From af513a03ced28baca1bcf2683061566acd50ab67 Mon Sep 17 00:00:00 2001
From: adelikat <adelikat@tasvideos.org>
Date: Sat, 29 Feb 2020 14:14:55 -0600
Subject: [PATCH] convert more decoders

---
 .../cheats/SmsActionReplayDecoder.cs          | 38 +++++++++----------
 BizHawk.Client.EmuHawk/tools/GameShark.cs     | 27 ++++++-------
 2 files changed, 29 insertions(+), 36 deletions(-)

diff --git a/BizHawk.Client.Common/cheats/SmsActionReplayDecoder.cs b/BizHawk.Client.Common/cheats/SmsActionReplayDecoder.cs
index 7cf658a832..8f6b83529f 100644
--- a/BizHawk.Client.Common/cheats/SmsActionReplayDecoder.cs
+++ b/BizHawk.Client.Common/cheats/SmsActionReplayDecoder.cs
@@ -3,32 +3,28 @@ using System.Globalization;
 
 namespace BizHawk.Client.Common.cheats
 {
-	// TODO: validate string and throw
-	public class SmsActionReplayDecoder
+	public static class SmsActionReplayDecoder
 	{
-		private readonly string _code;
-
-		public SmsActionReplayDecoder(string code)
+		public static IDecodeResult Decode(string code)
 		{
-			_code = code;
-			Decode();
-		}
-
-		public int Address { get; private set; }
-		public int Value { get; private set; }
-
-		public void Decode()
-		{
-			if (_code.IndexOf("-") != 3 && _code.Length != 9)
+			if (code == null)
 			{
-				throw new InvalidOperationException("Invalid Action Replay Code");
+				throw new ArgumentNullException(nameof(code));
 			}
 
-			var parseString = _code.Remove(0, 2);
-			var ramAddress = parseString.Remove(4, 2).Replace("-", "");
-			var ramValue = parseString.Remove(0, 5);
-			Address = int.Parse(ramAddress, NumberStyles.HexNumber);
-			Value = int.Parse(ramValue, NumberStyles.HexNumber);
+			if (code.IndexOf("-") != 3 && code.Length != 9)
+			{
+				return new InvalidCheatCode("Action Replay Codes must be 9 characters with a dash after the third character");
+			}
+
+			var result = new DecodeResult { Size = WatchSize.Byte };
+
+			var s = code.Remove(0, 2);
+			var ramAddress = s.Remove(4, 2).Replace("-", "");
+			var ramValue = s.Remove(0, 5);
+			result.Address = int.Parse(ramAddress, NumberStyles.HexNumber);
+			result.Value = int.Parse(ramValue, NumberStyles.HexNumber);
+			return result;
 		}
 	}
 }
diff --git a/BizHawk.Client.EmuHawk/tools/GameShark.cs b/BizHawk.Client.EmuHawk/tools/GameShark.cs
index 187ffdc25c..479df98d67 100644
--- a/BizHawk.Client.EmuHawk/tools/GameShark.cs
+++ b/BizHawk.Client.EmuHawk/tools/GameShark.cs
@@ -313,7 +313,7 @@ namespace BizHawk.Client.EmuHawk
 			}
 		}
 
-		// This also handles Game Gear due to shared hardware. Go figure.
+		// Note: this also handles Game Gear due to shared hardware
 		private void Sms(string code)
 		{
 			// Game Genie
@@ -334,22 +334,19 @@ namespace BizHawk.Client.EmuHawk
 			// Action Replay
 			else if (code.IndexOf("-") == 3 && code.Length == 9)
 			{
-				var decoder = new SmsActionReplayDecoder(code);
-				var watch = Watch.GenerateWatch(MemoryDomains["Main RAM"], decoder.Address, WatchSize.Byte, Common.DisplayType.Hex, false, txtDescription.Text);
-				Global.CheatList.Add(new Cheat(watch, decoder.Value));
+				var result = SmsActionReplayDecoder.Decode(code);
+				if (result.IsValid)
+				{
+					var description = Description(code);
+					Global.CheatList.Add(result.ToCheat(MemoryDomains.SystemBus, description));
+				}
+				else
+				{
+					InputError(result.Error);
+				}
 			}
 
-			// It's an Action Replay
-			else if (code.Length != 9 && code.LastIndexOf("-") != 7)
-			{
-				InputError("All Master System Action Replay Codes need to be nine characters in length.");
-			}
-
-			// Game Genie
-			else if (code.LastIndexOf("-") != 7 && code.IndexOf("-") != 3)
-			{
-				InputError("All Master System Game Genie Codes need to have a dash after the third character and seventh character.");
-			}
+			InputError($"Unknown code type: {code}");
 		}
 
 		private void Snes(string cheat)