/***************************************************************************
 *   Copyright (C) 2007 PCSX-df Team                                       *
 *   Copyright (C) 2009 Wei Mingzhi                                        *
 *                                                                         *
 *   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.,                                       *
 *   51 Franklin Steet, Fifth Floor, Boston, MA 02111-1307 USA.            *
 ***************************************************************************/

#include "psxcommon.h"
#include "plugins.h"
#include "cdrom.h"
#include "cdriso.h"

#ifdef _WIN32
#include <process.h>
#include <windows.h>
#else
#include <pthread.h>
#include <sys/time.h>
#endif

FILE *cdHandle = NULL;
FILE *cddaHandle = NULL;
FILE *subHandle = NULL;

static char subChanInterleaved = 0;

static unsigned char cdbuffer[DATA_SIZE];
static unsigned char subbuffer[SUB_FRAMESIZE];

static unsigned char sndbuffer[CD_FRAMESIZE_RAW * 10];

#define CDDA_FRAMETIME			(1000 * (sizeof(sndbuffer) / CD_FRAMESIZE_RAW) / 75)

#ifdef _WIN32
static HANDLE threadid;
#else
static pthread_t threadid;
#endif
static unsigned int initial_offset = 0;
static volatile char playing = 0;
static char cddaBigEndian = 0;
static volatile unsigned int cddaCurOffset = 0;

char* CALLBACK CDR__getDriveLetter(void);
long CALLBACK CDR__configure(void);
long CALLBACK CDR__test(void);
void CALLBACK CDR__about(void);
long CALLBACK CDR__setfilename(char *filename);
long CALLBACK CDR__getStatus(struct CdrStat *stat);

extern void *hCDRDriver;

struct trackinfo {
	enum {DATA, CDDA} type;
	char start[3];		// MSF-format
	char length[3];		// MSF-format
};

#define MAXTRACKS 100 /* How many tracks can a CD hold? */

static int numtracks = 0;
static struct trackinfo ti[MAXTRACKS];

// get a sector from a msf-array
static unsigned int msf2sec(char *msf) {
	return ((msf[0] * 60 + msf[1]) * 75) + msf[2];
}

static void sec2msf(unsigned int s, char *msf) {
	msf[0] = s / 75 / 60;
	s = s - msf[0] * 75 * 60;
	msf[1] = s / 75;
	s = s - msf[1] * 75;
	msf[2] = s;
}

// divide a string of xx:yy:zz into m, s, f
static void tok2msf(char *time, char *msf) {
	char *token;

	token = strtok(time, ":");
	if (token) {
		msf[0] = atoi(token);
	}
	else {
		msf[0] = 0;
	}

	token = strtok(NULL, ":");
	if (token) {
		msf[1] = atoi(token);
	}
	else {
		msf[1] = 0;
	}

	token = strtok(NULL, ":");
	if (token) {
		msf[2] = atoi(token);
	}
	else {
		msf[2] = 0;
	}
}

#ifndef _WIN32
static long GetTickCount(void) {
	static time_t		initial_time = 0;
	struct timeval		now;

	gettimeofday(&now, NULL);

	if (initial_time == 0) {
		initial_time = now.tv_sec;
	}

	return (now.tv_sec - initial_time) * 1000L + now.tv_usec / 1000L;
}
#endif

// this thread plays audio data
#ifdef _WIN32
static void playthread(void *param)
#else
static void *playthread(void *param)
#endif
{
	long			d, t, i, s;
	unsigned char	tmp;

	t = GetTickCount();

	while (playing) {
		d = t - (long)GetTickCount();
		if (d <= 0) {
			d = 1;
		}
		else if (d > CDDA_FRAMETIME) {
			d = CDDA_FRAMETIME;
		}
#ifdef _WIN32
		Sleep(d);
#else
		usleep(d * 1000);
#endif

		t = GetTickCount() + CDDA_FRAMETIME;

		if (subChanInterleaved) {
			s = 0;

			for (i = 0; i < sizeof(sndbuffer) / CD_FRAMESIZE_RAW; i++) {
				// read one sector
				d = fread(sndbuffer + CD_FRAMESIZE_RAW * i, 1, CD_FRAMESIZE_RAW, cddaHandle);
				if (d < CD_FRAMESIZE_RAW) {
					break;
				}

				s += d;

