/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "dreamweb/dreamweb.h"
#include "engines/metaengine.h"
#include "gui/saveload.h"
#include "common/config-manager.h"
#include "common/translation.h"

namespace DreamGen {

// Temporary storage for loading the room from a savegame
Room g_madeUpRoomDat;

void DreamGenContext::loadGame() {
	if (data.byte(kCommandtype) != 246) {
		data.byte(kCommandtype) = 246;
		commandOnly(41);
	}
	if (data.word(kMousebutton) == data.word(kOldbutton))
		return; // "noload"
	if (data.word(kMousebutton) == 1)
		doLoad(-1);
}

// if -1, open menu to ask for slot to load
// if >= 0, directly load from that slot
void DreamGenContext::doLoad(int savegameId) {
	data.byte(kLoadingorsave) = 1;

	if (ConfMan.getBool("dreamweb_originalsaveload") && savegameId == -1) {
		showOpBox();
		showLoadOps();
		data.byte(kCurrentslot) = 0;
		showSlots();
		showNames();
		data.byte(kPointerframe) = 0;
		workToScreenM();
		namesToOld();
		data.byte(kGetback) = 0;

		while (data.byte(kGetback) == 0) {
			if (quitRequested())
				return;
			delPointer();
			readMouse();
			showPointer();
			vSync();
			dumpPointer();
			dumpTextLine();
			RectWithCallback loadlist[] = {
				{ kOpsx+176,kOpsx+192,kOpsy+60,kOpsy+76,&DreamGenContext::getBackToOps },
				{ kOpsx+128,kOpsx+190,kOpsy+12,kOpsy+100,&DreamGenContext::actualLoad },
				{ kOpsx+2,kOpsx+92,kOpsy+4,kOpsy+81,&DreamGenContext::selectSlot },
				{ 0,320,0,200,&DreamGenContext::blank },
				{ 0xFFFF,0,0,0,0 }
			};
			checkCoords(loadlist);
			if (data.byte(kGetback) == 2)
				return; // "quitloaded"
		}
	} else {

		if (savegameId == -1) {
			// Open dialog to get savegameId

			const EnginePlugin *plugin = NULL;
			Common::String gameId = ConfMan.get("gameid");
			EngineMan.findGame(gameId, &plugin);
			GUI::SaveLoadChooser *dialog = new GUI::SaveLoadChooser(_("Restore game:"), _("Restore"));
			dialog->setSaveMode(false);
			savegameId = dialog->runModalWithPluginAndTarget(plugin, ConfMan.getActiveDomainName());
			delete dialog;
		}

		if (savegameId < 0) {
			data.byte(kGetback) = 0;
			return;
		}

		loadPosition(savegameId);

		data.byte(kGetback) = 1;
	}

	// If we reach this point, loadPosition() has just been called.
	// Among other things, it will have filled g_MadeUpRoomDat.

	// kTempgraphics might not have been allocated if we bypassed all menus
	if (data.word(kTempgraphics) != 0xFFFF)
		getRidOfTemp();

	startLoading(g_madeUpRoomDat);
	loadRoomsSample();
	data.byte(kRoomloaded) = 1;
	data.byte(kNewlocation) = 255;
	clearSprites();
	initMan();
	initRain();
	data.word(kTextaddressx) = 13;
	data.word(kTextaddressy) = 182;
	data.byte(kTextlen) = 240;
	startup();
	workToScreenCPP();
	data.byte(kGetback) = 4;
}


void DreamGenContext::saveGame() {
	if (data.byte(kMandead) == 2) {
		blank();
		return;
	}

	if (data.byte(kCommandtype) != 247) {
		data.byte(kCommandtype) = 247;
		commandOnly(44);
	}
	if (data.word(kMousebutton) != 1)
		return;

	data.byte(kLoadingorsave) = 2;

	if (ConfMan.getBool("dreamweb_originalsaveload")) {
		showOpBox();
		showSaveOps();
		data.byte(kCurrentslot) = 0;
		showSlots();
		showNames();
		workToScreenM();
		namesToOld();
		data.word(kBufferin) = 0;
		data.word(kBufferout) = 0;
		data.byte(kGetback) = 0;

		while (data.byte(kGetback) == 0) {
			if (quitRequested())
				return;
			delPointer();
			checkInput();
			readMouse();
			showPointer();
			vSync();
			dumpPointer();
			dumpTextLine();

