From e7734f572b36372828dbb5204a12070148a072a8 Mon Sep 17 00:00:00 2001
From: Jeremy Latt <jeremy.latt@gmail.com>
Date: Tue, 17 Apr 2012 21:13:12 -0700
Subject: [PATCH] Implement nick changing.

---
 src/irc/client.go    | 18 ++++++++++++++++++
 src/irc/commands.go  | 11 ++++++++---
 src/irc/constants.go |  3 ++-
 src/irc/responses.go |  8 ++++++--
 4 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/src/irc/client.go b/src/irc/client.go
index 52221a3d..d7246b03 100644
--- a/src/irc/client.go
+++ b/src/irc/client.go
@@ -2,6 +2,7 @@ package irc
 
 import (
 	"net"
+	"strings"
 )
 
 type Client struct {
@@ -46,3 +47,20 @@ func (c *Client) UModeString() string {
 	}
 	return ""
 }
+
+func (c *Client) HasNick() bool {
+	return c.nick != ""
+}
+
+func (c *Client) HasUser() bool {
+	return c.username != ""
+}
+
+func (c *Client) Hostname() string {
+	addr := c.conn.RemoteAddr().String()
+	index := strings.LastIndex(addr, ":")
+	if index != -1 {
+		return addr[0:index]
+	}
+	return addr
+}
diff --git a/src/irc/commands.go b/src/irc/commands.go
index 6afd061b..57d72e2a 100644
--- a/src/irc/commands.go
+++ b/src/irc/commands.go
@@ -9,12 +9,17 @@ func (m *NickMessage) Handle(s *Server, c *Client) {
 		c.send <- ErrNickNameInUse(m.nickname)
 		return
 	}
+	oldNick := c.nick
 	if c.nick != "" {
 		delete(s.nicks, c.nick)
 	}
 	c.nick = m.nickname
 	s.nicks[c.nick] = c
-	tryRegister(s, c)
+	if c.registered {
+		c.send <- ReplyNick(oldNick, c)
+	} else {
+		tryRegister(s, c)
+	}
 }
 
 func (m *UserMessage) Handle(s *Server, c *Client) {
@@ -56,9 +61,9 @@ func (m *ModeMessage) Handle(s *Server, c *Client) {
 }
 
 func tryRegister(s *Server, c *Client) {
-	if (!c.registered && c.nick != "" && c.username != "") {
+	if (!c.registered && c.HasNick() && c.HasUser()) {
 		c.registered = true
-		c.send <- ReplyWelcome(c.Nick(), c.username, "localhost")
+		c.send <- ReplyWelcome(c)
 		c.send <- ReplyYourHost(c.Nick(), "irc.jlatt.com")
 		c.send <- ReplyCreated(c.Nick(), "2012/04/07")
 		c.send <- ReplyMyInfo(c.Nick(), "irc.jlatt.com")
diff --git a/src/irc/constants.go b/src/irc/constants.go
index b7796e66..dc9ce40f 100644
--- a/src/irc/constants.go
+++ b/src/irc/constants.go
@@ -11,7 +11,8 @@ const (
 	RPL_CREATED  = "003"
 	RPL_MYINFO   = "004"
 	RPL_UMODEIS  = "221"
-	RPL_NONE     = "300"
+	RPL_INFO     = "371"
+	RPL_NICK     = "NICK"
 )
 
 const (
diff --git a/src/irc/responses.go b/src/irc/responses.go
index b444c213..4ab4681d 100644
--- a/src/irc/responses.go
+++ b/src/irc/responses.go
@@ -4,8 +4,12 @@ import (
 	"fmt"
 )
 
-func ReplyWelcome(nick string, user string, host string) string {
-	return fmt.Sprintf("%s %s Welcome to the Internet Relay Network %s!%s@%s", RPL_WELCOME, nick, nick, user, host)
+func ReplyNick(oldNick string, c *Client) string {
+	return fmt.Sprintf(":%s!%s@%s %s :%s", oldNick, c.username, c.Hostname(), RPL_NICK, c.Nick())
+}
+
+func ReplyWelcome(c *Client) string {
+	return fmt.Sprintf("%s %s Welcome to the Internet Relay Network %s!%s@%s", RPL_WELCOME, c.Nick(), c.Nick(), c.username, c.Hostname())
 }
 
 func ReplyYourHost(nick string, server string) string {