/*
 *  sydra
 *
 *  sydra is a toolbox which allows you to set up multiple bidirectional
 *  Video/Audio streams from external locations.
 *  sydra has been written to be used for the Elevate Festival in Graz
 *  Austria in order to involve external locations to present themselves
 *  at the festival.
 *  Sydra is based on GStreamer and is written in C.
 *
 *
 *  Copyright (C) 2014 Christian Pointner <equinox@helsinki.at>
 *
 *  This file is part of sydra.
 *
 *  sydra 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 3 of the License, or
 *  any later version.
 *
 *  sydra 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 sydra. If not, see <http://www.gnu.org/licenses/>.
 *
 *  In addition, as a special exception, the copyright holders hereby
 *  grant permission for non-GPL-compatible GStreamer plugins to be used
 *  and distributed together with GStreamer and sydra.
 *  This permission goes above and beyond the permissions granted by the
 *  GPL license sydra is covered by.
 */

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <sys/select.h>
#include <time.h>

#include <glib.h>
#include <glib-unix.h>
#include <gst/gst.h>

#include "datatypes.h"
#include "options.h"
#include "string_list.h"
#include "log.h"
#include "daemon.h"

static gboolean sig_handler_terminate(gpointer user_data)
{
  GMainLoop *loop = (GMainLoop *)user_data;

  log_printf(NOTICE, "signal received, closing application");
  g_main_loop_quit(loop);
  return TRUE;
}

static gboolean bus_call(GstBus *bus, GstMessage *msg, gpointer data)
{
  GMainLoop *loop = (GMainLoop *)data;

  switch (GST_MESSAGE_TYPE(msg)) {
  case GST_MESSAGE_EOS: {
    log_printf(NOTICE, "End of stream");
    g_main_loop_quit(loop);
    break;
  }
  case GST_MESSAGE_INFO: {
    GError *info;
    gst_message_parse_info(msg, &info, NULL);
    log_printf(INFO, "%s", info->message);
    g_error_free(info);
    break;
  }
  case GST_MESSAGE_WARNING: {
    GError *warning;
    gst_message_parse_warning(msg, &warning, NULL);
    log_printf(WARNING, "%s", warning->message);
    g_error_free(warning);
    break;
  }
  case GST_MESSAGE_ERROR: {
    GError *error;
    gst_message_parse_error(msg, &error, NULL);
    log_printf(ERROR, "%s", error->message);
    g_error_free(error);
    g_main_loop_quit(loop);
    break;
  }
  case GST_MESSAGE_STATE_CHANGED: {
    GstState old_state, new_state;
    gst_message_parse_state_changed(msg, &old_state, &new_state, NULL);
    log_printf(DEBUG, "Element '%s' changed state from %s to %s",
        (msg->src ? GST_OBJECT_NAME(msg->src) : "NULL"),
        gst_element_state_get_name(old_state),
        gst_element_state_get_name(new_state));
    break;
  }
  case GST_MESSAGE_NEW_CLOCK:
  {
    GstClock *clock;
    gst_message_parse_new_clock(msg, &clock);
    log_printf(INFO, "New clock: %s", (clock ? GST_OBJECT_NAME (clock) : "NULL"));
    break;
  }
  /* case GST_MESSAGE_STREAM_STATUS: */
  /* { */
  /*   GstStreamStatusType type; */
  /*   GstElement *owner; */
  /*   const GValue *val; */
  /*   gchar *path, *ownerstr; */
  /*   GstTask *task = NULL; */

  /*   gst_message_parse_stream_status (msg, &type, &owner); */
  /*   val = gst_message_get_stream_status_object (msg); */

  /*   path = gst_object_get_path_string (GST_MESSAGE_SRC (msg)); */
  /*   ownerstr = gst_object_get_path_string (GST_OBJECT (owner)); */
  /*   log_printf(DEBUG,"Recevied Stream-Status message type: %d, source: %s, owner: %s, object: type %s, value %p", */
  /*                       type, path, ownerstr, G_VALUE_TYPE_NAME (val), g_value_get_object (val)); */
  /*   g_free (path); */
  /*   g_free (ownerstr); */

