/* 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "dragons/dragons.h"
#include "dragons/sequenceopcodes.h"
#include "dragons/actor.h"

namespace Dragons {
// OpCall

void OpCall::skip(uint size) {
	_code += size;
}

byte OpCall::readByte() {
	return *_code++;
}

int16 OpCall::readSint16() {
	int16 value = READ_LE_UINT16(_code);
	_code += 2;
	return value;
}

uint32 OpCall::readUint32() {
	uint32 value = READ_LE_UINT32(_code);
	_code += 4;
	return value;
}

// SequenceOpcodes

SequenceOpcodes::SequenceOpcodes(DragonsEngine *vm)
	: _vm(vm) {
	initOpcodes();
}

SequenceOpcodes::~SequenceOpcodes() {
	freeOpcodes();
}

void SequenceOpcodes::execOpcode(Actor *control, OpCall &opCall) {
	assert(opCall._op < DRAGONS_NUM_SEQ_OPCODES);
	if (!_opcodes[opCall._op])
		error("SequenceOpcodes::execOpcode() Unimplemented opcode %d", opCall._op);
	debug(4, "execSequenceOpcode(%d) %s", opCall._op, _opcodeNames[opCall._op].c_str());
	(*_opcodes[opCall._op])(control, opCall);
}

typedef Common::Functor2Mem<Actor*, OpCall&, void, SequenceOpcodes> SequenceOpcodeI;
#define OPCODE(op, func) \
	_opcodes[op] = new SequenceOpcodeI(this, &SequenceOpcodes::func); \
	_opcodeNames[op] = #func;

void SequenceOpcodes::initOpcodes() {
	// First clear everything
	for (uint i = 0; i < DRAGONS_NUM_SEQ_OPCODES; ++i) {
		_opcodes[i] = nullptr;
	}
	// Register opcodes
	OPCODE(1, opSetFramePointer);
	OPCODE(2, opSetFramePointerAndStop);
	OPCODE(3, opJmp);
	OPCODE(4, opSetSequenceTimerStartValue);
	OPCODE(5, opSetSequenceTimer);
	OPCODE(6, opUpdateXYResetSeqTimer);
	OPCODE(7, opUpdateXYResetSeqTimerAndStop);
	// unused
	OPCODE(9, opSetActorFlag4AndStop);
	// unused
	OPCODE(11, opSetActorFlags404);
	OPCODE(12, opClearActorFlag400);
	OPCODE(13, opChangeSequence);
	// unused
	OPCODE(15, opSetField7a);
	OPCODE(16, opUpdateFlags);
	OPCODE(17, opPlaySound);
	OPCODE(18, opSetXY);
	OPCODE(19, opSetXYAndStop);

}

#undef OPCODE

void SequenceOpcodes::freeOpcodes() {
	for (uint i = 0; i < DRAGONS_NUM_SEQ_OPCODES; ++i) {
		delete _opcodes[i];
	}
}

void SequenceOpcodes::updateReturn(OpCall &opCall, uint16 size) {
	opCall._deltaOfs = size * 2 + 2;
}

// Opcodes

void SequenceOpcodes::opSetFramePointer(Actor *actor, OpCall &opCall) {
	ARG_INT16(framePointer);
	debug(4, "set frame pointer %X", framePointer);
	actor->loadFrame((uint16)framePointer);
	actor->_flags |= ACTOR_FLAG_2;
	actor->_sequenceTimer = actor->_sequenceTimerMaxValue;
	updateReturn(opCall, 1);
}

void SequenceOpcodes::opSetFramePointerAndStop(Actor *actor, OpCall &opCall) {
	opSetFramePointer(actor, opCall);
	opCall._result = 0;
}

void SequenceOpcodes::opJmp(Actor *actor, OpCall &opCall) {
	ARG_INT16(newIp);

	if (!(actor->_flags & ACTOR_FLAG_1000)) {
		byte *newOffset = actor->getSeqIpAtOffset((uint32)newIp);
		opCall._deltaOfs = (int32)(newOffset - actor->_seqCodeIp); //opCall._code);
		debug(5, "opJump delta: %d", opCall._deltaOfs);
	} else {
		updateReturn(opCall, 1);
	}
}

