/*

    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

*/

#include "SDL_config.h"

#ifdef SDL_CDROM_LINUX

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

#include <string.h>	/* For strerror() */

#include <sys/types.h>

#include <sys/stat.h>

#include <sys/ioctl.h>

#include <fcntl.h>

#include <errno.h>

#include <unistd.h>

#ifdef __LINUX__

#ifdef HAVE_LINUX_VERSION_H

/* linux 2.6.9 workaround */

#include <linux/version.h>

#if LINUX_VERSION_CODE == KERNEL_VERSION(2,6,9)

#include <asm/types.h>

#define __le64 __u64

#define __le32 __u32

#define __le16 __u16

#define __be64 __u64

#define __be32 __u32

#define __be16 __u16

#endif /* linux 2.6.9 workaround */

#endif /* HAVE_LINUX_VERSION_H */

#include <linux/cdrom.h>

#endif

#ifdef __SVR4

#include <sys/cdio.h>

#endif

/* Define this to use the alternative getmntent() code */

#ifndef __SVR4

#define USE_MNTENT

#endif

#ifdef USE_MNTENT

#if defined(__USLC__)

#include <sys/mntent.h>

#else

#include <mntent.h>

#endif

#ifndef _PATH_MNTTAB

#ifdef MNTTAB

#define _PATH_MNTTAB	MNTTAB

#else

#define _PATH_MNTTAB	"/etc/fstab"

#endif

#endif /* !_PATH_MNTTAB */

#ifndef _PATH_MOUNTED

#define _PATH_MOUNTED	"/etc/mtab"

#endif /* !_PATH_MOUNTED */

#ifndef MNTTYPE_CDROM

#define MNTTYPE_CDROM	"iso9660"

#endif

#ifndef MNTTYPE_SUPER

#define MNTTYPE_SUPER	"supermount"

#endif

#endif /* USE_MNTENT */

#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 */

#ifndef ENOMEDIUM

#define ENOMEDIUM ENOENT

#endif

#define ERRNO_TRAYEMPTY(errno)	\

	((errno == EIO)    || (errno == ENOENT) || \

	 (errno == EINVAL) || (errno == ENOMEDIUM))

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

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

{

	int is_cd, cdfd;

	struct cdrom_subchnl 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_NONBLOCK), 0);

		if ( cdfd >= 0 ) {

			info.cdsc_format = CDROM_MSF;

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

			 */

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

						ERRNO_TRAYEMPTY(errno) ) {

				is_cd = 1;

			}

			close(cdfd);

		}

#ifdef USE_MNTENT

		/* Even if we can't read it, it might be mounted */

		else if ( mnttype && (SDL_strcmp(mnttype, MNTTYPE_CDROM) == 0) ) {

			is_cd = 1;

		}

#endif

	}

	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] = SDL_strdup(drive);

		if ( SDL_cdlist[i] == NULL ) {

			SDL_OutOfMemory();

			return;

		}

		SDL_cdmode[i] = stbuf->st_rdev;

		++SDL_numcds;

#ifdef DEBUG_CDROM

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

#endif

	}

}

#ifdef USE_MNTENT

static void CheckMounts(const char *mtab)

{

	FILE *mntfp;

	struct mntent *mntent;

	struct stat stbuf;

	mntfp = setmntent(mtab, "r");

	if ( mntfp != NULL ) {

		char *tmp;

		char *mnt_type;

		size_t mnt_type_len;

		char *mnt_dev;

		size_t mnt_dev_len;

		while ( (mntent=getmntent(mntfp)) != NULL ) {

			mnt_type_len = SDL_strlen(mntent->mnt_type) + 1;

			mnt_type = SDL_stack_alloc(char, mnt_type_len);

			if (mnt_type == NULL)

				continue;  /* maybe you'll get lucky next time. */

			mnt_dev_len = SDL_strlen(mntent->mnt_fsname) + 1;

			mnt_dev = SDL_stack_alloc(char, mnt_dev_len);

			if (mnt_dev == NULL) {

				SDL_stack_free(mnt_type);

				continue;

			}

			SDL_strlcpy(mnt_type, mntent->mnt_type, mnt_type_len);

			SDL_strlcpy(mnt_dev, mntent->mnt_fsname, mnt_dev_len);

			/* Handle "supermount" filesystem mounts */

			if ( SDL_strcmp(mnt_type, MNTTYPE_SUPER) == 0 ) {

				tmp = SDL_strstr(mntent->mnt_opts, "fs=");

				if ( tmp ) {

					SDL_stack_free(mnt_type);

					mnt_type = SDL_strdup(tmp + SDL_strlen("fs="));

					if ( mnt_type ) {

						tmp = SDL_strchr(mnt_type, ',');

						if ( tmp ) {

							*tmp = '\0';

						}

					}

				}

				tmp = SDL_strstr(mntent->mnt_opts, "dev=");

				if ( tmp ) {

					SDL_stack_free(mnt_dev);

					mnt_dev = SDL_strdup(tmp + SDL_strlen("dev="));

					if ( mnt_dev ) {

						tmp = SDL_strchr(mnt_dev, ',');

						if ( tmp ) {

							*tmp = '\0';

						}

					}

				}

			}

			if ( SDL_strcmp(mnt_type, MNTTYPE_CDROM) == 0 ) {

#ifdef DEBUG_CDROM

  fprintf(stderr, "Checking mount path from %s: %s mounted on %s of %s\n",

	mtab, mnt_dev, mntent->mnt_dir, mnt_type);

