MOHAWK: Add support for the ScummVM save metadata features

The metadata is saved in a separate file to keep compatibility with
the original engine saves.

4 files changed, 255 insertions, 38 deletions

diff --git a/engines/mohawk/detection.cpp b/engines/mohawk/detection.cpp
index 926c296257..986b35c85e 100644
--- a/engines/mohawk/detection.cpp
+++ b/engines/mohawk/detection.cpp
@@ -35,6 +35,7 @@
 
 #ifdef ENABLE_MYST
 #include "mohawk/myst.h"
+#include "mohawk/myst_state.h"
 #endif
 
 #ifdef ENABLE_RIVEN
@@ -184,13 +185,18 @@ public:
 	virtual SaveStateList listSaves(const char *target) const;
 	virtual int getMaximumSaveSlot() const { return 999; }
 	virtual void removeSaveState(const char *target, int slot) const;
+	virtual SaveStateDescriptor querySaveMetaInfos(const char *target, int slot) const;
 };
 
 bool MohawkMetaEngine::hasFeature(MetaEngineFeature f) const {
 	return
 		(f == kSupportsListSaves)
 		|| (f == kSupportsLoadingDuringStartup)
-		|| (f == kSupportsDeleteSave);
+		|| (f == kSupportsDeleteSave)
+		|| (f == kSavesSupportMetaInfo)
+		|| (f == kSavesSupportThumbnail)
+		|| (f == kSavesSupportCreationDate)
+		|| (f == kSavesSupportPlayTime);
 }
 
 SaveStateList MohawkMetaEngine::listSaves(const char *target) const {
@@ -198,12 +204,15 @@ SaveStateList MohawkMetaEngine::listSaves(const char *target) const {
 	SaveStateList saveList;
 
 	// Loading games is only supported in Myst/Riven currently.
+#ifdef ENABLE_MYST
 	if (strstr(target, "myst")) {
-		filenames = g_system->getSavefileManager()->listSavefiles("*.mys");
+		filenames = Mohawk::MystGameState::generateSaveGameList();
 
 		for (uint32 i = 0; i < filenames.size(); i++)
 			saveList.push_back(SaveStateDescriptor(i, filenames[i]));
-	} else if (strstr(target, "riven")) {
+	} else
+#endif
+	if (strstr(target, "riven")) {
 		filenames = g_system->getSavefileManager()->listSavefiles("*.rvn");
 
 		for (uint32 i = 0; i < filenames.size(); i++)
@@ -215,15 +224,35 @@ SaveStateList MohawkMetaEngine::listSaves(const char *target) const {
 
 void MohawkMetaEngine::removeSaveState(const char *target, int slot) const {
 	// Removing saved games is only supported in Myst/Riven currently.
+#ifdef ENABLE_MYST
 	if (strstr(target, "myst")) {
-		Common::StringArray filenames = g_system->getSavefileManager()->listSavefiles("*.mys");
-		g_system->getSavefileManager()->removeSavefile(filenames[slot].c_str());
-	} else if (strstr(target, "riven")) {
+		Common::StringArray filenames = Mohawk::MystGameState::generateSaveGameList();
+		Mohawk::MystGameState::deleteSave(filenames[slot]);
+	} else
+#endif
+	if (strstr(target, "riven")) {
 		Common::StringArray filenames = g_system->getSavefileManager()->listSavefiles("*.rvn");
 		g_system->getSavefileManager()->removeSavefile(filenames[slot].c_str());
 	}
 }
 
+SaveStateDescriptor MohawkMetaEngine::querySaveMetaInfos(const char *target, int slot) const {
+#ifdef ENABLE_MYST
+	if (strstr(target, "myst")) {
+		Common::StringArray filenames = Mohawk::MystGameState::generateSaveGameList();
+
+		if (slot >= (int) filenames.size()) {
+			return SaveStateDescriptor();
+		}
+
+		return Mohawk::MystGameState::querySaveMetaInfos(filenames[slot]);
+	} else
+#endif
+	{
+		return SaveStateDescriptor();
+	}
+}
+
 bool MohawkMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
 	const Mohawk::MohawkGameDescription *gd = (const Mohawk::MohawkGameDescription *)desc;
 