				// skip the subchannel data
				fseek(cddaHandle, SUB_FRAMESIZE, SEEK_CUR);
			}
		}
		else {
			s = fread(sndbuffer, 1, sizeof(sndbuffer), cddaHandle);
		}

		if (s == 0) {
			playing = 0;
			fclose(cddaHandle);
			cddaHandle = NULL;
			initial_offset = 0;
			break;
		}

		if (!cdr.Muted && playing) {
			if (cddaBigEndian) {
				for (i = 0; i < s / 2; i++) {
					tmp = sndbuffer[i * 2];
					sndbuffer[i * 2] = sndbuffer[i * 2 + 1];
					sndbuffer[i * 2 + 1] = tmp;
				}
			}

			SPU_playCDDAchannel((short *)sndbuffer, s);
		}

		cddaCurOffset += s;
	}

#ifdef _WIN32
	_endthread();
#else
	pthread_exit(0);
	return NULL;
#endif
}

// stop the CDDA playback
static void stopCDDA() {
	if (!playing) {
		return;
	}

	playing = 0;
#ifdef _WIN32
	WaitForSingleObject(threadid, INFINITE);
#else
	pthread_join(threadid, NULL);
#endif

	if (cddaHandle != NULL) {
		fclose(cddaHandle);
		cddaHandle = NULL;
	}

	initial_offset = 0;
}

// start the CDDA playback
static void startCDDA(unsigned int offset) {
	if (playing) {
		if (initial_offset == offset) {
			return;
		}
		stopCDDA();
	}

	cddaHandle = fopen(cdrfilename, "rb");
	if (cddaHandle == NULL) {
		return;
	}

	initial_offset = offset;
	cddaCurOffset = initial_offset;
	fseek(cddaHandle, initial_offset, SEEK_SET);

	playing = 1;

#ifdef _WIN32
	threadid = (HANDLE)_beginthread(playthread, 0, NULL);
#else
	pthread_create(&threadid, NULL, playthread, NULL);
#endif
}

// this function tries to get the .toc file of the given .bin
// the necessary data is put into the ti (trackinformation)-array
static int parsetoc(const char *isofile) {
	char			tocname[MAXPATHLEN];
	FILE			*fi;
	char			linebuf[256], dummy[256], name[256];
	char			*token;
	char			time[20], time2[20];
	unsigned int	t;

	numtracks = 0;

	// copy name of the iso and change extension from .bin to .toc
	strncpy(tocname, isofile, sizeof(tocname));
	tocname[MAXPATHLEN - 1] = '\0';
	if (strlen(tocname) >= 4) {
		strcpy(tocname + strlen(tocname) - 4, ".toc");
	}
	else {
		return -1;
	}

	if ((fi = fopen(tocname, "r")) == NULL) {
		// check for image.bin.toc (for AcetoneISO)
		sprintf(tocname, "%s.toc", isofile);
		if ((fi = fopen(tocname, "r")) == NULL) {
			// if filename is image.toc.bin, try removing .bin (for Brasero)
			strcpy(tocname, isofile);
			t = strlen(tocname);
			if (t >= 8 && strcmp(tocname + t - 8, ".toc.bin") == 0) {
				tocname[t - 4] = '\0';
				if ((fi = fopen(tocname, "r")) == NULL) {
					return -1;
				}
			}
			else {
				return -1;
			}
		}
	}

	memset(&ti, 0, sizeof(ti));

	// parse the .toc file
	while (fgets(linebuf, sizeof(linebuf), fi) != NULL) {
		// search for tracks
		strncpy(dummy, linebuf, sizeof(linebuf));
		token = strtok(dummy, " ");

		if (token == NULL) {
			continue;
		}

		if (!strcmp(token, "TRACK")) {
			// get type of track
			token = strtok(NULL, " ");
			numtracks++;

			if (!strcmp(token, "MODE2_RAW\n")) {
				ti[numtracks].type = DATA;
				sec2msf(2 * 75, ti[numtracks].start); // assume data track on 0:2:0
			}
			else if (!strcmp(token, "AUDIO\n")) {
				ti[numtracks].type = CDDA;
			}
		}
		else if (!strcmp(token, "DATAFILE")) {
			sscanf(linebuf, "DATAFILE \"%[^\"]\" %8s", name, time);
			tok2msf((char *)&time, (char *)&ti[numtracks].length);
		}
		else if (!strcmp(token, "FILE")) {
			sscanf(linebuf, "FILE \"%[^\"]\" #%d %8s %8s", name, &t, time, time2);
			tok2msf((char *)&time, (char *)&ti[numtracks].start);
			t /= CD_FRAMESIZE_RAW;
			t += msf2sec(ti[numtracks].start) + 2 * 75;
			sec2msf(t, (char *)&ti[numtracks].start);
			tok2msf((char *)&time2, (char *)&ti[numtracks].length);
		}
	}