			RectWithCallback savelist[] = {
				{ kOpsx+176,kOpsx+192,kOpsy+60,kOpsy+76,&DreamGenContext::getBackToOps },
				{ kOpsx+128,kOpsx+190,kOpsy+12,kOpsy+100,&DreamGenContext::actualSave },
				{ kOpsx+2,kOpsx+92,kOpsy+4,kOpsy+81,&DreamGenContext::selectSlot },
				{ 0,320,0,200,&DreamGenContext::blank },
				{ 0xFFFF,0,0,0,0 }
			};
			checkCoords(savelist);
		}
		return;
	} else {
		const EnginePlugin *plugin = NULL;
		Common::String gameId = ConfMan.get("gameid");
		EngineMan.findGame(gameId, &plugin);
		GUI::SaveLoadChooser *dialog = new GUI::SaveLoadChooser(_("Save game:"), _("Save"));
		dialog->setSaveMode(true);
		int savegameId = dialog->runModalWithPluginAndTarget(plugin, ConfMan.getActiveDomainName());
		Common::String game_description = dialog->getResultString();
		if (game_description.empty())
			game_description = "Untitled";
		delete dialog;

		if (savegameId < 0) {
			data.byte(kGetback) = 0;
			return;
		}

		char descbuf[17] = { 2, 0 };
		strncpy((char*)descbuf+1, game_description.c_str(), 16);
		unsigned int desclen = game_description.size();
		if (desclen > 15)
			desclen = 15;
		// zero terminate, and pad with ones
		descbuf[++desclen] = 0;
		while (desclen < 17)
			descbuf[++desclen] = 1;
		if (savegameId < 7)
			memcpy(&_saveNames[17*savegameId], descbuf, 17);

		savePosition(savegameId, descbuf);

		// TODO: The below is copied from actualsave
		getRidOfTemp();
		restoreAll(); // reels
		data.word(kTextaddressx) = 13;
		data.word(kTextaddressy) = 182;
		data.byte(kTextlen) = 240;
		redrawMainScrn();
		workToScreenM();
		data.byte(kGetback) = 4;
	}
}

void DreamGenContext::namesToOld() {
	memcpy(_saveNamesOld, _saveNames, 17*7);
}

void DreamGenContext::oldToNames() {
	memcpy(_saveNames, _saveNamesOld, 17*7);
}

void DreamGenContext::saveLoad() {
	if (data.word(kWatchingtime) || (data.byte(kPointermode) == 2)) {
		blank();
		return;
	}
	if (data.byte(kCommandtype) != 253) {
		data.byte(kCommandtype) = 253;
		commandOnly(43);
	}
	if ((data.word(kMousebutton) != data.word(kOldbutton)) && (data.word(kMousebutton) & 1))
		doSaveLoad();
}

void DreamGenContext::showMainOps() {
	showFrame(tempGraphics(), kOpsx+10, kOpsy+10, 8, 0);
	showFrame(tempGraphics(), kOpsx+59, kOpsy+30, 7, 0);
	showFrame(tempGraphics(), kOpsx+128+4, kOpsy+12, 1, 0);
}

void DreamGenContext::showDiscOps() {
	showFrame(tempGraphics(), kOpsx+128+4, kOpsy+12, 1, 0);
	showFrame(tempGraphics(), kOpsx+10, kOpsy+10, 9, 0);
	showFrame(tempGraphics(), kOpsx+59, kOpsy+30, 10, 0);
	showFrame(tempGraphics(), kOpsx+176+2, kOpsy+60-4, 5, 0);
}

void DreamGenContext::actualSave() {
	if (data.byte(kCommandtype) != 222) {
		data.byte(kCommandtype) = 222;
		commandOnly(44);
	}

	if (!(data.word(kMousebutton) & 1))
		return;

	unsigned int slot = data.byte(kCurrentslot);

	const char *desc = &_saveNames[17*slot];
	if (desc[1] == 0) // The actual description string starts at desc[1]
		return;

	savePosition(slot, desc);

	getRidOfTemp();
	restoreAll(); // reels
	data.word(kTextaddressx) = 13;
	data.word(kTextaddressy) = 182;
	data.byte(kTextlen) = 240;
	redrawMainScrn();
	workToScreenM();
	data.byte(kGetback) = 4;
}

void DreamGenContext::actualLoad() {
	if (data.byte(kCommandtype) != 221) {
		data.byte(kCommandtype) = 221;
		commandOnly(41);
	}

	if (data.word(kMousebutton) == data.word(kOldbutton) || data.word(kMousebutton) != 1)
		return;

	unsigned int slot = data.byte(kCurrentslot);

	const char *desc = &_saveNames[17*slot];
	if (desc[1] == 0) // The actual description string starts at desc[1]
		return;

	loadPosition(data.byte(kCurrentslot));
	data.byte(kGetback) = 1;
}

void DreamGenContext::savePosition(unsigned int slot, const char *descbuf) {

	const Room &currentRoom = g_roomData[data.byte(kLocation)];

