/* 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 "mads/scene.h"
#include "mads/compression.h"
#include "mads/mads.h"
#include "mads/dragonsphere/dragonsphere_scenes.h"
#include "mads/nebular/nebular_scenes.h"
#include "mads/phantom/phantom_scenes.h"

namespace MADS {

Scene::Scene(MADSEngine *vm): _vm(vm), _action(_vm), _depthSurface(vm),
		_dirtyAreas(_vm),  _dynamicHotspots(vm), _hotspots(vm),
		_kernelMessages(vm), _sequences(vm), _sprites(vm), _spriteSlots(vm),
		_textDisplay(vm), _userInterface(vm) {
	_priorSceneId = 0;
	_nextSceneId = 0;
	_currentSceneId = 0;
	_sceneLogic = nullptr;
	_sceneInfo = nullptr;
	_cyclingActive = false;
	_cyclingThreshold = 0;
	_cyclingDelay = 0;
	_totalCycleColors = 0;
	_depthStyle = 0;
	_roomChanged = false;
	_reloadSceneFlag = false;
	_freeAnimationFlag = false;
	_animationData = nullptr;
	_activeAnimation = nullptr;
	_textSpacing = -1;
	_frameStartTime = 0;
	_layer = LAYER_GUI;
	_lookFlag = false;
	_bandsRange = 0;
	_scaleRange = 0;
	_interfaceY = 0;
	_spritesCount = 0;
	_variant = 0;

	_paletteUsageF.push_back(PaletteUsage::UsageEntry(0xF));

	// Set up a scene surface that maps to our physical screen drawing surface
	_sceneSurface.init(MADS_SCREEN_WIDTH, MADS_SCENE_HEIGHT, MADS_SCREEN_WIDTH,
		_vm->_screen.getPixels(), Graphics::PixelFormat::createFormatCLUT8());

	// Set up the verb list
	_verbList.push_back(VerbInit(VERB_LOOK, VERB_THAT, PREP_NONE));
	_verbList.push_back(VerbInit(VERB_TAKE, VERB_THAT, PREP_NONE));
	_verbList.push_back(VerbInit(VERB_PUSH, VERB_THAT, PREP_NONE));
	_verbList.push_back(VerbInit(VERB_OPEN, VERB_THAT, PREP_NONE));
	_verbList.push_back(VerbInit(VERB_PUT, VERB_THIS, PREP_RELATIONAL));
	_verbList.push_back(VerbInit(VERB_TALKTO, VERB_THAT, PREP_NONE));
	_verbList.push_back(VerbInit(VERB_GIVE, VERB_THIS, PREP_TO));
	_verbList.push_back(VerbInit(VERB_PULL, VERB_THAT, PREP_NONE));
	_verbList.push_back(VerbInit(VERB_CLOSE, VERB_THAT, PREP_NONE));
	_verbList.push_back(VerbInit(VERB_THROW, VERB_THIS, PREP_TO));
}

Scene::~Scene() {
	delete _sceneLogic;
	delete _sceneInfo;
}

void Scene::clearVocab() {
	_activeVocabs.clear();
}

void Scene::addActiveVocab(int vocabId) {
	if (activeVocabIndexOf(vocabId) == -1) {
		assert(_activeVocabs.size() < 200);
		_activeVocabs.push_back(vocabId);
	}
}

int Scene::activeVocabIndexOf(int vocabId) {
	for (uint i = 0; i < _activeVocabs.size(); ++i) {
		if (_activeVocabs[i] == vocabId)
			return i;
	}

	return -1;
}

void Scene::clearSequenceList() {
	_sequences.clear();
}

void Scene::clearMessageList() {
	_kernelMessages.clear();
	_talkFont = FONT_CONVERSATION;
	_textSpacing  = -1;
}

void Scene::loadSceneLogic() {
	delete _sceneLogic;

	switch (_vm->getGameID()) {
	case GType_RexNebular:
		_sceneLogic = Nebular::SceneFactory::createScene(_vm);
		break;
	case GType_Dragonsphere:
		_sceneLogic = Dragonsphere::SceneFactory::createScene(_vm);
		break;
	case GType_Phantom:
		_sceneLogic = Phantom::SceneFactory::createScene(_vm);
		break;
	default:
		error("Scene logic: Unknown game");
	}
}

void Scene::loadScene(int sceneId, const Common::String &prefix, bool palFlag) {
	// Store the previously active scene number and set the new one
	_priorSceneId = _currentSceneId;
	_currentSceneId = sceneId;