	fclose(fi);

	return 0;
}

// this function tries to get the .cue file of the given .bin
// the necessary data is put into the ti (trackinformation)-array
static int parsecue(const char *isofile) {
	char			cuename[MAXPATHLEN];
	FILE			*fi;
	char			*token;
	char			time[20];
	char			*tmp;
	char			linebuf[256], dummy[256];
	unsigned int	t;

	numtracks = 0;

	// copy name of the iso and change extension from .bin to .cue
	strncpy(cuename, isofile, sizeof(cuename));
	cuename[MAXPATHLEN - 1] = '\0';
	if (strlen(cuename) >= 4) {
		strcpy(cuename + strlen(cuename) - 4, ".cue");
	}
	else {
		return -1;
	}

	if ((fi = fopen(cuename, "r")) == NULL) {
		return -1;
	}

	memset(&ti, 0, sizeof(ti));

	while (fgets(linebuf, sizeof(linebuf), fi) != NULL) {
		strncpy(dummy, linebuf, sizeof(linebuf));
		token = strtok(dummy, " ");

		if (token == NULL) {
			continue;
		}

		if (!strcmp(token, "TRACK")){
			numtracks++;

			if (strstr(linebuf, "AUDIO") != NULL) {
				ti[numtracks].type = CDDA;
			}
			else if (strstr(linebuf, "MODE1/2352") != NULL || strstr(linebuf, "MODE2/2352") != NULL) {
				ti[numtracks].type = DATA;
			}
		}
		else if (!strcmp(token, "INDEX")) {
			tmp = strstr(linebuf, "INDEX");
			if (tmp != NULL) {
				tmp += strlen("INDEX") + 3; // 3 - space + numeric index
				while (*tmp == ' ') tmp++;
				if (*tmp != '\n') sscanf(tmp, "%8s", time);
			}

			tok2msf((char *)&time, (char *)&ti[numtracks].start);

			t = msf2sec(ti[numtracks].start) + 2 * 75;
			sec2msf(t, ti[numtracks].start);

			// If we've already seen another track, this is its end
			if (numtracks > 1) {
				t = msf2sec(ti[numtracks].start) - msf2sec(ti[numtracks - 1].start);
				sec2msf(t, ti[numtracks - 1].length);
			}
		}
	}

	fclose(fi);

	// Fill out the last track's end based on size
	if (numtracks >= 1) {
		fseek(cdHandle, 0, SEEK_END);
		t = ftell(cdHandle) / 2352 - msf2sec(ti[numtracks].start) + 2 * 75;
		sec2msf(t, ti[numtracks].length);
	}

	return 0;
}

// this function tries to get the .ccd file of the given .img
// the necessary data is put into the ti (trackinformation)-array
static int parseccd(const char *isofile) {
	char			ccdname[MAXPATHLEN];
	FILE			*fi;
	char			linebuf[256];
	unsigned int	t;

	numtracks = 0;

	// copy name of the iso and change extension from .img to .ccd
	strncpy(ccdname, isofile, sizeof(ccdname));
	ccdname[MAXPATHLEN - 1] = '\0';
	if (strlen(ccdname) >= 4) {
		strcpy(ccdname + strlen(ccdname) - 4, ".ccd");
	}
	else {
		return -1;
	}

	if ((fi = fopen(ccdname, "r")) == NULL) {
		return -1;
	}

	memset(&ti, 0, sizeof(ti));

	while (fgets(linebuf, sizeof(linebuf), fi) != NULL) {
		if (!strncmp(linebuf, "[TRACK", 6)){
			numtracks++;
		}
		else if (!strncmp(linebuf, "MODE=", 5)) {
			sscanf(linebuf, "MODE=%d", &t);
			ti[numtracks].type = ((t == 0) ? CDDA : DATA);
		}
		else if (!strncmp(linebuf, "INDEX 1=", 8)) {
			sscanf(linebuf, "INDEX 1=%d", &t);
			sec2msf(t + 2 * 75, ti[numtracks].start);

