/* 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 "common/scummsys.h"
#include "common/config-manager.h"
#include "common/memstream.h"
#include "common/serializer.h"
#include "graphics/palette.h"
#include "graphics/scaler.h"
#include "graphics/thumbnail.h"
#include "mads/mads.h"
#include "mads/compression.h"
#include "mads/game.h"
#include "mads/game_data.h"
#include "mads/events.h"
#include "mads/screen.h"
#include "mads/msurface.h"
#include "mads/resources.h"
#include "mads/dragonsphere/game_dragonsphere.h"
#include "mads/nebular/game_nebular.h"
#include "mads/phantom/game_phantom.h"

namespace MADS {

Game *Game::init(MADSEngine *vm) {
	switch (vm->getGameID()) {
	case GType_RexNebular:
		return new Nebular::GameNebular(vm);
	case GType_Dragonsphere:
		return new Dragonsphere::GameDragonsphere(vm);
	case GType_Phantom:
		return new Phantom::GamePhantom(vm);
	default:
		error("Game: Unknown game");
	}

	return nullptr;
}

Game::Game(MADSEngine *vm): _vm(vm), _surface(nullptr), _objects(vm), 
		_scene(vm), _screenObjects(vm), _player(vm) {
	_sectionNumber = _priorSectionNumber = 0;
	_loadGameSlot = -1;
	_lastSave = -1;
	_saveFile = nullptr;
	_statusFlag = 0;
	_sectionHandler = nullptr;
	_sectionNumber = 1;
	_priorSectionNumber = 0;
	_currentSectionNumber = -1;
	_kernelMode = KERNEL_GAME_LOAD;
	_quoteEmergency = false;
	_vocabEmergency = false;
	_aaName = "*I0.AA";
	_priorFrameTimer = 0;
	_anyEmergency = false;
	_triggerMode = SEQUENCE_TRIGGER_PARSER;
	_triggerSetupMode = SEQUENCE_TRIGGER_DAEMON;
	_winStatus = 0;
	_widepipeCtr = 0;

	// Load the inventory object list
	_objects.load();
	if (_objects._inventoryList.size() > 0)
		// At least one item in default inventory, so select first item for display
		_scene._userInterface._selectedInvIndex = 0;

	// Load the quotes
	loadQuotes();
}

Game::~Game() {
	delete _saveFile;
	delete _surface;
	delete _sectionHandler;
}

void Game::run() {
	initialiseGlobals();

	// If requested, load a savegame instead of showing the intro
	if (ConfMan.hasKey("save_slot")) {
		int saveSlot = ConfMan.getInt("save_slot");
		if (saveSlot >= 0 && saveSlot <= 999)
			_loadGameSlot = saveSlot;
	}

	_statusFlag = true;
	int protectionResult = -1;
	
	if (_loadGameSlot == -1) {
		protectionResult = checkCopyProtection();
		switch (protectionResult) {
		case PROTECTION_FAIL:
			// Copy protection failed
			_scene._nextSceneId = 804;
			break;
		case PROTECTION_ESCAPE:
			// User escaped out of copy protection dialog
			_vm->quitGame();
			break;
		default:
			// Copy protection check succeeded
			_scene._nextSceneId = 101;
			_scene._priorSceneId = -1;
			break;
		}
	}

	// Get the initial starting time for the first scene
	_scene._frameStartTime = _vm->_events->getFrameCounter();

	if (_saveFile == nullptr && protectionResult != -1 && protectionResult != -2) {
		initSection(_sectionNumber);
		_statusFlag = true;

		_vm->_dialogs->_pendingDialog = DIALOG_DIFFICULTY;
		_vm->_dialogs->showDialog();
		_vm->_dialogs->_pendingDialog = DIALOG_NONE;

		_priorSectionNumber = 0;
		_priorSectionNumber = -1;
		_scene._priorSceneId = 0;
		_scene._currentSceneId = -1;
	}

	if (protectionResult != 1 && protectionResult != 2) {
		initialiseGlobals();
	}

	if (_statusFlag)
		gameLoop();
}

void Game::gameLoop() {
	while (!_vm->shouldQuit() && _statusFlag) {
		if (_loadGameSlot != -1) {
			loadGame(_loadGameSlot);
			_loadGameSlot = -1;
		}

		setSectionHandler();
		_sectionHandler->preLoadSection();
		initSection(_sectionNumber);
		_sectionHandler->postLoadSection();

		_scene._spriteSlots.reset();

		if (_sectionNumber == _currentSectionNumber) {
			sectionLoop();
		}

		_player.releasePlayerSprites();
		assert(_scene._sprites.size() == 0);

