/*
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 *
 * =======================================================================
 *
 * This file implements an interface to libvorbis for decoding
 * OGG/Vorbis files. Strongly spoken this file isn't part of the sound
 * system but part of the main client. It justs converts Vorbis streams
 * into normal, raw Wave stream which are injected into snd_mem.c as if
 * they were normal wave files. At this moment only background music
 * playback and in theory .cin movie file playback is supported.
 *
 * =======================================================================
 */

#include <sys/time.h>
#include <errno.h>
#include <vorbis/vorbisfile.h>

#include "../header/client.h"
#include "header/local.h"
#include "header/vorbis.h"

extern int	sound_started; /* Sound initialization flag. */
extern cvar_t	*fs_basedir; /* Path to "music". */

qboolean	ogg_first_init = true; /* First initialization flag. */
qboolean	ogg_started = false; /* Initialization flag. */
byte		*ogg_buffer; /* File buffer. */
char		**ogg_filelist; /* List of Ogg Vorbis files. */
char		ovBuf[4096]; /* Buffer for sound. */
int		ogg_curfile; /* Index of currently played file. */
int		ogg_numfiles; /* Number of Ogg Vorbis files. */
int		ovSection; /* Position in Ogg Vorbis file. */
ogg_status_t	ogg_status; /* Status indicator. */
cvar_t		*ogg_autoplay; /* Play this song when started. */
cvar_t		*ogg_check; /* Check Ogg files or not. */
cvar_t		*ogg_playlist; /* Playlist. */
cvar_t		*ogg_sequence; /* Sequence play indicator. */
cvar_t		*ogg_volume; /* Music volume. */
OggVorbis_File	ovFile; /* Ogg Vorbis file. */

/*
 * Initialize the Ogg Vorbis subsystem.
 */
void OGG_Init(void) {
	cvar_t	*cv; /* Cvar pointer. */

	if (ogg_started)
		return;

	Com_Printf("Starting Ogg Vorbis.\n");

	/* Skip initialization if disabled. */
	cv = Cvar_Get ("ogg_enable", "0", CVAR_ARCHIVE);

	if (cv->value != 1) {
		Com_Printf ("Ogg Vorbis not initializing.\n");
		return;
	}

	/* Cvars. */
	ogg_autoplay = Cvar_Get("ogg_autoplay", "?", CVAR_ARCHIVE);
	ogg_check = Cvar_Get("ogg_check", "0", CVAR_ARCHIVE);
	ogg_playlist = Cvar_Get("ogg_playlist", "playlist", CVAR_ARCHIVE);
	ogg_sequence = Cvar_Get("ogg_sequence", "loop", CVAR_ARCHIVE);
	ogg_volume = Cvar_Get("ogg_volume", "0.7", CVAR_ARCHIVE);

	/* Console commands. */
	Cmd_AddCommand("ogg_list", OGG_ListCmd);
	Cmd_AddCommand("ogg_pause", OGG_PauseCmd);
	Cmd_AddCommand("ogg_play", OGG_PlayCmd);
	Cmd_AddCommand("ogg_reinit", OGG_Reinit);
	Cmd_AddCommand("ogg_resume", OGG_ResumeCmd);
	Cmd_AddCommand("ogg_seek", OGG_SeekCmd);
	Cmd_AddCommand("ogg_status", OGG_StatusCmd);
	Cmd_AddCommand("ogg_stop", OGG_Stop);

	/* Build list of files. */
	ogg_numfiles = 0;

	if (ogg_playlist->string[0] != '\0')
		OGG_LoadPlaylist(ogg_playlist->string);

	if (ogg_numfiles == 0)
		OGG_LoadFileList();

	/* Check if we have Ogg Vorbis files. */
	if (ogg_numfiles <= 0) {
		Com_Printf("No Ogg Vorbis files found.\n");
		ogg_started = true;	/* For OGG_Shutdown(). */
		OGG_Shutdown();
		return;
	}

	/* Initialize variables. */
	if (ogg_first_init) {
		srand(time(NULL));
		ogg_buffer = NULL;
		ogg_curfile = -1;
		ogg_status = STOP;
		ogg_first_init = false;
	}

	ogg_started = true;

