodyKey:    []string{"+w"},
+	})
+
+	tserver.pollMessages(operToken, 0)
+
+	// Send WALLOPS.
+	tserver.sendCommand(operToken, map[string]any{
+		commandKey: "WALLOPS",
+		bodyKey:    []string{"server going down"},
+	})
+
+	// Receiver should get the WALLOPS message.
+	msgs, _ := tserver.pollMessages(receiverToken, lastRecv)
+
+	foundWallops := false
+
+	for _, msg := range msgs {
+		cmd, _ := msg["command"].(string)
+		if cmd == "WALLOPS" {
+			foundWallops = true
+
+			break
+		}
+	}
+
+	if !foundWallops {
+		t.Fatalf(
+			"expected WALLOPS message, got %v",
+			msgs,
+		)
+	}
+}
+
+func TestWallopsNotOper(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("notoper2")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "WALLOPS",
+		bodyKey:    []string{"hello"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 481 ERR_NOPRIVILEGES.
+	if !findNumeric(msgs, "481") {
+		t.Fatalf(
+			"expected ERR_NOPRIVILEGES (481), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestWallopsNoParams(t *testing.T) {
+	tserver := newTestServerWithOper(t)
+
+	token := tserver.createSession("operempty")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "OPER",
+		bodyKey:    []string{testOperName, testOperPassword},
+	})
+
+	_, lastID = tserver.pollMessages(token, lastID)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "WALLOPS",
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 461 ERR_NEEDMOREPARAMS.
+	if !findNumeric(msgs, "461") {
+		t.Fatalf(
+			"expected ERR_NEEDMOREPARAMS (461), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestWallopsNotReceivedWithoutW(t *testing.T) {
+	tserver := newTestServerWithOper(t)
+
+	// Create receiver WITHOUT +w.
+	receiverToken := tserver.createSession("nowallops")
+	_, lastRecv := tserver.pollMessages(receiverToken, 0)
+
+	// Create oper.
+	operToken := tserver.createSession("walloper2")
+
+	tserver.pollMessages(operToken, 0)
+
+	tserver.sendCommand(operToken, map[string]any{
+		commandKey: "OPER",
+		bodyKey:    []string{testOperName, testOperPassword},
+	})
+
+	tserver.pollMessages(operToken, 0)
+
+	// Send WALLOPS.
+	tserver.sendCommand(operToken, map[string]any{
+		commandKey: "WALLOPS",
+		bodyKey:    []string{"secret message"},
+	})
+
+	// Receiver should NOT get the WALLOPS message.
+	msgs, _ := tserver.pollMessages(receiverToken, lastRecv)
+
+	for _, msg := range msgs {
+		cmd, _ := msg["command"].(string)
+		if cmd == "WALLOPS" {
+			t.Fatalf(
+				"did not expect WALLOPS for user "+
+					"without +w, got %v",
+				msgs,
+			)
+		}
+	}
+}
+
+// --- User Mode +w ---
+
+func TestUserModeSetW(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("wmoder")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	// Set +w.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "MODE",
+		toKey:      "wmoder",
+		bodyKey:    []string{"+w"},
+	})
+
+	msgs, lastID := tserver.pollMessages(token, lastID)
+
+	// Expect 221 RPL_UMODEIS with "+w".
+	msg := findNumericWithParams(msgs, "221")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_UMODEIS (221), got %v",
+			msgs,
+		)
+	}
+
+	body := getNumericBody(msg)
+	if !strings.Contains(body, "w") {
+		t.Fatalf(
+			"expected mode string to contain 'w', got %q",
+			body,
+		)
+	}
+
+	// Now query mode.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "MODE",
+		toKey:      "wmoder",
+	})
+
+	msgs, _ = tserver.pollMessages(token, lastID)
+
+	msg = findNumericWithParams(msgs, "221")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_UMODEIS (221) on query, got %v",
+			msgs,
+		)
+	}
+
+	body = getNumericBody(msg)
+	if !strings.Contains(body, "w") {
+		t.Fatalf(
+			"expected mode '+w' in query, got %q",
+			body,
+		)
+	}
+}
+
+func TestUserModeUnsetW(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("wunsetter")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	// Set +w first.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "MODE",
+		toKey:      "wunsetter",
+		bodyKey:    []string{"+w"},
+	})