	_variant = 0;
	if (palFlag)
		_vm->_palette->resetGamePalette(18, 10);

	_spriteSlots.reset(false);
	_sequences.clear();
	_kernelMessages.clear();
	_vm->_palette->_paletteUsage.load(&_scenePaletteUsage);

	int flags = SCENEFLAG_LOAD_SHADOW;
	if (_vm->_dithering)
		flags |= SCENEFLAG_DITHER;

	_sceneInfo = SceneInfo::init(_vm);
	_sceneInfo->load(_currentSceneId, _variant, Common::String(), flags,
		_depthSurface, _backgroundSurface);

	// Initialise palette animation for the scene
	initPaletteAnimation(_sceneInfo->_paletteCycles, false);

	// Copy over nodes
	_rails.load(_sceneInfo->_nodes, &_depthSurface, _sceneInfo->_depthStyle);

	// Load hotspots
	loadHotspots();

	// Load vocab
	loadVocab();

	// Load palette usage
	_vm->_palette->_paletteUsage.load(&_paletteUsageF);

	// Load interface
	flags = PALFLAG_RESERVED | ANIMFLAG_LOAD_BACKGROUND;
	if (_vm->_dithering)
		flags |= ANIMFLAG_DITHER;
	if (_vm->_textWindowStill)
		flags |= ANIMFLAG_LOAD_BACKGROUND_ONLY;

	_animationData = Animation::init(_vm, this);
	DepthSurface depthSurface(_vm);
	_animationData->load(_userInterface, depthSurface, prefix, flags, nullptr, nullptr);

	_vm->_palette->_paletteUsage.load(&_scenePaletteUsage);

	_bandsRange = _sceneInfo->_yBandsEnd - _sceneInfo->_yBandsStart;
	_scaleRange = _sceneInfo->_maxScale - _sceneInfo->_minScale;

	_spriteSlots.reset(false);
	_interfaceY = MADS_SCENE_HEIGHT;
	_spritesCount = _sprites.size();

	_userInterface.setup(_vm->_game->_screenObjects._inputMode);

	_vm->_game->_screenObjects._category = CAT_NONE;
	_vm->_events->showCursor();
}

void Scene::loadHotspots() {
	File f(Resources::formatName(RESPREFIX_RM, _currentSceneId, ".HH"));
	MadsPack madsPack(&f);
	bool isV2 = (_vm->getGameID() != GType_RexNebular);

	Common::SeekableReadStream *stream = madsPack.getItemStream(0);
	int count = stream->readUint16LE();
	delete stream;

	stream = madsPack.getItemStream(1);
	_hotspots.clear();
	for (int i = 0; i < count; ++i)
		_hotspots.push_back(Hotspot(*stream, isV2));

	delete stream;
	f.close();
}

void Scene::loadVocab() {
	// Add all the verbs to the active vocab list
	for (uint i = 0; i < _verbList.size(); ++i)
		addActiveVocab(_verbList[i]._id);

	// Load the vocabs for any object descriptions and custom actions
	for (uint objIndex = 0; objIndex < _vm->_game->_objects.size(); ++objIndex) {
		InventoryObject &io = _vm->_game->_objects[objIndex];
		addActiveVocab(io._descId);

		for (int vocabIndex = 0; vocabIndex <io._vocabCount; ++vocabIndex) {
			addActiveVocab(io._vocabList[vocabIndex]._vocabId);
		}
	}

