#include <assert.h>
#include <ctype.h>
#include <getopt.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include "util/versie.h"
#include "util/error.h"
#include "util/debug.h"
#include "util/map.h"

static void usage(FILE *f) {
  fprintf(f,
      "Gebruik: toilet [-nchV] [BESTAND]...\n"
      "\n"
      "Toon de hoeveelheid regels, woorden en beten for elk BESTAND\n"
      "\n"
      "  -c          Geef het aantal beten weer\n"
      "  -w          Geef het aantal woorden weer\n"
      "  -l          Geef het aantal regels weer\n"
      "  -h          Toon deze hulptekst\n"
      "  -V          Toon versienummer\n");
}

enum MODE {
  M_BYTES,
  M_WORDS,
  M_LINES,
};

// Returns pointer to argument array containing the file names
static char** parse_options(int argc, char **argv, enum MODE *mode) {
  int opt;
  while ((opt = getopt(argc, argv, "cwlhV")) != -1) {
    switch (opt) {
      case 'c':
        *mode = M_BYTES;
        break;

      case 'w':
        *mode = M_WORDS;
        break;

      case 'l':
        *mode = M_LINES;
        break;

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

      case 'V':
        drukkedoos_print_versie(stdout, "toilet");
        exit(0);

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

  return argv + optind;
}

size_t get_count(enum MODE mode, struct map *map) {
  switch (mode) {
    case M_BYTES:
      return map->sb.st_size;

    case M_WORDS: {
      size_t words = 0;

      assert(map->sb.st_size >= 0);
      // (c) Tom Forging
      for (size_t i = 0; i < (size_t)map->sb.st_size;) {
        size_t previ = i;
        while (!isspace(map->addr[i])) i++;
        words += i != previ;
        while (isspace(map->addr[i])) i++;
      }

      return words;
    }

    case M_LINES: {
      size_t lines = 0;

      while (map->addr != map->end) {
        if (*map->addr == '\n') lines++;
        map->addr++;
      }

      // handle case if file does not have trailing newline
      if (*(map->addr - 1) != '\n') {
        lines++;
      }

      return lines;
    }
  }
}

int entry_toilet(int argc, char **argv) {
  enum MODE mode;
  char **args = parse_options(argc, argv, &mode);

  while (*args != NULL) {
    struct map *map = open_map(*args);
    if (map == NULL) {
      fprintf(stderr, "toilet: fout bij lezen bestand");
      return 1;
    }

    size_t count = get_count(mode, map);
    printf("%li %s\n", count, *args);

    close_map(map);
    args++;
  }

  return 0;
}