diff --git a/engines/mohawk/myst.cpp b/engines/mohawk/myst.cpp
index 852196e6ac..5337a5e773 100644
--- a/engines/mohawk/myst.cpp
+++ b/engines/mohawk/myst.cpp
@@ -236,7 +236,7 @@ Common::Error MohawkEngine_Myst::run() {
 	// Load game from launcher/command line if requested
 	if (ConfMan.hasKey("save_slot") && canLoadGameStateCurrently()) {
 		uint32 gameToLoad = ConfMan.getInt("save_slot");
-		Common::StringArray savedGamesList = _gameState->generateSaveGameList();
+		Common::StringArray savedGamesList = MystGameState::generateSaveGameList();
 		if (gameToLoad > savedGamesList.size())
 			error ("Could not find saved game");
 		_gameState->load(savedGamesList[gameToLoad]);
@@ -1066,19 +1066,19 @@ void MohawkEngine_Myst::loadResources() {
 }
 
 Common::Error MohawkEngine_Myst::loadGameState(int slot) {
-	if (_gameState->load(_gameState->generateSaveGameList()[slot]))
+	if (_gameState->load(MystGameState::generateSaveGameList()[slot]))
 		return Common::kNoError;
 
 	return Common::kUnknownError;
 }
 
 Common::Error MohawkEngine_Myst::saveGameState(int slot, const Common::String &desc) {
-	Common::StringArray saveList = _gameState->generateSaveGameList();
+	Common::StringArray saveList = MystGameState::generateSaveGameList();
 
 	if ((uint)slot < saveList.size())
-		_gameState->deleteSave(saveList[slot]);
+		MystGameState::deleteSave(saveList[slot]);
 
-	return _gameState->save(Common::String(desc)) ? Common::kNoError : Common::kUnknownError;
+	return _gameState->save(desc) ? Common::kNoError : Common::kUnknownError;
 }
 
 bool MohawkEngine_Myst::canLoadGameStateCurrently() {
diff --git a/engines/mohawk/myst_state.cpp b/engines/mohawk/myst_state.cpp
index 9bfbba67b6..06cd69b23c 100644
--- a/engines/mohawk/myst_state.cpp
+++ b/engines/mohawk/myst_state.cpp
@@ -26,11 +26,41 @@
 
 #include "common/debug.h"
 #include "common/serializer.h"
+#include "common/system.h"
 #include "common/textconsole.h"
 #include "common/util.h"
 
+#include "graphics/thumbnail.h"
+
 namespace Mohawk {
 
+MystSaveMetadata::MystSaveMetadata() {
+	saveDay = 0;
+	saveMonth = 0;
+	saveYear = 0;
+	saveHour = 0;
+	saveMinute = 0;
+	totalPlayTime = 0;
+}
+
+bool MystSaveMetadata::sync(Common::Serializer &s) {
+	static const Common::Serializer::Version kCurrentVersion = 1;
+
+	if (!s.syncVersion(kCurrentVersion)) {
+		return false;
+	}
+
+	s.syncAsByte(saveDay);
+	s.syncAsByte(saveMonth);
+	s.syncAsUint16LE(saveYear);
+	s.syncAsByte(saveHour);
+	s.syncAsByte(saveMinute);
+	s.syncString(saveDescription);
+	s.syncAsUint32LE(totalPlayTime);
+
+	return true;
+}
+
 MystGameState::MystGameState(MohawkEngine_Myst *vm, Common::SaveFileManager *saveFileMan) : _vm(vm), _saveFileMan(saveFileMan) {
 	// Most of the variables are zero at game start.
 	memset(&_globals, 0, sizeof(_globals));
@@ -77,28 +107,15 @@ MystGameState::~MystGameState() {
 }
 
 Common::StringArray MystGameState::generateSaveGameList() {
-	return _saveFileMan->listSavefiles("*.mys");
+	return g_system->getSavefileManager()->listSavefiles("*.mys");
 }
 
 bool MystGameState::load(const Common::String &filename) {
-	Common::InSaveFile *loadFile = _saveFileMan->openForLoading(filename);
-	if (!loadFile)
-		return false;
-
-	debugC(kDebugSaveLoad, "Loading game from '%s'", filename.c_str());
-
-	// First, let's make sure we're using a saved game file from this version of Myst
-	// By checking length of file...
-	int32 size = loadFile->size();
-	if (size != 664 && size != 601) {
-		warning("Incompatible saved game version");
-		delete loadFile;
+	if (!loadState(filename)) {
 		return false;
 	}
 
-	Common::Serializer s(loadFile, nullptr);
-	syncGameState(s, size == 664);
-	delete loadFile;
+	loadMetadata(filename);
 