  /*   /\* see if we know how to deal with this object *\/ */
  /*   if (G_VALUE_TYPE (val) == GST_TYPE_TASK) { */
  /*     task = g_value_get_object (val); */
  /*   } */

  /*   switch (type) { */
  /*     case GST_STREAM_STATUS_TYPE_CREATE: */
  /*       log_printf(DEBUG,"   created task %p", task); */
  /*       break; */
  /*     case GST_STREAM_STATUS_TYPE_ENTER: */
  /*       /\* log_printf(DEBUG,"   raising task priority"); *\/ */
  /*       /\* setpriority (PRIO_PROCESS, 0, -10); *\/ */
  /*       break; */
  /*     case GST_STREAM_STATUS_TYPE_LEAVE: */
  /*       break; */
  /*     default: */
  /*       break; */
  /*   } */
  /*   break; */
  /* } */
  default:
    log_printf(DEBUG, "unkonwn message %s from %s", GST_MESSAGE_TYPE_NAME(msg), GST_MESSAGE_SRC_NAME(msg));
    return TRUE;
  }
  return TRUE;
}

static GstElement* sydra_create_bin_from_desc(const char* type, const char* desc)
{
  GError *error = NULL;
  GstElement *bin =  gst_parse_bin_from_description(desc, TRUE, &error);
  if(!bin) {
    log_printf(ERROR, "Bin description for %s parser error: %s", type, error ? error->message : "unknown");
    g_error_free(error);
    return NULL;
  }
  if(error) {
    log_printf(WARNING, "Bin description for %s parser warning: %s", type, error ? error->message : "unknown");
    g_error_free(error);
  }
  return bin;
}

static GstElement* sydra_create_element(const char* type, const char* name)
{
  GstElement *e = gst_element_factory_make (type, name);
  if(!e) {
    log_printf(ERROR, "Error creating element %s%sof type %s", name ? name : "", name ? " " : "", type);
    return NULL;
  }
  return e;
}

static gboolean sydra_link_pads(GstElement* src, GstPad* src_pad, const char* src_pad_name, GstElement* sink, GstPad* sink_pad, const char* sink_pad_name)
{
  if(!src_pad || !sink_pad)
    return FALSE;

  GstPadLinkReturn ret = gst_pad_link(src_pad, sink_pad);
  gst_object_unref(GST_OBJECT(src_pad));
  gst_object_unref(GST_OBJECT(sink_pad));

  if(GST_PAD_LINK_FAILED(ret)) {
    gchar* src_name = gst_element_get_name(src);
    gchar* sink_name = gst_element_get_name(sink);
    log_printf(ERROR, "Error linking request pad '%s' of '%s' with static pad '%s' of '%s'",
               src_pad_name, src_name, sink_pad_name, sink_name);
    g_free(src_name);
    g_free(sink_name);
    return FALSE;
  }
  return TRUE;
}

static gboolean sydra_link_request_static(GstElement* src, const char* src_pad_name, GstElement* sink, const char* sink_pad_name)
{
  GstPad *src_pad = gst_element_get_request_pad(src, src_pad_name);
  GstPad *sink_pad = gst_element_get_static_pad(sink, sink_pad_name);
  return sydra_link_pads(src, src_pad, src_pad_name, sink, sink_pad, sink_pad_name);
}

static gboolean sydra_link_static_request(GstElement* src, const char* src_pad_name, GstElement* sink, const char* sink_pad_name)
{
  GstPad *src_pad = gst_element_get_static_pad(src, src_pad_name);
  GstPad *sink_pad = gst_element_get_request_pad(sink, sink_pad_name);
  return sydra_link_pads(src, src_pad, src_pad_name, sink, sink_pad, sink_pad_name);
}

static gboolean sydra_link_static_static(GstElement* src, const char* src_pad_name, GstElement* sink, const char* sink_pad_name)
{
  GstPad *src_pad = gst_element_get_static_pad(src, src_pad_name);
  GstPad *sink_pad = gst_element_get_static_pad(sink, sink_pad_name);
  return sydra_link_pads(src, src_pad, src_pad_name, sink, sink_pad, sink_pad_name);
}

struct media_elements {
  const char* name_;

  const char* src_str_;
  GstElement* src_;

  GstElement* tee_raw_;

  const char* enc_str_;
  GstElement* enc_;