		_vm->_palette->unlock();
		_vm->_events->waitCursor();
		_vm->_events->freeCursors();
		_vm->_sound->closeDriver();
	}

	_vm->_palette->close();
}

void Game::sectionLoop() {
	while (!_vm->shouldQuit() && _statusFlag && _sectionNumber == _currentSectionNumber) {
		_kernelMode = KERNEL_ROOM_PRELOAD;
		_player._spritesChanged = true;
		_quoteEmergency = false;
		_vocabEmergency = false;
		_vm->_events->waitCursor();

		_scene.clearVocab();
		_scene._dynamicHotspots.clear();
		_scene.loadSceneLogic();

		_player._walkAnywhere = false;
		_player._stepEnabled = true;
		_player._visible = true;
		_vm->_dialogs->_defaultPosition = Common::Point(-1, -1);
		_visitedScenes.add(_scene._nextSceneId);

		// Reset the user interface
		_screenObjects._forceRescan = true;
		_screenObjects._inputMode = kInputBuildingSentences;
		_scene._userInterface._scrollbarActive = SCROLLBAR_NONE;
		
		_player._loadsFirst = true;

		_scene._sceneLogic->setup();
		if (_player._spritesChanged || _player._loadsFirst) {
			if (_player._spritesLoaded)
				_player.releasePlayerSprites();
			_vm->_palette->resetGamePalette(18, 10);
			_scene._spriteSlots.reset();
		} else {
			_vm->_palette->initPalette();
		}

		// Set up scene palette usage
		_scene._scenePaletteUsage.clear();
		_scene._scenePaletteUsage.push_back(PaletteUsage::UsageEntry(0xF0));
		_scene._scenePaletteUsage.push_back(PaletteUsage::UsageEntry(0xF1));
		_scene._scenePaletteUsage.push_back(PaletteUsage::UsageEntry(0xF2));
		_vm->_palette->_paletteUsage.load(&_scene._scenePaletteUsage);
		
		if (!_player._spritesLoaded && _player._loadsFirst) {
			if (_player.loadSprites(""))
				_vm->quitGame();
			_player._loadedFirst = true;
		}

		_scene.loadScene(_scene._nextSceneId, _aaName, 0);
		_vm->_sound->pauseNewCommands();

		if (!_player._spritesLoaded) {
			if (_player.loadSprites(""))
				_vm->quitGame();
			_player._loadedFirst = false;
		}

		_vm->_events->initVars();
		_scene._userInterface._highlightedCommandIndex = -1;
		_scene._userInterface._highlightedInvIndex = -1;
		_scene._userInterface._highlightedItemVocabIndex = -1;

		_scene._action.clear();
		_player.setFinalFacing();
		_player._facing = _player._turnToFacing;
		_player.cancelCommand();
		_kernelMode = KERNEL_ROOM_INIT;

		switch (_vm->_screenFade) {
		case SCREEN_FADE_SMOOTH:
			_fx = kTransitionFadeOutIn;
			break;
		case SCREEN_FADE_FAST:
			_fx = kCenterVertTransition;
			break;
		default:
			_fx = kTransitionNone;
			break;
		}

		_trigger = 0;
		_priorFrameTimer = _scene._frameStartTime;

		// Call the scene logic for entering the given scene
		_triggerSetupMode = SEQUENCE_TRIGGER_DAEMON;
		_scene._sceneLogic->enter();

		// If in the middle of restoring a game, handle the rest of the loading
		if (_saveFile != nullptr) {
			Common::Serializer s(_saveFile, nullptr);
			synchronize(s, false);
			delete _saveFile;
			_saveFile = nullptr;
		}

		// Set player data
		_player._targetPos = _player._playerPos;
		_player._turnToFacing = _player._facing;
		_player._targetFacing = _player._facing;
		_player.selectSeries();
		_player.updateFrame();

		_player._beenVisible = _player._visible;
		_player._special = _scene.getDepthHighBits(_player._playerPos);
		_player._priorTimer = _scene._frameStartTime - _player._ticksAmount;
		_player.idle();

		if (_scene._userInterface._selectedInvIndex >= 0) {
			_scene._userInterface.loadInventoryAnim(
				_objects._inventoryList[_scene._userInterface._selectedInvIndex]);
		} else {
			_scene._userInterface.noInventoryAnim();
		}

