From 6711995c5bca6a2f3f5e4a7351317403f2e66782 Mon Sep 17 00:00:00 2001
From: "andres.delikat" <andres.delikat@4bbf4f03-6f44-549e-7e59-35d4b0962838>
Date: Sun, 31 Jul 2011 22:29:56 +0000
Subject: [PATCH] Undo savestate context menu item implemented

---
 BizHawk.MultiClient/MainForm.MenuItems.cs | 29 +++++++++++++++++------
 BizHawk.MultiClient/MainForm.cs           | 19 +++++++++++++++
 2 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/BizHawk.MultiClient/MainForm.MenuItems.cs b/BizHawk.MultiClient/MainForm.MenuItems.cs
index 3038fd8e87..f86185d1b6 100644
--- a/BizHawk.MultiClient/MainForm.MenuItems.cs
+++ b/BizHawk.MultiClient/MainForm.MenuItems.cs
@@ -767,11 +767,6 @@ namespace BizHawk.MultiClient
 			}
 		}
 
-		private void undoSavestateToolStripMenuItem_Click(object sender, EventArgs e)
-		{
-			//TODO
-		}
-
 		private void screenshotToolStripMenuItem1_Click(object sender, EventArgs e)
 		{
 			TakeScreenshot();
@@ -878,9 +873,22 @@ namespace BizHawk.MultiClient
 			else
 				contextMenuStrip1.Items[7].Enabled = true;
 
+			string path = Global.Game.SaveStatePrefix + "." + "QuickSave" + SaveSlot.ToString() + ".State.bak";
+			var file = new FileInfo(path);
+			if (file.Exists == true)
+			{
+				contextMenuStrip1.Items[13].Enabled = true;
+				contextMenuStrip1.Items[13].Text = "Undo Save to slot " + SaveSlot.ToString();
+				contextMenuStrip1.Items[13].Image = BizHawk.MultiClient.Properties.Resources.undo;
+			}
+			else
+			{
+				contextMenuStrip1.Items[13].Enabled = false;
+				contextMenuStrip1.Items[13].Text = "Undo Savestate";
+				contextMenuStrip1.Items[13].Image = BizHawk.MultiClient.Properties.Resources.undo;
+			}
 
-			//TODO:
-			contextMenuStrip1.Items[13].Enabled = false;
+			//contextMenuStrip1.Items[13].Enabled = false;
 		}
 
 
@@ -1296,5 +1304,12 @@ namespace BizHawk.MultiClient
 		{
 			Global.Config.BackupSavestates ^= true;
 		}
+
+		private void undoSavestateToolStripMenuItem_Click(object sender, EventArgs e)
+		{
+			string path = Global.Game.SaveStatePrefix + "." + "QuickSave" + SaveSlot.ToString() + ".State";
+			SwapBackupSavestate(path);
+			Global.RenderPanel.AddMessage("Save slot " + SaveSlot.ToString() + " restored.");
+		}
 	}
 }
\ No newline at end of file
diff --git a/BizHawk.MultiClient/MainForm.cs b/BizHawk.MultiClient/MainForm.cs
index 9894cddc77..0b6b1326ce 100644
--- a/BizHawk.MultiClient/MainForm.cs
+++ b/BizHawk.MultiClient/MainForm.cs
@@ -2178,5 +2178,24 @@ namespace BizHawk.MultiClient
 			AVIStatusLabel.Image = BizHawk.MultiClient.Properties.Resources.Blank;
 			AVIStatusLabel.ToolTipText = "";
 		}
+
+		private void SwapBackupSavestate(string path)
+		{
+			//Takes the .state and .bak files and swaps them
+			var state = new FileInfo(path);
+			var backup = new FileInfo(path + ".bak");
+			var temp = new FileInfo(path + ".bak.tmp");
+
+			if (state.Exists == false) return;
+			if (backup.Exists == false) return;
+			if (temp.Exists == true) temp.Delete();
+
+			backup.CopyTo(path + ".bak.tmp");
+			backup.Delete();
+			state.CopyTo(path + ".bak");
+			state.Delete();
+			temp.CopyTo(path);
+			temp.Delete();
+		}
 	}
 }
\ No newline at end of file