/* ScummVM - Scumm Interpreter
 * Copyright (C) 2003 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 "queen/queen.h"
#include "queen/resource.h"

namespace Queen {

#define	DEMO_JAS_VERSION_OFFSET	0x119A8
#define JAS_VERSION_OFFSET	0x12484

static const char *dataFilename = "queen.1";
static const char *tableFilename = "queen.tbl";

const GameVersion Resource::_gameVersions[] = {
	{ "PEM10", true,  false, 0x00000008 },
	{ "CEM10", false, false, 0x0000584E },
	{ "PFM10", true,  false, 0x0002CD93 },
	{ "CFM10", false, false, 0x00032585 },
	{ "PGM10", true,  false, 0x00059ACA },
	{ "CGM10", false, false, 0x0005F2A7 },
	{ "PIM10", true,  false, 0x000866B1 },
	{ "CIM10", false, false, 0x0008BEE2 },
	{ "PE100", true,  true,  0x000B343C },
	{ "PE100", true,  true,  0x000B40F5 }
};

Resource::Resource(const Common::String &datafilePath)
	: _resourceEntries(0), _resourceTable(NULL), _datafilePath(datafilePath) {

	_resourceFile = new File();
	_resourceFile->open(dataFilename, _datafilePath);
	if (_resourceFile->isOpen() == false)
		error("Could not open resource file '%s%s'", _datafilePath.c_str(), dataFilename);

	
	_gameVersion = detectGameVersion(_resourceFile->size());
	
	if (!readTableFile()) {
		//check if it is the english floppy version, for which we have a hardcoded version of the tables
		if (!strcmp(_gameVersion->versionString, _gameVersions[VER_ENG_FLOPPY].versionString)) {
			_gameVersion = &_gameVersions[VER_ENG_FLOPPY];
			_resourceEntries = 1076;
			_resourceTable = _resourceTablePEM10;
		} else {
			error("Couldn't find tablefile '%s%s'",  _datafilePath.c_str(), tableFilename);
		}
	}

	if (strcmp(_gameVersion->versionString, JASVersion()))
		error("Verifying game version failed! (expected: '%s', found: '%s')", _gameVersion->versionString, JASVersion());

	debug(5, "Detected game version: %s, which has %d resource entries", _gameVersion->versionString, _resourceEntries);
}

Resource::~Resource() {
	_resourceFile->close();
	if(_resourceTable != _resourceTablePEM10) 
		delete[] _resourceTable;
}

int32 Resource::resourceIndex(const char *filename) {

	char entryName[14];
	char *ptr = entryName;
	
	assert(strlen(filename));
	strcpy(entryName, filename);
	do
		*ptr = toupper(*ptr);
	while (*ptr++);

	uint32 low = 0;
	uint32 high = _resourceEntries - 1;

	if (!strcmp(entryName, _resourceTable[low].filename))
		return low;
	if (!strcmp(entryName, _resourceTable[high].filename))
		return high;
	

	//Use simple binary search to locate file
	for(;;) {
		uint32 cur = (low + high) / 2;
		int32 diff = strcmp(entryName, _resourceTable[cur].filename);

		if (!diff)
			return cur;

		if ((cur == low) || (cur == high))
			break;

		if (diff > 0)
			low = cur;
		else
			high = cur;
	}

	error("Couldn't find file '%s'", entryName);
	return -1;
}

uint32 Resource::fileSize(const char *filename) {
	return _resourceTable[resourceIndex(filename)].size;
}

uint32 Resource::fileOffset(const char *filename) {
	return _resourceTable[resourceIndex(filename)].offset;
}

uint8 *Resource::loadFile(const char *filename, uint32 skipBytes) {
	uint32 size = fileSize(filename);
	byte *mem = new byte[size];
	// skip 'skipBytes' bytes (useful for headers)
	_resourceFile->seek(fileOffset(filename) + skipBytes, SEEK_SET);
	_resourceFile->read(mem, size - skipBytes);
	return mem;
}

bool Resource::exists(const char *filename) {
	return resourceIndex(filename) >= 0;
}

const char *Resource::JASVersion() {
	static char versionStr[6];
	if (_gameVersion->isDemo)
		_resourceFile->seek(fileOffset("QUEEN.JAS") + DEMO_JAS_VERSION_OFFSET, SEEK_SET );
	else
		_resourceFile->seek(fileOffset("QUEEN.JAS") + JAS_VERSION_OFFSET, SEEK_SET);
	_resourceFile->read(versionStr, 6);
	return versionStr;
}

bool Resource::isDemo() {
	return _gameVersion->isDemo;
}

const GameVersion *Resource::detectGameVersion(uint32 dataFilesize) {
	const GameVersion *pgv = NULL;
	//detect game version based on resource file size.
	//we try to verify that it is indeed the version we think it is later on
	switch(dataFilesize) {
	case 3724538:
		pgv = &_gameVersions[VER_DEMO_PCGAMES];
		break;
	case 3732177:
		pgv = &_gameVersions[VER_DEMO];
		break;
	case 22677657:
		pgv = &_gameVersions[VER_ENG_FLOPPY];
		break;
	case 190787021:
		pgv = &_gameVersions[VER_ENG_TALKIE];
		break;
	case 22157304: // computed from FREH_FAT.H
		pgv = &_gameVersions[VER_FRE_FLOPPY];
		break;
	case 186689095:
		pgv = &_gameVersions[VER_FRE_TALKIE];
		break;
	case 22240013: // computed from GERH_FAT.H
		pgv = &_gameVersions[VER_GER_FLOPPY];
		break;
	case 217648975: // computed from GERC_FAT.H
		pgv = &_gameVersions[VER_GER_TALKIE];
		break;
	case 22461366: // computed from ITAH_FAT.H
		pgv = &_gameVersions[VER_ITA_FLOPPY];
		break;
	case 190795582: // computed from ITAC_FAT.H
		pgv = &_gameVersions[VER_ITA_TALKIE];
		break;
	default:
		error("Unknown/unsupported FOTAQ version");
	}
	return pgv;
}

bool Resource::readTableFile() {
	File tableFile;
	tableFile.open(tableFilename, _datafilePath);
	if (tableFile.isOpen() && tableFile.readUint32BE() == 'QTBL') {
		tableFile.seek(_gameVersion->tableOffset);
		_resourceEntries = tableFile.readUint16BE();
		_resourceTable = new ResourceEntry[_resourceEntries];
		ResourceEntry *pre = _resourceTable;
		for (uint32 i = 0; i < _resourceEntries; ++i, ++pre) {
			tableFile.read(pre->filename, 12);
			pre->filename[12] = '\0';
			pre->inBundle = tableFile.readByte();
			pre->offset = tableFile.readUint32BE();
			pre->size = tableFile.readUint32BE();
		}
		return true;
	}
	return false;
}

} // End of namespace Queen