		_kernelMode = KERNEL_ACTIVE_CODE;
		_scene._roomChanged = false;

		if ((_quoteEmergency || _vocabEmergency) && !_anyEmergency) {
			_scene._currentSceneId = _scene._priorSceneId;
			_anyEmergency = true;
		} else {
			_anyEmergency = false;
			_scene.loop();
		}

		_vm->_events->waitCursor();
		_kernelMode = KERNEL_ROOM_PRELOAD;

		delete _scene._activeAnimation;
		_scene._activeAnimation = nullptr;

		_scene._reloadSceneFlag = false;

		_scene._userInterface.noInventoryAnim();
		_scene.removeSprites();

		if (!_player._loadedFirst) {
			_player._spritesLoaded = false;
			_player._spritesChanged = true;
		}

		// Clear the scene
		_scene.freeCurrentScene();
		_sectionNumber = _scene._nextSceneId / 100;

		// Check whether to show a dialog
		checkShowDialog();
	}
}

void Game::initSection(int sectionNumber) {
	_priorSectionNumber = _currentSectionNumber;
	_currentSectionNumber = sectionNumber;

	_vm->_palette->resetGamePalette(18, 10);
	_vm->_palette->setLowRange();

	if (_scene._layer == LAYER_GUI)
		_vm->_palette->setPalette(_vm->_palette->_mainPalette, 0, 4);

	_vm->_events->loadCursors("*CURSOR.SS");
	
	assert(_vm->_events->_cursorSprites);
	_vm->_events->setCursor2((_vm->_events->_cursorSprites->getCount() <= 1) ? 
		CURSOR_ARROW : CURSOR_WAIT);
}

void Game::loadQuotes() {
	File f("*QUOTES.DAT");

	Common::String msg;
	while (true) {
		uint8 b = f.readByte();

		msg += b;
		if (f.eos() || b == '\0') {
			// end of string, add it to the strings list
			_quotes.push_back(msg);
			msg = "";
		}

		if (f.eos()) break;
	}

	f.close();
}

Common::StringArray Game::getMessage(uint32 id) {
	File f("*MESSAGES.DAT");
	int count = f.readUint16LE();

	for (int idx = 0; idx < count; ++idx) {
		uint32 itemId = f.readUint32LE();
		uint32 offset = f.readUint32LE();
		uint16 size = f.readUint16LE();

		if (itemId == id) {
			// Get the source buffer size
			uint16 sizeIn;
			if (idx == (count - 1)) {
				sizeIn = f.size() - offset;
			} else {
				f.skip(4);
				uint32 nextOffset = f.readUint32LE();
				sizeIn = nextOffset - offset;
			}

			// Get the compressed data
			f.seek(offset);
			byte *bufferIn = new byte[sizeIn];
			f.read(bufferIn, sizeIn);

			// Decompress it
			char *bufferOut = new char[size];
			FabDecompressor fab;
			fab.decompress(bufferIn, sizeIn, (byte *)bufferOut, size);

			// Form the output string list
			Common::StringArray result;
			const char *p = bufferOut;
			while (p < (bufferOut + size)) {
				result.push_back(p);
				p += strlen(p) + 1;
			}

			delete[] bufferIn;
			delete[] bufferOut;
			return result;
		}
	}

	error("Invalid message Id specified");
}

static const char *const DEBUG_STRING = "WIDEPIPE";

void Game::handleKeypress(const Common::Event &event) {
	if (event.kbd.flags & Common::KBD_CTRL) {
		if (_widepipeCtr == 8) {
			// Implement original game cheating keys here someday
		} else {
			if (event.kbd.keycode == (Common::KEYCODE_a +
					(DEBUG_STRING[_widepipeCtr] - 'a'))) {
				if (++_widepipeCtr == 8) {
					MessageDialog *dlg = new MessageDialog(_vm, 2,
						"CHEATING ENABLED", "(for your convenience).");
					dlg->show();
					delete dlg;
				}
			}
		}
	}

	switch (event.kbd.keycode) {
	case Common::KEYCODE_F1:
		_vm->_dialogs->_pendingDialog = DIALOG_GAME_MENU;
		break;
	case Common::KEYCODE_F5:
		_vm->_dialogs->_pendingDialog = DIALOG_SAVE;
		break;
	case Common::KEYCODE_F7:
		_vm->_dialogs->_pendingDialog = DIALOG_RESTORE;
		break;
	default:
		break;
	}

	warning("TODO: handleKeypress - %d", (int)event.kbd.keycode);
}

void Game::synchronize(Common::Serializer &s, bool phase1) {
	if (phase1) {
		s.syncAsSint16LE(_fx);
		s.syncAsSint16LE(_trigger);
		s.syncAsUint16LE(_triggerSetupMode);
		s.syncAsUint16LE(_triggerMode);
		synchronizeString(s, _aaName);
		s.syncAsSint16LE(_lastSave);

