Add the tier 3 utility IRC commands (closes #87)

USERHOST, VERSION, ADMIN, INFO, TIME, KILL and WALLOPS work on the
HTTP API and on the IRC listener. The USERHOST reply, the VERSION and
INFO text, KILL and WALLOPS are each one service function that both
transports call. User mode +w selects who receives WALLOPS. MODE on
your own nick queries or changes your user modes through one parser
on both transports: the whole mode string is checked before anything
is stored, and both flags are stored in one transaction. KILL closes
the victim's IRC connection after sending it KILL and ERROR. The
sessions table gains is_wallops in 001_initial.sql, as the pre-1.0
rule in REPO_POLICIES.md asks.

Model: opus-5-5

internal/ircserver/commands.go

@@ -13,7 +13,7 @@ import (
 )
 
 // sendIRCError maps a service.IRCError to an IRC numeric
-// reply on the wire.
+// reply on the wire, and logs any other error.
 func (c *Conn) sendIRCError(err error) {
 	var ircErr *service.IRCError
 	if errors.As(err, &ircErr) {
@@ -21,7 +21,11 @@ func (c *Conn) sendIRCError(err error) {
 		args = append(args, ircErr.Params...)
 		args = append(args, ircErr.Message)
 		c.sendNumeric(ircErr.Code, args...)
+
+		return
 	}
+
+	c.log.Error("command failed", "error", err)
 }
 
 // handleCAP silently acknowledges CAP negotiation.
@@ -345,7 +349,10 @@ func (c *Conn) handleQuit(msg *Message) {
 
 	c.send("ERROR :Closing Link: " + c.hostname +
 		" (Quit: " + reason + ")")
+
+	c.mu.Lock()
 	c.closed = true
+	c.mu.Unlock()
 }
 
 // handleTopic gets or sets a channel topic via the shared
@@ -427,7 +434,7 @@ func (c *Conn) handleMode(
 	if strings.HasPrefix(target, "#") {
 		c.handleChannelMode(ctx, msg)
 	} else {
-		c.handleUserMode(msg)
+		c.handleUserMode(ctx, msg)
 	}
 }
 
@@ -686,11 +693,14 @@ func (c *Conn) applyChannelModes(
 	}
 }
 
-// handleUserMode handles MODE for users.
-func (c *Conn) handleUserMode(msg *Message) {
-	target := msg.Params[0]
-
-	if !strings.EqualFold(target, c.nick) {
+// handleUserMode handles MODE for a nick: a query without a
+// mode string, otherwise a change. Only the client's own
+// nick, in any letter case, is allowed.
+func (c *Conn) handleUserMode(
+	ctx context.Context,
+	msg *Message,
+) {
+	if !strings.EqualFold(msg.Params[0], c.currentNick()) {
 		c.sendNumeric(
 			irc.ErrUsersDoNotMatch,
 			"Can't change mode for other users",
@@ -699,8 +709,26 @@ func (c *Conn) handleUserMode(msg *Message) {
 		return
 	}
 
-	// We don't support user modes beyond the basics.
-	c.sendNumeric(irc.RplUmodeIs, "+")
+	var (
+		modes string
+		err   error
+	)
+
+	if len(msg.Params) == 1 {
+		modes, err = c.svc.QueryUserMode(ctx, c.sessionID)
+	} else {
+		modes, err = c.svc.ApplyUserMode(
+			ctx, c.sessionID, msg.Params[1],
+		)
+	}
+
+	if err != nil {
+		c.sendIRCError(err)
+
+		return
+	}
+
+	c.sendNumeric(irc.RplUmodeIs, modes)
 }
 
 // handleNames replies with channel member list.
@@ -1248,47 +1276,114 @@ func (c *Conn) handleInvite(
 	)
 }
 