#endif

				if (CheckDrive(mnt_dev, mnt_type, &stbuf) > 0) {

					AddDrive(mnt_dev, &stbuf);

				}

			}

			SDL_stack_free(mnt_dev);

			SDL_stack_free(mnt_type);

		}

		endmntent(mntfp);

	}

}

#endif /* USE_MNTENT */

int  SDL_SYS_CDInit(void)

{

	/* checklist: /dev/cdrom, /dev/hd?, /dev/scd? /dev/sr? */

	static char *checklist[] = {

		"cdrom", "?a hd?", "?0 scd?", "?0 sr?", 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;

		size_t len = SDL_strlen(SDLcdrom)+1;

		cdpath = SDL_stack_alloc(char, len);

		if ( cdpath != NULL ) {

			SDL_strlcpy(cdpath, SDLcdrom, len);

			SDLcdrom = cdpath;

			do {

				delim = SDL_strchr(SDLcdrom, ':');

				if ( delim ) {

					*delim++ = '\0';

				}

#ifdef DEBUG_CDROM

  fprintf(stderr, "Checking CD-ROM drive from SDL_CDROM: %s\n", SDLcdrom);

#endif

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

					AddDrive(SDLcdrom, &stbuf);

				}

				if ( delim ) {

					SDLcdrom = delim;

				} else {

					SDLcdrom = NULL;

				}

			} while ( SDLcdrom );

			SDL_stack_free(cdpath);

		}

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

		if ( SDL_numcds > 0 ) {

			return(0);

		}

	}

#ifdef USE_MNTENT

	/* Check /dev/cdrom first :-) */

	if (CheckDrive("/dev/cdrom", NULL, &stbuf) > 0) {

		AddDrive("/dev/cdrom", &stbuf);

	}

	/* Now check the currently mounted CD drives */

	CheckMounts(_PATH_MOUNTED);

	/* Finally check possible mountable drives in /etc/fstab */

	CheckMounts(_PATH_MNTTAB);

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

	if ( SDL_numcds > 0 ) {

		return(0);

	}

#endif /* USE_MNTENT */

	/* Scan the system for CD-ROM drives.

	   Not always 100% reliable, so use the USE_MNTENT code above first.

	 */

	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/%s", &checklist[i][3]);

				insert = SDL_strchr(drive, '?');

				if ( insert != NULL ) {

					*insert = j;

				}

#ifdef DEBUG_CDROM

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

#endif

				switch (CheckDrive(drive, NULL, &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]);

#ifdef DEBUG_CDROM

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

#endif

			if ( CheckDrive(drive, NULL, &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_NONBLOCK), 0));

}

static int SDL_SYS_CDGetTOC(SDL_CD *cdrom)

{

	struct cdrom_tochdr toc;

	int i, okay;

	struct cdrom_tocentry entry;

	okay = 0;

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

		cdrom->numtracks = toc.cdth_trk1-toc.cdth_trk0+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 = CDROM_LEADOUT;

			} else {

				cdrom->track[i].id = toc.cdth_trk0+i;

			}

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

			entry.cdte_format = CDROM_MSF;

			if ( SDL_SYS_CDioctl(cdrom->id, CDROMREADTOCENTRY,

								&entry) < 0 ) {

				break;

			} else {

				if ( entry.cdte_ctrl & CDROM_DATA_TRACK ) {

					cdrom->track[i].type = SDL_DATA_TRACK;

				} else {

					cdrom->track[i].type = SDL_AUDIO_TRACK;

				}

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

						entry.cdte_addr.msf.minute,

						entry.cdte_addr.msf.second,

						entry.cdte_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 cdrom_tochdr toc;

	struct cdrom_subchnl info;

	info.cdsc_format = CDROM_MSF;

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

		if ( ERRNO_TRAYEMPTY(errno) ) {

			status = CD_TRAYEMPTY;

		} else {

			status = CD_ERROR;

		}

	} else {

		switch (info.cdsc_audiostatus) {

			case CDROM_AUDIO_INVALID:

			case CDROM_AUDIO_NO_STATUS:

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

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

					status = CD_STOPPED;

				else

					status = CD_TRAYEMPTY;

				break;

			case CDROM_AUDIO_COMPLETED:

				status = CD_STOPPED;

				break;

			case CDROM_AUDIO_PLAY:

				status = CD_PLAYING;

				break;

			case CDROM_AUDIO_PAUSED:

				/* Workaround buggy CD-ROM drive */

				if ( info.cdsc_trk == CDROM_LEADOUT ) {

					status = CD_STOPPED;

				} else {

					status = CD_PAUSED;

				}

				break;

			default:

				status = CD_ERROR;

				break;

		}

	}

	if ( position ) {

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

			*position = MSF_TO_FRAMES(

					info.cdsc_absaddr.msf.minute,

					info.cdsc_absaddr.msf.second,

					info.cdsc_absaddr.msf.frame);

		} else {

			*position = 0;

		}

	}

	return(status);

}

/* Start play */

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

{

	struct cdrom_msf playtime;

	FRAMES_TO_MSF(start,

	   &playtime.cdmsf_min0, &playtime.cdmsf_sec0, &playtime.cdmsf_frame0);

	FRAMES_TO_MSF(start+length,

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

#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

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

}

/* Pause play */

static int SDL_SYS_CDPause(SDL_CD *cdrom)

{

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

}

/* Resume play */