add support for ircv3's userhost-in-names

cap.go

@@ -12,14 +12,15 @@ import (
 )
 
 var possibleCap = map[string][]string{
-	"account-notify": nil,
-	"account-tag":    nil,
-	"away-notify":    nil,
-	"batch":          nil,
-	"cap-notify":     nil,
-	"chghost":        nil,
-	"extended-join":  nil,
-	"message-tags":   nil,
+	"account-notify":    nil,
+	"account-tag":       nil,
+	"away-notify":       nil,
+	"batch":             nil,
+	"cap-notify":        nil,
+	"chghost":           nil,
+	"extended-join":     nil,
+	"message-tags":      nil,
+	"userhost-in-names": nil,
 }
 
 func (c *Client) listCAP() error {

handlers.go

@@ -338,18 +338,45 @@ func handleNAMES(c *Client, e Event) {
 
 	parts := strings.Split(e.Trailing, " ")
 
+	var host, ident, modes, nick string
+	var ok bool
+
 	c.state.mu.Lock()
 	for i := 0; i < len(parts); i++ {
-		modes, nick, ok := parseUserPrefix(parts[i])
+		modes, nick, ok = parseUserPrefix(parts[i])
 		if !ok {
 			continue
 		}
 
+		// If userhost-in-names.
+		if strings.Contains(nick, "@") {
+			s := ParseSource(nick)
+			if s == nil {
+				continue
+			}
+
+			host = s.Host
+			nick = s.Name
+			ident = s.Ident
+		}
+
+		if !IsValidNick(nick) {
+			continue
+		}
+
 		user := c.state.createUserIfNotExists(e.Params[len(e.Params)-1], nick)
 		if user == nil {
 			continue
 		}
 
+		// Add necessary userhost-in-names data into the user.
+		if host != "" {
+			user.Host = host
+		}
+		if ident != "" {
+			user.Ident = ident
+		}
+
 		// Don't append modes, overwrite them.
 		user.Perms.set(modes, false)
 	}

modes.go

@@ -452,13 +452,7 @@ func parseUserPrefix(raw string) (modes, nick string, success bool) {
 		}
 
 		// Assume we've gotten to the nickname part.
-		if !IsValidNick(raw[i:]) {
-			return modes, nick, false
-		}
-
-		nick = raw[i:]
-
-		return modes, nick, true
+		return modes, raw[i:], true
 	}
 
 	return