-// handleUserhost replies with USERHOST info.
+// handleUserhost replies with user@host for each of up to
+// five nicks.
 func (c *Conn) handleUserhost(
 	ctx context.Context,
 	msg *Message,
 ) {
 	if len(msg.Params) < 1 {
+		c.sendNumeric(
+			irc.ErrNeedMoreParams,
+			irc.CmdUserhost, "Not enough parameters",
+		)
+
 		return
 	}
 
-	replies := make([]string, 0, len(msg.Params))
+	reply, err := c.svc.UserhostReply(
+		ctx, msg.Params, c.serverSfx,
+	)
+	if err != nil {
+		c.sendIRCError(err)
 
-	for _, nick := range msg.Params {
-		sid, err := c.database.GetSessionByNick(ctx, nick)
-		if err != nil {
-			continue
-		}
-
-		hostInfo, _ := c.database.GetSessionHostInfo(
-			ctx, sid,
-		)
-
-		host := "*"
-		if hostInfo != nil {
-			host = hostInfo.Hostname
-		}
-
-		isOper, _ := c.database.IsSessionOper(ctx, sid)
-
-		operStar := ""
-		if isOper {
-			operStar = "*"
-		}
-
-		replies = append(
-			replies,
-			nick+operStar+"=+"+nick+"@"+host,
-		)
+		return
 	}
 
+	c.sendNumeric(irc.RplUserHost, reply)
+}
+
+// handleVersion replies with the server version.
+func (c *Conn) handleVersion() {
 	c.sendNumeric(
-		irc.RplUserHost,
-		strings.Join(replies, " "),
+		irc.RplVersion,
+		c.svc.ServerVersion()+".", c.serverSfx, "",
 	)
 }
+
+// handleAdmin replies with the server's admin info.
+func (c *Conn) handleAdmin() {
+	c.sendNumeric(
+		irc.RplAdminMe, c.serverSfx, "Administrative info",
+	)
+	c.sendNumeric(irc.RplAdminLoc1, "neoirc server")
+	c.sendNumeric(irc.RplAdminLoc2, "IRC over HTTP")
+	c.sendNumeric(irc.RplAdminEmail, "admin@"+c.serverSfx)
+}
+
+// handleInfo replies with the server's software info.
+func (c *Conn) handleInfo() {
+	for _, line := range c.svc.InfoLines() {
+		c.sendNumeric(irc.RplInfo, line)
+	}
+
+	c.sendNumeric(irc.RplEndOfInfo, "End of /INFO list")
+}
+
+// handleTime replies with the server's local time.
+func (c *Conn) handleTime() {
+	c.sendNumeric(
+		irc.RplTime,
+		c.serverSfx, time.Now().Format(time.RFC1123),
+	)
+}
+
+// handleKill handles KILL <nick> [<reason>].
+func (c *Conn) handleKill(
+	ctx context.Context,
+	msg *Message,
+) {
+	if len(msg.Params) < 1 {
+		c.sendNumeric(
+			irc.ErrNeedMoreParams,
+			irc.CmdKill, "Not enough parameters",
+		)
+
+		return
+	}
+
+	reason := "KILLed"
+	if len(msg.Params) > 1 {
+		reason = msg.Params[1]
+	}
+
+	err := c.svc.KillUser(
+		ctx, c.sessionID, c.currentNick(),
+		msg.Params[0], reason,
+	)
+	if err != nil {
+		c.sendIRCError(err)
+	}
+}
+
+// handleWallops handles WALLOPS <message>.
+func (c *Conn) handleWallops(
+	ctx context.Context,
+	msg *Message,
+) {
+	if len(msg.Params) < 1 {
+		c.sendNumeric(
+			irc.ErrNeedMoreParams,
+			irc.CmdWallops, "Not enough parameters",
+		)
+
+		return
+	}
+
+	err := c.svc.SendWallops(
+		ctx, c.sessionID, c.currentNick(), msg.Params[0],
+	)
+	if err != nil {
+		c.sendIRCError(err)
+	}
+}