/*
 *  rharchive
 *
 *  The Radio Helsinki Archive Daemon
 *
 *
 *  Copyright (C) 2009-2015 Christian Pointner <equinox@helsinki.at>
 *
 *  This file is part of rharchive.
 *
 *  rharchive 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.
 *
 *  rharchive 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 rharchive. 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 rharchive.
 *  This permission goes above and beyond the permissions granted by the
 *  GPL license rharchive is covered by.
 */

#include <gst/gst.h>

#include <sys/types.h>

#include <errno.h>
#include <string.h>
#include <time.h>

#include "writer.h"

#include "datatypes.h"
#include "log.h"
#include "file_list.h"

static int init_time_boundaries(writer_t* writer)
{
  if(!writer)
    return -1;

  struct timespec now;
  clock_gettime(CLOCK_REALTIME, &now);

  struct tm bd_time;
  localtime_r(&(now.tv_sec), &bd_time);

  writer->current_ = file_list_add(&(writer->files_), &bd_time, "current", writer->name_format_, writer->output_dir_, writer->mode_, writer->nocache_);
  if(writer->current_ == NULL) return -2;

  bd_time.tm_sec = 0;
  bd_time.tm_min = 0;
  time_t T = mktime(&bd_time);
  T+=3600;
  localtime_r(&T, &bd_time);

  struct timespec b = { T, 0 };
  writer->next_boundary_ = b;

  writer->next_ = file_list_add(&(writer->files_), &bd_time, "next", writer->name_format_, writer->output_dir_, writer->mode_, writer->nocache_);
  if(writer->next_ == NULL) return -2;

  return 0;
}

static void added_cb(GstElement* sink, gint fd, gpointer data)
{
  gint num_fds;
  g_object_get(G_OBJECT(sink), "num_fds", &num_fds, NULL);
  log_printf(INFO, "fdsink: successfully added client %d (sink has now %d fds)", fd, num_fds);
}

static void removed_cb(GstElement* sink, gint fd, gpointer data)
{
  gint num_fds;
  g_object_get(G_OBJECT(sink), "num_fds", &num_fds, NULL);
  log_printf(INFO, "fdsink: successfully removed client %d (sink has now %d fds)", fd, num_fds);
}

static void fdremoved_cb(GstElement* sink, gint fd, gpointer data)
{
  gint num_fds;
  g_object_get(G_OBJECT(sink), "num_fds", &num_fds, NULL);
  log_printf(INFO, "fdsink: successfully removed fd %d (sink has now %d fds)", fd, num_fds);

  writer_t *writer = (writer_t*)data;
  if(writer->post_process_)
    file_list_call_post_process(&(writer->files_), fd, writer->post_process_);
  else
    file_list_remove(&(writer->files_), fd);
}

int writer_init(writer_t* writer, GMainLoop *loop, const char* name_format, mode_t mode, int nocache, const char* output_dir, int interval, int offset, char* post_process)
{
  if(!writer)
    return -1;

  writer->loop_ = loop;
  writer->sink_ = gst_element_factory_make("multifdsink", "writer");
  if(!writer->sink_) {
    log_printf(ERROR, "the writer object could not be created. Exiting.");
    return -1;
  }
      // TODO: how the heck should we get the right value? 3 means keyframe...
  g_object_set(G_OBJECT(writer->sink_), "recover-policy", 3, NULL);
  g_signal_connect(G_OBJECT(writer->sink_), "client-added", G_CALLBACK(added_cb), writer);
  g_signal_connect(G_OBJECT(writer->sink_), "client-removed", G_CALLBACK(removed_cb), writer);
  g_signal_connect(G_OBJECT(writer->sink_), "client-fd-removed", G_CALLBACK(fdremoved_cb), writer);

  writer->clock_ = gst_system_clock_obtain();
  if(!writer->clock_) {
    log_printf(ERROR, "unable to obtain the system clock");
    return -1;
  }
  writer->name_format_ = name_format;
  writer->mode_ = mode;
  writer->nocache_ = nocache;
  writer->output_dir_ = output_dir;
  writer->interval_ = interval * GST_MSECOND;
  writer->offset_ = offset * GST_MSECOND;
  writer->post_process_ = post_process;
  writer->clock_id_ = NULL;
  writer->thread_ = NULL;
  int ret = file_list_init(&(writer->files_));
  if(ret) return ret;