  GstElement* tee_enc_;

  const char* payloader_str_;
  GstElement* payloader_;
};

static gboolean create_media_elements(struct media_elements *me, GstElement* pipeline, GstElement *rtp, uint32_t idx)
{
  char bin_name[32];

  snprintf(bin_name, sizeof(bin_name), "%s source", me->name_);
  me->src_ = sydra_create_bin_from_desc(bin_name, me->src_str_);
  me->tee_raw_ = sydra_create_element("tee", NULL);
  GstElement *qr = sydra_create_element("queue", NULL);

  snprintf(bin_name, sizeof(bin_name), "%s encoder", me->name_);
  me->enc_ = sydra_create_bin_from_desc(bin_name, me->enc_str_);
  me->tee_enc_ = sydra_create_element("tee", NULL);
  GstElement *qe = sydra_create_element("queue", NULL);

  me->payloader_ = sydra_create_element(me->payloader_str_, NULL);

  if(!me->src_ || !me->tee_raw_ || !qr || !me->enc_ || !me->tee_enc_ || !qe || !me->payloader_) {
    return FALSE;
  }

  log_printf(DEBUG, "%s path created successfully!", me->name_);

  gst_bin_add_many (GST_BIN(pipeline), me->src_, me->tee_raw_, qr, me->enc_, me->tee_enc_, qe, me->payloader_, NULL);
  gst_element_link(me->src_, me->tee_raw_);
  gst_element_link_many(qr, me->enc_, me->tee_enc_, NULL);
  gst_element_link(qe, me->payloader_);

  char pad_name[32];
  snprintf(pad_name, sizeof(bin_name), "send_rtp_sink_%u", idx);
  if(!sydra_link_request_static(me->tee_raw_, "src_%u", qr, "sink") ||
     !sydra_link_request_static(me->tee_enc_, "src_%u", qe, "sink") ||
     !sydra_link_static_request(me->payloader_, "src", rtp, pad_name)) {
    return FALSE;
  }

  log_printf(DEBUG, "%s path linked successfully!", me->name_);
  return TRUE;
}

static gboolean create_udp_elements(options_t* opt, GstElement* pipeline, GstElement* rtp)
{
  GstElement *udp_rtp_video = sydra_create_element("udpsink", "udprtpv");
  GstElement *udp_rtcp_video = sydra_create_element("udpsink", "udprtcpv");
  GstElement *udp_rtp_audio = sydra_create_element("udpsink", "udprtpa");
  GstElement *udp_rtcp_audio = sydra_create_element("udpsink", "udprtcpa");

  if(!udp_rtp_video || !udp_rtcp_video || !udp_rtp_audio || !udp_rtcp_audio)
    return FALSE;

  log_printf(DEBUG, "udp elements created successfully!");

  int rtp_port_v = opt->rtp_port_base_;
  int rtcp_port_v = opt->rtp_port_base_ + 100;
  int rtp_port_a = opt->rtp_port_base_ + 200;
  int rtcp_port_a = opt->rtp_port_base_ + 300;

  g_object_set(G_OBJECT(udp_rtp_video), "host", opt->rtp_host_, "port", rtp_port_v, NULL);
  g_object_set(G_OBJECT(udp_rtcp_video), "host", opt->rtp_host_, "port", rtcp_port_v, "sync", FALSE, "async", FALSE, NULL);
  g_object_set(G_OBJECT(udp_rtp_audio), "host", opt->rtp_host_, "port", rtp_port_a, NULL);
  g_object_set(G_OBJECT(udp_rtcp_audio), "host", opt->rtp_host_, "port", rtcp_port_a, "sync", FALSE, "async", FALSE, NULL);

  gst_bin_add_many(GST_BIN (pipeline), udp_rtp_video, udp_rtcp_video, udp_rtp_audio, udp_rtcp_audio, NULL);

  if(!sydra_link_static_static(rtp, "send_rtp_src_0", udp_rtp_video, "sink") ||
     !sydra_link_request_static(rtp, "send_rtcp_src_0", udp_rtcp_video, "sink") ||
     !sydra_link_static_static(rtp, "send_rtp_src_1", udp_rtp_audio, "sink") ||
     !sydra_link_request_static(rtp, "send_rtcp_src_1", udp_rtcp_audio, "sink"))
    return FALSE;

  log_printf(DEBUG, "udp elements linked successfully!");

  return TRUE;
}

static GstElement* create_pipeline(options_t* opt)
{
  log_printf(DEBUG, "creating pipeline");