			// If we've already seen another track, this is its end
			if (numtracks > 1) {
				t = msf2sec(ti[numtracks].start) - msf2sec(ti[numtracks - 1].start);
				sec2msf(t, ti[numtracks - 1].length);
			}
		}
	}

	fclose(fi);

	// Fill out the last track's end based on size
	if (numtracks >= 1) {
		fseek(cdHandle, 0, SEEK_END);
		t = ftell(cdHandle) / 2352 - msf2sec(ti[numtracks].start) + 2 * 75;
		sec2msf(t, ti[numtracks].length);
	}

	return 0;
}

// this function tries to get the .mds file of the given .mdf
// the necessary data is put into the ti (trackinformation)-array
static int parsemds(const char *isofile) {
	char			mdsname[MAXPATHLEN];
	FILE			*fi;
	unsigned int	offset, extra_offset, l, i;
	unsigned short	s;

	numtracks = 0;

	// copy name of the iso and change extension from .mdf to .mds
	strncpy(mdsname, isofile, sizeof(mdsname));
	mdsname[MAXPATHLEN - 1] = '\0';
	if (strlen(mdsname) >= 4) {
		strcpy(mdsname + strlen(mdsname) - 4, ".mds");
	}
	else {
		return -1;
	}

	if ((fi = fopen(mdsname, "rb")) == NULL) {
		return -1;
	}

	memset(&ti, 0, sizeof(ti));

	// check if it's a valid mds file
	fread(&i, 1, sizeof(unsigned int), fi);
	i = SWAP32(i);
	if (i != 0x4944454D) {
		// not an valid mds file
		fclose(fi);
		return -1;
	}

	// get offset to session block
	fseek(fi, 0x50, SEEK_SET);
	fread(&offset, 1, sizeof(unsigned int), fi);
	offset = SWAP32(offset);

	// get total number of tracks
	offset += 14;
	fseek(fi, offset, SEEK_SET);
	fread(&s, 1, sizeof(unsigned short), fi);
	s = SWAP16(s);
	numtracks = s;

	// get offset to track blocks
	fseek(fi, 4, SEEK_CUR);
	fread(&offset, 1, sizeof(unsigned int), fi);
	offset = SWAP32(offset);

	// skip lead-in data
	while (1) {
		fseek(fi, offset + 4, SEEK_SET);
		if (fgetc(fi) < 0xA0) {
			break;
		}
		offset += 0x50;
	}

	// check if the image contains interleaved subchannel data
	fseek(fi, offset + 1, SEEK_SET);
	subChanInterleaved = fgetc(fi);

	// read track data
	for (i = 1; i <= numtracks; i++) {
		fseek(fi, offset, SEEK_SET);

		// get the track type
		ti[i].type = ((fgetc(fi) == 0xA9) ? CDDA : DATA);
		fseek(fi, 8, SEEK_CUR);

		// get the track starting point
		ti[i].start[0] = fgetc(fi);
		ti[i].start[1] = fgetc(fi);
		ti[i].start[2] = fgetc(fi);

		if (i > 1) {
			l = msf2sec(ti[i].start);
			sec2msf(l - 2 * 75, ti[i].start); // ???
		}

		// get the track length
		fread(&extra_offset, 1, sizeof(unsigned int), fi);
		extra_offset = SWAP32(extra_offset);

		fseek(fi, extra_offset + 4, SEEK_SET);
		fread(&l, 1, sizeof(unsigned int), fi);
		l = SWAP32(l);
		sec2msf(l, ti[i].length);

		offset += 0x50;
	}

	fclose(fi);
	return 0;
}

// this function tries to get the .sub file of the given .img
static int opensubfile(const char *isoname) {
	char		subname[MAXPATHLEN];

	// copy name of the iso and change extension from .img to .sub
	strncpy(subname, isoname, sizeof(subname));
	subname[MAXPATHLEN - 1] = '\0';
	if (strlen(subname) >= 4) {
		strcpy(subname + strlen(subname) - 4, ".sub");
	}
	else {
		return -1;
	}

	subHandle = fopen(subname, "rb");
	if (subHandle == NULL) {
		return -1;
	}

	return 0;
}

static long CALLBACK ISOinit(void) {
	assert(cdHandle == NULL);
	assert(subHandle == NULL);

	return 0; // do nothing
}

static long CALLBACK ISOshutdown(void) {
	if (cdHandle != NULL) {
		fclose(cdHandle);
		cdHandle = NULL;
	}
	if (subHandle != NULL) {
		fclose(subHandle);
		subHandle = NULL;
	}
	stopCDDA();
	return 0;
}

