#include <stdlib.h>
#include <unistd.h>

#include <corelib/alloc.h>
#include <corelib/dir_array.h>
#include <corelib/dstring.h>
#include <corelib/error.h>
#include <corelib/fmt.h>
#include <corelib/get_opt.h>
#include <corelib/scan.h>
#include <corelib/syserr.h>

#include "db.h"
#include "file_rw.h"
#include "person.h"
#include "seed.h"

const char progname[] = "au-choose";
const char *db_path = DB_PATH;
dstring path;
dstring wstr;
dir_array people;
unsigned int *weights; 
char **files;

void usage()
{
  syserr_warn2x(progname, ": usage: [-d dbpath]");
}

int main(int argc, char *argv[])
{
  unsigned long ind;
  unsigned long max;
  long total_w;
  long select;
  int ch;

  while ((ch = get_opt(argc, argv, "d:")) != opteof)
    switch (ch) {
      case 'd': db_path = optarg; break;
      default: usage(); return 111;
    }
  argc -= optind;
  argv += optind;

  seed();
  if (!dstring_init(&wstr, 2))
    syserr_die1sys(112, "fatal: dstring_init: ");
  if (!dstring_init(&path, 1024))
    syserr_die1sys(112, "fatal: dstring_init: ");
  if (!dstring_cats(&path, db_path))
    syserr_die1sys(112, "fatal: cats: ");
  if (!dstring_cats(&path, "/persons"))
    syserr_die1sys(112, "fatal: cats: ");
  dstring_0(&path);

  if (chdir(path.s) == -1)
    syserr_die1sys(112, "fatal: open database - ");

  if (!dir_array_init(&people, "."))
    syserr_die1sys(112, "fatal: dir_init: ");  
  if (people.n == 2)
    syserr_die1x(112, "fatal: no people in database");

  max = people.n - 2;
  files = people.a + 2;

  weights = (unsigned int *) alloc(sizeof(unsigned int) * max);
  if (!weights)
    syserr_die1sys(112, "fatal: alloc: ");

  for (ind = 0; ind < max; ++ind) {
    dstring_trunc(&path);
    if (!dstring_cats(&path, files[ind]))
      syserr_die1sys(112, "fatal: cats: ");
    if (!dstring_cats(&path, "/weight"))
      syserr_die1sys(112, "fatal: catb: ");
    dstring_0(&path);
    dstring_trunc(&wstr);
    if (file_orac(path.s, &wstr) != -1) {
      if (!scan_uint(wstr.s, &weights[ind])) weights[ind] = 50;
    } else {
      if (errno == error_noent)
        weights[ind] = 50;
      else
        syserr_die3sys(112, "fatal: file_orac: ", path.s, " - ");
    }
  }

  total_w = 0;
  for (ind = 0; ind < max; ++ind)
    total_w += weights[ind];

  if (!total_w)
    syserr_die1x(112, "fatal: total weight is 0");

  select = random() % total_w + 1;

  for (ind = 0; ind < max; ++ind)
    if ((select -= weights[ind]) <= 0) {
      buffer_puts(buffer1, files[ind]);
      buffer_put(buffer1, "\n", 1);
      break;
    }

  if (buffer_flush(buffer1) == -1) 
    syserr_die1sys(112, "fatal: write: ");  

  return 0;
}