/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library 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

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

/* Functions for system-level CD-ROM audio control */

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <errno.h>

#include <unistd.h>

#include <sys/cdio.h>

#include "SDL_cdrom.h"

#include "SDL_syscdrom.h"

/* The maximum number of CD-ROM drives we'll detect */

#define MAX_DRIVES	16	

/* A list of available CD-ROM drives */

static char *SDL_cdlist[MAX_DRIVES];

static dev_t SDL_cdmode[MAX_DRIVES];

/* The system-dependent CD control functions */

static const char *SDL_SYS_CDName(int drive);

static int SDL_SYS_CDOpen(int drive);

static int SDL_SYS_CDGetTOC(SDL_CD *cdrom);

static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position);

static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length);

static int SDL_SYS_CDPause(SDL_CD *cdrom);

static int SDL_SYS_CDResume(SDL_CD *cdrom);

static int SDL_SYS_CDStop(SDL_CD *cdrom);

static int SDL_SYS_CDEject(SDL_CD *cdrom);

static void SDL_SYS_CDClose(SDL_CD *cdrom);

/* Some ioctl() errno values which occur when the tray is empty */

#define ERRNO_TRAYEMPTY(errno)	\

	((errno == EIO) || (errno == ENOENT) || (errno == EINVAL))

/* Check a drive to see if it is a CD-ROM */

static int CheckDrive(char *drive, struct stat *stbuf)

{

	int is_cd, cdfd;

	struct ioc_read_subchannel info;

	/* If it doesn't exist, return -1 */

	if ( stat(drive, stbuf) < 0 ) {

		return(-1);

	}

	/* If it does exist, verify that it's an available CD-ROM */

	is_cd = 0;

	if ( S_ISCHR(stbuf->st_mode) || S_ISBLK(stbuf->st_mode) ) {

		cdfd = open(drive, (O_RDONLY|O_EXCL|O_NONBLOCK), 0);

		if ( cdfd >= 0 ) {

			info.address_format = CD_MSF_FORMAT;

			info.data_format = CD_CURRENT_POSITION;

			info.data_len = 0;

			info.data = NULL;

			/* Under Linux, EIO occurs when a disk is not present.

			   This isn't 100% reliable, so we use the USE_MNTENT

			   code above instead.

			 */

			if ( (ioctl(cdfd, CDIOCREADSUBCHANNEL, &info) == 0) ||

						ERRNO_TRAYEMPTY(errno) ) {

				is_cd = 1;

			}

			close(cdfd);

		}

	}

	return(is_cd);

}

/* Add a CD-ROM drive to our list of valid drives */

static void AddDrive(char *drive, struct stat *stbuf)

{

	int i;

	if ( SDL_numcds < MAX_DRIVES ) {

		/* Check to make sure it's not already in our list.

	 	   This can happen when we see a drive via symbolic link.

		 */

		for ( i=0; i<SDL_numcds; ++i ) {

			if ( stbuf->st_rdev == SDL_cdmode[i] ) {

#ifdef DEBUG_CDROM

  fprintf(stderr, "Duplicate drive detected: %s == %s\n", drive, SDL_cdlist[i]);

#endif

				return;

			}

		}

		/* Add this drive to our list */

		i = SDL_numcds;

		SDL_cdlist[i] = (char *)SDL_malloc(SDL_strlen(drive)+1);

		if ( SDL_cdlist[i] == NULL ) {

			SDL_OutOfMemory();

			return;

		}

		SDL_strcpy(SDL_cdlist[i], drive);

		SDL_cdmode[i] = stbuf->st_rdev;

		++SDL_numcds;

#ifdef DEBUG_CDROM

  fprintf(stderr, "Added CD-ROM drive: %s\n", drive);

#endif

	}

}

int  SDL_SYS_CDInit(void)

{

	/* checklist: /dev/cdrom,/dev/cd?c /dev/acd?c

			/dev/matcd?c /dev/mcd?c /dev/scd?c */

	static char *checklist[] = {

	"cdrom", "?0 cd?", "?0 acd?", "?0 matcd?", "?0 mcd?", "?0 scd?",NULL

	};

	char *SDLcdrom;

	int i, j, exists;

	char drive[32];

	struct stat stbuf;

	/* Fill in our driver capabilities */

	SDL_CDcaps.Name = SDL_SYS_CDName;

	SDL_CDcaps.Open = SDL_SYS_CDOpen;

	SDL_CDcaps.GetTOC = SDL_SYS_CDGetTOC;