	Com_Printf("%d Ogg Vorbis files found.\n", ogg_numfiles);

	/* Autoplay support. */
	if (ogg_autoplay->string[0] != '\0')
		OGG_ParseCmd(ogg_autoplay->string);
}

/*
 * Shutdown the Ogg Vorbis subsystem.
 */
void OGG_Shutdown(void) {

	if (!ogg_started)
		return;

	Com_Printf("Shutting down Ogg Vorbis.\n");

	OGG_Stop();

	/* Free the list of files. */
	FS_FreeList(ogg_filelist, ogg_numfiles + 1);

	/* Remove console commands. */
	Cmd_RemoveCommand("ogg_list");
	Cmd_RemoveCommand("ogg_pause");
	Cmd_RemoveCommand("ogg_play");
	Cmd_RemoveCommand("ogg_reinit");
	Cmd_RemoveCommand("ogg_resume");
	Cmd_RemoveCommand("ogg_seek");
	Cmd_RemoveCommand("ogg_status");
	Cmd_RemoveCommand("ogg_stop");

	ogg_started = false;
}

/*
 * Reinitialize the Ogg Vorbis subsystem.
 */
void OGG_Reinit(void) {

	OGG_Shutdown();
	OGG_Init();
}

/*
 * Check if the file is a valid Ogg Vorbis file.
 */
qboolean OGG_Check(char *name) {
	qboolean	 	res; /* Return value. */
	byte			*buffer; /* File buffer. */
	int		 		size; /* File size. */
	OggVorbis_File	 ovf; /* Ogg Vorbis file. */

	if (ogg_check->value == 0)
		return (true);

	res = false;

	if ((size = FS_LoadFile(name, (void**)&buffer)) > 0) {
		if (ov_test(NULL, &ovf, (char *)buffer, size) == 0) {
			res = true;
			ov_clear(&ovf);
		}

		FS_FreeFile(buffer);
	}

	return (res);
}

/*
 * Change position in the file.
 */
void OGG_Seek(ogg_seek_t type, double offset) {
	double pos; /* Position in file (in seconds). */
	double total; /* Length of file (in seconds). */

	/* Check if the file is seekable. */
	if (ov_seekable(&ovFile) == 0) {
		Com_Printf("OGG_Seek: file is not seekable.\n");
		return;
	}

	/* Get file information. */
	pos = ov_time_tell(&ovFile);
	total = ov_time_total(&ovFile, -1);

	switch (type) {
		case ABS:

			if (offset >= 0 && offset <= total) {
				if (ov_time_seek(&ovFile, offset) != 0)
					Com_Printf("OGG_Seek: could not seek.\n");

				else
					Com_Printf("%0.2f -> %0.2f of %0.2f.\n", pos, offset, total);

			} else
				Com_Printf("OGG_Seek: invalid offset.\n");

			break;
		case REL:

			if (pos + offset >= 0 && pos + offset <= total) {
				if (ov_time_seek(&ovFile, pos + offset) != 0)
					Com_Printf("OGG_Seek: could not seek.\n");

				else
					Com_Printf("%0.2f -> %0.2f of %0.2f.\n", pos, pos + offset, total);

			} else
				Com_Printf("OGG_Seek: invalid offset.\n");

			break;
	}
}

/*
 * Load list of Ogg Vorbis files in "music".
 */
void OGG_LoadFileList(void) {
	char	**list; /* List of .ogg files. */
	int		i; /* Loop counter. */
	int		j; /* Real position in list. */

	/* Get file list. */
	list = FS_ListFiles2(va("%s/*.ogg", OGG_DIR), &ogg_numfiles, 0,
	                     SFF_SUBDIR | SFF_HIDDEN | SFF_SYSTEM);
	ogg_numfiles--;

	/* Check if there are posible Ogg files. */
	if (list == NULL)
		return;

	/* Allocate list of files. */
	ogg_filelist = malloc(sizeof(char *) * ogg_numfiles);

