feat: validate host, port and nickname fields

ui/login/login.go

@@ -61,15 +61,18 @@ func NewLogin() State {
 			t.Focus()
 			t.CharLimit = 40
 			t.TextStyle = FocusedStyle
+			t.Validate = NoSpacesValidation
 		case 1:
 			t.Placeholder = "Port"
 			t.CharLimit = 5
+			t.Validate = ValidatePort
 		case 2:
 			t.Placeholder = "Channel"
 			t.CharLimit = 32
 		case 3:
 			t.Placeholder = "Nickname"
 			t.CharLimit = 32
+			t.Validate = NoSpacesValidation
 		case 4:
 			t.Placeholder = "Password"
 			t.CharLimit = 64

ui/login/validators.go

@@ -0,0 +1,44 @@
+// gorc project
+// Copyright (C) 2023 IllusionMan1212
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, see https://www.gnu.org/licenses.
+
+package login
+
+import (
+	"errors"
+	"strconv"
+	"strings"
+)
+
+func NoSpacesValidation(input string) error {
+	if strings.Contains(input, " ") {
+		return errors.New("Field cannot contain spaces")
+	}
+
+	return nil
+}
+
+func ValidatePort(input string) error {
+	pNum, err := strconv.ParseUint(input, 10, 16)
+	if err != nil {
+		return err
+	}
+
+	if pNum < 1 || pNum > 65535 {
+		return errors.New("Invalid port number")
+	}
+
+	return nil
+}