	SDL_CDcaps.Status = SDL_SYS_CDStatus;

	SDL_CDcaps.Play = SDL_SYS_CDPlay;

	SDL_CDcaps.Pause = SDL_SYS_CDPause;

	SDL_CDcaps.Resume = SDL_SYS_CDResume;

	SDL_CDcaps.Stop = SDL_SYS_CDStop;

	SDL_CDcaps.Eject = SDL_SYS_CDEject;

	SDL_CDcaps.Close = SDL_SYS_CDClose;

	/* Look in the environment for our CD-ROM drive list */

	SDLcdrom = SDL_getenv("SDL_CDROM");	/* ':' separated list of devices */

	if ( SDLcdrom != NULL ) {

		char *cdpath, *delim;

		cdpath = SDL_malloc(SDL_strlen(SDLcdrom)+1);

		if ( cdpath != NULL ) {

			SDL_strcpy(cdpath, SDLcdrom);

			SDLcdrom = cdpath;

			do {

				delim = SDL_strchr(SDLcdrom, ':');

				if ( delim ) {

					*delim++ = '\0';

				}

				if ( CheckDrive(SDLcdrom, &stbuf) > 0 ) {

					AddDrive(SDLcdrom, &stbuf);

				}

				if ( delim ) {

					SDLcdrom = delim;

				} else {

					SDLcdrom = NULL;

				}

			} while ( SDLcdrom );

			SDL_free(cdpath);

		}

		/* If we found our drives, there's nothing left to do */

		if ( SDL_numcds > 0 ) {

			return(0);

		}

	}

	/* Scan the system for CD-ROM drives */

	for ( i=0; checklist[i]; ++i ) {

		if ( checklist[i][0] == '?' ) {

			char *insert;

			exists = 1;

			for ( j=checklist[i][1]; exists; ++j ) {

				SDL_snprintf(drive, SDL_arraysize(drive), "/dev/%sc", &checklist[i][3]);

				insert = SDL_strchr(drive, '?');

				if ( insert != NULL ) {

					*insert = j;

				}

				switch (CheckDrive(drive, &stbuf)) {

					/* Drive exists and is a CD-ROM */

					case 1:

						AddDrive(drive, &stbuf);

						break;

					/* Drive exists, but isn't a CD-ROM */

					case 0:

						break;

					/* Drive doesn't exist */

					case -1:

						exists = 0;

						break;

				}

			}

		} else {

			SDL_snprintf(drive, SDL_arraysize(drive), "/dev/%s", checklist[i]);

			if ( CheckDrive(drive, &stbuf) > 0 ) {

				AddDrive(drive, &stbuf);

			}

		}

	}

	return(0);

}

/* General ioctl() CD-ROM command function */

static int SDL_SYS_CDioctl(int id, int command, void *arg)

{

	int retval;

	retval = ioctl(id, command, arg);

	if ( retval < 0 ) {

		SDL_SetError("ioctl() error: %s", strerror(errno));

	}

	return(retval);

}

static const char *SDL_SYS_CDName(int drive)

{

	return(SDL_cdlist[drive]);

}

static int SDL_SYS_CDOpen(int drive)

{

	return(open(SDL_cdlist[drive], (O_RDONLY|O_EXCL|O_NONBLOCK), 0));

}

static int SDL_SYS_CDGetTOC(SDL_CD *cdrom)

{

	struct ioc_toc_header toc;

	int i, okay;

	struct ioc_read_toc_entry entry;

	struct cd_toc_entry data;

	okay = 0;

	if ( SDL_SYS_CDioctl(cdrom->id, CDIOREADTOCHEADER, &toc) == 0 ) {

		cdrom->numtracks = toc.ending_track-toc.starting_track+1;

		if ( cdrom->numtracks > SDL_MAX_TRACKS ) {

			cdrom->numtracks = SDL_MAX_TRACKS;

		}

		/* Read all the track TOC entries */

		for ( i=0; i<=cdrom->numtracks; ++i ) {

			if ( i == cdrom->numtracks ) {

				cdrom->track[i].id = 0xAA; /* CDROM_LEADOUT */

			} else {

				cdrom->track[i].id = toc.starting_track+i;

			}

			entry.starting_track = cdrom->track[i].id;

			entry.address_format = CD_MSF_FORMAT;

			entry.data_len = sizeof(data);

			entry.data = &data;

			if ( SDL_SYS_CDioctl(cdrom->id, CDIOREADTOCENTRYS,

								&entry) < 0 ) {

				break;

