TAStudio: improve saving behavior (#2337)

* TAStudio import: ask before saving the bk2

* Only save cycle count at movie end; fixes #2203

* Rework the movie end cycle count warning.

* TAStudio import: allow saving even if no changes are detected

src/BizHawk.Client.Common/movie/MovieSession.cs

@@ -287,7 +287,6 @@ namespace BizHawk.Client.Common
 
 		public void ConvertToTasProj()
 		{
-			Movie.Save();
 			Movie = Movie.ToTasMovie();
 			Movie.Save();
 			Movie.SwitchToPlay();
@@ -335,13 +334,21 @@ namespace BizHawk.Client.Common
 
 		private void HandlePlaybackEnd()
 		{
-			if (Movie.Core ==  CoreNames.Gambatte)
+			if (Movie.IsAtEnd() && Movie.Core == CoreNames.Gambatte)
 			{
-				var movieCycles = Convert.ToUInt64(Movie.HeaderEntries[HeaderKeys.CycleCount]);
-				var coreCycles = ((Gameboy)Movie.Emulator).CycleCount;
-				if (movieCycles != (ulong)coreCycles)
+				var coreCycles = (ulong) ((Gameboy)Movie.Emulator).CycleCount;
+				var cyclesSaved = Movie.HeaderEntries.ContainsKey(HeaderKeys.CycleCount);
+				ulong previousCycles = 0;
+				if (cyclesSaved)
 				{
-					PopupMessage($"Cycle count in the movie ({movieCycles}) doesn't match the emulated value ({coreCycles}).");
+					previousCycles = Convert.ToUInt64(Movie.HeaderEntries[HeaderKeys.CycleCount]);
+				}
+				var cyclesMatch = previousCycles == coreCycles;
+				if (!cyclesSaved || !cyclesMatch)
+				{
+					var previousState = !cyclesSaved ? "The saved movie is currently missing a cycle count." : $"The previous cycle count ({previousCycles}) doesn't match.";
+					// TODO: Ideally, this would be a Yes/No MessageBox that saves when "Yes" is pressed.
+					PopupMessage($"The end of the movie has been reached.\n\n{previousState}\n\nSave to update to the new cycle count ({coreCycles}).");
 				}
 			}
 

src/BizHawk.Client.Common/movie/bk2/Bk2Movie.IO.cs

@@ -52,7 +52,7 @@ namespace BizHawk.Client.Common
 
 		protected virtual void Write(string fn, bool isBackup = false)
 		{
-			SetCycleValues(); // We are pretending these only need to be set on save
+			SetCycleValues();
 			// EmulatorVersion used to store the unchanging original emulator version.
 			if (!Header.ContainsKey(HeaderKeys.OriginalEmulatorVersion))
 			{
@@ -72,17 +72,26 @@ namespace BizHawk.Client.Common
 
 		private void SetCycleValues()
 		{
-			if (Emulator is Emulation.Cores.Nintendo.SubNESHawk.SubNESHawk subNes)
-			{
-				Header[HeaderKeys.VBlankCount] = subNes.VblankCount.ToString();
+			// The saved cycle value will only be valid if the end of the movie has been emulated.
+			if (this.IsAtEnd())
+			{ 
+				if (Emulator is Emulation.Cores.Nintendo.SubNESHawk.SubNESHawk subNes)
+				{
+					Header[HeaderKeys.VBlankCount] = subNes.VblankCount.ToString();
+				}
+				else if (Emulator is Emulation.Cores.Nintendo.Gameboy.Gameboy gameboy)
+				{
+					Header[HeaderKeys.CycleCount] = gameboy.CycleCount.ToString();
+				}
+				else if (Emulator is Emulation.Cores.Nintendo.SubGBHawk.SubGBHawk subGb)
+				{
+					Header[HeaderKeys.CycleCount] = subGb.CycleCount.ToString();
+				}
 			}
-			else if (Emulator is Emulation.Cores.Nintendo.Gameboy.Gameboy gameboy)
+			else
 			{
-				Header[HeaderKeys.CycleCount] = gameboy.CycleCount.ToString();
-			}
-			else if (Emulator is Emulation.Cores.Nintendo.SubGBHawk.SubGBHawk subGb)
-			{
-				Header[HeaderKeys.CycleCount] = subGb.CycleCount.ToString();
+				Header.Remove(HeaderKeys.CycleCount);
+				Header.Remove(HeaderKeys.VBlankCount);
 			}
 		}
 