// This function is invoked by the front-end when opening an ISO
// file for playback
static long CALLBACK ISOopen(void) {
	if (cdHandle != NULL) {
		return 0; // it's already open
	}

	cdHandle = fopen(cdrfilename, "rb");
	if (cdHandle == NULL) {
		return -1;
	}

	SysPrintf(_("Loaded CD Image: %s"), cdrfilename);

	cddaBigEndian = 0;
	subChanInterleaved = 0;

	if (parsetoc(cdrfilename) == 0) {
		cddaBigEndian = 1; // cdrdao uses big-endian for CD Audio
		SysPrintf("[+toc]");
	}
	else if (parsecue(cdrfilename) == 0) {
		SysPrintf("[+cue]");
	}
	else if (parseccd(cdrfilename) == 0) {
		SysPrintf("[+ccd]");
	}
	else if (parsemds(cdrfilename) == 0) {
		SysPrintf("[+mds]");
	}

	if (!subChanInterleaved && opensubfile(cdrfilename) == 0) {
		SysPrintf("[+sub]");
	}

	SysPrintf(".\n");

	return 0;
}

static long CALLBACK ISOclose(void) {
	if (cdHandle != NULL) {
		fclose(cdHandle);
		cdHandle = NULL;
	}
	if (subHandle != NULL) {
		fclose(subHandle);
		subHandle = NULL;
	}
	stopCDDA();
	return 0;
}

// return Starting and Ending Track
// buffer:
//  byte 0 - start track
//  byte 1 - end track
static long CALLBACK ISOgetTN(unsigned char *buffer) {
	buffer[0] = 1;

	if (numtracks > 0) {
		buffer[1] = numtracks;
	}
	else {
		buffer[1] = 1;
	}

	return 0;
}

// return Track Time
// buffer:
//  byte 0 - frame
//  byte 1 - second
//  byte 2 - minute
static long CALLBACK ISOgetTD(unsigned char track, unsigned char *buffer) {
	if (numtracks > 0 && track <= numtracks) {
		buffer[2] = ti[track].start[0];
		buffer[1] = ti[track].start[1];
		buffer[0] = ti[track].start[2];
	}
	else {
		buffer[2] = 0;
		buffer[1] = 2;
		buffer[0] = 0;
	}

	return 0;
}

// lookup table for crc calculation
static unsigned short crctab[256] = {
	0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7, 0x8108,
	0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF, 0x1231, 0x0210,
	0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6, 0x9339, 0x8318, 0xB37B,
	0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE, 0x2462, 0x3443, 0x0420, 0x1401,
	0x64E6, 0x74C7, 0x44A4, 0x5485, 0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE,
	0xF5CF, 0xC5AC, 0xD58D, 0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6,
	0x5695, 0x46B4, 0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D,
	0xC7BC, 0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
	0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B, 0x5AF5,
	0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12, 0xDBFD, 0xCBDC,
	0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A, 0x6CA6, 0x7C87, 0x4CE4,
	0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41, 0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD,
	0xAD2A, 0xBD0B, 0x8D68, 0x9D49, 0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13,
	0x2E32, 0x1E51, 0x0E70, 0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A,
	0x9F59, 0x8F78, 0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E,
	0xE16F, 0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
	0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E, 0x02B1,
	0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256, 0xB5EA, 0xA5CB,
	0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D, 0x34E2, 0x24C3, 0x14A0,
	0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 0xA7DB, 0xB7FA, 0x8799, 0x97B8,
	0xE75F, 0xF77E, 0xC71D, 0xD73C, 0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657,
	0x7676, 0x4615, 0x5634, 0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9,
	0xB98A, 0xA9AB, 0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882,
	0x28A3, 0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
	0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92, 0xFD2E,
	0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9, 0x7C26, 0x6C07,
	0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1, 0xEF1F, 0xFF3E, 0xCF5D,
	0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8, 0x6E17, 0x7E36, 0x4E55, 0x5E74,
	0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
};

