/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * Old-style G.723 frame/timestamp format.
 * 
 * Copyright (C) 1999, Mark Spencer
 *
 * Mark Spencer <markster@linux-support.net>
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License
 */
 
#include <asterisk/channel.h>
#include <asterisk/file.h>
#include <asterisk/logger.h>
#include <asterisk/sched.h>
#include <asterisk/module.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>
#include <sys/time.h>
#include "../channels/adtranvofr.h"


#define G723_MAX_SIZE 1024

struct ast_filestream {
	/* First entry MUST be reserved for the channel type */
	void *reserved[AST_RESERVED_POINTERS];
	/* This is what a filestream means to us */
	int fd; /* Descriptor */
	u_int32_t lasttimeout;	/* Last amount of timeout */
	struct ast_channel *owner;
	struct ast_filestream *next;
	struct ast_frame *fr;	/* Frame representation of buf */
	struct timeval orig;	/* Original frame time */
	char buf[G723_MAX_SIZE + AST_FRIENDLY_OFFSET];	/* Buffer for sending frames, etc */
};


static struct ast_filestream *glist = NULL;
static pthread_mutex_t g723_lock = PTHREAD_MUTEX_INITIALIZER;
static int glistcnt = 0;

static char *name = "g723sf";
static char *desc = "G.723.1 Simple Timestamp File Format";
static char *exts = "g723";

static struct ast_filestream *g723_open(int fd)
{
	/* We don't have any header to read or anything really, but
	   if we did, it would go here.  We also might want to check
	   and be sure it's a valid file.  */
	struct ast_filestream *tmp;
	if ((tmp = malloc(sizeof(struct ast_filestream)))) {
		if (ast_pthread_mutex_lock(&g723_lock)) {
			ast_log(LOG_WARNING, "Unable to lock g723 list\n");
			free(tmp);
			return NULL;
		}
		tmp->next = glist;
		glist = tmp;
		tmp->fd = fd;
		tmp->owner = NULL;
		tmp->fr = (struct ast_frame *)tmp->buf;
		tmp->fr->data = tmp->buf + sizeof(struct ast_frame);
		tmp->fr->frametype = AST_FRAME_VOICE;
		tmp->fr->subclass = AST_FORMAT_G723_1;
		/* datalen will vary for each frame */
		tmp->fr->src = name;
		tmp->fr->mallocd = 0;
		tmp->lasttimeout = -1;
		tmp->orig.tv_usec = 0;
		tmp->orig.tv_sec = 0;
		glistcnt++;
		ast_pthread_mutex_unlock(&g723_lock);
		ast_update_use_count();
	}
	return tmp;
}

static struct ast_filestream *g723_rewrite(int fd, char *comment)
{
	/* We don't have any header to read or anything really, but
	   if we did, it would go here.  We also might want to check
	   and be sure it's a valid file.  */
	struct ast_filestream *tmp;
	if ((tmp = malloc(sizeof(struct ast_filestream)))) {
		if (ast_pthread_mutex_lock(&g723_lock)) {
			ast_log(LOG_WARNING, "Unable to lock g723 list\n");
			free(tmp);
			return NULL;
		}
		tmp->next = glist;
		glist = tmp;
		tmp->fd = fd;
		tmp->owner = NULL;
		tmp->fr = NULL;
		tmp->lasttimeout = -1;
		tmp->orig.tv_usec = 0;
		tmp->orig.tv_sec = 0;
		glistcnt++;
		ast_pthread_mutex_unlock(&g723_lock);
		ast_update_use_count();
	} else
		ast_log(LOG_WARNING, "Out of memory\n");
	return tmp;
}

static struct ast_frame *g723_read(struct ast_filestream *s)
{
	return NULL;
}

static void g723_close(struct ast_filestream *s)
{
	struct ast_filestream *tmp, *tmpl = NULL;
	if (ast_pthread_mutex_lock(&g723_lock)) {
		ast_log(LOG_WARNING, "Unable to lock g723 list\n");
		return;
	}
	tmp = glist;
	while(tmp) {
		if (tmp == s) {
			if (tmpl)
				tmpl->next = tmp->next;
			else
				glist = tmp->next;
			break;
		}
		tmpl = tmp;
		tmp = tmp->next;
	}
	glistcnt--;
	if (s->owner) {
		s->owner->stream = NULL;
		if (s->owner->streamid > -1)
			ast_sched_del(s->owner->sched, s->owner->streamid);
		s->owner->streamid = -1;
	}
	ast_pthread_mutex_unlock(&g723_lock);
	ast_update_use_count();
	if (!tmp) 
		ast_log(LOG_WARNING, "Freeing a filestream we don't seem to own\n");
	close(s->fd);
	free(s);
}