			} else {

				cdrom->track[i].type = data.control;

				cdrom->track[i].offset = MSF_TO_FRAMES(

						data.addr.msf.minute,

						data.addr.msf.second,

						data.addr.msf.frame);

				cdrom->track[i].length = 0;

				if ( i > 0 ) {

					cdrom->track[i-1].length =

						cdrom->track[i].offset-

						cdrom->track[i-1].offset;

				}

			}

		}

		if ( i == (cdrom->numtracks+1) ) {

			okay = 1;

		}

	}

	return(okay ? 0 : -1);

}

/* Get CD-ROM status */

static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position)

{

	CDstatus status;

	struct ioc_toc_header toc;

	struct ioc_read_subchannel info;

	struct cd_sub_channel_info data;

	info.address_format = CD_MSF_FORMAT;

	info.data_format = CD_CURRENT_POSITION;

	info.track = 0;

	info.data_len = sizeof(data);

	info.data = &data;

	if ( ioctl(cdrom->id, CDIOCREADSUBCHANNEL, &info) < 0 ) {

		if ( ERRNO_TRAYEMPTY(errno) ) {

			status = CD_TRAYEMPTY;

		} else {

			status = CD_ERROR;

		}

	} else {

		switch (data.header.audio_status) {

			case CD_AS_AUDIO_INVALID:

			case CD_AS_NO_STATUS:

				/* Try to determine if there's a CD available */

				if (ioctl(cdrom->id,CDIOREADTOCHEADER,&toc)==0)

					status = CD_STOPPED;

				else

					status = CD_TRAYEMPTY;

				break;

			case CD_AS_PLAY_COMPLETED:

				status = CD_STOPPED;

				break;

			case CD_AS_PLAY_IN_PROGRESS:

				status = CD_PLAYING;

				break;

			case CD_AS_PLAY_PAUSED:

				status = CD_PAUSED;

				break;

			default:

				status = CD_ERROR;

				break;

		}

	}

	if ( position ) {

		if ( status == CD_PLAYING || (status == CD_PAUSED) ) {

			*position = MSF_TO_FRAMES(

					data.what.position.absaddr.msf.minute,

					data.what.position.absaddr.msf.second,

					data.what.position.absaddr.msf.frame);

		} else {

			*position = 0;

		}

	}

	return(status);

}

/* Start play */

static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length)

{

	struct ioc_play_msf playtime;

	FRAMES_TO_MSF(start,

		&playtime.start_m, &playtime.start_s, &playtime.start_f);

	FRAMES_TO_MSF(start+length,

		&playtime.end_m, &playtime.end_s, &playtime.end_f);

#ifdef DEBUG_CDROM

  fprintf(stderr, "Trying to play from %d:%d:%d to %d:%d:%d\n",

	playtime.cdmsf_min0, playtime.cdmsf_sec0, playtime.cdmsf_frame0,

	playtime.cdmsf_min1, playtime.cdmsf_sec1, playtime.cdmsf_frame1);

#endif

	ioctl(cdrom->id, CDIOCSTART, 0);

	return(SDL_SYS_CDioctl(cdrom->id, CDIOCPLAYMSF, &playtime));

}

/* Pause play */

static int SDL_SYS_CDPause(SDL_CD *cdrom)

{

	return(SDL_SYS_CDioctl(cdrom->id, CDIOCPAUSE, 0));

}

/* Resume play */

static int SDL_SYS_CDResume(SDL_CD *cdrom)

{

	return(SDL_SYS_CDioctl(cdrom->id, CDIOCRESUME, 0));

}

/* Stop play */

static int SDL_SYS_CDStop(SDL_CD *cdrom)

{

	return(SDL_SYS_CDioctl(cdrom->id, CDIOCSTOP, 0));

}

/* Eject the CD-ROM */

static int SDL_SYS_CDEject(SDL_CD *cdrom)

{

	return(SDL_SYS_CDioctl(cdrom->id, CDIOCEJECT, 0));

}

/* Close the CD-ROM handle */

static void SDL_SYS_CDClose(SDL_CD *cdrom)

{

	close(cdrom->id);

}

void SDL_SYS_CDQuit(void)

{

	int i;

	if ( SDL_numcds > 0 ) {

		for ( i=0; i<SDL_numcds; ++i ) {

			SDL_free(SDL_cdlist[i]);

		}

		SDL_numcds = 0;

	}

}