	// Load scene hotspot list vocabs and verbs
	for (uint i = 0; i < _hotspots.size(); ++i) {
		addActiveVocab(_hotspots[i]._vocabId);
		if (_hotspots[i]._verbId)
			addActiveVocab(_hotspots[i]._verbId);
	}

	loadVocabStrings();
}

void Scene::loadVocabStrings() {
	_vocabStrings.clear();
	File f("*VOCAB.DAT");
	Common::String msg;

	for (;;) {
		char c = (char)f.readByte();
		if (f.eos()) break;

		if (c == '\0') {
			_vocabStrings.push_back(msg);
			msg = "";
		} else {
			msg += c;
		}
	}

	f.close();
}

uint32 Scene::getVocabStringsCount() const {
	return _vocabStrings.size();
}

void Scene::initPaletteAnimation(Common::Array<PaletteCycle> &palCycles, bool animFlag) {
	// Initialize the animation palette and ticks list
	_cycleTicks.clear();
	_paletteCycles.clear();

	for (uint i = 0; i < palCycles.size(); ++i) {
		_cycleTicks.push_back(_vm->_events->getFrameCounter());
		_paletteCycles.push_back(palCycles[i]);
	}

	// Save the initial starting palette
	Common::copy(&_vm->_palette->_mainPalette[0], &_vm->_palette->_mainPalette[PALETTE_SIZE],
		&_vm->_palette->_cyclingPalette[0]);

	// Calculate total
	_totalCycleColors = 0;
	for (uint i = 0; i < _paletteCycles.size(); ++i)
		_totalCycleColors += _paletteCycles[i]._colorCount;

	_cyclingThreshold = (_totalCycleColors > 16) ? 3 : 0;
	_cyclingActive = animFlag;
}

void Scene::animatePalette() {
	byte rgb[3];

	if (_cyclingActive) {
		Scene::_cyclingDelay++;
		if (_cyclingDelay >= _cyclingThreshold) {
			uint32 frameCounter = _vm->_events->getFrameCounter();
			bool changesFlag = false;
			for (uint16 idx = 0; idx < _paletteCycles.size(); idx++) {
				if (frameCounter >= (_cycleTicks[idx] + _paletteCycles[idx]._ticks)) {
					_cycleTicks[idx] = frameCounter;
					int count = _paletteCycles[idx]._colorCount;
					int first = _paletteCycles[idx]._firstColorIndex;
					int listIndex = _paletteCycles[idx]._firstListColor;
					changesFlag = true;

					if (count > 1) {
						// Make a copy of the last color
						byte *pSrc = &_vm->_palette->_cyclingPalette[first * 3];
						byte *pEnd = pSrc + count * 3;
						Common::copy(pEnd - 3, pEnd, &rgb[0]);

						// Shift the cycle palette forward one entry
						Common::copy_backward(pSrc, pEnd - 3, pEnd);

						// Move the saved color to the start of the cycle
						Common::copy(&rgb[0], &rgb[3], pSrc);

						if (++listIndex >= count)
							listIndex = 0;
					}

					_paletteCycles[idx]._firstListColor = listIndex;
				}
			}

			if (changesFlag) {
				int firstColor = _paletteCycles[0]._firstColorIndex;
				byte *pSrc = &_vm->_palette->_cyclingPalette[firstColor * 3];
				_vm->_palette->setPalette(pSrc, firstColor, _totalCycleColors);
			}

			_cyclingDelay = 0;
		}
	}
}

bool Scene::getDepthHighBits(const Common::Point &pt) {
	if (_sceneInfo->_depthStyle == 2) {
		return 0;
	} else {
		const byte *p = _depthSurface.getBasePtr(pt.x, pt.y);
		return (*p & 0x70) >> 4;
	}
}

void Scene::loop() {
	while (!_vm->shouldQuit() && !_reloadSceneFlag && (_nextSceneId == _currentSceneId)) {
		// Handle drawing a game frame
		doFrame();

		// TODO: Verify correctness of frame wait
		_vm->_events->waitForNextFrame();

		if (_vm->_dialogs->_pendingDialog != DIALOG_NONE && !_vm->_game->_trigger
			&& _vm->_game->_player._stepEnabled)
			_reloadSceneFlag = true;
	}
}

void Scene::doFrame() {
	Player &player = _vm->_game->_player;
	bool flag = false;

	if (_action._selectedAction || !player._stepEnabled) {
		_action.clear();
		_action._selectedAction = 0;
	}

	if (!_vm->_game->_trigger && !player._trigger) {
		// Refresh the dynamic hotspots if they've changed
		if (_dynamicHotspots._changed)
			_dynamicHotspots.refresh();

		// Check all on-screen visual objects
		_vm->_game->_screenObjects.check(player._stepEnabled && !player._needToWalk &&
				!_vm->_game->_fx);
	}

	if (_action._selectedAction && player._stepEnabled && !player._needToWalk &&
			!_vm->_game->_trigger && !player._trigger) {
		_action.startAction();
		if (_action._activeAction._verbId == Nebular::VERB_LOOK_AT) {
			_action._activeAction._verbId = VERB_LOOK;
			_action._savedFields._command = false;
		}

		flag = true;
	}

	if (flag || (_vm->_game->_trigger && _vm->_game->_triggerMode == SEQUENCE_TRIGGER_PREPARE)) {
		doPreactions();
	}

	player.newWalk();
	if (!_vm->_game->_fx)
		_frameStartTime = _vm->_events->getFrameCounter();

	// Handle parser actions as well as game triggers
	if ((_action._inProgress && !player._moving && !player._needToWalk &&
			(player._facing == player._turnToFacing) && !_vm->_game->_trigger) ||
			(_vm->_game->_trigger && (_vm->_game->_triggerMode == SEQUENCE_TRIGGER_PARSER))) {
		doAction();
	}

	if (_currentSceneId != _nextSceneId) {
		_freeAnimationFlag = true;
	} else {
		doSceneStep();
		checkKeyboard();

		if (_currentSceneId != _nextSceneId) {
			_freeAnimationFlag = true;
		} else {
			player.nextFrame();

			// Cursor update code
			updateCursor();

			if (!_vm->_game->_trigger) {
				// Handle any active sequences
				_sequences.tick();

				// Handle any active animation
				if (_activeAnimation)
					_activeAnimation->update();
			}

			// If the debugget flag is set, show the mouse position
			int mouseTextIndex = 0;
			if (_vm->_debugger->_showMousePos) {
				Common::Point pt = _vm->_events->mousePos();
				Common::String msg = Common::String::format("(%d,%d)", pt.x, pt.y);
				mouseTextIndex = _kernelMessages.add(Common::Point(5, 5),
					0x203, 0, 0, 1, msg);
			}

			if (!_vm->_game->_trigger) {
				if (_reloadSceneFlag || _currentSceneId != _nextSceneId)
					_kernelMessages.reset();
				_kernelMessages.update();
			}

			_userInterface._uiSlots.draw(!_vm->_game->_fx, _vm->_game->_fx);

			// Write any text needed by the interface
			if (_vm->_game->_fx)
				_userInterface.drawTextElements();

			// Draw any elements
			drawElements((ScreenTransition)_vm->_game->_fx, _vm->_game->_fx);

			// Handle message updates
			if (_vm->_game->_fx) {
				uint32 priorTime = _vm->_game->_priorFrameTimer;
				uint32 newTime = _vm->_events->getFrameCounter();
				_sequences.delay(newTime, priorTime);
				_kernelMessages.delay(newTime, priorTime);
			}

			if (_vm->_debugger->_showMousePos)
				// Mouse position display isn't persistent, so remove it
				_kernelMessages.remove(mouseTextIndex);

			// Original had a debugger check/call here to allow pausing after
			// drawing each frame. Not implemented under ScummVM
		}
	}

	if (_vm->_game->_fx)
		_cyclingActive = true;
	_vm->_game->_fx = kTransitionNone;

	if (_freeAnimationFlag)
		freeAnimation();
}

void  Scene::drawElements(ScreenTransition transitionType, bool surfaceFlag) {
	// Draw any sprite backgrounds
	_spriteSlots.drawBackground();

	// Set up dirty areas for any text display
	_textDisplay.setDirtyAreas();

	// Merge any identified dirty areas
	_dirtyAreas.merge(1, DIRTY_AREAS_SIZE);