static int ast_read_callback(void *data)
{
	u_int16_t size;
	u_int32_t delay = -1;
	int looper = 1;
	int retval = 0;
	int res;
	struct ast_filestream *s = data;
	/* Send a frame from the file to the appropriate channel */
	while(looper) {
		if (read(s->fd, &size, 2) != 2) {
			/* Out of data, or the file is no longer valid.  In any case
			   go ahead and stop the stream */
			s->owner->streamid = -1;
			return 0;
		}
		/* Looks like we have a frame to read from here */
		size = ntohs(size);
		if (size > G723_MAX_SIZE - sizeof(struct ast_frame)) {
			ast_log(LOG_WARNING, "Size %d is invalid\n", size);
			/* The file is apparently no longer any good, as we
			   shouldn't ever get frames even close to this 
			   size.  */
			s->owner->streamid = -1;
			return 0;
		}
		/* Read the data into the buffer */
		s->fr->offset = AST_FRIENDLY_OFFSET;
		s->fr->datalen = size;
		s->fr->data = s->buf + sizeof(struct ast_frame) + AST_FRIENDLY_OFFSET;
		if ((res = read(s->fd, s->fr->data , size)) != size) {
			ast_log(LOG_WARNING, "Short read (%d of %d bytes) (%s)!\n", res, size, strerror(errno));
			s->owner->streamid = -1;
			return 0;
		}
		/* Read the delay for the next packet, and schedule again if necessary */
		if (read(s->fd, &delay, 4) == 4) 
			delay = ntohl(delay);
		else
			delay = -1;
#if 0
		/* Average out frames <= 50 ms */
		if (delay < 50)
			s->fr->timelen = 30;
		else
			s->fr->timelen = delay;
#else
		s->fr->timelen = 30;
#endif
		/* Unless there is no delay, we're going to exit out as soon as we
		   have processed the current frame. */
		if (delay > VOFR_FUDGE) {
			looper = 0;
			/* If there is a delay, lets schedule the next event */
			if (delay != s->lasttimeout) {
				/* We'll install the next timeout now. */
				s->owner->streamid = ast_sched_add(s->owner->sched, 
													  delay - VOFR_FUDGE, 
													  ast_read_callback, s);
				
				s->lasttimeout = delay;
			} else
				/* Just come back again at the same time */
				retval = -1;
		}
		/* Lastly, process the frame */
		if (ast_write(s->owner, s->fr)) {
			ast_log(LOG_WARNING, "Failed to write frame\n");
			s->owner->streamid = -1;
			return 0;
		}
	}
	return retval;
}

static int g723_apply(struct ast_channel *c, struct ast_filestream *s)
{
	u_int32_t delay;
	/* Select our owner for this stream, and get the ball rolling. */
	s->owner = c;
	/* Read and ignore the first delay */
	if (read(s->fd, &delay, 4) != 4) {
		/* Empty file */
		return 0;
	}
	ast_read_callback(s);
	return 0;
}

static int g723_write(struct ast_filestream *fs, struct ast_frame *f)
{
	struct timeval now;
	u_int32_t delay;
	u_int16_t size;
	int res;
	if (fs->fr) {
		ast_log(LOG_WARNING, "Asked to write on a read stream??\n");
		return -1;
	}
	if (f->frametype != AST_FRAME_VOICE) {
		ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
		return -1;
	}
	if (f->subclass != AST_FORMAT_G723_1) {
		ast_log(LOG_WARNING, "Asked to write non-g723 frame!\n");
		return -1;
	}
	if (!(fs->orig.tv_usec || fs->orig.tv_sec)) {
		/* First frame should have zeros for delay */
		delay = 0;
		if (gettimeofday(&fs->orig, NULL)) {
			ast_log(LOG_WARNING, "gettimeofday() failed??  What is this?  Y2k?\n");
			return -1;
		}
	} else {
		if (gettimeofday(&now, NULL)) {
			ast_log(LOG_WARNING, "gettimeofday() failed??  What is this?  Y2k?\n");
			return -1;
		}
		delay = (now.tv_sec - fs->orig.tv_sec) * 1000 + (now.tv_usec - fs->orig.tv_usec) / 1000;
		delay = htonl(delay);
		fs->orig.tv_sec = now.tv_sec;
		fs->orig.tv_usec = now.tv_usec;
	}
	if (f->datalen <= 0) {
		ast_log(LOG_WARNING, "Short frame ignored (%d bytes long?)\n", f->datalen);
		return 0;
	}
	if ((res = write(fs->fd, &delay, 4)) != 4) {
		ast_log(LOG_WARNING, "Unable to write delay: res=%d (%s)\n", res, strerror(errno));
		return -1;
	}
	size = htons(f->datalen);
	if ((res =write(fs->fd, &size, 2)) != 2) {
		ast_log(LOG_WARNING, "Unable to write size: res=%d (%s)\n", res, strerror(errno));
		return -1;
	}
	if ((res = write(fs->fd, f->data, f->datalen)) != f->datalen) {
		ast_log(LOG_WARNING, "Unable to write frame: res=%d (%s)\n", res, strerror(errno));
		return -1;
	}	
	return 0;
}

static char *g723_getcomment(struct ast_filestream *s)
{
	return NULL;
}

int load_module()
{
	return ast_format_register(name, exts, AST_FORMAT_G723_1,
								g723_open,
								g723_rewrite,
								g723_apply,
								g723_write,
								g723_read,
								g723_close,
								g723_getcomment);
								
								
}

int unload_module()
{
	struct ast_filestream *tmp, *tmpl;
	if (ast_pthread_mutex_lock(&g723_lock)) {
		ast_log(LOG_WARNING, "Unable to lock g723 list\n");
		return -1;
	}
	tmp = glist;
	while(tmp) {
		if (tmp->owner)
			ast_softhangup(tmp->owner);
		tmpl = tmp;
		tmp = tmp->next;
		free(tmpl);
	}
	ast_pthread_mutex_unlock(&g723_lock);
	return ast_format_unregister(name);
}	

int usecount()
{
	int res;
	if (ast_pthread_mutex_lock(&g723_lock)) {
		ast_log(LOG_WARNING, "Unable to lock g723 list\n");
		return -1;
	}
	res = glistcnt;
	ast_pthread_mutex_unlock(&g723_lock);
	return res;
}

char *description()
{
	return desc;
}


char *key()
{
	return ASTERISK_GPL_KEY;
}