  GstElement *pipeline = gst_pipeline_new ("sydra");
  if(!pipeline) {
    log_printf(ERROR, "Creating pipeline failed");
    return NULL;
  }
  GstElement *rtp = sydra_create_element("rtpbin", "rtpbin");
  if(!rtp || !gst_bin_add(GST_BIN(pipeline), rtp)) {
    return NULL;
  }

  log_printf(DEBUG, "rtpbin created");

  struct media_elements video = { "video", opt->video_src_, NULL, NULL,
                                  opt->video_enc_, NULL, NULL,
                                  opt->video_payloader_, NULL };
  struct media_elements audio = { "audio", opt->audio_src_, NULL, NULL,
                                  opt->audio_enc_stream_, NULL, NULL,
                                  opt->audio_payloader_, NULL };
  if(!create_media_elements(&video, pipeline, rtp, 0) ||
     !create_media_elements(&audio, pipeline, rtp, 1) ||
     !create_udp_elements(opt, pipeline, rtp)) {
    return NULL;
  }

  return pipeline;
}

/* static char* build_sender_pipeline_desc(options_t* opt) */
/* { */
  /* struct timespec now; */
  /* clock_gettime(CLOCK_REALTIME, &now); */
  /* struct tm bd_time; */
  /* localtime_r(&(now.tv_sec), &bd_time); */
  /* char recfile[1024]; //TODO: fix this hardcoded length */
  /* strftime(recfile, sizeof(recfile), opt->rec_name_format_, &bd_time); */

/*   char* sender_desc; */
/*   int slen = asprintf(&sender_desc, "rtpbin name=rtpbin                              \ */
/*     %s ! tee name=vt                                                                 \ */
/*         vt. ! queue silent=true ! %s ! tee name=cvt                                  \ */
/*         cvt. ! %s ! rtpbin.send_rtp_sink_0                                           \ */
/*         rtpbin.send_rtp_src_0 ! udpsink port=%d host=%s                              \ */
/*         rtpbin.send_rtcp_src_0 ! udpsink port=%d host=%s sync=false async=false      \ */
/*     %s ! tee name=at                                                                 \ */
/*         at. ! queue silent=true ! %s ! %s ! rtpbin.send_rtp_sink_1                   \ */
/*         rtpbin.send_rtp_src_1 ! udpsink port=%d host=%s                              \ */
/*         rtpbin.send_rtcp_src_1 ! udpsink port=%d host=%s sync=false async=false      \ */
/*     at. ! queue silent=true ! %s name=recmux ! filesink location=\"%s\"              \ */
/*     vt. ! queue silent=true ! textoverlay text=\" local \" shaded-background=true halignment=center valignment=baseline font-desc=\"Sans 18\" ! %s", */
/*      opt->video_src_, opt->video_enc_, opt->video_payloader_, rtp_port_v, opt->rtp_host_, rtcp_port_v, opt->rtp_host_, */
/*      opt->audio_src_, opt->audio_enc_stream_, opt->audio_payloader_, rtp_port_a, opt->rtp_host_, rtcp_port_a, opt->rtp_host_, */
/*      opt->rec_mux_, recfile, opt->videosink_); */

/*   return (slen < 0) ? NULL : sender_desc; */
/* } */

int main_loop(options_t* opt)
{
  log_printf(INFO, "entering main loop");

  GstElement *pipeline = create_pipeline(opt);
  if(!pipeline) {
    log_printf(ERROR, "creating pipeline failed");
    return -1;
  }

  GMainLoop *loop = g_main_loop_new(NULL, FALSE);

