rework prechecks to return a precheckresult

SPTInstaller/Controllers/InstallController.cs

@@ -32,7 +32,7 @@ public class InstallController
         {
             var result = await check.RunCheck();
 
-            Log.Information($"PreCheck: {check.Name} ({(check.IsRequired ? "Required" : "Optional")}) -> {(result.Succeeded ? "Passed" : "Failed")}");
+            Log.Information($"PreCheck: {check.Name} ({(check.IsRequired ? "Required" : "Optional")}) -> {(result.Succeeded ? "Passed" : "Failed")}\nDetail: {check.PreCheckDetails.ReplaceLineEndings(" ")}");
             
             if (check.IsRequired)
             {

SPTInstaller/Helpers/DirectorySizeHelper.cs

@@ -1,29 +1,38 @@
 using System.Linq;
-using Serilog;
 
 namespace SPTInstaller.Helpers;
 
 public static class DirectorySizeHelper
 {
-    public static bool CheckAvailableSize(string eftSourceDirPath, string installTargetDirPath)
+    // SizeSuffix implementation found here:
+    // https://stackoverflow.com/a/14488941
+    static readonly string[] SizeSuffixes =
+                   { "bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" };
+    public static string SizeSuffix(Int64 value, int decimalPlaces = 1)
     {
-        try
+        if (decimalPlaces < 0) { throw new ArgumentOutOfRangeException("decimalPlaces"); }
+        if (value < 0) { return "-" + SizeSuffix(-value, decimalPlaces); }
+        if (value == 0) { return string.Format("{0:n" + decimalPlaces + "} bytes", 0); }
+
+        // mag is 0 for bytes, 1 for KB, 2, for MB, etc.
+        int mag = (int)Math.Log(value, 1024);
+
+        // 1L << (mag * 10) == 2 ^ (10 * mag) 
+        // [i.e. the number of bytes in the unit corresponding to mag]
+        decimal adjustedSize = (decimal)value / (1L << (mag * 10));
+
+        // make adjustment when the value is large enough that
+        // it would round up to 1000 or more
+        if (Math.Round(adjustedSize, decimalPlaces) >= 1000)
         {
-            var eftSourceDirectoryInfo = new DirectoryInfo(eftSourceDirPath);
-            var installTargetDirectoryInfo = new DirectoryInfo(installTargetDirPath);
-                
-            var eftSourceDirSize = GetSizeOfDirectory(eftSourceDirectoryInfo);
-            var availableSize = DriveInfo.GetDrives().FirstOrDefault(d => d.Name.ToLower() == installTargetDirectoryInfo.Root.Name.ToLower())?.AvailableFreeSpace ?? 0;
-
-            return eftSourceDirSize < availableSize;
+            mag += 1;
+            adjustedSize /= 1024;
         }
-        catch (Exception ex)
-        {
-            Log.Error(ex, "Error while checking available size");
 
-            return false;
-        }
+        return string.Format("{0:n" + decimalPlaces + "} {1}",
+            adjustedSize,
+            SizeSuffixes[mag]);
     }
 
-    private static long GetSizeOfDirectory(DirectoryInfo sourceDir) => sourceDir.EnumerateFiles("*", SearchOption.AllDirectories).Sum(fi => fi.Length);
+    public static long GetSizeOfDirectory(DirectoryInfo sourceDir) => sourceDir.EnumerateFiles("*", SearchOption.AllDirectories).Sum(fi => fi.Length);
 }

SPTInstaller/Interfaces/IPreCheck.cs

@@ -12,5 +12,7 @@ public interface IPreCheck
         
     public bool Passed { get; }
 
+    public string PreCheckDetails { get; }
+
     public Task<IResult> RunCheck();
 }

SPTInstaller/Models/PreCheckBase.cs

@@ -1,6 +1,7 @@
 using ReactiveUI;
 using SPTInstaller.Interfaces;
 using System.Threading.Tasks;
+using System.Windows.Input;
 
 namespace SPTInstaller.Models;
 
