Move OS and system environment checks to a helper class

AGENTS.md

@@ -29,7 +29,7 @@ most important change points.
   entities, and mapping helpers.
 - `OF DL.Core/Widevine/` implements Widevine CDM handling and key derivation.
 - `OF DL.Core/Helpers/`, `OF DL.Core/Utils/`, `OF DL.Core/Crypto/`, `OF DL.Core/Enumerations/` contain shared core
-  logic.
+  logic. `OF DL.Core/Helpers/EnvironmentHelper.cs` centralizes environment checks (Docker and Windows).
 - `docs/` and `mkdocs.yml` define the documentation site.
 - `site/` is generated MkDocs output and should not be edited by hand.
 - `docker/` contains container entrypoint and supervisor configuration.
@@ -239,6 +239,7 @@ cookies/user-agent. Output is written to `{filename}_source.mp4`, then moved and
 - `OF DL.Core/Widevine/` for CDM key generation and license parsing.
 - `OF DL.Core/Models/Config/Config.cs` and `OF DL.Core/Services/ConfigService.cs` for config shape and parsing.
 - `OF DL.Core/Services/AuthService.cs` for user-facing authentication behavior and browser login flow.
+- `OF DL.Core/Helpers/EnvironmentHelper.cs` for shared Docker/Windows runtime checks.
 - `docs/` for public documentation; update docs whenever user-facing behavior or configuration changes.
 
 ## Documentation updates for common changes:

OF DL.Core/Helpers/EnvironmentHelper.cs

@@ -0,0 +1,14 @@
+namespace OF_DL.Helpers;
+
+public static class EnvironmentHelper
+{
+    private const string DockerEnvironmentVariableName = "OFDL_DOCKER";
+
+    public static bool IsRunningInDocker()
+    {
+        string? dockerValue = Environment.GetEnvironmentVariable(DockerEnvironmentVariableName);
+        return string.Equals(dockerValue, "true", StringComparison.OrdinalIgnoreCase);
+    }
+
+    public static bool IsRunningOnWindows() => OperatingSystem.IsWindows();
+}

OF DL.Core/Services/AuthService.cs

@@ -2,6 +2,7 @@ using System.Text.RegularExpressions;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Playwright;
 using Newtonsoft.Json;
+using OF_DL.Helpers;
 using OF_DL.Models;
 using Serilog;
 using UserEntities = OF_DL.Models.Entities.Users;
@@ -79,7 +80,7 @@ public class AuthService(IServiceProvider serviceProvider) : IAuthService
 
         try
         {
-            bool runningInDocker = Environment.GetEnvironmentVariable("OFDL_DOCKER") != null;
+            bool runningInDocker = EnvironmentHelper.IsRunningInDocker();
             await SetupBrowser(runningInDocker);
         }
         catch (Exception ex)

OF DL.Core/Services/DownloadService.cs

@@ -412,14 +412,14 @@ public class DownloadService(
         {
             string firstFullPath = Path.GetFullPath(firstPath);
             string secondFullPath = Path.GetFullPath(secondPath);
-            StringComparison comparison = OperatingSystem.IsWindows()
+            StringComparison comparison = EnvironmentHelper.IsRunningOnWindows()
                 ? StringComparison.OrdinalIgnoreCase
                 : StringComparison.Ordinal;
             return string.Equals(firstFullPath, secondFullPath, comparison);
         }
         catch
         {
-            StringComparison comparison = OperatingSystem.IsWindows()
+            StringComparison comparison = EnvironmentHelper.IsRunningOnWindows()
                 ? StringComparison.OrdinalIgnoreCase
                 : StringComparison.Ordinal;
             return string.Equals(firstPath, secondPath, comparison);

OF DL.Core/Services/StartupService.cs

@@ -1,6 +1,5 @@
 using System.Diagnostics;
 using System.Reflection;
-using System.Runtime.InteropServices;
 using Newtonsoft.Json;
 using OF_DL.Helpers;
 using OF_DL.Models;
@@ -24,9 +23,9 @@ public class StartupService(IConfigService configService, IAuthService authServi
         // OS validation
         OperatingSystem os = Environment.OSVersion;
         result.OsVersionString = os.VersionString;
-        Log.Debug($"Operating system information: {os.VersionString}");
+        Log.Debug("Operating system information: {OsVersionString}", os.VersionString);
 
-        if (os.Platform == PlatformID.Win32NT && os.Version.Major < 10)
+        if (EnvironmentHelper.IsRunningOnWindows() && os.Version.Major < 10)
         {
             result.IsWindowsVersionValid = false;
             Log.Error("Windows version prior to 10.x: {0}", os.VersionString);
@@ -40,7 +39,7 @@ public class StartupService(IConfigService configService, IAuthService authServi
         if (result is { FfmpegFound: true, FfmpegPath: not null })
         {
             // Escape backslashes for Windows
-            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows) &&
+            if (EnvironmentHelper.IsRunningOnWindows() &&
                 result.FfmpegPath.Contains(@":\") &&
                 !result.FfmpegPath.Contains(@":\\"))
             {
@@ -55,7 +54,7 @@ public class StartupService(IConfigService configService, IAuthService authServi
         if (result is { FfprobeFound: true, FfprobePath: not null })
         {
             // Escape backslashes for Windows
-            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows) &&
+            if (EnvironmentHelper.IsRunningOnWindows() &&
                 result.FfprobePath.Contains(@":\") &&
                 !result.FfprobePath.Contains(@":\\"))
             {
@@ -211,7 +210,7 @@ public class StartupService(IConfigService configService, IAuthService authServi
             string? ffmpegDirectory = Path.GetDirectoryName(result.FfmpegPath);
             if (!string.IsNullOrEmpty(ffmpegDirectory))
             {
-                string ffprobeFileName = RuntimeInformation.IsOSPlatform(OSPlatform.Windows)
+                string ffprobeFileName = EnvironmentHelper.IsRunningOnWindows()
                     ? "ffprobe.exe"
                     : "ffprobe";
                 string inferredFfprobePath = Path.Combine(ffmpegDirectory, ffprobeFileName);

