// bcrypt_tool.c - CLI tool for bcrypt password hashing and verification
// Compile: ( cd tools/ && rm bcrypt_tool; mk bcrypt_tool )
// Usage:
//   ./bcrypt_tool hash <password> [cost]
//   ./bcrypt_tool verify <password> <hash>

#define _XOPEN_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <ctype.h>
#include <string.h>
#include <unistd.h>
#include <crypt.h>
#include <time.h>
#include <stdbool.h>

typedef unsigned char byte;
#include "util/defs.h"
#include "util/arenastr.c"
#include "util/strmanip.c"
#include "util/passwordhash.c"

static void print_usage(const char *prog) {
  fprintf(stderr,
    "Usage: %s <command> [arguments]\n"
    "\n"
    "Commands:\n"
    "  hash <password> [cost]    Hash a password (cost default: %d, range: %d-%d)\n"
    "  verify <password> <hash>  Verify a password against a hash\n"
    "\n"
    "Examples:\n"
    "  %s hash mysecretpassword\n"
    "  %s hash mysecretpassword 12\n"
    "  %s verify mysecretpassword '$2b$10$...'\n",
    prog, BCRYPT_DEFAULT_COST, BCRYPT_MIN_COST, BCRYPT_MAX_COST,
    prog, prog, prog);
}

int main(int argc, char **argv) {
  if (argc < 2) {
    print_usage(argv[0]);
    return 1;
  }

  // Arena for temporary allocations (4KB is plenty)
  uint8_t buf[4096];
  arena tmp;
  arena_init(&tmp, buf, sizeof(buf));

  if (strcmp(argv[1], "hash") == 0) {
    if (argc < 3) {
      fprintf(stderr, "Error: password required\n");
      print_usage(argv[0]);
      return 1;
    }
    str password = str_from_cstr(argv[2]);
    int cost = BCRYPT_DEFAULT_COST;
    if (argc >= 4) {
      cost = atoi(argv[3]);
    }

    str hash = create_password_hash(&tmp, password, cost);
    if (hash.len == 0) {
      fprintf(stderr, "Error: failed to create password hash\n");
      return 1;
    }

    printf("%.*s\n", (int)hash.len, hash.data);
    return 0;
  }
  else if (strcmp(argv[1], "verify") == 0) {
    if (argc < 4) {
      fprintf(stderr, "Error: password and hash required\n");
      print_usage(argv[0]);
      return 1;
    }
    str password = str_from_cstr(argv[2]);
    str hash = str_from_cstr(argv[3]);

    if (verify_password(password, hash)) {
      printf("MATCH\n");
      return 0;
    } else {
      printf("FAIL\n");
      return 1;
    }
  }
  else {
    fprintf(stderr, "Error: unknown command '%s'\n", argv[1]);
    print_usage(argv[0]);
    return 1;
  }
}