/***************************************************************************
 *   Copyright (C) 2007 by Sindre Aamås                                    *
 *   aamas@stud.ntnu.no                                                    *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License version 2 as     *
 *   published by the Free Software Foundation.                            *
 *                                                                         *
 *   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 version 2 for more details.                *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   version 2 along with this program; if not, write to the               *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#ifndef GAMBATTE_H
#define GAMBATTE_H

#include "inputgetter.h"
#include "gbint.h"
#include <string>
#include <sstream>

namespace gambatte {
enum { BG_PALETTE = 0, SP1_PALETTE = 1, SP2_PALETTE = 2 };

class GB {
public:
	GB();
	~GB();
	
	enum LoadFlag {
		FORCE_DMG        = 1, /**< Treat the ROM as not having CGB support regardless of what its header advertises. */
		GBA_CGB          = 2, /**< Use GBA intial CPU register values when in CGB mode. */
		MULTICART_COMPAT = 4  /**< Use heuristics to detect and support some multicart MBCs disguised as MBC1. */
	};
	
	/** Load ROM image.
	  *
	  * @param romfile  Path to rom image file. Typically a .gbc, .gb, or .zip-file (if zip-support is compiled in).
	  * @param flags    ORed combination of LoadFlags.
	  * @return 0 on success, negative value on failure.
	  */
	int load(const char *romfiledata, unsigned romfilelength, unsigned flags = 0);
	
	/** Emulates until at least 'samples' stereo sound samples are produced in the supplied buffer,
	  * or until a video frame has been drawn.
	  *
	  * There are 35112 stereo sound samples in a video frame.
	  * May run for up to 2064 stereo samples too long.
	  * A stereo sample consists of two native endian 2s complement 16-bit PCM samples,
	  * with the left sample preceding the right one. Usually casting soundBuf to/from
	  * short* is OK and recommended. The reason for not using a short* in the interface
	  * is to avoid implementation-defined behaviour without compromising performance.
	  *
	  * Returns early when a new video frame has finished drawing in the video buffer,
	  * such that the caller may update the video output before the frame is overwritten.
	  * The return value indicates whether a new video frame has been drawn, and the
	  * exact time (in number of samples) at which it was drawn.
	  *
	  * @param videoBuf 160x144 RGB32 (native endian) video frame buffer or 0
	  * @param pitch distance in number of pixels (not bytes) from the start of one line to the next in videoBuf.
	  * @param soundBuf buffer with space >= samples + 2064
	  * @param samples in: number of stereo samples to produce, out: actual number of samples produced
	  * @return sample number at which the video frame was produced. -1 means no frame was produced.
	  */
	long runFor(gambatte::uint_least32_t *videoBuf, int pitch,
			gambatte::uint_least32_t *soundBuf, unsigned &samples);
	
	/** Reset to initial state.
	  * Equivalent to reloading a ROM image, or turning a Game Boy Color off and on again.
	  */
	void reset();
	
	/** @param palNum 0 <= palNum < 3. One of BG_PALETTE, SP1_PALETTE and SP2_PALETTE.
	  * @param colorNum 0 <= colorNum < 4
	  */
	void setDmgPaletteColor(unsigned palNum, unsigned colorNum, unsigned rgb32);
	
	/** Sets the callback used for getting input state. */
	void setInputGetter(InputGetter *getInput);
	
	/** Sets the directory used for storing save data. The default is the same directory as the ROM Image file. */
	void setSaveDir(const std::string &sdir);
	
	/** Returns true if the currently loaded ROM image is treated as having CGB support. */
	bool isCgb() const;
	
	/** Returns true if a ROM image is loaded. */
	bool isLoaded() const;

	/** Writes persistent cartridge data to disk. NOT Done implicitly on ROM close. */
	void loadSavedata(const char *data);
	int saveSavedataLength();
	void saveSavedata(char *dest);
	
	// 0 = vram, 1 = rom, 2 = wram, 3 = cartram, 4 = oam, 5 = hram
	bool getMemoryArea(int which, unsigned char **data, int *length);

	/** Saves emulator state to the state slot selected with selectState().
	  * The data will be stored in the directory given by setSaveDir().
	  *
	  * @param  videoBuf 160x144 RGB32 (native endian) video frame buffer or 0. Used for saving a thumbnail.
	  * @param  pitch distance in number of pixels (not bytes) from the start of one line to the next in videoBuf.
	  * @return success
	  */
	//bool saveState(const gambatte::uint_least32_t *videoBuf, int pitch);
	
	/** Loads emulator state from the state slot selected with selectState().
	  * @return success
	  */
	//bool loadState();
	
	/** Saves emulator state to the file given by 'filepath'.
	  *
	  * @param  videoBuf 160x144 RGB32 (native endian) video frame buffer or 0. Used for saving a thumbnail.
	  * @param  pitch distance in number of pixels (not bytes) from the start of one line to the next in videoBuf.
	  * @return success
	  */
	bool saveState(const gambatte::uint_least32_t *videoBuf, int pitch, std::ostream &file);
	
	/** Loads emulator state from the file given by 'filepath'.
	  * @return success
	  */
	bool loadState(std::istream &file);
	
	/** Selects which state slot to save state to or load state from.
	  * There are 10 such slots, numbered from 0 to 9 (periodically extended for all n).
	  */
	void selectState(int n);
	
	/** Current state slot selected with selectState(). Returns a value between 0 and 9 inclusive. */
	int currentState() const;
	
	/** ROM header title of currently loaded ROM image. */
	const std::string romTitle() const;
	
	/** Set Game Genie codes to apply to currently loaded ROM image. Cleared on ROM load.
	  * @param codes Game Genie codes in format HHH-HHH-HHH;HHH-HHH-HHH;... where H is [0-9]|[A-F]
	  */
	void setGameGenie(const std::string &codes);
	
	/** Set Game Shark codes to apply to currently loaded ROM image. Cleared on ROM load.
	  * @param codes Game Shark codes in format 01HHHHHH;01HHHHHH;... where H is [0-9]|[A-F]
	  */
	void setGameShark(const std::string &codes);

	unsigned char ExternalRead(unsigned short addr);
	void ExternalWrite(unsigned short addr, unsigned char val);

	
private:
	struct Priv;
	Priv *const p_;

	GB(const GB &);
	GB & operator=(const GB &);
};
}

#endif