#include <pthread.h>
#include <vector>
#include <netdb.h>
#include "io.h"
#include "parse_args.h"
#include "cache.h"
#include "vw.h"
#include "simple_label.h"
#include "network.h"
#include "multisource.h"
#include "delay_ring.h"

pthread_t* thread;
size_t d_1;
size_t d_2;
v_array<v_array<io_buf *> > bufs;
bool second_of_pair[256];
bool pairs_exist=false;

size_t log_int_r(size_t v)
{
  if (v > 1)
    return 1+log_int_r(v >> 1);
  else
    return 0;
}

size_t log_int(size_t v)
{//find largest number n such that 2^n <= v
  return log_int_r(v);
}

size_t find_split(size_t number)
{// approximately factor number into d_1 and d_2, each a power of 2 as large as possible so that (1) d_1 >= d_2, and (2) d_1 * d_2 <= number
  d_1 = 1;
  d_2 = 1;
  if (number > 1)
    {
      size_t log_2 = log_int(number);
      if (!pairs_exist)
        d_1 = 1 << log_2;
      else
        {
          size_t a = log_2 / 2;
          d_1 = 1 << (log_2 - a);
          d_2 = 1 << a;
        }
      if (d_1 * d_2 < number)
        cerr << "warning: number of remote hosts is not a factor of 2, so some are wasted" << endl;
      return log_2;
    }
  return 0;
}

void open_sockets(vector<string>& hosts)
{
  size_t new_id = global.unique_id;
  for (size_t i = 0; i < d_1; i++)
    {
      v_array<io_buf *> t;
      push(bufs,t);
      for (size_t j = 0; j< d_2; j++)
        {
          size_t number = j + d_2*i;
          int sd = open_socket(hosts[number].c_str(), new_id);
          if (new_id == 0)
            global.local_prediction = sd;
          new_id++;
          io_buf *b = new io_buf();
          push(b->files, sd);
          push(bufs[i], b);
        }
    }
}

void parse_send_args(po::variables_map& vm, vector<string> pairs)
{
  if (vm.count("sendto"))
    {      
      if (pairs.size() > 0)
        {
          pairs_exist=true;
          for (int i = 0; i<256;i++)
            second_of_pair[i]=false;
          for (vector<string>::iterator i = pairs.begin(); i != pairs.end();i++) 
            second_of_pair[(int)(*i)[1]] = true;
        }

      vector<string> hosts = vm["sendto"].as< vector<string> >();
      global.partition_bits = find_split(hosts.size());
      open_sockets(hosts);
    }
}

void send_features(int i, int j, io_buf *b, example* ec)
{
  // note: subtracting 1 b/c not sending constant
  output_byte(*b,ec->indices.index()-1);
  
  for (size_t* index = ec->indices.begin; index != ec->indices.end; index++) {
    if (*index == constant_namespace)
      continue;
    
    if (second_of_pair[*index])
      output_features(*b, *index, ec->subsets[*index][j*d_1], ec->subsets[*index][(j+1)*d_1]);
    else
      output_features(*b, *index, ec->subsets[*index][i*d_2], ec->subsets[*index][(i+1)*d_2]);
  }
  b->flush();
}

void* send_thread(void*)
{
  example* ec = NULL;
  v_array<char> null_tag;
  null_tag.erase();

  bool finished = false;
  while ( true )
    {//this is a poor man's select operation.
      if ((ec = get_example(0)) != NULL)//semiblocking operation.
        {
	  if (finished) 
	    cout << "NOT POSSIBLE! " << endl;
          label_data* ld = (label_data*)ec->ld;
          
          for (size_t i = 0; i < d_1; i++)
            for (size_t j = 0; j < d_2; j++)
              {
                simple_label.cache_label(ld, *bufs[i][j]);//send label information.
                cache_tag(*bufs[i][j], ec->tag);
                send_features(i,j,bufs[i][j],ec);
              }
          delay_example(ec,0);
        }
      else if (!finished && parser_done())
        { //close our outputs to signal finishing.
	  finished = true;
          for (size_t i = 0; i < d_1; i++)
            {
              for (size_t j = 0; j < d_2; j++)
                {
                  bufs[i][j]->flush();
                  shutdown(bufs[i][j]->files[0],SHUT_WR);
                  free(bufs[i][j]->files.begin);
                  free(bufs[i][j]->space.begin);
                }
              free(bufs[i].begin);
            }
          free(bufs.begin);
        }
      else if (!finished)
	;
      else
	return NULL;
    }
  return NULL;
}

void setup_send()
{
  thread = (pthread_t*)calloc(1,sizeof(pthread_t));
  
  pthread_create(thread, NULL, send_thread, NULL);
}

void destroy_send()
{
  pthread_join(*thread, NULL);
  free(thread);
}