	/* Add valid Ogg Vorbis file to the list. */
	for (i = 0, j = 0; i < ogg_numfiles; i++) {
		if (!OGG_Check(list[i])) {
			free(list[i]);
			continue;
		}

		ogg_filelist[j++] = list[i];
	}

	/* Free the file list. */
	free(list);

	/* Adjust the list size (remove space for invalid music files). */
	ogg_numfiles = j;
	ogg_filelist = realloc(ogg_filelist, sizeof(char *) * ogg_numfiles);
}

/*
 * Load playlist.
 */
void OGG_LoadPlaylist(char *playlist) {
	byte	*buffer; /* Buffer to read the file. */
	char	*ptr; /* Pointer for parsing the file. */
	int		i; /* Loop counter. */
	int		size; /* Length of buffer and strings. */

	/* Open playlist. */
	if ((size = FS_LoadFile(va("%s/%s.lst", OGG_DIR, ogg_playlist->string),
	                        (void **)&buffer)) < 0) {
		Com_Printf("OGG_LoadPlaylist: could not open playlist: %s.\n", strerror(errno));
		return;
	}

	/* Count the files in playlist. */
	for (ptr = strsep((char **) &buffer, "\n");
	        ptr != NULL;
	        ptr = strsep(NULL, "\n")) {
		if ((byte *)ptr != buffer)
			ptr[-1] = '\n';

		if (OGG_Check(va("%s/%s", OGG_DIR, ptr)))
			ogg_numfiles++;
	}

	/* Allocate file list. */
	ogg_filelist = malloc(sizeof(char *) * ogg_numfiles);

	i = 0;

	for (ptr = strsep((char **) &buffer, "\n");
	        ptr != NULL;
	        ptr = strsep(NULL, "\n"))
		if (OGG_Check(va("%s/%s", OGG_DIR, ptr)))
			ogg_filelist[i++] = strdup(va("%s/%s", OGG_DIR, ptr));

	/* Free file buffer. */
	FS_FreeFile(buffer);
}

/*
 * Play Ogg Vorbis file (with absolute or relative index).
 */
qboolean OGG_Open(ogg_seek_t type, int offset) {
	int		 size; /* File size. */
	int		 pos; /* Absolute position. */
	int		 res; /* Error indicator. */

	pos = -1;

	switch (type) {
		case ABS:

			/* Absolute index. */
			if (offset < 0 || offset >= ogg_numfiles) {
				Com_Printf("OGG_Open: %d out of range.\n", offset+1);
				return (false);

			} else
				pos = offset;

			break;
		case REL:

			/* Simulate a loopback. */
			if (ogg_curfile == -1 && offset < 0)
				offset++;

			while (ogg_curfile + offset < 0)
				offset += ogg_numfiles;

			while (ogg_curfile + offset >= ogg_numfiles)
				offset -= ogg_numfiles;

			pos = ogg_curfile + offset;
			break;
	}

	/* Check running music. */
	if (ogg_status == PLAY) {
		if (ogg_curfile == pos)
			return (true);

		else
			OGG_Stop();
	}

	/* Find file. */
	if ((size = FS_LoadFile(ogg_filelist[pos], (void **)&ogg_buffer)) == -1) {
		Com_Printf("OGG_Open: could not open %d (%s): %s.\n", pos, ogg_filelist[pos], strerror(errno));
		return (false);
	}

	/* Open ogg vorbis file. */
	if ((res = ov_open(NULL, &ovFile, (char *)ogg_buffer, size)) < 0) {
		Com_Printf("OGG_Open: '%s' is not a valid Ogg Vorbis file (error %i).\n", ogg_filelist[pos], res);
		FS_FreeFile(ogg_buffer);
		return (false);
	}

	/* Play file. */
	ovSection = 0;
	ogg_curfile = pos;
	ogg_status = PLAY;

	return (true);
}

/*
 * Play Ogg Vorbis file (with name only).
 */
qboolean OGG_OpenName(char *filename) {
	char	*name;	/* File name. */
	int	 i;	/* Loop counter. */

	name = va("%s/%s.ogg", OGG_DIR, filename);

	for (i = 0; i < ogg_numfiles; i++)
		if (strcmp(name, ogg_filelist[i]) == 0)
			break;

	if (i < ogg_numfiles)
		return (OGG_Open(ABS, i));

	else {
		Com_Printf("OGG_OpenName: '%s' not in the list.\n", filename);
		return (false);
	}
}