		_scene.synchronize(s);
		_objects.synchronize(s);
		_visitedScenes.synchronize(s);
		_player.synchronize(s);
		_screenObjects.synchronize(s);
	} else {
		// Load scene specific data for the loaded scene
		_scene._sceneLogic->synchronize(s);
	}
}

void Game::loadGame(int slotNumber) {
	_saveFile = g_system->getSavefileManager()->openForLoading(
		_vm->generateSaveName(slotNumber));
	
	Common::Serializer s(_saveFile, nullptr);
	
	// Load the savaegame header
	MADSSavegameHeader header;
	if (!readSavegameHeader(_saveFile, header))
		error("Invalid savegame");

	if (header._thumbnail) {
		header._thumbnail->free();
		delete header._thumbnail;
	}

	// Load most of the savegame data with the exception of scene specific info
	synchronize(s, true);

	// Set up section/scene and other initial states for post-load
	_scene._userInterface._selectedInvIndex = -1;
	_currentSectionNumber = -2;
	_scene._currentSceneId = -2;
	_sectionNumber = _scene._nextSceneId / 100;
	_scene._frameStartTime = _vm->_events->getFrameCounter();

	_player._spritesLoaded = false;
	_player._spritesChanged = true;
}

void Game::saveGame(int slotNumber, const Common::String &saveName) {
	Common::OutSaveFile *out = g_system->getSavefileManager()->openForSaving(
		_vm->generateSaveName(slotNumber));

	MADSSavegameHeader header;
	header._saveName = saveName;
	writeSavegameHeader(out, header);

	Common::Serializer s(nullptr, out);
	synchronize(s, true);
	synchronize(s, false);

	out->finalize();
	delete out;
}

const char *const SAVEGAME_STR = "MADS";
#define SAVEGAME_STR_SIZE 4

bool Game::readSavegameHeader(Common::InSaveFile *in, MADSSavegameHeader &header) {
	char saveIdentBuffer[SAVEGAME_STR_SIZE + 1];
	header._thumbnail = nullptr;

	// Validate the header Id
	in->read(saveIdentBuffer, SAVEGAME_STR_SIZE + 1);
	if (strncmp(saveIdentBuffer, SAVEGAME_STR, SAVEGAME_STR_SIZE))
		return false;

	header._version = in->readByte();
	if (header._version > MADS_SAVEGAME_VERSION)
		return false;

	// Read in the string
	header._saveName.clear();
	char ch;
	while ((ch = (char)in->readByte()) != '\0') header._saveName += ch;

	// Get the thumbnail
	header._thumbnail = Graphics::loadThumbnail(*in);
	if (!header._thumbnail)
		return false;

	// Read in save date/time
	header._year = in->readSint16LE();
	header._month = in->readSint16LE();
	header._day = in->readSint16LE();
	header._hour = in->readSint16LE();
	header._minute = in->readSint16LE();
	header._totalFrames = in->readUint32LE();

	return true;
}

void Game::writeSavegameHeader(Common::OutSaveFile *out, MADSSavegameHeader &header) {
	// Write out a savegame header
	out->write(SAVEGAME_STR, SAVEGAME_STR_SIZE + 1);

	out->writeByte(MADS_SAVEGAME_VERSION);

	// Write savegame name
	out->write(header._saveName.c_str(), header._saveName.size());
	out->writeByte('\0');

	// Get the active palette
	uint8 thumbPalette[256 * 3];
	g_system->getPaletteManager()->grabPalette(thumbPalette, 0, 256);

	// Create a thumbnail and save it
	Graphics::Surface *thumb = new Graphics::Surface();
	::createThumbnail(thumb, _vm->_screen.getData(), MADS_SCREEN_WIDTH, MADS_SCREEN_HEIGHT, thumbPalette);
	Graphics::saveThumbnail(*out, *thumb);
	thumb->free();
	delete thumb;

	// Write out the save date/time
	TimeDate td;
	g_system->getTimeAndDate(td);
	out->writeSint16LE(td.tm_year + 1900);
	out->writeSint16LE(td.tm_mon + 1);
	out->writeSint16LE(td.tm_mday);
	out->writeSint16LE(td.tm_hour);
	out->writeSint16LE(td.tm_min);
	out->writeUint32LE(_vm->_events->getFrameCounter());
}

} // End of namespace MADS