@@ -48,6 +49,34 @@ public abstract class PreCheckBase : ReactiveObject, IPreCheck
         set => this.RaiseAndSetIfChanged(ref _isRunning, value);
     }
 
+    private string _preCheckDetails;
+    public string PreCheckDetails
+    {
+        get => _preCheckDetails;
+        set => this.RaiseAndSetIfChanged(ref _preCheckDetails, value);
+    }
+
+    private bool _actionButtonIsVisible;
+    public bool ActionButtonIsVisible
+    {
+        get => _actionButtonIsVisible;
+        set => this.RaiseAndSetIfChanged(ref _actionButtonIsVisible, value);
+    }
+
+    private string _actionButtonText;
+    public string ActionButtonText
+    {
+        get => _actionButtonText;
+        set => this.RaiseAndSetIfChanged(ref _actionButtonText, value);
+    }
+
+    private ICommand _actionButtonCommand;
+    public ICommand ActionButtonCommand
+    {
+        get => _actionButtonCommand;
+        set => this.RaiseAndSetIfChanged(ref _actionButtonCommand, value);
+    }
+
     /// <summary>
     /// Base class for pre-checks to run before installation
     /// </summary>
@@ -63,12 +92,23 @@ public abstract class PreCheckBase : ReactiveObject, IPreCheck
     public async Task<IResult> RunCheck()
     {
         IsRunning = true;
-        Passed = await CheckOperation();
+
+        var result = await CheckOperation();
+        Passed = result.Succeeded;
+
+        PreCheckDetails = !string.IsNullOrWhiteSpace(result.Message)
+            ? result.Message
+            : (result.Succeeded ? "Pre-Check succeeded, but no details were provided" : "Pre-Check failed, but no details were provided");
+
+        ActionButtonText = result.ActionButtonText;
+        ActionButtonCommand = result.ButtonPressedCommand;
+        ActionButtonIsVisible = result.ActionButtonIsVisible;
+
         IsRunning = false;
         IsPending = false;
 
         return Passed ? Result.FromSuccess() : Result.FromError($"PreCheck Failed: {Name}");
     }
 
-    public abstract Task<bool> CheckOperation();
+    public abstract Task<PreCheckResult> CheckOperation();
 }

SPTInstaller/Models/PreCheckResult.cs

@@ -0,0 +1,37 @@
+using ReactiveUI;
+using SPTInstaller.Interfaces;
+using System.Windows.Input;
+
+namespace SPTInstaller.Models;
+public class PreCheckResult : IResult
+{
+    public bool Succeeded { get; private set; }
+
+    public string Message { get; private set; }
+
+    public bool ActionButtonIsVisible { get; private set; }
+
+    public string ActionButtonText { get; private set; }
+
+    public ICommand ButtonPressedCommand { get; private set; }
+
+    protected PreCheckResult(string message, bool succeeded, string actionButtonText, Action? buttonPressedAction)
+    {
+        Message = message;
+        Succeeded = succeeded;
+
+        ActionButtonText = actionButtonText;
+
+        ActionButtonIsVisible = buttonPressedAction != null && !string.IsNullOrWhiteSpace(actionButtonText);
+
+        buttonPressedAction ??= () => { };
+
+        ButtonPressedCommand = ReactiveCommand.Create(buttonPressedAction);
+    }
+
+    public static PreCheckResult FromSuccess(string message = "") => new PreCheckResult(message, true, "", null);
+
+    public static PreCheckResult FromError(string message, string actionButtonText = "", Action? actionButtonPressedAction = null) => new PreCheckResult(message, false, actionButtonText, actionButtonPressedAction);
+
+    public static PreCheckResult FromException(Exception ex, string actionButtonText = "", Action? actionButtonPressedAction = null) => new PreCheckResult($"An exception was thrown during this precheck\n\nException:\n{ex.Message}\n\nStacktrace:\n{ex.StackTrace}", false, actionButtonText, actionButtonPressedAction);
+}