/*
 * Play a portion of the currently opened file.
 */
int OGG_Read(void) {
	int res;	/* Number of bytes read. */

	/* Read and resample. */
	res = ov_read(&ovFile, ovBuf, sizeof(ovBuf), 0, 2, 1, &ovSection);
	S_RawSamplesVol(res>>2, 44100, 2, 2, (byte*)ovBuf, ogg_volume->value);

	/* Check for end of file. */
	if (res == 0) {
		OGG_Stop();
		OGG_Sequence();
	}

	return (res);
}

/*
 * Play files in sequence.
 */
void OGG_Sequence(void) {

	if (strcmp(ogg_sequence->string, "next") == 0)
		OGG_Open(REL, 1);

	else if (strcmp(ogg_sequence->string, "prev") == 0)
		OGG_Open(REL, -1);

	else if (strcmp(ogg_sequence->string, "random") == 0)
		OGG_Open(ABS, rand() % ogg_numfiles);

	else if (strcmp(ogg_sequence->string, "loop") == 0)
		OGG_Open(REL, 0);

	else if (strcmp(ogg_sequence->string, "none") != 0) {
		Com_Printf("Invalid value of ogg_sequence: %s\n", ogg_sequence->string);
		Cvar_Set("ogg_sequence", "none");
	}
}

/*
 * Stop playing the current file.
 */
void OGG_Stop(void) {

	if (ogg_status == STOP)
		return;

	ov_clear(&ovFile);
	ogg_status = STOP;

	if (ogg_buffer != NULL) {
		FS_FreeFile(ogg_buffer);
		ogg_buffer = NULL;
	}
}

/*
 * Stream music.
 */
void OGG_Stream(void) {
	if (!ogg_started)
		return;

	while (ogg_status == PLAY && paintedtime + MAX_RAW_SAMPLES - 2048 > s_rawend)
		OGG_Read();
}

/*
 * Cinematic streaming
 */
void S_RawSamplesVol (int samples, int rate, int width, int channels, byte *data, float volume) {
	int	i;
	int	src, dst;
	float	scale;

	if (!sound_started)
		return;

	if (s_rawend < paintedtime)
		s_rawend = paintedtime;

	scale = (float)rate / dma.speed;

	if (channels == 2 && width == 2) {
		if (scale == 1.0) {
			/* optimized case */
			for (i=0 ; i<samples ; i++) {
				dst = s_rawend&(MAX_RAW_SAMPLES-1);
				s_rawend++;
				s_rawsamples[dst].left =
				    (int)(volume * LittleShort(((short *)data)[i*2])) << 8;
				s_rawsamples[dst].right =
				    (int)(volume * LittleShort(((short *)data)[i*2+1])) << 8;
			}

		} else {
			for (i=0 ; ; i++) {
				src = i*scale;

				if (src >= samples)
					break;

				dst = s_rawend&(MAX_RAW_SAMPLES-1);
				s_rawend++;
				s_rawsamples[dst].left =
				    (int)(volume * LittleShort(((short *)data)[src*2])) << 8;
				s_rawsamples[dst].right =
				    (int)(volume * LittleShort(((short *)data)[src*2+1])) << 8;
			}
		}

	} else if (channels == 1 && width == 2) {
		for (i=0 ; ; i++) {
			src = i*scale;

			if (src >= samples)
				break;

			dst = s_rawend&(MAX_RAW_SAMPLES-1);
			s_rawend++;
			s_rawsamples[dst].left =
			    (int)(volume * LittleShort(((short *)data)[src])) << 8;
			s_rawsamples[dst].right =
			    (int)(volume * LittleShort(((short *)data)[src])) << 8;
		}

