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

#include "genpass.h"

void genpass(int count, bool issecure) {
  const char* charset_risky = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  const char* charset_secure = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!\"#$%&'()=~-^\\|_@`[{]};:+*<>,./?";
  const char* charset = issecure ? charset_secure : charset_risky;

  FILE *fp = fopen("/dev/random", "rb");
  if (fp == NULL) {
    perror("/dev/randomを開けられませんでした。");
    exit(EXIT_FAILURE);
  }

  char password[count + 1];
  for (int i = 0; i < count; i++) {
    unsigned char key;
    fread(&key, sizeof(key), 1, fp);
    password[i] = charset[key % strlen(charset)];
  }

  password[count] = '\0';
  fclose(fp);

  printf("%s\n", password);
}