/**
 * mod_dvb  
 * -------  
 * Simple DVB-Streaming via Apache 2.0
 *   
 * This work is distributed within the terms of  
 * creative commons attribution-share alike 2.0 germany  
 *   
 * See http://creativecommons.org/licenses/by-sa/2.0/ for more information  
 *   
 * @author Bernd Holzmueller <bernd@tiggerswelt.net>  
 * @revision 05
 * @license http://creativecommons.org/licenses/by-sa/2.0/de/ Creative Commons Attribution-Share Alike 2.0 Germany  
 * @homepage http://oss.tiggerswelt.net/mod_dvb/
 * @copyright Copyright &copy; 2008 tiggersWelt.net   
 * 
 * Usage:
 *   Compile and load the module into your webserver and set it up as
 *   a special location-handler (see provided httpd.conf for an example).
 *   Point your MPEG2-capable Media-Player to the configured URL to see
 *   the default programme. If you want to watch another station just
 *   append its name at the end of the URL (e.g. /dvb/Das Erste).
 *   You may also use the Playlist-Feature by using the special /playlist
 *   handler: mplayer -playlist http://my-dvb-server/dvb/playlist
 * 
 * ChangeLog:
 *   20071012: Added kaffine-compatible Playlist-Output
 * 
 *   20070613: Made open to wait a bit for the devices
 *             (useful when zapping)
 *
 *   20070611: Added initial support for playlists (useful with mplayer)
 *             Added support to rewrite PIDs (defaulting to 51/64)
 *             Wrote a lot of useless stuff to this header
 *             Watched many hours TV and listened to radio using mod_dvb
 *
 *   20070610: Added support for channels.conf
 *             Added support for zapping
 *             Removed some memory leaks
 *             Moved channel stuff to own library
 * 
 *   20070603: Initial release
 *
 * Ideas:
 *   - Convert MPEG TS-Streams with one Audio- and Video-Stream to
 *     one single MPEG PS-Stream.
 *   - Seperate Tunning-Stuff from Streaming-Stuff
 *   - Allow reading/streaming multiple PIDs to multiple clients
 *   - Add support for more than one DVB-Device
 */

#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <sys/time.h>
#include <string.h>  
#include <stdint.h>   
#include <ctype.h>
#include <errno.h>

#include <linux/dvb/dmx.h>
#include <linux/dvb/frontend.h>
#include <linux/dvb/video.h>  

#include "httpd.h"
#include "http_config.h"
#include "http_protocol.h"
#include "http_log.h"

#include "mod_dvb.h"

int dvb_wait_open (char *fn, int flags, dvb_config *config) {
  int i, ret;

  /* Wait n seconds while trying to open the device */
  for (i = 0; i < config->dvbwait * 20; i++) {
    if (!((ret = open (fn, flags)) < 0))
      return ret;
    
    usleep (50000);
  }
  
  return ret;
}

static int dvb_playlist_handler (request_rec *r, char *uri) {
  dvb_config *config = ap_get_module_config (r->per_dir_config, &dvb_module);
  dvb_channel *chan = config->channels;
  
  char *base;
  int count = 0, index = 0;
  
  for (index = 0; index < strlen (r->uri); index++)
    if (!strcasecmp (r->path_info, r->uri + index)) break;
  
  base = malloc (index);
  memset (base, 0, index);
  strncpy (base, r->uri + 1, index - 1);
  
  while (chan != NULL) {
    count++;
    chan = chan->next;
  }
  
  chan = config->channels;
  index = 0;
  
  if (!strncasecmp (uri, "/kaffeine", 9)) {
    r->content_type = "text/xml";
     
    ap_rputs ("<!DOCTYPE XMLPlaylist>\n", r);
    ap_rputs ("<playlist client=\"kaffeine\" >\n", r);
    
    while (chan != NULL) {
      ap_rprintf (r, "<entry title=\"%s\" currentSub=\"-1\" mime=\"video/mpeg\" track=\"\" artist=\"\" length=\"0:00:00\" url=\"http://%s/%s/%s\" album=\"\" genre=\"\" year=\"\" />\n", chan->name, r->hostname, base, chan->name);
      chan = chan->next;
    }

    ap_rputs ("</playlist>\n", r);
     
