From d2fd1dc11c13054010d7421ee6aebfdac6fd3cc1 Mon Sep 17 00:00:00 2001
From: adelikat <adelikat@tasvideos.org>
Date: Fri, 28 Feb 2020 19:12:46 -0600
Subject: [PATCH] GameShark - move genesis game genie coding logic to its own
 class

---
 .../cheats/GenesisGameGenieDecoder.cs         | 89 +++++++++++++++++++
 BizHawk.Client.EmuHawk/tools/GameShark.cs     | 74 ++-------------
 2 files changed, 94 insertions(+), 69 deletions(-)
 create mode 100644 BizHawk.Client.Common/cheats/GenesisGameGenieDecoder.cs

diff --git a/BizHawk.Client.Common/cheats/GenesisGameGenieDecoder.cs b/BizHawk.Client.Common/cheats/GenesisGameGenieDecoder.cs
new file mode 100644
index 0000000000..3f2627d35e
--- /dev/null
+++ b/BizHawk.Client.Common/cheats/GenesisGameGenieDecoder.cs
@@ -0,0 +1,89 @@
+using System;
+using System.Collections.Generic;
+
+namespace BizHawk.Client.Common.cheats
+{
+	public class GenesisGameGenieDecoder
+	{
+		private readonly string _code;
+
+		private readonly Dictionary<char, long> _genGameGenieTable = new Dictionary<char, long>
+		{
+			['A'] = 0,
+			['B'] = 1,
+			['C'] = 2,
+			['D'] = 3,
+			['E'] = 4,
+			['F'] = 5,
+			['G'] = 6,
+			['H'] = 7,
+			['J'] = 8,
+			['K'] = 9,
+			['L'] = 10,
+			['M'] = 11,
+			['N'] = 12,
+			['P'] = 13,
+			['R'] = 14,
+			['S'] = 15,
+			['T'] = 16,
+			['V'] = 17,
+			['W'] = 18,
+			['X'] = 19,
+			['Y'] = 20,
+			['Z'] = 21,
+			['0'] = 22,
+			['1'] = 23,
+			['2'] = 24,
+			['3'] = 25,
+			['4'] = 26,
+			['5'] = 27,
+			['6'] = 28,
+			['7'] = 29,
+			['8'] = 30,
+			['9'] = 31
+		};
+
+		public GenesisGameGenieDecoder(string code)
+		{
+			_code = code;
+			Decode();
+		}
+
+		public int Address { get; private set; }
+		public int Value { get; private set; }
+
+		public void Decode()
+		{
+			if (_code.IndexOf("-") != 4)
+			{
+				throw new InvalidOperationException("All Genesis Game Genie Codes need to contain a dash after the fourth character");
+			}
+			if (_code.Contains("I") | _code.Contains("O") | _code.Contains("Q") | _code.Contains("U"))
+			{
+				throw new InvalidOperationException("Genesis Game Genie Codes do not use I, O, Q or U.");
+			}
+
+			// Remove the -
+			string code = _code.Remove(4, 1);
+			long hexCode = 0;
+
+			// convert code to a long binary string
+			foreach (var t in code)
+			{
+				hexCode <<= 5;
+				_genGameGenieTable.TryGetValue(t, out var y);
+				hexCode |= y;
+			}
+
+			long decoded = (hexCode & 0xFF00000000) >> 32;
+			decoded |= hexCode & 0x00FF000000;
+			decoded |= (hexCode & 0x0000FF0000) << 16;
+			decoded |= (hexCode & 0x00000000700) << 5;
+			decoded |= (hexCode & 0x000000F800) >> 3;
+			decoded |= (hexCode & 0x00000000FF) << 16;
+
+			Value = (int)(decoded & 0x000000FFFF);
+			Address= (int)((decoded & 0xFFFFFF0000) >> 16);
+		}
+	}
+}
diff --git a/BizHawk.Client.EmuHawk/tools/GameShark.cs b/BizHawk.Client.EmuHawk/tools/GameShark.cs
index 45b133e320..da2c18cf92 100644
--- a/BizHawk.Client.EmuHawk/tools/GameShark.cs
+++ b/BizHawk.Client.EmuHawk/tools/GameShark.cs
@@ -4,6 +4,7 @@ using System.Globalization;
 using System.Windows.Forms;
 using BizHawk.Emulation.Common;
 using BizHawk.Client.Common;
+using BizHawk.Client.Common.cheats;
 