 	// Set Channelwood elevator state to down, because we start on the lower level
 	_channelwood.elevatorState = 0;
@@ -119,15 +136,72 @@ bool MystGameState::load(const Common::String &filename) {
 	return true;
 }
 
-bool MystGameState::save(const Common::String &fname) {
-	Common::String filename(fname);
-	// Make sure we have the right extension
-	if (!filename.hasSuffix(".mys") && !filename.hasSuffix(".MYS"))
-		filename += ".mys";
+bool MystGameState::loadState(const Common::String &filename) {
+	Common::InSaveFile *loadFile = _saveFileMan->openForLoading(filename);
+	if (!loadFile) {
+		return false;
+	}
+
+	debugC(kDebugSaveLoad, "Loading game from '%s'", filename.c_str());
+
+	// First, let's make sure we're using a saved game file from this version of Myst
+	// By checking length of file...
+	int32 size = loadFile->size();
+	if (size != 664 && size != 601) {
+		warning("Incompatible saved game version");
+		delete loadFile;
+		return false;
+	}
+
+	Common::Serializer s(loadFile, nullptr);
+	syncGameState(s, size == 664);
+	delete loadFile;
+
+	return true;
+}
 
+void MystGameState::loadMetadata(const Common::String &filename) {
+	// Open the metadata file
+	Common::InSaveFile *metadataFile = openMetadataFile(filename);
+	if (!metadataFile) {
+		return;
+	}
+
+	debugC(kDebugSaveLoad, "Loading metadata from '%s'", filename.c_str());
+
+	Common::Serializer m(metadataFile, nullptr);
+
+	// Read the metadata file
+	if (_metadata.sync(m)) {
+		_vm->setTotalPlayTime(_metadata.totalPlayTime);
+	}
+
+	delete metadataFile;
+}
+
+bool MystGameState::save(const Common::String &filename) {
+	// Make sure the description does not have an extension
+	Common::String desc = filename;
+	if (filename.hasSuffix(".mys") || filename.hasSuffix(".MYS")) {
+		desc = removeExtension(filename);
+	}
+
+	if (!saveState(desc)) {
+		return false;
+	}
+
+	updateMetadateForSaving(desc);
+
+	return saveMetadata(desc);
+}
+
+bool MystGameState::saveState(const Common::String &desc) {
+	// Make sure we have the right extension
+	Common::String filename = desc + ".mys";
 	Common::OutSaveFile *saveFile = _saveFileMan->openForSaving(filename);
-	if (!saveFile)
+	if (!saveFile) {
 		return false;
+	}
 
 	debugC(kDebugSaveLoad, "Saving game to '%s'", filename.c_str());
 
@@ -139,6 +213,88 @@ bool MystGameState::save(const Common::String &fname) {
 	return true;
 }
 
+void MystGameState::updateMetadateForSaving(const Common::String &desc) {
+	// Update save creation info
+	TimeDate t;
+	g_system->getTimeAndDate(t);
+	_metadata.saveYear = t.tm_year + 1900;
+	_metadata.saveMonth = t.tm_mon + 1;
+	_metadata.saveDay = t.tm_mday;
+	_metadata.saveHour = t.tm_hour;
+	_metadata.saveMinute = t.tm_min;
+	_metadata.saveDescription = desc;
+	_metadata.totalPlayTime = _vm->getTotalPlayTime();
+}
+
+bool MystGameState::saveMetadata(const Common::String &desc) {
+	// Write the metadata to a separate file so that the save files
+	// are still compatible with the original engine
+	Common::String metadataFilename = desc + ".mym";
+	Common::OutSaveFile *metadataFile = _saveFileMan->openForSaving(metadataFilename);
+	if (!metadataFile) {
+		return false;
+	}
+
+	// Save the metadata
+	Common::Serializer m(nullptr, metadataFile);
+	_metadata.sync(m);
+
+	// Append a thumbnail
+	Graphics::saveThumbnail(*metadataFile);
+
+	metadataFile->finalize();
+	delete metadataFile;
+
+	return true;
+}
+
+SaveStateDescriptor MystGameState::querySaveMetaInfos(const Common::String filename) {
+	SaveStateDescriptor desc;
+	desc.setDescription(filename);
+
+	// Open the metadata file
+	Common::InSaveFile *metadataFile = openMetadataFile(filename);
+	if (!metadataFile) {
+		return desc;
+	}
+
+	Common::Serializer m(metadataFile, nullptr);
+
+	// Read the metadata file
+	Mohawk::MystSaveMetadata metadata;
+	if (!metadata.sync(m)) {
+		delete metadataFile;
+		return desc;
+	}
+
+	// Set the save description
+	desc.setDescription(metadata.saveDescription);
+	desc.setSaveDate(metadata.saveYear, metadata.saveMonth, metadata.saveDay);
+	desc.setSaveTime(metadata.saveHour, metadata.saveMinute);
+	desc.setPlayTime(metadata.totalPlayTime);
+	desc.setThumbnail(Graphics::loadThumbnail(*metadataFile));
+
+	delete metadataFile;
+
+	return desc;
+}
+
+Common::InSaveFile *MystGameState::openMetadataFile(const Common::String &filename) {
+	// Remove the extension
+	Common::String baseName = removeExtension(filename);
+
+	// Open the metadata file
+	return g_system->getSavefileManager()->openForLoading(baseName + ".mym");
+}
+
+Common::String MystGameState::removeExtension(const Common::String &filename) {
+	Common::String baseName = filename;
+	for (uint i = 0; i < 4; i++) {
+		baseName.deleteLastChar();
+	}
+	return baseName;
+}
+
 void MystGameState::syncGameState(Common::Serializer &s, bool isME) {
 	// Globals first
 	s.syncAsUint16LE(_globals.u0);
@@ -317,7 +473,10 @@ void MystGameState::syncGameState(Common::Serializer &s, bool isME) {
 