	} else if (channels == 2 && width == 1) {
		for (i=0 ; ; i++) {
			src = i*scale;

			if (src >= samples)
				break;

			dst = s_rawend&(MAX_RAW_SAMPLES-1);
			s_rawend++;
			s_rawsamples[dst].left =
			    (int)(volume * ((char *)data)[src*2]) << 16;
			s_rawsamples[dst].right =
			    (int)(volume * ((char *)data)[src*2+1]) << 16;
		}

	} else if (channels == 1 && width == 1) {
		for (i=0 ; ; i++) {
			src = i*scale;

			if (src >= samples)
				break;

			dst = s_rawend&(MAX_RAW_SAMPLES-1);
			s_rawend++;
			s_rawsamples[dst].left =
			    (int)(volume * (((byte *)data)[src]-128)) << 16;
			s_rawsamples[dst].right =
			    (int)(volume * (((byte *)data)[src]-128)) << 16;
		}
	}
}

/*
 * List Ogg Vorbis files.
 */
void OGG_ListCmd(void) {
	int i;

	for (i = 0; i < ogg_numfiles; i++)
		Com_Printf("%d %s\n", i+1, ogg_filelist[i]);

	Com_Printf("%d Ogg Vorbis files.\n", ogg_numfiles);
}

/*
 * Parse play controls.
 */
void OGG_ParseCmd(char *arg) {
	int n;
	cvar_t *ogg_enable;
	ogg_enable = Cvar_Get ("ogg_enable", "0", CVAR_ARCHIVE);

	switch (arg[0]) {
		case '#':
			n = atoi(arg+1) - 1;
			OGG_Open(ABS, n);
			break;
		case '?':
			OGG_Open(ABS, rand() % ogg_numfiles);
			break;
		case '>':

			if (strlen(arg) > 1)
				OGG_Open(REL, atoi(arg+1));

			else
				OGG_Open(REL, 1);

			break;
		case '<':

			if (strlen(arg) > 1)
				OGG_Open(REL, -atoi(arg+1));

			else
				OGG_Open(REL, -1);

			break;
		default:

			if (ogg_enable->value != 0)
				OGG_OpenName(arg);

			break;
	}
}

/*
 * Pause current song.
 */
void OGG_PauseCmd(void) {

	if (ogg_status == PLAY)
		ogg_status = PAUSE;
}

/*
 * Play control.
 */
void OGG_PlayCmd( void ) {

	if (Cmd_Argc() < 2) {
		Com_Printf("Usage: ogg_play {filename | #n | ? | >n | <n}\n");
		return;
	}

	OGG_ParseCmd(Cmd_Argv(1));
}

/*
 * Resume current song.
 */
void OGG_ResumeCmd(void) {

	if (ogg_status == PAUSE)
		ogg_status = PLAY;
}

/*
 * Change position in the file being played.
 */
void OGG_SeekCmd(void) {

	if (ogg_status != STOP)
		return;

	if (Cmd_Argc() < 2) {
		Com_Printf("Usage: ogg_seek {n | <n | >n}\n");
		return;
	}

	switch (Cmd_Argv(1)[0]) {
		case '>':
			OGG_Seek(REL, atof(Cmd_Argv(1)+1));
			break;
		case '<':
			OGG_Seek(REL, -atof(Cmd_Argv(1)+1));
			break;
		default:
			OGG_Seek(ABS, atof(Cmd_Argv(1)));
			break;
	}
}

/*
 * Display status.
 */
void OGG_StatusCmd(void) {

	switch (ogg_status) {
		case PLAY:
			Com_Printf("Playing file %d (%s) at %0.2f seconds.\n",
			           ogg_curfile+1, ogg_filelist[ogg_curfile], ov_time_tell(&ovFile));
			break;
		case PAUSE:
			Com_Printf("Paused file %d (%s) at %0.2f seconds.\n",
			           ogg_curfile+1, ogg_filelist[ogg_curfile], ov_time_tell(&ovFile));
			break;
		case STOP:

			if (ogg_curfile == -1)
				Com_Printf("Stopped.\n");

			else
				Com_Printf("Stopped file %d (%s).\n",
				           ogg_curfile+1, ogg_filelist[ogg_curfile]);

			break;
	}
}