 // TODO:
 // Add Support/Handling for The Following Systems and Devices:
@@ -42,42 +43,6 @@ namespace BizHawk.Client.EmuHawk
 			['F'] = 15
 		};
 
-		private readonly Dictionary<char, long> _genGameGenieTable = new Dictionary<char, long>
-		{
-			['A'] = 0,
-			['B'] = 1,
-			['C'] = 2,
-			['D'] = 3,
-			['E'] = 4,
-			['F'] = 5,
-			['G'] = 6,
-			['H'] = 7,
-			['J'] = 8,
-			['K'] = 9,
-			['L'] = 10,
-			['M'] = 11,
-			['N'] = 12,
-			['P'] = 13,
-			['R'] = 14,
-			['S'] = 15,
-			['T'] = 16,
-			['V'] = 17,
-			['W'] = 18,
-			['X'] = 19,
-			['Y'] = 20,
-			['Z'] = 21,
-			['0'] = 22,
-			['1'] = 23,
-			['2'] = 24,
-			['3'] = 25,
-			['4'] = 26,
-			['5'] = 27,
-			['6'] = 28,
-			['7'] = 29,
-			['8'] = 30,
-			['9'] = 31
-		};
-
 		// including transposition
 		// Code: D F 4 7 0 9 1 5 6 B C 8 A 2 3 E
 		// Hex:  0 1 2 3 4 5 6 7 8 9 A B C D E F
@@ -2353,8 +2318,7 @@ namespace BizHawk.Client.EmuHawk
 
 		private void Gen()
 		{
-			// Game Genie only, for now.
-			// This applies to the Game Genie
+			// Game Genie only
 			if (_singleCheat.Length == 9 && _singleCheat.Contains("-"))
 			{
 				if (_singleCheat.IndexOf("-") != 4)
@@ -2368,39 +2332,11 @@ namespace BizHawk.Client.EmuHawk
 					return;
 				}
 
-				// This is taken from the GenGameGenie.CS file.
-				string code = _singleCheat;
-
-				// Remove the -
-				code = code.Remove(4, 1);
-				long hexCode = 0;
-
-				// convert code to a long binary string
-				foreach (var t in code)
-				{
-					hexCode <<= 5;
-					_genGameGenieTable.TryGetValue(t, out var y);
-					hexCode |= y;
-				}
-
-				long decoded = (hexCode & 0xFF00000000) >> 32;
-				decoded |= hexCode & 0x00FF000000;
-				decoded |= (hexCode & 0x0000FF0000) << 16;
-				decoded |= (hexCode & 0x00000000700) << 5;
-				decoded |= (hexCode & 0x000000F800) >> 3;
-				decoded |= (hexCode & 0x00000000FF) << 16;
-
-				var val = (int)(decoded & 0x000000FFFF);
-				var add = (int)((decoded & 0xFFFFFF0000) >> 16);
-
-				// Make our Strings get the Hex Values.
-				string address = add.ToString("X6");
+				var decoder = new GenesisGameGenieDecoder(_singleCheat);
 
 				// Game Genie, modifies the "ROM" which is why it says, "MD CART"
-				var watch = Watch.GenerateWatch(MemoryDomains["M68K BUS"], long.Parse(address, NumberStyles.HexNumber), WatchSize.Word, Common.DisplayType.Hex, true, txtDescription.Text);
-				
-				// Add Cheat
-				Global.CheatList.Add(new Cheat(watch, val));
+				var watch = Watch.GenerateWatch(MemoryDomains["M68K BUS"], decoder.Address, WatchSize.Word, Common.DisplayType.Hex, true, txtDescription.Text);
+				Global.CheatList.Add(new Cheat(watch, decoder.Value));
 			}
 
 			// Action Replay?