OF DL.Gui/Program.cs

@@ -1,5 +1,6 @@
 using Avalonia;
 using Microsoft.Extensions.DependencyInjection;
+using OF_DL.Helpers;
 using OF_DL.Services;
 using Serilog;
 
@@ -21,11 +22,11 @@ public static class Program
 
         Log.Information("Starting OF DL GUI");
 
-        // Check if running in Docker and print message
+        // Check if running in Docker and print a message
-        string? ofdlDocker = Environment.GetEnvironmentVariable("OFDL_DOCKER");
+        if (EnvironmentHelper.IsRunningInDocker())
-        if (string.Equals(ofdlDocker, "true", StringComparison.OrdinalIgnoreCase))
         {
-            Console.WriteLine("In your web browser, navigate to the port forwarded from your docker container. For instance, if your docker run command included \"-p 8080:8080\", open your web browser to \"http://localhost:8080\".");
+            Console.WriteLine(
+                "In your web browser, navigate to the port forwarded from your docker container. For instance, if your docker run command included \"-p 8080:8080\", open your web browser to \"http://localhost:8080\".");
         }
 
         BuildAvaloniaApp()

OF DL.Gui/Views/FaqWindow.axaml.cs

@@ -3,6 +3,7 @@ using System.Diagnostics;
 using Avalonia.Controls;
 using Avalonia.Interactivity;
 using Avalonia.Platform;
+using OF_DL.Helpers;
 
 namespace OF_DL.Gui.Views;
 
@@ -65,11 +66,8 @@ public partial class FaqWindow : Window
     {
         Entries.Clear();
 
-        bool isDocker = string.Equals(
+        bool isDocker = EnvironmentHelper.IsRunningInDocker();
-            Environment.GetEnvironmentVariable("OFDL_DOCKER"),
+        bool isWindows = EnvironmentHelper.IsRunningOnWindows();
-            "true",
-            StringComparison.OrdinalIgnoreCase);
-        bool isWindows = OperatingSystem.IsWindows();
 
         Entries.Add(new FaqEntry(
             "Why are some users missing from the users list?",

OF DL.Gui/Views/MainWindow.axaml.cs

@@ -7,6 +7,7 @@ using Avalonia.Platform;
 using Avalonia.Platform.Storage;
 using Avalonia.VisualTree;
 using Avalonia.Threading;
+using OF_DL.Helpers;
 using OF_DL.Gui.ViewModels;
 
 namespace OF_DL.Gui.Views;
@@ -28,8 +29,7 @@ public partial class MainWindow : Window
         Icon = new WindowIcon(AssetLoader.Open(new Uri("avares://OF DL.Gui/Assets/icon.ico")));
 
         // Start maximized if running in Docker
-        string? ofdlDocker = Environment.GetEnvironmentVariable("OFDL_DOCKER");
+        if (EnvironmentHelper.IsRunningInDocker())
-        if (string.Equals(ofdlDocker, "true", StringComparison.OrdinalIgnoreCase))
         {
             WindowState = WindowState.Maximized;
         }

OF DL/Program.cs

@@ -3,6 +3,7 @@ using Microsoft.Extensions.DependencyInjection;
 using OF_DL.CLI;
 using OF_DL.Models;
 using OF_DL.Enumerations;
+using OF_DL.Helpers;
 using OF_DL.Models.Config;
 using OF_DL.Models.Downloads;
 using OF_DL.Models.Entities.Users;
@@ -17,14 +18,13 @@ public class Program(IServiceProvider serviceProvider)
     private async Task LoadAuthFromBrowser()
     {
         IAuthService authService = serviceProvider.GetRequiredService<IAuthService>();
-        bool runningInDocker = Environment.GetEnvironmentVariable("OFDL_DOCKER") != null;
 
         // Show the initial message
         AnsiConsole.MarkupLine("[yellow]Downloading dependencies. Please wait ...[/]");
 
         // Show instructions based on the environment
         await Task.Delay(5000);
-        if (runningInDocker)
+        if (EnvironmentHelper.IsRunningInDocker())
         {
             AnsiConsole.MarkupLine(
                 "[yellow]In your web browser, navigate to the port forwarded from your docker container.[/]");
@@ -846,8 +846,8 @@ public class Program(IServiceProvider serviceProvider)
     private static void DisplayStartupResult(StartupResult result)
     {
         // OS
-        if (result.IsWindowsVersionValid && result.OsVersionString != null &&
+        if (result is { IsWindowsVersionValid: true, OsVersionString: not null } &&
-            Environment.OSVersion.Platform == PlatformID.Win32NT)
+            EnvironmentHelper.IsRunningOnWindows())
         {
             AnsiConsole.Markup("[green]Valid version of Windows found.\n[/]");
         }