Initial commit - Pingerino network monitoring application

Utilities/ValidationHelper.cs

@@ -0,0 +1,90 @@
+using System;
+using System.Net;
+using System.Text.RegularExpressions;
+
+namespace Pingerino.Utilities
+{
+    public static class ValidationHelper
+    {
+        private static readonly Regex IpAddressRegex = new Regex(
+            @"^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$",
+            RegexOptions.Compiled);
+
+        private static readonly Regex HostnameRegex = new Regex(
+            @"^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)*[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?$",
+            RegexOptions.Compiled);
+
+        public static bool IsValidIpAddress(string ipAddress)
+        {
+            if (string.IsNullOrWhiteSpace(ipAddress))
+                return false;
+
+            return IPAddress.TryParse(ipAddress, out _) || IpAddressRegex.IsMatch(ipAddress);
+        }
+
+        public static bool IsValidHostname(string hostname)
+        {
+            if (string.IsNullOrWhiteSpace(hostname))
+                return false;
+
+            if (hostname.Length > 253)
+                return false;
+
+            return HostnameRegex.IsMatch(hostname);
+        }
+
+        public static bool IsValidIpAddressOrHostname(string address)
+        {
+            return IsValidIpAddress(address) || IsValidHostname(address);
+        }
+
+        public static bool IsValidPingInterval(string intervalText, out int interval)
+        {
+            interval = 0;
+            
+            if (string.IsNullOrWhiteSpace(intervalText))
+                return false;
+
+            if (!int.TryParse(intervalText, out interval))
+                return false;
+
+            return interval >= 100 && interval <= 60000; // 100ms to 60 seconds
+        }
+
+        public static bool IsValidPingInterval(int interval)
+        {
+            return interval >= 100 && interval <= 60000;
+        }
+
+        public static string SanitizeInput(string input)
+        {
+            if (string.IsNullOrEmpty(input))
+                return string.Empty;
+
+            return input.Trim();
+        }
+
+        public static string GetValidationErrorMessage(string fieldName, string value)
+        {
+            if (string.IsNullOrWhiteSpace(value))
+                return $"{fieldName} cannot be empty.";
+
+            switch (fieldName.ToLower())
+            {
+                case "ip address":
+                case "ipaddress":
+                    if (!IsValidIpAddressOrHostname(value))
+                        return "Please enter a valid IP address or hostname.";
+                    break;
+
+                case "interval":
+                case "ping interval":
+                    if (!IsValidPingInterval(value, out _))
+                        return "Ping interval must be between 100 and 60000 milliseconds.";
+                    break;
+            }
+
+            return null;
+        }
+    }
+}