/* 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 "hopkins/files.h"

#include "hopkins/hopkins.h"
#include "hopkins/globals.h"

#include "common/config-manager.h"
#include "common/system.h"
#include "common/debug.h"
#include "common/file.h"
#include "common/str.h"
#include "common/savefile.h"

namespace Hopkins {

FileManager::FileManager(HopkinsEngine *vm) {
	_vm = vm;

	_catalogPos = 0;
	_catalogSize = 0;
}

/**
 * Load a file
 */
byte *FileManager::loadFile(const Common::Path &file) {
	Common::File f;
	if (!f.open(file))
		error("Error opening %s", file.toString().c_str());

	// Allocate space for the file contents
	size_t filesize = f.size();
	byte *data = _vm->_globals->allocMemory(filesize+1);
	if (!data)
		error("Error allocating space for file being loaded - %s", file.toString().c_str());

	readStream(f, data, filesize);
	f.close();
	data[filesize] = '\0';

	return data;
}

/**
 * Read a given number of bytes from a Stream into a pre-allocated buffer
 */
int FileManager::readStream(Common::ReadStream &stream, void *buf, size_t nbytes) {
	return stream.read(buf, nbytes);
}

/**
 * The original censorship was based on blood.dat file.
 * It's now using the config manager and a per-engine GUI option.
 */
void FileManager::initCensorship() {
	_vm->_globals->_censorshipFl = !ConfMan.getBool("enable_gore");
}

/**
 * Check if a file is present
 */
bool FileManager::fileExists(const Common::Path &file) {
	Common::File f;

	return f.exists(file);
}

/**
 * Search file in Cat file
 */
byte *FileManager::searchCat(const Common::Path &file, CatMode mode, bool &fileFoundFl) {
	byte *ptr = nullptr;
	fileFoundFl = true;
	Common::File f;

	Common::String filename = file.toString('/');
	Common::Path secondaryFilename;
	filename.toUppercase();

	switch (mode) {
	case RES_INI:
		if (!f.exists("RES_INI.CAT")) {
			fileFoundFl = false;
			return nullptr;
		}

		ptr = loadFile("RES_INI.CAT");
		secondaryFilename = "RES_INI.RES";
		break;

	case RES_REP:
		if (!f.exists("RES_REP.CAT")) {
			fileFoundFl = false;
			return nullptr;
		}

		ptr = loadFile("RES_REP.CAT");
		secondaryFilename = "RES_REP.RES";
		break;

	case RES_LIN:
		if (!f.exists("RES_LIN.CAT")) {
			fileFoundFl = false;
			return nullptr;
		}

		ptr = loadFile("RES_LIN.CAT");
		secondaryFilename = "RES_LIN.RES";
		break;

	case RES_PER:
		if (!f.exists("RES_PER.CAT")) {
			fileFoundFl = false;
			return nullptr;
		}

		ptr = loadFile("RES_PER.CAT");
		secondaryFilename = "RES_PER.RES";
		break;

	case RES_PIC:
		if (!f.exists("PIC.CAT")) {
			fileFoundFl = false;
			return nullptr;
		}

		ptr = loadFile("PIC.CAT");
		break;

	case RES_SAN:
		if (!f.exists("RES_SAN.CAT")) {
			fileFoundFl = false;
			return nullptr;
		}

		ptr = loadFile("RES_SAN.CAT");
		break;

	case RES_SLI:
		if (!f.exists("RES_SLI.CAT")) {
			fileFoundFl = false;
			return nullptr;
		}

		ptr = loadFile("RES_SLI.CAT");
		break;

	case RES_VOI: {
		Common::Path tmpFilename;
		if (_vm->getPlatform() == Common::kPlatformOS2 || _vm->getPlatform() == Common::kPlatformBeOS)
			tmpFilename = "ENG_VOI.CAT";
		// Win95 and Linux versions uses another set of names
		else {
			switch (_vm->_globals->_language) {
			case LANG_EN:
				tmpFilename = "RES_VAN.CAT";
				break;
			case LANG_FR:
				tmpFilename = "RES_VFR.CAT";
				break;
			case LANG_SP:
				tmpFilename = "RES_VES.CAT";
				break;
			default:
				break;
			}
		}

		if (!f.exists(tmpFilename)) {
			fileFoundFl = false;
			return nullptr;
		}

		ptr = loadFile(tmpFilename);
		break;
		}

	default:
		break;
	}

	// Scan for an entry in the catalogue
	byte *result;
	bool matchFlag = false;
	int offsetVal = 0;

	while (!matchFlag) {
		Common::String name = (const char *)ptr + offsetVal;

		if (name == filename) {
			// Found entry for file, so get it's details from the catalogue entry
			const byte *pData = ptr + offsetVal;
			_catalogPos = READ_LE_UINT32(pData + 15);
			_catalogSize = READ_LE_UINT32(pData + 19);
			matchFlag = true;
		}

		if (name == "FINIS") {
			_vm->_globals->freeMemory(ptr);
			fileFoundFl = false;
			return nullptr;
		}

		offsetVal += 23;
	}

	_vm->_globals->freeMemory(ptr);

	if (!secondaryFilename.empty()) {
		if (!f.open(secondaryFilename))
			error("CHARGE_FICHIER");

		f.seek(_catalogPos);

		byte *catData = _vm->_globals->allocMemory(_catalogSize);
		if (catData == nullptr)
			error("CHARGE_FICHIER");

		readStream(f, catData, _catalogSize);
		f.close();
		result = catData;
	} else {
		result = nullptr;
	}

	return result;
}

/**
 * Returns the size of a file. Throws an error if the file can't be found
 */
uint32 FileManager::fileSize(const Common::Path &filename) {
	Common::File f;
	uint32 size;

	if (!f.open(filename))
		error("Could not find file %s", filename.toString().c_str());

	size = f.size();
	f.close();

	return size;
}

} // End of namespace Hopkins