	Room madeUpRoom = currentRoom;
	madeUpRoom.roomsSample = data.byte(kRoomssample);
	madeUpRoom.mapX = data.byte(kMapx);
	madeUpRoom.mapY = data.byte(kMapy);
	madeUpRoom.liftFlag = data.byte(kLiftflag);
	madeUpRoom.b21 = data.byte(kManspath);
	madeUpRoom.facing = data.byte(kFacing);
	madeUpRoom.b27 = 255;


	engine->processEvents();	// TODO: Is this necessary?

	Common::String filename = engine->getSavegameFilename(slot);
	debug(1, "savePosition: slot %d filename %s", slot, filename.c_str());
	Common::OutSaveFile *outSaveFile = engine->getSaveFileManager()->openForSaving(filename);
	if (!outSaveFile)	// TODO: Do proper error handling!
		error("save could not be opened for writing");

	// Initialize new header
	FileHeader header;

	// Note: _desc is not zero-terminated
	const char *desc = "DREAMWEB DATA FILE COPYRIGHT 1992 CREATIVE REALITY";
	assert(strlen(desc) == sizeof(header._desc));
	memcpy(header._desc, desc, sizeof(header._desc));
	memset(&header._len[0], 0, sizeof(header._len));
	memset(&header._padding[0], 0, sizeof(header._padding));

	// fill length fields in savegame file header
	uint16 len[6] = { 17, kLengthofvars, kLengthofextra,
	                  4*kNumchanges, 48, kLenofreelrouts };
	for (int i = 0; i < 6; ++i)
		header.setLen(i, len[i]);

	outSaveFile->write((const uint8 *)&header, sizeof(FileHeader));
	outSaveFile->write(descbuf, len[0]);
	outSaveFile->write(data.ptr(kStartvars, len[1]), len[1]);
	outSaveFile->write(getSegment(data.word(kExtras)).ptr(kExframedata, len[2]), len[2]);
	outSaveFile->write(getSegment(data.word(kBuffers)).ptr(kListofchanges, len[3]), len[3]);

	// len[4] == 48, which is sizeof(Room) plus 16 for 'Roomscango'
	outSaveFile->write((const uint8 *)&madeUpRoom, sizeof(Room));
	outSaveFile->write(data.ptr(kRoomscango, 16), 16);

	outSaveFile->write(data.ptr(kReelroutines, len[5]), len[5]);

	outSaveFile->finalize();
	if (outSaveFile->err()) {
		// TODO: Do proper error handling
		warning("an error occurred while writing the savegame");
	}

	delete outSaveFile;
}

void DreamGenContext::loadPosition(unsigned int slot) {
	data.word(kTimecount) = 0;
	clearChanges();

	Common::String filename = engine->getSavegameFilename(slot);
	debug(1, "loadPosition: slot %d filename %s", slot, filename.c_str());
	Common::InSaveFile *inSaveFile = engine->getSaveFileManager()->openForLoading(filename);
	if (!inSaveFile)	// TODO: Do proper error handling!
		error("save could not be opened for reading");

	FileHeader header;

	inSaveFile->read((uint8 *)&header, sizeof(FileHeader));

	// read segment lengths from savegame file header
	int len[6];
	for (int i = 0; i < 6; ++i)
		len[i] = header.len(i);
	if (len[0] != 17)
		::error("Error loading save: description buffer isn't 17 bytes");

	if (slot < 7) {
		inSaveFile->read(&_saveNames[17*slot], len[0]);
	} else {
		// The savenames buffer only has room for 7 descriptions
		uint8 namebuf[17];
		inSaveFile->read(namebuf, 17);
	}
	inSaveFile->read(data.ptr(kStartvars, len[1]), len[1]);
	inSaveFile->read(getSegment(data.word(kExtras)).ptr(kExframedata, len[2]), len[2]);
	inSaveFile->read(getSegment(data.word(kBuffers)).ptr(kListofchanges, len[3]), len[3]);