void SequenceOpcodes::opSetSequenceTimerStartValue(Actor *actor, OpCall &opCall) {
	ARG_INT16(startValue);
	actor->_sequenceTimerMaxValue = (uint16)startValue;
	debug(5, "set sequenceTimerStartValue: %d", startValue);
	updateReturn(opCall, 1);
}

void SequenceOpcodes::opSetSequenceTimer(Actor *actor, OpCall &opCall) {
	ARG_INT16(newSeqTimer);
	actor->_sequenceTimer = (uint16)newSeqTimer;
	debug(5, "set _sequenceTimer: %d", newSeqTimer);
	updateReturn(opCall, 1);
	opCall._result = 0;
}

void SequenceOpcodes::opUpdateXYResetSeqTimer(Actor *actor, OpCall &opCall) {
	ARG_INT8(xOffset);
	ARG_INT8(yOffset);
	actor->_x_pos += xOffset;
	actor->_y_pos += yOffset;
	actor->_sequenceTimer = actor->_sequenceTimerMaxValue;

	debug(5, "update actor %d XY offset (%d, %d) new values (%d, %d) %d", actor->_actorID, xOffset, yOffset, actor->_x_pos, actor->_y_pos, actor->_sequenceTimer);
	updateReturn(opCall, 1);
}

void SequenceOpcodes::opUpdateXYResetSeqTimerAndStop(Actor *actor, OpCall &opCall) {
	opUpdateXYResetSeqTimer(actor, opCall);
	opCall._result = 0;
}

void SequenceOpcodes::opSetActorFlag4AndStop(Actor *actor, OpCall &opCall) {
	actor->_flags |= ACTOR_FLAG_4;
	opCall._deltaOfs = 0;
	opCall._result = 0;
	//updateReturn(opCall, 1);
}

void SequenceOpcodes::opSetActorFlags404(Actor *actor, OpCall &opCall) {
	actor->_flags |= (ACTOR_FLAG_4 | Dragons::ACTOR_FLAG_400);
	updateReturn(opCall, 1);
}

void SequenceOpcodes::opClearActorFlag400(Actor *actor, OpCall &opCall) {
	actor->_flags &= ~ACTOR_FLAG_400;
	updateReturn(opCall, 1);
}

void SequenceOpcodes::opChangeSequence(Actor *actor, OpCall &opCall) {
	ARG_INT16(newValue);
	actor->_sequenceID = (uint16)newValue;
	updateReturn(opCall, 1);
}

void SequenceOpcodes::opSetField7a(Actor *actor, OpCall &opCall) {
	ARG_INT16(newValue);
	actor->_field_7a = (uint16)newValue;
	updateReturn(opCall, 1);
}

void SequenceOpcodes::opUpdateFlags(Actor *actor, OpCall &opCall) {
	if (actor->isFlagSet(ACTOR_FLAG_1000)) {
		actor->setFlag(ACTOR_FLAG_4);
	}
	updateReturn(opCall, 0);
}

void SequenceOpcodes::opPlaySound(Actor *actor, OpCall &opCall) {
	ARG_INT16(soundId);
	debug(5, "opPlaySound actorId: %d soundId: %d", actor->_actorID, soundId);

	_vm->playOrStopSound((uint16) soundId);
	updateReturn(opCall, 1);
}

void SequenceOpcodes::opSetXY(Actor *actor, OpCall &opCall) {
	ARG_INT16(x);
	ARG_INT16(y);
	actor->_x_pos = x;
	actor->_y_pos = y;
	updateReturn(opCall, 2);
}

void SequenceOpcodes::opSetXYAndStop(Actor *actor, OpCall &opCall) {
	opSetXY(actor, opCall);
	opCall._result = 0;
}





//void SequenceOpcodes::opYield(Control *control, OpCall &opCall) {
//	opCall._result = 2;
//}
//
//void SequenceOpcodes::opStopSubSequence(Control *control, OpCall &opCall) {
//	ARG_INT16(linkIndex);
//	control->stopSubSequence(linkIndex);
//}

} // End of namespace Dragons