  GstBus *bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));
  gst_bus_add_watch(bus, bus_call, loop);
  gst_object_unref(bus);

  gulong deep_notify_id = 0;
  if(opt->debug_) {
    deep_notify_id = g_signal_connect (pipeline, "deep-notify",
        G_CALLBACK (gst_object_default_deep_notify), NULL);
  }

  log_printf(INFO, "Set State: Paused");
  gst_element_set_state(pipeline, GST_STATE_PAUSED);
  log_printf(INFO, "Set State: Playing");
  gst_element_set_state(pipeline, GST_STATE_PLAYING);

  g_unix_signal_add(SIGHUP, sig_handler_terminate, loop);
  g_unix_signal_add(SIGINT, sig_handler_terminate, loop);
  g_unix_signal_add(SIGTERM, sig_handler_terminate, loop);
  g_main_loop_run(loop);

  if (deep_notify_id != 0)
    g_signal_handler_disconnect (pipeline, deep_notify_id);

  log_printf(NOTICE, "Stopping pipeline");
  gst_element_set_state (pipeline, GST_STATE_NULL);
  gst_object_unref(GST_OBJECT(pipeline));

  return 0;
}

int main(int argc, char* argv[])
{
  log_init();

  options_t opt;
  int ret = options_parse(&opt, argc, argv);
  if(ret) {
    if(ret > 0)
      fprintf(stderr, "syntax error near: %s\n\n", argv[ret]);
    if(ret == -2)
      fprintf(stderr, "memory error on options_parse, exitting\n");
    if(ret == -3)
      options_print_version();
    if(ret == -4)
      fprintf(stderr, "the port number is invalid\n");

    if(ret != -2 && ret != -3 && ret != -4)
      options_print_usage();

    if(ret == -1 || ret == -3)
      ret = 0;

    options_clear(&opt);
    log_close();
    exit(ret);
  }
  slist_element_t* tmp = opt.log_targets_.first_;
  while(tmp) {
    ret = log_add_target(tmp->data_);
    if(ret) {
      switch(ret) {
      case -2: fprintf(stderr, "memory error on log_add_target, exitting\n"); break;
      case -3: fprintf(stderr, "unknown log target: '%s', exitting\n", (char*)(tmp->data_)); break;
      case -4: fprintf(stderr, "this log target is only allowed once: '%s', exitting\n", (char*)(tmp->data_)); break;
      default: fprintf(stderr, "syntax error near: '%s', exitting\n", (char*)(tmp->data_)); break;
      }

      options_clear(&opt);
      log_close();
      exit(ret);
    }
    tmp = tmp->next_;
  }

  log_printf(NOTICE, "just started...");
  options_parse_post(&opt);

  if(opt.debug_)
    options_print(&opt);


  if(opt.appname_)
    g_set_prgname (opt.appname_);
  else
    g_set_prgname (opt.progname_);

  priv_info_t priv;
  if(opt.username_)
    if(priv_init(&priv, opt.username_, opt.groupname_)) {
      options_clear(&opt);
      log_close();
      exit(-1);
    }

  FILE* pid_file = NULL;
  if(opt.pid_file_) {
    pid_file = fopen(opt.pid_file_, "w");
    if(!pid_file) {
      log_printf(WARNING, "unable to open pid file: %s", strerror(errno));
    }
  }

  if(opt.chroot_dir_)
    if(do_chroot(opt.chroot_dir_)) {
      options_clear(&opt);
      log_close();
      exit(-1);
    }
  if(opt.username_)
    if(priv_drop(&priv)) {
      options_clear(&opt);
      log_close();
      exit(-1);
    }

  if(opt.daemonize_) {
    pid_t oldpid = getpid();
    daemonize();
    log_printf(INFO, "running in background now (old pid: %d)", oldpid);
  }

  if(pid_file) {
    pid_t pid = getpid();
    fprintf(pid_file, "%d", pid);
    fclose(pid_file);
  }

  gst_init(NULL, NULL);
  const gchar *nano_str;
  guint major, minor, micro, nano;
  gst_version(&major, &minor, &micro, &nano);
  if (nano == 1)
    nano_str = " (CVS)";
  else if (nano == 2)
    nano_str = " (Prerelease)";
  else
    nano_str = "";
  log_printf(NOTICE, "sydra linked against GStreamer %d.%d.%d%s", major, minor, micro, nano_str);

  ret = main_loop(&opt);

  options_clear(&opt);

  log_printf(NOTICE, "sydra shutdown");

  gst_deinit();
  log_close();

  return ret;
}