static unsigned short calcCrc(unsigned char *d, int len) {
	unsigned short crc = 0;
	int i;

	for (i = 0; i < len; i++) {
		crc = crctab[(crc >> 8) ^ d[i]] ^ (crc << 8);
	}

	return ~crc;
}

// read track
// time: byte 0 - minute; byte 1 - second; byte 2 - frame
// uses bcd format
static long CALLBACK ISOreadTrack(unsigned char *time) {
	if (cdHandle == NULL) {
		return -1;
	}

	if (subChanInterleaved) {
		fseek(cdHandle, MSF2SECT(btoi(time[0]), btoi(time[1]), btoi(time[2])) * (CD_FRAMESIZE_RAW + SUB_FRAMESIZE) + 12, SEEK_SET);
		fread(cdbuffer, 1, DATA_SIZE, cdHandle);
		fread(subbuffer, 1, SUB_FRAMESIZE, cdHandle);

		if ((((u16)subbuffer[22] << 8) | (u16)subbuffer[23]) != calcCrc(&subbuffer[12], 10)) {
			memset(&subbuffer[15], 0, 7); // CRC wrong, wipe out time data
		}
	}
	else {
		fseek(cdHandle, MSF2SECT(btoi(time[0]), btoi(time[1]), btoi(time[2])) * CD_FRAMESIZE_RAW + 12, SEEK_SET);
		fread(cdbuffer, 1, DATA_SIZE, cdHandle);

		if (subHandle != NULL) {
			fseek(subHandle, MSF2SECT(btoi(time[0]), btoi(time[1]), btoi(time[2])) * SUB_FRAMESIZE, SEEK_SET);
			fread(subbuffer, 1, SUB_FRAMESIZE, subHandle);

			if ((((u16)subbuffer[22] << 8) | (u16)subbuffer[23]) != calcCrc(&subbuffer[12], 10)) {
				memset(&subbuffer[15], 0, 7); // CRC wrong, wipe out time data
			}
		}
	}

	return 0;
}

// return readed track
static unsigned char * CALLBACK ISOgetBuffer(void) {
	return cdbuffer;
}

// plays cdda audio
// sector: byte 0 - minute; byte 1 - second; byte 2 - frame
// does NOT uses bcd format
static long CALLBACK ISOplay(unsigned char *time) {
	if (SPU_playCDDAchannel != NULL) {
		if (subChanInterleaved) {
			startCDDA(MSF2SECT(time[0], time[1], time[2]) * (CD_FRAMESIZE_RAW + SUB_FRAMESIZE));
		}
		else {
			startCDDA(MSF2SECT(time[0], time[1], time[2]) * CD_FRAMESIZE_RAW);
		}
	}
	return 0;
}

// stops cdda audio
static long CALLBACK ISOstop(void) {
	stopCDDA();
	return 0;
}

// gets subchannel data
static unsigned char* CALLBACK ISOgetBufferSub(void) {
	if (subHandle != NULL || subChanInterleaved) {
		return subbuffer;
	}

	return NULL;
}

static long CALLBACK ISOgetStatus(struct CdrStat *stat) {
	int sec;

	CDR__getStatus(stat);

	if (playing) {
		stat->Type = 0x02;
		stat->Status |= 0x80;
		sec = cddaCurOffset / CD_FRAMESIZE_RAW;
		sec2msf(sec, (char *)stat->Time);
	}
	else {
		stat->Type = 0x01;
	}

	return 0;
}

void imageReaderInit(void) {
	assert(hCDRDriver == NULL);

	CDR_init = ISOinit;
	CDR_shutdown = ISOshutdown;
	CDR_open = ISOopen;
	CDR_close = ISOclose;
	CDR_getTN = ISOgetTN;
	CDR_getTD = ISOgetTD;
	CDR_readTrack = ISOreadTrack;
	CDR_getBuffer = ISOgetBuffer;
	CDR_play = ISOplay;
	CDR_stop = ISOstop;
	CDR_getBufferSub = ISOgetBufferSub;
	CDR_getStatus = ISOgetStatus;

	CDR_getDriveLetter = CDR__getDriveLetter;
	CDR_configure = CDR__configure;
	CDR_test = CDR__test;
	CDR_about = CDR__about;
	CDR_setfilename = CDR__setfilename;

	numtracks = 0;
}