#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"

static int max_depth = -1;

static bool show_hidden = false;
static bool dirs_only = false;

static void usage(FILE *f) {
  fprintf(f,
      "Gebruik: boom [-thV] [STARTPUNTEN]...\n"
      "\n"
      "Geef inhoud van mapjes weer in een boom-achtig formaat.\n"
      "\n"
      "  -a          Alle bestanden worden weergegeven, ookal beginnen ze met een puntje\n"
      "  -m          Geef alleen mapjes weer\n"
      "  -d          Maximale diepte\n"
      "  -o          Omvang van n beten (+, - voor meer of minder)\n"
      "  -h          Toon deze hulptekst\n"
      "  -V          Toon versienummer\n");
}

// Returns pointer to argument array containing the starting points
static char** parse_options(int argc, char **argv) {
  int opt;
  while ((opt = getopt(argc, argv, "amd:hV")) != -1) {
    switch (opt) {
      case 'a':
        show_hidden = true;
        break;

      case 'm':
        dirs_only = true;
        break;

      case 'd':
        max_depth = atoi(optarg);
        if (max_depth <= 0) {
          fprintf(stderr, "boom: maximale diepte moet groter zijn dan 0\n");
          exit(1);
        }
        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 prev_level = -1;
static int skip_level = -1;

static int f(const char *fpath, const struct stat *, int typeflag, struct FTW *ftwbuf) {
  int level = ftwbuf->level;
  bool is_dir
     = typeflag == FTW_D
    || typeflag == FTW_DNR
    || typeflag == FTW_DP;

  if (level < skip_level) {
    skip_level = -1;
  } else if (skip_level != -1 && level >= skip_level) {
    return 0;
  }

  // check max depth
  if (max_depth >= 0 && level >= (max_depth + 1)) return 0;

  const char *fname = basename(fpath);

  // don't show hidden files
  if (!show_hidden && fname[0] == '.' && strlen(fpath) > 2 && level != 0) {
    skip_level = level + 1;
    goto done;
  }
  // don't show files in dirs only mode
  if (dirs_only && !is_dir) return 0;

  for (int i = 1; i < level; i++) {
    printf("|   ");
  }

  if (level != 0) {
    printf("|-- ");
  }
  printf("%s", fname);
  if (typeflag == FTW_SL) {
    char real_name[PATH_MAX] = {0};
    if (readlink(fpath, real_name, PATH_MAX-1) != -1)
      printf(" -> %s", real_name);
  }
  printf("\n");

done:
  prev_level = level;
  return 0;
}

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

  int flags = 0;
  flags |= FTW_PHYS;

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

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

  return 0;
}