  } else {
    r->content_type = "audio/x-scpls";
    
    ap_rputs ("[playlist]\r\n", r);
    ap_rprintf (r, "NumberOfEntries=%i\r\n", count);
    
    while (chan != NULL) {
      ap_rprintf (r, "File%i=http://%s/%s/%s\r\n", ++index, r->hostname, base, chan->name);
      ap_rprintf (r, "Title%i=%s\r\n", index, chan->name);
      ap_rprintf (r, "Length%i=-1\r\n", index);
      
      chan = chan->next;
    }

    ap_rputs ("Version=2\r\n", r);
  }
  
  return 0;
}

static int dvb_handler (request_rec *r) {
  dvb_config *config = ap_get_module_config (r->per_dir_config, &dvb_module);
  dvb_channel *chan;
  
  struct pollfd poll_dvr[1];
  
  unsigned char buffer[MPEG_TS_SIZE];
  int dvr_fd, len, pid, remap;
  
  /* DVB Processing */
  if (strcmp(r->handler, "dvb-provider"))
    return DECLINED;
  
  /* Check if we have to deliver a playlist */
  if (!strncasecmp (r->path_info, "/playlist", 9))
    return dvb_playlist_handler (r, r->path_info + 9);
  
  /* Try to find the right channel */
  if (((chan = dvb_find_channel (config->channels, r->path_info + 1)) == NULL) &&
      ((chan = config->cdefault) == NULL) &&
      ((chan = config->channels) == NULL))
    return HTTP_INTERNAL_SERVER_ERROR;

  /* Check for at least one valid PID */
  if ((chan->vpid < 1) && (chan->apid < 1))
    return HTTP_INTERNAL_SERVER_ERROR;
  
  /* Setup the frontend */
  if (config->tuner == NULL)
    config->tuner = dvb_tuner_create (0, config->tuner);
  
  if (dvb_tuner_set (config->tuner, chan) == NULL) {
    ap_log_error (APLOG_MARK, APLOG_ERR, 0, NULL, "mod_dvb: Could not setup the tuner");
    return HTTP_SERVICE_UNAVAILABLE;
  }
  
  /* Open the Video Pipe */
  if ((dvr_fd = dvb_wait_open ("/dev/dvb/adapter0/dvr0", O_RDONLY|O_NONBLOCK, config)) < 0) {
    ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL, "mod_dvb: Open DVR failed (%s)", strerror(errno));
    return HTTP_SERVICE_UNAVAILABLE;
  }
  
  poll_dvr[0].fd = dvr_fd;
  poll_dvr[0].events = POLLIN | POLLPRI;
  
  
  /* Set the content-type */
  /* Nice idea, but does not work for MPEG-TS
  if (chan->vpid > 0)
    r->content_type = "video/mpeg";
  else
    r->content_type = "audio/mpeg";
  */

  r->content_type = "video/mpeg";
  
  while (!r->connection->aborted) {
    if (poll (poll_dvr, 1, 100) && (read(dvr_fd, buffer, MPEG_TS_SIZE) == MPEG_TS_SIZE)) {
      /* Check packet-identifier */
      if (buffer [0] != 0x47) continue;
      
      /* Extract PID from current packet */
      pid = ((((unsigned) buffer [1]) << 8) | ((unsigned) buffer [2])) & 0x1FFF;
      remap = 0;
      
      /* Check wheter to rewrite the PID-Value */
      if ((pid == chan->vpid) && (config->vpid > 0)) remap = config->vpid;
      if ((pid == chan->apid) && (config->apid > 0)) remap = config->apid;
      
