/* ScummVM - Kyrandia Interpreter
 * Copyright (C) 2003-2004 The ScummVM project
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 *
 */

#include "stdafx.h"

#include "kyra.h"
#include "script.h"

namespace Kyra {
	// Command procs
	
	void VMContext::c1_unknownCommand(void) {
		debug("unknown command '0x%x'.", _currentCommand);
		debug("\targument: '0x%x'", _argument);
		
		_error = true;
	}
	
	void VMContext::c1_goToLine(void) {
		_instructionPos = _argument << 1;
	}
	
	void VMContext::c1_setReturn(void) {
		_returnValue = _argument;
	}
	
	void VMContext::c1_pushRetRec(void) {
		if (!_argument) {
			pushStack(_returnValue);
		} else {
			int32 rec = ((int16)_tempPos << 16) | ((_instructionPos >> 1) + 1);
			pushStack(rec);
			_tempPos = _instructionPos;
		}
	}
	
	void VMContext::c1_push(void) {
		pushStack(_argument);
	}
	
	void VMContext::c1_pushVar(void) {
		pushStack(_registers[_argument]);
	}
	
	void VMContext::c1_pushFrameNeg(void) {
		pushStack(_stack[_tempPos + _argument]);
	}
	
	void VMContext::c1_pushFramePos(void) {
		pushStack(_stack[_tempPos - _argument]);
	}
	
	void VMContext::c1_popRetRec(void) {
		if (!_argument) {
			_returnValue = popStack();
		} else {
			if (_stackPos <= 0) {
				_scriptState = kScriptStopped;
			}
			int32 rec = popStack();
			
			_tempPos = (int16)((rec & 0xFFFF0000) >> 16);
			_instructionPos = (rec & 0x0000FFFF) * 2;
		}
	}
	
	void VMContext::c1_popVar(void) {
		_registers[_argument] = popStack();
	}
	
	void VMContext::c1_popFrameNeg(void) {
		_stack[_tempPos + _argument] = popStack();
	}
	
	void VMContext::c1_popFramePos(void) {
		_stack[_tempPos - _argument] = popStack();
	}
	
	void VMContext::c1_addToSP(void) {
		_stackPos -= _argument;
	}
	
	void VMContext::c1_subFromSP(void) {
		_stackPos += _argument;
	}
	
	void VMContext::c1_execOpcode(void) {
		if (_argument < _numOpcodes) {
			OpcodeProc proc = _opcodes[_argument].proc;
			(this->*proc)();
		} else {
			error("Invalid opcode 0x%X", _argument);
		}
	}
	
	void VMContext::c1_ifNotGoTo(void) {
		if (!popStack()) {
			_instructionPos = _argument << 1;
		}
	}
	
	void VMContext::c1_negate(void) {
		switch(_argument) {
		case 0:
			topStack() = !topStack();
			break;
		
		case 1:
			topStack() = -topStack();
			break;
		
		case 2:
			topStack() = ~topStack();
			break;
		
		default:
			debug("unkown negate instruction %d", _argument);
			_error = true;
			break;
		};
	}
	
	void VMContext::c1_evaluate(void) {
		int32 x, y;
		int32 res = false;
		
		x = popStack();
		y = popStack();
		
		switch(_argument) {
		case 0:
			res = x && y;
			break;
		
		case 1:
			res = x || y;
			break;
		
		case 3:
			res = x != y;
			break;
		
		case 4:
			res = x < y;
			break;
		
		case 5:
			res = x <= y;
			break;
			
		case 6:
			res = x > y;
			break;
		
		case 7:
			res = x >= y;
			break;
		
		case 8:
			res = x + y;
			break;
			
		case 9:
			res = x - y;
			break;
		
		case 10:
			res = x * y;
			break;
		
		case 11:
			res = x / y;
			break;
		
		case 12:
			res = x >> y;
			break;
		
		case 13:
			res = x << y;
			break;
		
		case 14:
			res = x & y;
			break;
		
		case 15:
			res = x | y;
			break;
		
		case 16:
			res = x % y;
			break;
		
		case 17:
			res = x ^ y;
			break;
		
		default:
			debug("unknown evaluate command");
			break;
		};
		
		pushStack(res);
	}

	// opcode procs
	void VMContext::o1_unknownOpcode(void) {
		_error = true;

		debug("unknown opcode '0x%x'.", _argument);
		debug("parameters:\n"
			"Param0: %d\nParam1: %d\nParam2: %d\nParam3: %d\nParam4: %d\nParam5: %d\n"
			"Param0 as a string: %s\nParam1 as a string: %s\nParam2 as a string: %s\n"
			"Param3 as a string: %s\nParam4 as a string: %s\nParam5 as a string: %s\n",
			param(0), param(1), param(2), param(3), param(5), param(5),
			paramString(0), paramString(1), paramString(2), paramString(3), 
			paramString(4), paramString(5));
	}

	void VMContext::o1_0x68(void) {
		debug("o1_0x68 was called with param0: '%d' and param1: '%d'", param(0), param(1));
	}
} // end of namespace Kyra