/*
 *  rharchive
 *
 *  rharchive is a simple tcp connection proxy which combines the 
 *  features of rinetd and 6tunnel. rharchive supports IPv4 and 
 *  IPv6 and also supports connections from IPv6 to IPv4 
 *  endpoints and vice versa.
 *  
 *
 *  Copyright (C) 2010-2011 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/>.
 */

#include <gst/gst.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

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

#include "writer.h"

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

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

  struct timespec now;
  clock_gettime(CLOCK_REALTIME, &now);
  
  struct tm bd_time;
  localtime_r(&(now.tv_sec), &bd_time);
  
  log_printf(INFO, "it's now: %02d:%02d:%02d on %d.%d.%d", bd_time.tm_hour, bd_time.tm_min, bd_time.tm_sec, bd_time.tm_mday, bd_time.tm_mon+1, bd_time.tm_year+1900);

  char name[256];
  strftime(name, sizeof(name), writer->name_format_, &bd_time);
  asprintf(&(writer->current_.path_), "%s/%s", writer->output_dir_, name);
  if(!writer->current_.path_) {
    return -2;
  }
  log_printf(INFO, "current filename is: %s(.?)", writer->current_.path_);
  writer->current_.fd_ = -1;
  writer->current_.mode_ = writer->mode_;

  bd_time.tm_sec = 0;
  bd_time.tm_min = 0;

  time_t T = mktime(&bd_time);
  T+=3600;

  localtime_r(&T, &bd_time);

  log_printf(INFO, "next boundary is at: %02d:%02d:%02d on %d.%d.%d", bd_time.tm_hour, bd_time.tm_min, bd_time.tm_sec, bd_time.tm_mday, bd_time.tm_mon+1, bd_time.tm_year+1900);

  strftime(name, sizeof(name), writer->name_format_, &bd_time);
  asprintf(&(writer->next_.path_), "%s/%s", writer->output_dir_, name);
  if(!writer->next_.path_) {
    free(writer->current_.path_);
    return -2;
  }
  log_printf(INFO, "next filename will be: %s(.?)", writer->next_.path_);
  writer->next_.fd_ = -1;
  writer->next_.mode_ = writer->mode_;

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

  return 0;
}

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

  writer->loop_ = loop;
  writer->sink_ = gst_element_factory_make("fakesink", "writer");
  if(!writer->sink_) {
    log_printf(ERROR, "the writer object could not be created. Exiting.");
    return -1;
  }
  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->output_dir_ = output_dir;
  writer->interval_ = interval * GST_MSECOND;
  writer->offset_ = offset * GST_MSECOND;
  writer->current_.path_ = NULL;
  writer->next_.path_ = NULL;
  writer->clock_id_ = NULL;
  writer->thread_ = NULL;
  return init_time_boundaries(writer);
}

static int open_file(file_t* file)
{
  char* orig_path = file->path_;
  int cnt = 0;
  do {
    file->fd_ = open(file->path_, O_WRONLY | O_CREAT | O_EXCL, file->mode_);
    if(file->fd_ < 0) {
      if(errno != EEXIST) {
            // TODO: thread safe strerror
        log_printf(ERROR, "can't open file '%s': %s", file->path_, strerror(errno));
        if(orig_path != file->path_)
          free(orig_path);
        return -1;
      } 
      cnt++;
      char* tmp;
      asprintf(&tmp, "%s.%d", orig_path, cnt);
      if(!tmp) {
        if(orig_path != file->path_)
          free(orig_path);
        return -2;
      }
      
      if(file->path_ != orig_path)
        free(file->path_);
      file->path_ = tmp;
    }
    fchmod(file->fd_, file->mode_);
  }
  while(file->fd_ < 0);

  if(orig_path != file->path_)
    free(orig_path);

  return 0;
}

static int check_boundaries(writer_t* writer)
{
  struct timespec now;
  clock_gettime(CLOCK_REALTIME, &now);
  
  struct tm now_bd;
  localtime_r(&(now.tv_sec), &now_bd);
  log_printf(DEBUG, "it's now: %02d:%02d:%02d on %d.%d.%d", now_bd.tm_hour, now_bd.tm_min, now_bd.tm_sec, now_bd.tm_mday, now_bd.tm_mon+1, now_bd.tm_year+1900);

  return 0;
}
  
static gpointer writer_thread_func(gpointer data)
{
  writer_t *writer = (writer_t*)data;
  log_printf(NOTICE, "writer thread started");
  
  GstBuffer* buf = NULL;
  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;

        // TODO: children handling (waitpid)
  }
 
  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;

  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_create(writer_thread_func, writer, TRUE, NULL);
  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;

  if(writer->current_.path_) free(writer->current_.path_);
  if(writer->current_.fd_ >= 0) close(writer->current_.fd_);
  if(writer->next_.path_) free(writer->next_.path_);
  if(writer->next_.fd_ >= 0) close(writer->next_.fd_);

  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_));
}