	// len[4] == 48, which is sizeof(Room) plus 16 for 'Roomscango'
	// Note: the values read into g_madeUpRoomDat are only used in actualLoad,
	// which is (almost) immediately called after this function
	inSaveFile->read((uint8 *)&g_madeUpRoomDat, sizeof(Room));
	inSaveFile->read(data.ptr(kRoomscango, 16), 16);

	inSaveFile->read(data.ptr(kReelroutines, len[5]), len[5]);

	delete inSaveFile;
}

// Count number of save files, and load their descriptions into _saveNames
unsigned int DreamGenContext::scanForNames() {
	unsigned int count = 0;

	FileHeader header;

	// TODO: Change this to use SaveFileManager::listSavefiles()
	for (unsigned int slot = 0; slot < 7; ++slot) {
		_saveNames[17*slot+0] = 2;
		_saveNames[17*slot+1] = 0;
		for (int i = 2; i < 17; ++i)
			_saveNames[17*slot+i] = 1;

		// Try opening savegame with the given slot id
		Common::String filename = engine->getSavegameFilename(slot);
		Common::InSaveFile *inSaveFile = engine->getSaveFileManager()->openForLoading(filename);
		if (!inSaveFile)
			continue;

		++count;

		inSaveFile->read((uint8 *)&header, sizeof(FileHeader));

		if (header.len(0) != 17) {
			::warning("Error loading save: description buffer isn't 17 bytes");
			delete inSaveFile;
			continue;
		}

		// NB: Only possible if slot < 7
		inSaveFile->read(&_saveNames[17*slot], 17);

		delete inSaveFile;
	}

	al = (uint8)count;

	return count;
}

void DreamGenContext::loadOld() {
	if (data.byte(kCommandtype) != 252) {
		data.byte(kCommandtype) = 252;
		commandOnly(48);
	}

	if (!(data.word(kMousebutton) & 1))
		return;

	doLoad(-1);

	if (data.byte(kGetback) == 4 || quitRequested())
		return;

	showDecisions();
	workToScreenM();
	data.byte(kGetback) = 0;
}

void DreamGenContext::loadSaveBox() {
	loadIntoTemp("DREAMWEB.G08");
}

// show savegame names (original interface), and set kCursorpos
void DreamBase::showNames() {
	for (int slot = 0; slot < 7; ++slot) {
		// The first character of the savegame name is unused
		Common::String name(&_saveNames[17*slot + 1]);

		if (slot != data.byte(kCurrentslot)) {
			printDirect((const uint8 *)name.c_str(), kOpsx + 21, kOpsy + 10*slot + 10, 200, false);
			continue;
		}
		if (data.byte(kLoadingorsave) != 2) {
			data.word(kCharshift) = 91;
			printDirect((const uint8 *)name.c_str(), kOpsx + 21, kOpsy + 10*slot + 10, 200, false);
			data.word(kCharshift) = 0;
			continue;
		}

		int pos = name.size();
		data.byte(kCursorpos) = pos;
		name += '/'; // cursor character
		printDirect((const uint8 *)name.c_str(), kOpsx + 21, kOpsy + 10*slot + 10, 200, false);
	}
}

void DreamGenContext::checkInput() {
	if (data.byte(kLoadingorsave) == 3)
		return;

	readKey();

	// The first character of the savegame name is unused
	char *name = &_saveNames[17*data.byte(kCurrentslot) + 1];

	if (data.byte(kCurrentkey) == 0) {
		return;
	} else if (data.byte(kCurrentkey) == 13) {
		data.byte(kLoadingorsave) = 3;
	} else if (data.byte(kCurrentkey) == 8) {
		if (data.byte(kCursorpos) == 0)
			return;

		--data.byte(kCursorpos);
		name[data.byte(kCursorpos)] = 0;
		name[data.byte(kCursorpos)+1] = 1;
	} else {
		if (data.byte(kCursorpos) == 14)
			return;

		name[data.byte(kCursorpos)] = data.byte(kCurrentkey);
		name[data.byte(kCursorpos)+1] = 0;
		name[data.byte(kCursorpos)+2] = 1;
		++data.byte(kCursorpos);
	}

	showOpBox();
	showNames();
	showSlots();
	showSaveOps();
	workToScreenM();
}


} // End of namespace DreamGen