+
+	_, lastID = tserver.pollMessages(token, lastID)
+
+	// Unset -w.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "MODE",
+		toKey:      "wunsetter",
+		bodyKey:    []string{"-w"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	msg := findNumericWithParams(msgs, "221")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_UMODEIS (221), got %v",
+			msgs,
+		)
+	}
+
+	body := getNumericBody(msg)
+	if strings.Contains(body, "w") {
+		t.Fatalf(
+			"expected 'w' to be removed, got %q",
+			body,
+		)
+	}
+}
+
+func TestUserModeUnknownFlag(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("badmode")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "MODE",
+		toKey:      "badmode",
+		bodyKey:    []string{"+z"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 501 ERR_UMODEUNKNOWNFLAG.
+	if !findNumeric(msgs, "501") {
+		t.Fatalf(
+			"expected ERR_UMODEUNKNOWNFLAG (501), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestUserModeCannotSetO(t *testing.T) {
+	tserver := newTestServer(t)
+
+	token := tserver.createSession("tryoper")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	// Try to set +o via MODE (should fail).
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "MODE",
+		toKey:      "tryoper",
+		bodyKey:    []string{"+o"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 501 ERR_UMODEUNKNOWNFLAG.
+	if !findNumeric(msgs, "501") {
+		t.Fatalf(
+			"expected ERR_UMODEUNKNOWNFLAG (501), got %v",
+			msgs,
+		)
+	}
+}
+
+func TestUserModeDeoper(t *testing.T) {
+	tserver := newTestServerWithOper(t)
+
+	token := tserver.createSession("deoper")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	// Authenticate as oper.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "OPER",
+		bodyKey:    []string{testOperName, testOperPassword},
+	})
+
+	_, lastID = tserver.pollMessages(token, lastID)
+
+	// Use MODE -o to de-oper.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "MODE",
+		toKey:      "deoper",
+		bodyKey:    []string{"-o"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	msg := findNumericWithParams(msgs, "221")
+	if msg == nil {
+		t.Fatalf(
+			"expected RPL_UMODEIS (221), got %v",
+			msgs,
+		)
+	}
+
+	body := getNumericBody(msg)
+	if strings.Contains(body, "o") {
+		t.Fatalf(
+			"expected 'o' to be removed, got %q",
+			body,
+		)
+	}
+}
+
+func TestUserModeCannotChangeOtherUser(t *testing.T) {
+	tserver := newTestServer(t)
+
+	_ = tserver.createSession("other")
+
+	token := tserver.createSession("changer")
+	_, lastID := tserver.pollMessages(token, 0)
+
+	// Try to change another user's mode.
+	tserver.sendCommand(token, map[string]any{
+		commandKey: "MODE",
+		toKey:      "other",
+		bodyKey:    []string{"+w"},
+	})
+
+	msgs, _ := tserver.pollMessages(token, lastID)
+
+	// Expect 502 ERR_USERSDONTMATCH.
+	if !findNumeric(msgs, "502") {
+		t.Fatalf(
+			"expected ERR_USERSDONTMATCH (502), got %v",
+			msgs,
+		)
+	}
+}
+
+// getNumericBody extracts the body text from a numeric
+// message. The body is stored as a JSON array; this
+// returns the first element.
+func getNumericBody(msg map[string]any) string {
+	raw, exists := msg["body"]
+	if !exists || raw == nil {
+		return ""
+	}
+
+	arr, isArr := raw.([]any)
+	if !isArr || len(arr) == 0 {
+		return ""
+	}
+
+	str, isStr := arr[0].(string)
+	if !isStr {
+		return ""
+	}
+
+	return str
+}

pkg/irc/commands.go

@@ -2,10 +2,13 @@ package irc
 
 // IRC command names (RFC 1459 / RFC 2812).
 const (
+	CmdAdmin    = "ADMIN"
 	CmdAway     = "AWAY"
+	CmdInfo     = "INFO"
 	CmdInvite   = "INVITE"
 	CmdJoin     = "JOIN"
 	CmdKick     = "KICK"
+	CmdKill     = "KILL"
 	CmdList     = "LIST"
 	CmdLusers   = "LUSERS"
 	CmdMode     = "MODE"
@@ -20,7 +23,11 @@ const (
 	CmdPong     = "PONG"
 	CmdPrivmsg  = "PRIVMSG"
 	CmdQuit     = "QUIT"
+	CmdTime     = "TIME"
 	CmdTopic    = "TOPIC"
+	CmdUserhost = "USERHOST"
+	CmdVersion  = "VERSION"
+	CmdWallops  = "WALLOPS"
 	CmdWho      = "WHO"
 	CmdWhois    = "WHOIS"
 )