server: Add proposed RENAME command

irc/capability.go

@@ -14,8 +14,8 @@ import (
 type Capability string
 
 const (
-	AccountTag      Capability = "account-tag"
 	AccountNotify   Capability = "account-notify"
+	AccountTag      Capability = "account-tag"
 	AwayNotify      Capability = "away-notify"
 	CapNotify       Capability = "cap-notify"
 	ChgHost         Capability = "chghost"
@@ -26,6 +26,7 @@ const (
 	MessageIDs      Capability = "draft/message-ids"
 	MessageTags     Capability = "draft/message-tags-0.2"
 	MultiPrefix     Capability = "multi-prefix"
+	Rename          Capability = "draft/rename"
 	SASL            Capability = "sasl"
 	ServerTime      Capability = "server-time"
 	STS             Capability = "draft/sts"
@@ -47,6 +48,7 @@ var (
 		// MaxLine is set during server startup
 		MessageTags: true,
 		MultiPrefix: true,
+		Rename:      true,
 		// SASL is set during server startup
 		ServerTime: true,
 		// STS is set during server startup

irc/channelreg.go

@@ -53,6 +53,12 @@ type RegisteredChannel struct {
 	Invitelist []string
 }
 
+// deleteChannelNoMutex deletes a given channel from our store.
+func (server *Server) deleteChannelNoMutex(tx *buntdb.Tx, channelKey string) {
+	tx.Delete(fmt.Sprintf(keyChannelExists, channelKey))
+	server.registeredChannels[channelKey] = nil
+}
+
 // loadChannelNoMutex loads a channel from the store.
 func (server *Server) loadChannelNoMutex(tx *buntdb.Tx, channelKey string) *RegisteredChannel {
 	// return loaded chan if it already exists

irc/commands.go

@@ -209,6 +209,10 @@ var Commands = map[string]Command{
 		handler:   privmsgHandler,
 		minParams: 2,
 	},
+	"RENAME": {
+		handler:   renameHandler,
+		minParams: 2,
+	},
 	"SANICK": {
 		handler:   sanickHandler,
 		minParams: 2,

irc/help.go

@@ -354,6 +354,14 @@ Replies to a PING. Used to check link connectivity.`,
 		text: `PRIVMSG <target>{,<target>} <text to be sent>
 
 Sends the text to the given targets as a PRIVMSG.`,
+	},
+	"rename": {
+		text: `RENAME <channel> <newname> [<reason>]
+
+Renames the given channel with the given reason, if possible.
+
+For example:
+	RENAME #ircv2 #ircv3 :Protocol upgrades!`,
 	},
 	"sanick": {
 		oper: true,

irc/server.go

@@ -789,6 +789,115 @@ func pongHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool {
 	return false
 }
 
+// RENAME <oldchan> <newchan> [<reason>]
+//TODO(dan): Clean up this function so it doesn't look like an eldrich horror... prolly by putting it into a server.renameChannel function.
+func renameHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool {
+	// get lots of locks... make sure nobody touches anything while we're doing this
+	server.registeredChannelsMutex.Lock()
+	defer server.registeredChannelsMutex.Unlock()
+	server.channels.ChansLock.Lock()
+	defer server.channels.ChansLock.Unlock()
+
+	oldName := strings.TrimSpace(msg.Params[0])
+	newName := strings.TrimSpace(msg.Params[1])
+	reason := "No reason"
+	if 2 < len(msg.Params) {
+		reason = msg.Params[2]
+	}
+
+	// check for all the reasons why the rename couldn't happen
+	casefoldedOldName, err := CasefoldChannel(oldName)
+	if err != nil {
+		//TODO(dan): Change this to ERR_CANNOTRENAME
+		client.Send(nil, server.name, ERR_UNKNOWNERROR, client.nick, "RENAME", oldName, "Old channel name is invalid")
+		return false
+	}
+
+	channel := server.channels.Chans[casefoldedOldName]
+	if channel == nil {
+		client.Send(nil, server.name, ERR_NOSUCHCHANNEL, client.nick, oldName, "No such channel")
+		return false
+	}
+
+	channel.membersMutex.Lock()
+	defer channel.membersMutex.Unlock()
+
+	casefoldedNewName, err := CasefoldChannel(newName)
+	if err != nil {
+		//TODO(dan): Change this to ERR_CANNOTRENAME
+		client.Send(nil, server.name, ERR_UNKNOWNERROR, client.nick, "RENAME", newName, "New channel name is invalid")
+		return false
+	}
+
+	newChannel := server.channels.Chans[casefoldedNewName]
+	if newChannel != nil {
+		//TODO(dan): Change this to ERR_CHANNAMEINUSE
+		client.Send(nil, server.name, ERR_UNKNOWNERROR, client.nick, "RENAME", newName, "New channel name is in use")
+		return false
+	}
+
+	var canEdit bool
+	server.store.Update(func(tx *buntdb.Tx) error {
+		chanReg := server.loadChannelNoMutex(tx, casefoldedOldName)
+		if chanReg == nil || client.account == nil || client.account.Name == chanReg.Founder {
+			canEdit = true
+		}
+
+		chanReg = server.loadChannelNoMutex(tx, casefoldedNewName)
+		if chanReg != nil {
+			canEdit = false
+		}
+		return nil
+	})
+	if !canEdit {
+		//TODO(dan): Change this to ERR_CANNOTRENAME
+		client.Send(nil, server.name, ERR_UNKNOWNERROR, client.nick, "RENAME", oldName, "Only channel founders can change registered channels")
+		return false
+	}
+
+	// perform the channel rename
+	server.channels.Chans[casefoldedOldName] = nil
+	server.channels.Chans[casefoldedNewName] = channel
+
+	channel.name = strings.TrimSpace(msg.Params[1])
+	channel.nameCasefolded = casefoldedNewName
+
+	// rename stored channel info if any exists
+	server.store.Update(func(tx *buntdb.Tx) error {
+		chanReg := server.loadChannelNoMutex(tx, casefoldedOldName)
+		if chanReg == nil {
+			return nil
+		}
+
+		server.deleteChannelNoMutex(tx, casefoldedOldName)
+
+		chanReg.Name = newName
+
+		server.saveChannelNoMutex(tx, casefoldedNewName, *chanReg)
+		return nil
+	})
+
+	// send RENAME messages
+	for mcl := range channel.members {
+		if mcl.capabilities[Rename] {
+			mcl.Send(nil, client.nickMaskString, "RENAME", oldName, newName, reason)
+		} else {
+			mcl.Send(nil, mcl.nickMaskString, "PART", oldName, fmt.Sprintf("Channel renamed: %s", reason))
+			if mcl.capabilities[ExtendedJoin] {
+				accountName := "*"
+				if mcl.account != nil {
+					accountName = mcl.account.Name
+				}
+				mcl.Send(nil, mcl.nickMaskString, "JOIN", newName, accountName, mcl.realname)
+			} else {
+				mcl.Send(nil, mcl.nickMaskString, "JOIN", newName)
+			}
+		}
+	}
+
+	return false
+}
+
 // JOIN <channel>{,<channel>} [<key>{,<key>}]
 // JOIN 0
 func joinHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool {