/* 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/system.h"

#include "sci/sci.h"
#include "sci/engine/features.h"
#include "sci/engine/kernel.h"
#include "sci/engine/savegame.h"
#include "sci/engine/selector.h"
#include "sci/engine/state.h"
#include "sci/console.h"
#include "sci/debug.h"	// for g_debug_simulated_key
#include "sci/event.h"
#include "sci/graphics/coordadjuster.h"
#include "sci/graphics/cursor.h"
#include "sci/graphics/maciconbar.h"
#ifdef ENABLE_SCI32
#include "sci/graphics/frameout.h"
#endif

namespace Sci {

reg_t kGetEvent(EngineState *s, int argc, reg_t *argv) {
	int mask = argv[0].toUint16();
	reg_t obj = argv[1];
	SciEvent curEvent;
	int modifier_mask = getSciVersion() <= SCI_VERSION_01 ? SCI_KEYMOD_ALL : SCI_KEYMOD_NO_FOOLOCK;
	uint16 modifiers = 0;
	SegManager *segMan = s->_segMan;
	Common::Point mousePos;

	// For Mac games with an icon bar, handle possible icon bar events first
	if (g_sci->hasMacIconBar()) {
		reg_t iconObj = g_sci->_gfxMacIconBar->handleEvents();
		if (!iconObj.isNull())
			invokeSelector(s, iconObj, SELECTOR(select), argc, argv, 0, NULL);
	}

	// If there's a simkey pending, and the game wants a keyboard event, use the
	// simkey instead of a normal event
	if (g_debug_simulated_key && (mask & SCI_EVENT_KEYBOARD)) {
		// In case we use a simulated event we query the current mouse position
		mousePos = g_sci->_gfxCursor->getPosition();

		// Limit the mouse cursor position, if necessary
		g_sci->_gfxCursor->refreshPosition();

		writeSelectorValue(segMan, obj, SELECTOR(type), SCI_EVENT_KEYBOARD); // Keyboard event
		writeSelectorValue(segMan, obj, SELECTOR(message), g_debug_simulated_key);
		writeSelectorValue(segMan, obj, SELECTOR(modifiers), SCI_KEYMOD_NUMLOCK); // Numlock on
		writeSelectorValue(segMan, obj, SELECTOR(x), mousePos.x);
		writeSelectorValue(segMan, obj, SELECTOR(y), mousePos.y);
		g_debug_simulated_key = 0;
		return make_reg(0, 1);
	}
	
	curEvent = g_sci->getEventManager()->getSciEvent(mask);

	if (s->_delayedRestoreGame) {
		// delayed restore game from ScummVM menu got triggered
		gamestate_delayedrestore(s);
		return NULL_REG;
	}

	// For a real event we use its associated mouse position
#ifdef ENABLE_SCI32
	if (getSciVersion() >= SCI_VERSION_2)
		mousePos = curEvent.mousePosSci;
	else {
#endif
		mousePos = curEvent.mousePos;
		// Limit the mouse cursor position, if necessary
		g_sci->_gfxCursor->refreshPosition();
#ifdef ENABLE_SCI32
	}
#endif

	if (g_sci->getVocabulary())
		g_sci->getVocabulary()->parser_event = NULL_REG; // Invalidate parser event

	if (s->_cursorWorkaroundActive) {
		// We check if the actual cursor position is inside specific rectangles
		// where the cursor itself should be moved to. If this is the case, we
		// set the mouse cursor's position to be within the rectangle in
		// question. Check GfxCursor::setPosition(), for a more detailed
		// explanation and a list of cursor position workarounds.
		if (s->_cursorWorkaroundRect.contains(mousePos.x, mousePos.y)) {
			// For OpenPandora and possibly other platforms, that support analog-stick control + touch screen
			// control at the same time: in case the cursor is currently at the coordinate set by the scripts,
			// we will count down instead of immediately disabling the workaround.
			// On OpenPandora the cursor position is set, but it's overwritten shortly afterwards by the
			// touch screen. In this case we would sometimes disable the workaround, simply because the touch
			// screen hasn't yet overwritten the position and thus the workaround would not work anymore.
			// On OpenPandora it would sometimes work and sometimes not without this.
			if (s->_cursorWorkaroundPoint == mousePos) {
				// Cursor is still at the same spot as set by the scripts
				if (s->_cursorWorkaroundPosCount > 0) {
					s->_cursorWorkaroundPosCount--;
				} else {
					// Was for quite a bit of time at that spot, so disable workaround now
					s->_cursorWorkaroundActive = false;
				}
			} else {
				// Cursor has moved, but is within the rect -> disable workaround immediately
				s->_cursorWorkaroundActive = false;
			}
		} else {
			mousePos.x = s->_cursorWorkaroundPoint.x;
			mousePos.y = s->_cursorWorkaroundPoint.y;
		}
	}

	writeSelectorValue(segMan, obj, SELECTOR(x), mousePos.x);
	writeSelectorValue(segMan, obj, SELECTOR(y), mousePos.y);

	// Get current keyboard modifiers, only keep relevant bits
	modifiers = curEvent.modifiers & modifier_mask;
	if (g_sci->getPlatform() == Common::kPlatformDOS) {
		// We are supposed to emulate SCI running in DOS

		// We set the higher byte of the modifiers to 02h
		// Original SCI also did that indirectly, because it asked BIOS for shift status
		// via AH=0x02 INT16, which then sets the shift flags in AL
		// AH is supposed to be destroyed in that case and it's not defined that 0x02
		// is still in it on return. The value of AX was then set into the modifiers selector.
		// At least one fan-made game (Betrayed Alliance) requires 0x02 to be in the upper byte,
		// otherwise the darts game (script 111) will not work properly.

		// It seems Sierra fixed this behaviour (effectively bug) in the SCI1 keyboard driver.
		// SCI32 also resets the upper byte.

		// This was verified in SSCI itself by creating a SCI game and checking behavior.
		if (getSciVersion() <= SCI_VERSION_01) {
			modifiers |= 0x0200;
		}
	}

	switch (curEvent.type) {
	case SCI_EVENT_QUIT:
		s->abortScriptProcessing = kAbortQuitGame; // Terminate VM
		g_sci->_debugState.seeking = kDebugSeekNothing;
		g_sci->_debugState.runningStep = 0;
		break;

	case SCI_EVENT_KEYBOARD:
		writeSelectorValue(segMan, obj, SELECTOR(type), SCI_EVENT_KEYBOARD); // Keyboard event
		s->r_acc = make_reg(0, 1);

		writeSelectorValue(segMan, obj, SELECTOR(message), curEvent.character);
		// We only care about the translated character
		writeSelectorValue(segMan, obj, SELECTOR(modifiers), modifiers);
		break;

	case SCI_EVENT_MOUSE_RELEASE:
	case SCI_EVENT_MOUSE_PRESS:
		// track left buttton clicks, if requested
		if (curEvent.type == SCI_EVENT_MOUSE_PRESS && curEvent.modifiers == 0 && g_debug_track_mouse_clicks) {
			g_sci->getSciDebugger()->debugPrintf("Mouse clicked at %d, %d\n",
						mousePos.x, mousePos.y);
		}

		if (mask & curEvent.type) {
			writeSelectorValue(segMan, obj, SELECTOR(type), curEvent.type);
			writeSelectorValue(segMan, obj, SELECTOR(message), 0);
			writeSelectorValue(segMan, obj, SELECTOR(modifiers), modifiers);
			s->r_acc = make_reg(0, 1);
		}
		break;

	default:
		// Return a null event
		writeSelectorValue(segMan, obj, SELECTOR(type), SCI_EVENT_NONE);
		writeSelectorValue(segMan, obj, SELECTOR(message), 0);
		writeSelectorValue(segMan, obj, SELECTOR(modifiers), modifiers);
		s->r_acc = NULL_REG;
	}

	if ((s->r_acc.getOffset()) && (g_sci->_debugState.stopOnEvent)) {
		g_sci->_debugState.stopOnEvent = false;

		// A SCI event occurred, and we have been asked to stop, so open the debug console
		Console *con = g_sci->getSciDebugger();
		con->debugPrintf("SCI event occurred: ");
		switch (curEvent.type) {
		case SCI_EVENT_QUIT:
			con->debugPrintf("quit event\n");
			break;
		case SCI_EVENT_KEYBOARD:
			con->debugPrintf("keyboard event\n");
			break;
		case SCI_EVENT_MOUSE_RELEASE:
		case SCI_EVENT_MOUSE_PRESS:
			con->debugPrintf("mouse click event\n");
			break;
		default:
			con->debugPrintf("unknown or no event (event type %d)\n", curEvent.type);
		}

		con->attach();
		con->onFrame();
	}

	if (g_sci->_features->detectDoSoundType() <= SCI_VERSION_0_LATE) {
		// If we're running a sound-SCI0 game, update the sound cues, to
		// compensate for the fact that sound-SCI0 does not poll to update
		// the sound cues itself, like sound-SCI1 and later do with
		// cmdUpdateSoundCues. kGetEvent is called quite often, so emulate
		// the sound-SCI1 behavior of cmdUpdateSoundCues with this call
		g_sci->_soundCmd->updateSci0Cues();
	}

	// Wait a bit here, so that the CPU isn't maxed out when the game
	// is waiting for user input (e.g. when showing text boxes) - bug
	// #3037874. Make sure that we're not delaying while the game is
	// benchmarking, as that will affect the final benchmarked result -
	// check bugs #3058865 and #3127824
	if (s->_gameIsBenchmarking) {
		// Game is benchmarking, don't add a delay
	} else {
		g_system->delayMillis(10);
	}

	return s->r_acc;
}

struct KeyDirMapping {
	uint16 key;
	uint16 direction;
};

const KeyDirMapping keyToDirMap[] = {
	{ SCI_KEY_HOME,   8 }, { SCI_KEY_UP,     1 }, { SCI_KEY_PGUP,   2 },
	{ SCI_KEY_LEFT,   7 }, { SCI_KEY_CENTER, 0 }, { SCI_KEY_RIGHT,  3 },
	{ SCI_KEY_END,    6 }, { SCI_KEY_DOWN,   5 }, { SCI_KEY_PGDOWN, 4 },
};

