/* 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/>.
 *
 */

#ifndef BACKENDS_FS_STDIOSTREAM_H
#define BACKENDS_FS_STDIOSTREAM_H

#include "common/scummsys.h"
#include "common/noncopyable.h"
#include "common/stream.h"
#include "common/str.h"

class StdioStream : public Common::SeekableReadStream, public Common::SeekableWriteStream, public Common::NonCopyable {
public:
	enum WriteMode {
		WriteMode_Read = 0,
		WriteMode_Write = 1,
		WriteMode_WriteAtomic = 2,
	};

protected:
	/** File handle to the actual file. */
	void *_handle;
	Common::String *_path;

	static StdioStream *makeFromPathHelper(const Common::String &path, WriteMode writeMode,
			StdioStream *(*factory)(void *handle));

public:
	/**
	 * Given a path, invokes fopen on that path and wrap the result in a
	 * StdioStream instance.
	 */
	static StdioStream *makeFromPath(const Common::String &path, WriteMode writeMode) {
		return makeFromPathHelper(path, writeMode, [](void *handle) {
			return new StdioStream(handle);
		});
	}

	StdioStream(void *handle);
	~StdioStream() override;

	bool err() const override;
	void clearErr() override;
	bool eos() const override;

	uint32 write(const void *dataPtr, uint32 dataSize) override;
	bool flush() override;

	int64 pos() const override;
	int64 size() const override;
	bool seek(int64 offs, int whence = SEEK_SET) override;
	uint32 read(void *dataPtr, uint32 dataSize) override;

	/**
	 * Configure buffered IO
	 *
	 * Must be called immediately after opening the file.
	 * A buffer size of 0 disables buffering.
	 *
	 * @param bufferSize the size of the Stdio read / write buffer
	 * @return success or failure
	 */
	bool setBufferSize(uint32 bufferSize);

private:
	/**
	 * Move the file from src to dst.
	 * This must succeed even if the destination file already exists.
	 *
	 * This function cannot be overridden as it's called from the destructor.
	 *
	 * @param src The file to move
	 * @param dst The path where the file is to be moved.
	 *
	 * @returns Whether the renaming succeeded or not.
	 */
	bool moveFile(const Common::String &src, const Common::String &dst);
};

#endif