	// Copy background for the dirty areas to the screen
	_dirtyAreas.copy(&_backgroundSurface, &_vm->_screen, _posAdjust);

	// Handle dirty areas for foreground objects
	if (_vm->getGameID() == GType_RexNebular)	// TODO: Implement for V2 games
		_spriteSlots.setDirtyAreas();
	_textDisplay.setDirtyAreas2();
	_dirtyAreas.merge(1, DIRTY_AREAS_SIZE);

	// Draw sprites that have changed
	if (_vm->getGameID() == GType_RexNebular)	// TODO: Implement for V2 games
		_spriteSlots.drawSprites(&_sceneSurface);

	// Draw text elements onto the view
	_textDisplay.draw(&_vm->_screen);

	if (transitionType) {
		// Fading in the screen
		_vm->_screen.transition(transitionType, surfaceFlag);
		_vm->_sound->startQueuedCommands();
	} else {
		// Copy dirty areas to the screen
		_dirtyAreas.copyToScreen(_vm->_screen._offset);
	}

	_spriteSlots.cleanUp();
	_textDisplay.cleanUp();
}

void Scene::doPreactions() {
	if (_vm->_game->_screenObjects._inputMode == kInputBuildingSentences ||
			_vm->_game->_screenObjects._inputMode == kInputLimitedSentences) {
		_vm->_game->_triggerSetupMode = SEQUENCE_TRIGGER_PREPARE;
		_action.checkAction();
		_sceneLogic->preActions();

		if (_vm->_game->_triggerMode == SEQUENCE_TRIGGER_PREPARE)
			_vm->_game->_trigger = 0;
	}
}

void Scene::doAction() {
	bool flag = false;

	_vm->_game->_triggerSetupMode = SEQUENCE_TRIGGER_PARSER;
	if ((_action._inProgress || _vm->_game->_trigger) && !_action._savedFields._commandError) {
		_sceneLogic->actions();
		flag = !_action._inProgress;
	}

	if (_vm->_game->_screenObjects._inputMode == kInputConversation) {
		_action._inProgress = false;
	} else {
		if ((_action._inProgress || _vm->_game->_trigger) ||
			(!flag && _action._savedFields._commandError == flag)) {
			_vm->_game->_sectionHandler->sectionPtr2();
			flag = !_action._inProgress;
		}

		if ((_action._inProgress || _vm->_game->_trigger) &&
				(!flag || _action._savedFields._commandError == flag)) {
			_vm->_game->doObjectAction();
		}

		if (!_action._savedFields._lookFlag) {
			if (_action._inProgress) {
				_action._savedFields._commandError = true;
				_sceneLogic->postActions();
			}

			if (_action._inProgress) {
				_action._savedFields._commandError = true;
				_sceneLogic->unhandledAction();
			}

			if (_action._inProgress)
				_vm->_game->unhandledAction();
		}
	}

	_action._inProgress = false;
	if (_vm->_game->_triggerMode == SEQUENCE_TRIGGER_PARSER)
		_vm->_game->_trigger = 0;
}

void Scene::doSceneStep() {
	_vm->_game->_triggerSetupMode = SEQUENCE_TRIGGER_DAEMON;
	_sceneLogic->step();
	_vm->_game->_sectionHandler->step();
	_vm->_game->step();

	if (_vm->_game->_triggerMode == SEQUENCE_TRIGGER_DAEMON)
		_vm->_game->_trigger = 0;
}

void Scene::checkKeyboard() {
	if (_vm->_events->isKeyPressed()) {
		Common::Event evt = _vm->_events->_pendingKeys.pop();
		_vm->_game->handleKeypress(evt);
	}

	if ((_vm->_events->_mouseStatus & 3) == 3 && _vm->_game->_player._stepEnabled) {
		_reloadSceneFlag = true;
		_vm->_dialogs->_pendingDialog = DIALOG_GAME_MENU;
		_action.clear();
		_action._selectedAction = 0;
	}
}

void Scene::loadAnimation(const Common::String &resName, int trigger) {
	// WORKAROUND: If there's already a previous active animation used by the
	// scene, then free it before we create the new one
	if (_activeAnimation)
		freeAnimation();
	
