Add xmldoc for mystery gift class names

refactor pattern checking to simpler representation, add null abort when
extension is not provided.

PKHeX.Core/MysteryGifts/MysteryGift.cs

@@ -3,6 +3,9 @@ using System.Linq;
 
 namespace PKHeX.Core
 {
+    /// <summary>
+    /// Mystery Gift Template File
+    /// </summary>
     public abstract class MysteryGift : IEncounterable, IMoveset
     {
 
@@ -25,27 +28,25 @@ namespace PKHeX.Core
         /// <remarks>This overload differs from <see cref="GetMysteryGift(byte[])"/> by checking the <paramref name="data"/>/<paramref name="ext"/> combo for validity.  If either is invalid, a null reference is returned.</remarks>
         public static MysteryGift GetMysteryGift(byte[] data, string ext)
         {
-            // Generation 7
+            if (ext == null)
-            if (data.Length == WC7.SizeFull && ext == ".wc7full")
+                return GetMysteryGift(data);
-                return new WC7(data);
-            if (data.Length == WC7.Size && ext == ".wc7")
-                return new WC7(data);
 
-            // Generation 6
+            switch (data.Length)
-            if (data.Length == WC6.SizeFull && ext == ".wc6full")
+            {
-                return new WC6(data);
+                case WC7.SizeFull when ext == ".wc7full":
-            if (data.Length == WC6.Size && ext == ".wc6")
+                case WC7.Size when ext == ".wc7":
-                return new WC6(data);
+                    return new WC7(data);
+                case WC6.SizeFull when ext == ".wc6full":
+                case WC6.Size when ext == ".wc6":
+                    return new WC6(data);
 
-            // Generation 5
+                case PGF.Size when ext == ".pgf":
-            if (data.Length == PGF.Size && ext == ".pgf")
+                    return new PGF(data);
-                return new PGF(data);
+                case PGT.Size when ext == ".pgt":
-
+                    return new PGT(data);
-            // Generation 4
+                case PCD.Size when ext == ".pcd":
-            if (data.Length == PGT.Size && ext == ".pgt")
+                    return new PCD(data);
-                return new PGT(data);
+            }
-            if (data.Length == PCD.Size && ext == ".pcd")
-                return new PCD(data);
 
             return null;
         }
@@ -69,14 +70,11 @@ namespace PKHeX.Core
                     if (BitConverter.ToUInt32(data, 0x4C) / 10000 < 2000)
                         return new WC7(data);
                     return new WC6(data);
-                case PGF.Size:
+
-                    return new PGF(data);
+                case PGF.Size: return new PGF(data);
-                case PGT.Size:
+                case PGT.Size: return new PGT(data);
-                    return new PGT(data);
+                case PCD.Size: return new PCD(data);
-                case PCD.Size:
+                default: return null;
-                    return new PCD(data);
-                default:
-                    return null;
             }
         }
 

PKHeX.Core/MysteryGifts/PGF.cs

@@ -3,6 +3,9 @@ using System.Text;
 
 namespace PKHeX.Core
 {
+    /// <summary>
+    /// Generation 5 Mystery Gift Template File
+    /// </summary>
     public sealed class PGF : MysteryGift, IRibbonSetEvent3, IRibbonSetEvent4
     {
         public const int Size = 0xCC;

PKHeX.Core/MysteryGifts/PGT.cs

@@ -3,11 +3,15 @@ using System.Linq;
 
 namespace PKHeX.Core
 {
-    /* Big thanks to Grovyle91's Pokémon Mystery Gift Editor, from which the structure was referenced.
+    /// <summary>
-     * http://projectpokemon.org/forums/member.php?829-Grovyle91
+    /// Generation 4 Mystery Gift Template File
-     * http://projectpokemon.org/forums/showthread.php?6524
+    /// </summary>
-     * See also: http://tccphreak.shiny-clique.net/debugger/pcdfiles.htm
+    /// <remarks>
-     */
+    /// Big thanks to Grovyle91's Pokémon Mystery Gift Editor, from which the structure was referenced.
+    /// http://projectpokemon.org/forums/member.php?829-Grovyle91
+    /// http://projectpokemon.org/forums/showthread.php?6524
+    /// See also: http://tccphreak.shiny-clique.net/debugger/pcdfiles.htm
+    /// </remarks>
     public sealed class PCD : MysteryGift
     {
         public const int Size = 0x358; // 856
@@ -106,6 +110,10 @@ namespace PKHeX.Core
 
         public bool CanBeReceivedBy(int pkmVersion) => (CardCompatibility >> pkmVersion & 1) == 1;
     }
+
+    /// <summary>
+    /// Generation 4 Mystery Gift Template File (Inner Gift Data, no card data)
+    /// </summary>
     public sealed class PGT : MysteryGift
     {
         public const int Size = 0x104; // 260

PKHeX.Core/MysteryGifts/WC6.cs

@@ -4,6 +4,9 @@ using System.Text;
 
 namespace PKHeX.Core
 {
+    /// <summary>
+    /// Generation 6 Mystery Gift Template File
+    /// </summary>
     public sealed class WC6 : MysteryGift, IRibbonSetEvent3, IRibbonSetEvent4
     {
         public const int Size = 0x108;

PKHeX.Core/MysteryGifts/WC7.cs

@@ -4,6 +4,9 @@ using System.Text;
 
 namespace PKHeX.Core
 {
+    /// <summary>
+    /// Generation 7 Mystery Gift Template File
+    /// </summary>
     public sealed class WC7 : MysteryGift, IRibbonSetEvent3, IRibbonSetEvent4
     {
         public const int Size = 0x108;