      /* Perform rewrite */
      if ((remap > 0x0) && (remap < 0x2000)) {
        buffer [1] = (buffer [1] & 0xE0) | (remap >> 8);
        buffer [2] = (remap & 0xFF);
      }

      /* Send packet to client */
      if (ap_rwrite (buffer, MPEG_TS_SIZE, r) < 0) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, NULL, "mod_dvb: write error");
        break;
      }

      /* You should NEVER do this - your system would run out of memory ;-) */      
      /* ap_rflush (r); */
    }
  }
  
  dvb_tuner_stop (config->tuner);
  
  close (dvr_fd);
}



static void *dvb_create_config (apr_pool_t *p, char *dummy) {
  dvb_config *config = apr_palloc (p, sizeof (dvb_config));
  
  config->tuner = NULL;
  config->chanfile = NULL;
  config->channels = NULL;
  config->cdefault = NULL;
  
  config->dvbwait = 5;
  
  config->vpid = 51;
  config->apid = 64;
  
  return (void *)config;
}

const char *dvb_set_channels (cmd_parms *cmd, void *dirconfig, const char *arg) {
  dvb_config *config = (dvb_config *)dirconfig;
  dvb_channel *chan;
  
  if ((chan = dvb_load_channels (arg)) == NULL) return NULL;
  
  dvb_free_channels (config->channels);
  
  config->chanfile = arg;
  config->channels = chan;
  
  return NULL;
}

const char *dvb_set_channel (cmd_parms *cmd, void *dirconfig, const char *arg) {
  dvb_config *config = (dvb_config *)dirconfig;
  dvb_channel *chan;
  
  if ((chan = dvb_find_channel (config->channels, arg)) != NULL)
    config->cdefault = chan;
  
  return NULL;
}

const char *dvb_set_vpid (cmd_parms *cmd, void *dirconfig, const char *arg) {
  dvb_config *config = (dvb_config *)dirconfig;
  config->vpid = atol (arg);
  return NULL;
}

const char *dvb_set_apid (cmd_parms *cmd, void *dirconfig, const char *arg) {
  dvb_config *config = (dvb_config *)dirconfig;
  config->apid = atol (arg);
  return NULL;
}

const char *dvb_set_iowait (cmd_parms *cmd, void *dirconfig, const char *arg) {
  dvb_config *config = (dvb_config *)dirconfig;
  config->dvbwait = atol (arg);
  return NULL;
}


static void dvb_register_hooks(apr_pool_t *p) {
  ap_hook_handler(dvb_handler, NULL, NULL, APR_HOOK_MIDDLE);
}

static const command_rec dvb_module_cmds[] = {
  AP_INIT_TAKE1 ("dvbChannelFile",  dvb_set_channels, NULL, OR_FILEINFO,
                 "Load a set of DVB-Channels"),
  AP_INIT_TAKE1 ("dvbDefaultChannel",  dvb_set_channel, NULL, OR_FILEINFO,
                 "Set the default channel"),
  AP_INIT_TAKE1 ("dvbRemapVideoPID", dvb_set_vpid, NULL, OR_FILEINFO,
                 "Remap Video PID to given value"),
  AP_INIT_TAKE1 ("dvbRemapAudioPID", dvb_set_apid, NULL, OR_FILEINFO,
                 "Remap Audio PID to given value"),
  AP_INIT_TAKE1 ("dvbOpenWait", dvb_set_iowait, NULL, OR_FILEINFO,
                 "Wait a brunch of seconds for DVB-Devices to become available"),
  {NULL}
};

module AP_MODULE_DECLARE_DATA dvb_module = {
    STANDARD20_MODULE_STUFF,
    dvb_create_config,          /* dir config creater */
    NULL,                       /* dir merger --- default is to override */
    NULL,                       /* server config */
    NULL,                       /* merge server config */
    dvb_module_cmds,		/* command table */
    dvb_register_hooks		/* register_hooks */
};