src/BizHawk.Client.Common/movie/interfaces/IMovie.cs

@@ -258,6 +258,11 @@ namespace BizHawk.Client.Common
 		public static bool IsFinished(this IMovie movie) => movie?.Mode == MovieMode.Finished;
 		public static bool IsPlayingOrFinished(this IMovie movie) => movie?.Mode == MovieMode.Play || movie?.Mode == MovieMode.Finished;
 		public static bool IsPlayingOrRecording(this IMovie movie) => movie?.Mode == MovieMode.Play || movie?.Mode == MovieMode.Record;
+		/// <summary>
+		/// Emulation is currently right after the movie's last input frame,
+		/// but no further frames have been emulated.
+		/// </summary>
+		public static bool IsAtEnd(this IMovie movie) => movie != null && movie.Emulator?.Frame == movie.InputLogLength;
 
 
 		/// <summary>

src/BizHawk.Client.EmuHawk/DisplayManager/OSDManager.cs

@@ -273,7 +273,7 @@ namespace BizHawk.Client.EmuHawk
 			{
 				var moviePlaying = GlobalWin.MovieSession.Movie.IsPlaying();
 				// After the last frame of the movie, we want both the last movie input and the current inputs.
-				var atMovieEnd = (GlobalWin.MovieSession.Movie.IsFinished() && GlobalWin.Emulator.Frame == GlobalWin.MovieSession.Movie.InputLogLength);
+				var atMovieEnd = GlobalWin.MovieSession.Movie.IsFinished() && GlobalWin.MovieSession.Movie.IsAtEnd();
 				if (moviePlaying || atMovieEnd)
 				{
 					var input = InputStrMovie();

src/BizHawk.Client.EmuHawk/tools/TAStudio/TAStudio.cs

@@ -203,17 +203,28 @@ namespace BizHawk.Client.EmuHawk
 			// Start Scenario 1: A regular movie is active
 			if (MovieSession.Movie.IsActive() && !(MovieSession.Movie is ITasMovie))
 			{
-				var result = MessageBox.Show("In order to use Tastudio, a new project must be created from the current movie\nThe current movie will be saved and closed, and a new project file will be created\nProceed?", "Convert movie", MessageBoxButtons.OKCancel, MessageBoxIcon.Question);
-				if (result.IsOk())
+				var changesString = "Would you like to save the current movie before closing it?";
+				if (MovieSession.Movie.Changes)
 				{
-					ConvertCurrentMovieToTasproj();
-					StartNewMovieWrapper(CurrentTasMovie);
-					SetUpColumns();
+					changesString = "The current movie has unsaved changes. Would you like to save before closing it?";
 				}
-				else
+				var result = MessageBox.Show(
+					"TAStudio will create a new project file from the current movie.\n\n" + changesString,
+					"Convert movie",
+					MessageBoxButtons.YesNoCancel,
+					MessageBoxIcon.Question);
+				if (result.Equals(DialogResult.Yes))
+				{
+					MovieSession.Movie.Save();
+				}
+				else if (result.Equals(DialogResult.Cancel))
 				{
 					return false;
 				}
+
+				ConvertCurrentMovieToTasproj();
+				StartNewMovieWrapper(CurrentTasMovie);
+				SetUpColumns();
 			}
 
 			// Start Scenario 2: A tasproj is already active