#define _GNU_SOURCE             /* See feature_test_macros(7) */
#include <fcntl.h>              /* Obtain O_* constant definitions */
#include <unistd.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "main.h"
#include "common.h"

#include "child.h"
#include "parent.h"
#include "dist.h"

static char* app_name;

void usage( FILE* output ) {
  fprintf(output, "usage: %s -p <x>\n", app_name);
  fprintf(output, "`x` must be int between 1 and %d\n", MAX_X);
}

int main(int argc, char* argv[]) {
  uint8_t i;
  dist_info_t info;
  app_name = argv[0];

  if( argc != 3 || strcmp( argv[1], "-p") != 0 ) {
    usage(stdout);
    return 1;
  }

  // fill info about distributed network
  info.x = atoi(argv[2]);
  if( info.x < 0 || info.x > MAX_X ) {
    usage(stdout);
    return 1;
  }

  info.proccnt    = info.x + 1;
  info.parent_pid = getpid();
  info.events_log = fopen( events_log, "w" );
  info.pipes_log  = fopen( pipes_log, "w" );

  // open all (N * (N-1)) pipes for a full mesh topology
  for( i = 0; i < info.proccnt * (info.proccnt - 1); i++ ) {
    pipe2( info.pipes[i], O_NONBLOCK | O_DIRECT );
    fprintf( info.pipes_log, "Opened pipe #%d (%d;%d)\n", i, info.pipes[i][0], info.pipes[i][1] );
  }
  fclose( info.pipes_log );

  for( i = 1; i < info.proccnt; i++ ) {
    pid_t pid = fork();
    switch(pid) {
      case 0:
        /* Child branch */
        child_workflow( &info, i );
        exit(0);
        break;
      case -1:
        /* Error */
        perror("fork");
        return 1;
      default:
        break;
    }
  }

  parent_workflow( &info );
  return 0;
}