	DepthSurface depthSurface(_vm);
	UserInterface interfaceSurface(_vm);

	_activeAnimation = Animation::init(_vm, this);
	_activeAnimation->load(interfaceSurface, depthSurface, resName,
		_vm->_dithering ? ANIMFLAG_DITHER : 0, nullptr, nullptr);
	_activeAnimation->startAnimation(trigger);
}

void Scene::updateCursor() {
	Player &player = _vm->_game->_player;

	CursorType cursorId = CURSOR_ARROW;
	if (_action._interAwaiting == AWAITING_COMMAND && !_vm->_events->_rightMousePressed &&
		_vm->_game->_screenObjects._category == CAT_HOTSPOT) {
		int idx = _vm->_game->_screenObjects._selectedObject -
			_userInterface._categoryIndexes[CAT_HOTSPOT - 1];
		assert(idx >= 0);

		if (idx >= (int)_hotspots.size()) {
			idx -= _hotspots.size();
			_vm->_events->_newCursorId = _dynamicHotspots[idx]._cursor;
		} else {
			idx = _hotspots.size() - idx - 1;
			_vm->_events->_newCursorId = _hotspots[idx]._cursor;
		}

		cursorId = _vm->_events->_newCursorId == CURSOR_NONE ?
		CURSOR_ARROW : _vm->_events->_newCursorId;
	}

	if (!player._stepEnabled)
		cursorId = CURSOR_WAIT;
	if (cursorId >= _vm->_events->_cursorSprites->getCount())
		cursorId = (CursorType)_vm->_events->_cursorSprites->getCount();
	_vm->_events->_newCursorId = cursorId;

	if (cursorId != _vm->_events->_cursorId) {
		_vm->_events->setCursor(cursorId);
	}
}

void Scene::freeCurrentScene() {
	if (_animationData) {
		delete _animationData;
		_animationData = nullptr;
	}
	if (_activeAnimation) {
		delete _activeAnimation;
		_activeAnimation = nullptr;
	}

	_vm->_palette->_paletteUsage.load(nullptr);
	_hotspots.clear();
	_backgroundSurface.free();
	_depthSurface.free();

	delete _sceneInfo;
	_sceneInfo = nullptr;
}

void Scene::removeSprites() {
	for (int idx = _sprites.size() - 1; idx >= _spritesCount; --idx)
		_sprites.remove(idx);
}

void Scene::changeVariant(int variant) {
	_variant = variant;
	_sceneInfo->loadCodes(_depthSurface, variant);
	_spriteSlots.fullRefresh();
}

void Scene::resetScene() {
	_vm->_game->clearQuotes();
	_spriteSlots.fullRefresh(true);
	_sequences.clear();
}

void Scene::freeAnimation() {
	if (_activeAnimation) {
		Player &player = _vm->_game->_player;

		if (!_freeAnimationFlag) {
			_spriteSlots.fullRefresh(true);
			_sequences.scan();
		}

		// Refresh the player
		if (player._visible) {
			player._forceRefresh = true;
			player.update();
		}

		// Remove any kernel messages in use by the animation
		for (uint i = 0; i < _activeAnimation->_messages.size(); ++i) {
			int msgIndex = _activeAnimation->_messages[i]._kernelMsgIndex;
			if (msgIndex >= 0)
				_kernelMessages.remove(msgIndex);
		}

		// Delete the animation
		delete _activeAnimation;
		_activeAnimation = nullptr;
	}

	_freeAnimationFlag = false;
}

void Scene::synchronize(Common::Serializer &s) {
	_action.synchronize(s);
	_rails.synchronize(s);
	_userInterface.synchronize(s);
	s.syncAsByte(_reloadSceneFlag);
	s.syncAsByte(_roomChanged);
	s.syncAsUint16LE(_nextSceneId);
	s.syncAsUint16LE(_priorSceneId);
	_dynamicHotspots.synchronize(s);
}

} // End of namespace MADS