reg_t kMapKeyToDir(EngineState *s, int argc, reg_t *argv) {
	reg_t obj = argv[0];
	SegManager *segMan = s->_segMan;

	if (readSelectorValue(segMan, obj, SELECTOR(type)) == SCI_EVENT_KEYBOARD) { // Keyboard
		uint16 message = readSelectorValue(segMan, obj, SELECTOR(message));
		uint16 eventType = SCI_EVENT_DIRECTION;
		// It seems with SCI1 Sierra started to add the SCI_EVENT_DIRECTION bit instead of setting it directly.
		// It was done inside the keyboard driver and is required for the PseudoMouse functionality and class
		// to work (script 933).
		if (g_sci->_features->detectPseudoMouseAbility() == kPseudoMouseAbilityTrue) {
			eventType |= SCI_EVENT_KEYBOARD;
		}

		for (int i = 0; i < 9; i++) {
			if (keyToDirMap[i].key == message) {
				writeSelectorValue(segMan, obj, SELECTOR(type), eventType);
				writeSelectorValue(segMan, obj, SELECTOR(message), keyToDirMap[i].direction);
				return TRUE_REG;	// direction mapped
			}
		}

		return NULL_REG;	// unknown direction
	}

	return s->r_acc;	// no keyboard event to map, leave accumulator unchanged
}

reg_t kGlobalToLocal(EngineState *s, int argc, reg_t *argv) {
	reg_t obj = argv[0];
	SegManager *segMan = s->_segMan;

	if (obj.getSegment()) {
		int16 x = readSelectorValue(segMan, obj, SELECTOR(x));
		int16 y = readSelectorValue(segMan, obj, SELECTOR(y));

		g_sci->_gfxCoordAdjuster->kernelGlobalToLocal(x, y);

		writeSelectorValue(segMan, obj, SELECTOR(x), x);
		writeSelectorValue(segMan, obj, SELECTOR(y), y);
	}

	return s->r_acc;

}

reg_t kLocalToGlobal(EngineState *s, int argc, reg_t *argv) {
	reg_t obj = argv[0];
	SegManager *segMan = s->_segMan;

	if (obj.getSegment()) {
		int16 x = readSelectorValue(segMan, obj, SELECTOR(x));
		int16 y = readSelectorValue(segMan, obj, SELECTOR(y));

		g_sci->_gfxCoordAdjuster->kernelLocalToGlobal(x, y);

		writeSelectorValue(segMan, obj, SELECTOR(x), x);
		writeSelectorValue(segMan, obj, SELECTOR(y), y);
	}

	return s->r_acc;
}

reg_t kJoystick(EngineState *s, int argc, reg_t *argv) {
	// Subfunction 12 sets/gets joystick repeat rate
	debug(5, "Unimplemented syscall 'Joystick()'");
	return NULL_REG;
}

#ifdef ENABLE_SCI32
reg_t kGlobalToLocal32(EngineState *s, int argc, reg_t *argv) {
	const reg_t result = argv[0];
	const reg_t planeObj = argv[1];

	bool visible = true;
	Plane *plane = g_sci->_gfxFrameout->getVisiblePlanes().findByObject(planeObj);
	if (plane == nullptr) {
		plane = g_sci->_gfxFrameout->getPlanes().findByObject(planeObj);
		visible = false;
	}
	if (plane == nullptr) {
		error("kGlobalToLocal: Plane %04x:%04x not found", PRINT_REG(planeObj));
	}

	const int16 x = readSelectorValue(s->_segMan, result, SELECTOR(x)) - plane->_gameRect.left;
	const int16 y = readSelectorValue(s->_segMan, result, SELECTOR(y)) - plane->_gameRect.top;

	writeSelectorValue(s->_segMan, result, SELECTOR(x), x);
	writeSelectorValue(s->_segMan, result, SELECTOR(y), y);

	return make_reg(0, visible);
}

reg_t kLocalToGlobal32(EngineState *s, int argc, reg_t *argv) {
	const reg_t result = argv[0];
	const reg_t planeObj = argv[1];

	bool visible = true;
	Plane *plane = g_sci->_gfxFrameout->getVisiblePlanes().findByObject(planeObj);
	if (plane == nullptr) {
		plane = g_sci->_gfxFrameout->getPlanes().findByObject(planeObj);
		visible = false;
	}
	if (plane == nullptr) {
		error("kLocalToGlobal: Plane %04x:%04x not found", PRINT_REG(planeObj));
	}

	const int16 x = readSelectorValue(s->_segMan, result, SELECTOR(x)) + plane->_gameRect.left;
	const int16 y = readSelectorValue(s->_segMan, result, SELECTOR(y)) + plane->_gameRect.top;

	writeSelectorValue(s->_segMan, result, SELECTOR(x), x);
	writeSelectorValue(s->_segMan, result, SELECTOR(y), y);

	return make_reg(0, visible);
}
#endif

} // End of namespace Sci