#include <assert.h>
#include <ftw.h>
#include <getopt.h>
#include <limits.h>
#include <pwd.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>

#include "util/versie.h"

int ftmap = 0;
int max_depth = -1;

ssize_t min_size = 0;
ssize_t max_size = SSIZE_MAX;

static void usage(FILE *f) {
  fprintf(f,
      "Gebruik: vind [-thV] [STARTPUNTEN]...\n"
      "\n"
      "TODO\n"
      "\n"
      "  -t          Bestandtypes om weer te geven, kan zijn b(estand), m(apje) of een combinatie gescheiden door komma's\n"
      "  -d          Maximale diepte\n"
      "  -o          Omvang van n beten (+, - voor meer of minder)\n"
      "  -h          Toon deze hulptekst\n"
      "  -V          Toon versienummer\n");
}

enum filetype_flags {
  FT_FILE = 1 << 0,
  FT_DIR = 1 << 1,
};

static int parse_filetypes(char *s) {
  int res = 0;

  char *pat = NULL;
  while ((pat = strtok(s, "\n")) != NULL) {
    s = NULL;

    if (!strcmp(pat, "b")) {
      res |= FT_FILE;
    } else if (!strcmp(pat, "m")) {
      res |= FT_DIR;
    }
  }

  return res;
}

// Returns pointer to argument array containing the starting points
static char** parse_options(int argc, char **argv) {
  int opt;
  while ((opt = getopt(argc, argv, "t:d:o:hV")) != -1) {
    switch (opt) {
      case 't':
        ftmap = parse_filetypes(optarg);
        break;

      case 'd':
        max_depth = atoi(optarg);
        break;

      case 'o':
        if (optarg[0] == '+') {
          min_size = atoi(optarg + 1);
        } else if (optarg[0] == '-') {
          max_size = atoi(optarg + 1);
        } else {
          min_size = max_size = atoi(optarg);
        }
        break;

      case 'h':
        usage(stdout);
        exit(0);

      case 'V':
        drukkedoos_print_versie(stdout);
        exit(0);

      case '?':
        usage(stderr);
        exit(1);
    }
  }

  return argv + optind;
}

static int f(const char *fpath, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
  bool skip = false;
  switch (typeflag) {
  case FTW_F:
    skip = !(ftmap == 0 || (ftmap & FT_FILE));
    break;
  case FTW_D:
  case FTW_DNR:
  case FTW_DP:
    skip = !(ftmap == 0 || (ftmap & FT_DIR));
    break;
  }

  if (skip) return 0;
  if (max_depth >= 0 && ftwbuf->level >= max_depth) return 0;

  if (sb->st_size < min_size) return 0;
  if (sb->st_size > max_size) return 0;

  puts(fpath);
  return 0;
}

int entry_vind(int argc, char **argv) {
  char **args = parse_options(argc, argv);

  int flags = 0;

  if (*args == NULL) {
    nftw(".", f, 4096, flags);
    return 0;
  }

  for (int i = 0; args[i]; i++) {
    nftw(args[i], f, 4096, flags);
  }

  return 0;
}