Implement XIV & GShade path localisation procedures

This commit integrates a few procedures for figuring out the paths for
the XIV game directory, and the GShade installation directory.

Issue #1 on GitHub will benefit from this update.

-----------------------------------------------------------------------

XIV
---

1.  Attempt to retrieve value from the GShade registry key.
2.  Attempt to check the default non-Steam installation path.
3.  Attempt to check the current working directory.

GSHADE
------

1.  Attempt to retrieve value from the GShade registry key.
2.  Attempt to check the default Program Files installation path.

-----------------------------------------------------------------------

Signed-off-by: Emilian Roman <git@miris.design>

src/Paths.cs

@@ -17,8 +17,11 @@
  * along with GShade.Nuke.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
+using static System.Console;
 using static System.Environment;
 using static System.Environment.SpecialFolder;
 using static System.IO.Path;
@@ -29,6 +32,87 @@ public static class Paths
   {
     public static readonly string GShade = "GShade";
 
+    /**
+     * Attempts to figure out the XIV game directory path using the following methods:
+     * 
+     * 1.  Retrieving the location path from the GShade registry key.
+     * 2.  Asserting the existence of the game in the default non-Steam installation path.
+     * 3.  Asserting the existence of the game in the current directory.
+     */
+    public static DirectoryInfo Game()
+    {
+      try
+      {
+        return Registry.Infer(Registry.Type.Game);
+      }
+      catch (Exception e)
+      {
+        WriteLine(e.Message + "-- Attempting next XIV game path detection method.");
+      }
+
+      var defaultPath = Combine(GetFolderPath(ProgramFilesX86),
+        "SquareEnix",
+        "FINAL FANTASY XIV - A Realm Reborn",
+        "game");
+
+      var executables = new List<FileInfo>
+      {
+        new(Combine(defaultPath,      "ffxiv.exe")),
+        new(Combine(defaultPath,      "ffxiv_dx11.exe")),
+        new(Combine(CurrentDirectory, "ffxiv.exe")),
+        new(Combine(CurrentDirectory, "ffxiv_dx11.exe"))
+      };
+
+      var path = new DirectoryInfo(string.Empty);
+
+      foreach (var executable in executables.Where(executable => executable.Exists))
+        path = executable.Directory;
+
+      if (path is not {Exists: true})
+        throw new DirectoryNotFoundException("Could not find the XIV game directory.");
+
+      return path;
+    }
+
+    /**
+     * Attempts to figure out the GShade installation directory path using the following methods:
+     * 
+     * 1.  Retrieving the location path from the GShade registry key.
+     * 2.  Asserting the existence of assets in the default installation path.
+     */
+    public static DirectoryInfo Root()
+    {
+      try
+      {
+        return Registry.Infer(Registry.Type.Install);
+      }
+      catch (Exception e)
+      {
+        WriteLine(e.Message + "-- Attempting next GShade installation path detection method.");
+      }
+
+      var defaultPath = Combine(GetFolderPath(ProgramFiles),
+        "GShade");
+
+      var assets = new List<FileInfo>
+      {
+        new(Combine(defaultPath,      "GShade32.dll")),
+        new(Combine(defaultPath,      "GShade64.dll")),
+        new(Combine(CurrentDirectory, "inject32.exe")),
+        new(Combine(CurrentDirectory, "inject75.exe"))
+      };
+
+      var path = new DirectoryInfo(string.Empty);
+
+      foreach (var asset in assets.Where(asset => asset.Exists))
+        path = asset.Directory;
+
+      if (path is not {Exists: true})
+        throw new DirectoryNotFoundException("Could not find the GShade installation directory.");
+
+      return path;
+    }
+
     /**
      * Principal Post-Processing directories, along with presets. These are the most important user files!
      */

src/Program.cs

@@ -18,7 +18,9 @@
  */
 
 using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using Mono.Options;
 using static System.Console;
 using static System.DateTime;
@@ -51,9 +53,9 @@ internal class Program
       }
     };
 
-    private static DirectoryInfo Root  { get; set; } = Registry.Infer(Registry.Type.Install);
-    private static DirectoryInfo Game  { get; set; } = Registry.Infer(Registry.Type.Game);
-    private static bool          Force { get; set; }
+    private static DirectoryInfo Root    { get; set; }
+    private static DirectoryInfo Game    { get; set; }
+    private static bool          Force   { get; set; }
     private static bool          Migrate { get; set; }
 
     private static string Backup { get; set; } =
@@ -114,6 +116,7 @@ private static void Main(string[] args)
 
       try
       {
+        Localise();
         Archive();
         Uninstall();
         Rename();
@@ -123,10 +126,42 @@ private static void Main(string[] args)
         var log = Combine(GetFolderPath(Desktop), "GShade.Nuke.log");
         WriteAllText(log, e.StackTrace);
         WriteLine($"An error has occurred: {e.Message}. Refer to the log file for more details: {log}");
+        Exit(1);
       }
 
       WriteLine("Press any key to continue...");
       ReadLine();
     }
+
+    private static void Localise()
+    {
+      if (!Game.Exists)
+        try
+        {
+          Game = Paths.Game();
+        }
+        catch (Exception)
+        {
+          WriteLine("XIV path not found. Perhaps you've ran the GShade uninstaller before?");
+          WriteLine("Either move gshade-nuke.exe to your XIV 'game' folder, or the path:");
+          WriteLine(@"    gshade-nuke.exe --game 'C:\Path\To\XIV\game\folder'");
+          WriteLine("GShade Nuke will still try to delete any other known GShade files.");
+          ReadLine();
+        }
+
+      if (!Root.Exists)
+        try
+        {
+          Root = Paths.Root();
+        }
+        catch (Exception)
+        {
+          WriteLine("GShade path not found. Perhaps you've ran the GShade uninstaller before?");
+          WriteLine("Either manually delete the GShade folder, or specify the GShade install path:");
+          WriteLine(@"    gshade-nuke.exe --install 'C:\Path\To\GShade\installation'");
+          WriteLine("GShade Nuke will still try to delete any other known GShade files.");
+          ReadLine();
+        }
+    }
   }
 }