  return init_time_boundaries(writer);
}

static void add_fd(writer_t* writer, int fd)
{
  log_printf(INFO, "adding fd %d to fdsink", fd);
  g_signal_emit_by_name(G_OBJECT(writer->sink_), "add", fd, NULL);
}

static void remove_fd(writer_t* writer, int fd)
{
  log_printf(INFO, "removing fd %d from fdsink", fd);
  g_signal_emit_by_name(G_OBJECT(writer->sink_), "remove-flush", fd, NULL);
}

static int check_boundaries(writer_t* writer)
{
  struct timespec now;
  clock_gettime(CLOCK_REALTIME, &now);

  GstClockTime tmp = GST_TIMESPEC_TO_TIME(now);
  GstClockTime boundary = GST_TIMESPEC_TO_TIME(writer->next_boundary_);
  tmp -= writer->offset_;
  if(tmp >= boundary) {
    struct tm now_bd;
    localtime_r(&(now.tv_sec), &now_bd);
    log_printf(INFO, "boundary reached! it's now: %02d:%02d:%02d.%06d on %d.%d.%d%s (%d ms offset)", now_bd.tm_hour, now_bd.tm_min, now_bd.tm_sec, now.tv_nsec/1000, now_bd.tm_mday, now_bd.tm_mon+1, now_bd.tm_year+1900, now_bd.tm_isdst > 0 ? " (DST)": "", GST_TIME_AS_MSECONDS(writer->offset_));

    int ret = open_file(writer->next_);
    if(ret) return ret; // TODO: stop writer on open_file error ???

    add_fd(writer, writer->next_->fd_);
    remove_fd(writer, writer->current_->fd_);
    writer->current_ = writer->next_;

    writer->next_boundary_.tv_sec += 3600;
    struct tm bd_time;
    localtime_r(&(writer->next_boundary_.tv_sec), &bd_time);

    writer->next_ = file_list_add(&(writer->files_), &bd_time, "next", writer->name_format_, writer->output_dir_, writer->mode_, writer->nocache_);
    if(writer->next_ == NULL) return -2;
  }

  return 0;
}

static gpointer writer_thread_func(gpointer data)
{
  writer_t *writer = (writer_t*)data;
  log_printf(NOTICE, "writer thread started");

  for(;;) {
    GstClockReturn wret =  gst_clock_id_wait(writer->clock_id_, NULL);
    if(GST_CLOCK_UNSCHEDULED == wret)
      break;
    if(GST_CLOCK_EARLY == wret)
      continue;

    int ret = check_boundaries(writer);
    if(ret) break;

    ret = file_list_waitpid(&(writer->files_));
    if(ret) break;
  }

  log_printf(NOTICE, "writer thread stopped");
  g_main_loop_quit(writer->loop_);
  return NULL;
}

int writer_start(writer_t* writer)
{
  if(!writer)
    return -1;

  int ret = open_file(writer->current_);
  if(ret)
    return ret;

  add_fd(writer, writer->current_->fd_);

  writer->clock_id_ = gst_clock_new_periodic_id(writer->clock_, 0, writer->interval_);
  if(!writer->clock_id_) {
    log_printf(ERROR, "clock id could not be created");
    return -1;
  }
  writer->thread_ = g_thread_new("writer", writer_thread_func, writer);
  if(!writer->thread_) {
    log_printf(ERROR, "writer thread could not be started");
    return -1;
  }

  return 0;
}

void writer_stop(writer_t* writer)
{
  if(!writer)
    return;

  file_list_clear(&(writer->files_));
  if(writer->clock_id_) {
    gst_clock_id_unschedule(writer->clock_id_);
  }
  if(writer->thread_) {
    log_printf(NOTICE, "waiting for writer thread to stop");
    g_thread_join(writer->thread_);
  }
  gst_object_unref(GST_OBJECT(writer->clock_));
}