 void MystGameState::deleteSave(const Common::String &saveName) {
 	debugC(kDebugSaveLoad, "Deleting save file \'%s\'", saveName.c_str());
-	_saveFileMan->removeSavefile(saveName.c_str());
+	Common::String basename = removeExtension(saveName);
+
+	g_system->getSavefileManager()->removeSavefile(saveName);
+	g_system->getSavefileManager()->removeSavefile(basename + ".mym");
 }
 
 void MystGameState::addZipDest(uint16 stack, uint16 view) {
diff --git a/engines/mohawk/myst_state.h b/engines/mohawk/myst_state.h
index b07a0f2469..50359a5b52 100644
--- a/engines/mohawk/myst_state.h
+++ b/engines/mohawk/myst_state.h
@@ -27,6 +27,8 @@
 #include "common/file.h"
 #include "common/str.h"
 
+#include "engines/savestate.h"
+
 namespace Common {
 class Serializer;
 }
@@ -35,15 +37,33 @@ namespace Mohawk {
 
 class MohawkEngine_Myst;
 
+struct MystSaveMetadata {
+	uint8 saveDay;
+	uint8 saveMonth;
+	uint16 saveYear;
+
+	uint8 saveHour;
+	uint8 saveMinute;
+
+	uint32 totalPlayTime;
+
+	Common::String saveDescription;
+
+	MystSaveMetadata();
+	bool sync(Common::Serializer &s);
+};
+
 class MystGameState {
 public:
 	MystGameState(MohawkEngine_Myst*, Common::SaveFileManager*);
 	~MystGameState();
 
-	Common::StringArray generateSaveGameList();
-	bool load(const Common::String &);
-	bool save(const Common::String &);
-	void deleteSave(const Common::String &);
+	static Common::StringArray generateSaveGameList();
+	static SaveStateDescriptor querySaveMetaInfos(const Common::String filename);
+
+	bool load(const Common::String &filename);
+	bool save(const Common::String &filename);
+	static void deleteSave(const Common::String &saveName);
 
 	void addZipDest(uint16 stack, uint16 view);
 	bool isReachableZipDest(uint16 stack, uint16 view);
@@ -268,8 +288,17 @@ public:
 		uint32 generatorDepletionTime;
 	} _stoneship;
 
+	MystSaveMetadata _metadata;
+
 private:
 	void syncGameState(Common::Serializer &s, bool isME);
+	static Common::InSaveFile *openMetadataFile(const Common::String &filename);
+	bool loadState(const Common::String &filename);
+	void loadMetadata(const Common::String &filename);
+	bool saveState(const Common::String &desc);
+	void updateMetadateForSaving(const Common::String &desc);
+	bool saveMetadata(const Common::String &desc);
+	static Common::String removeExtension(const Common::String &filename);
 
 	// The values in these regions are lists of VIEW resources
 	// which correspond to visited zip destinations