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

#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <limits.h> // necesar pentru PATH_MAX

int main(int argc, char *argv[])
{
    unsigned long no_bytes, no_words;
    unsigned int no_newlines, max_length;
    unsigned char fc, fw, fn, fL;

    unsigned char last;

    unsigned int iterator, no_chars_per_line = 0;
    unsigned char ch;
    char *nume_fisier = NULL;
    int fd;

    no_bytes = no_words = no_newlines = max_length = 0;
    last = 0;
    fc = fw = fn = fL = 0;

    for (iterator = 1; iterator < argc; iterator++)
    {
        if (0 == strcmp(argv[iterator], "-c"))
            fc = 1;
        else if (0 == strcmp(argv[iterator], "-w"))
            fw = 1;
        else if (0 == strcmp(argv[iterator], "-l"))
            fn = 1;
        else if (0 == strcmp(argv[iterator], "-L"))
            fL = 1;
        else if (!nume_fisier)
            nume_fisier = argv[iterator];
        else
        {
            printf("Programul accepta (deocamdata) un singur nume de fisier, nu mai multe!\n");
            exit(1);
        }
    }
    if ((argc == 1) || (nume_fisier == NULL))
    {
        fprintf(stderr, "Ati uitat sa specificati numele fisierului de prelucrat!\n");
        exit(2);
    }

    if (0 == fc + fw + fn + fL)
        fc = fw = fn = 1;

    fd = open(nume_fisier, O_RDONLY);
    if (-1 == fd)
    {
        perror("Eroare la deschiderea fisierului de prelucrat!\n");
        exit(3);
    }

    struct stat sb;

    if (fstat(fd, &sb) == -1)
        perror("Eroare la fstat.");

    int offset = 0;
    int length = sb.st_size;

    char *map_addr = mmap(NULL, length, PROT_READ, MAP_PRIVATE, fd, offset);

    if (map_addr == MAP_FAILED)
        perror("Eroare la mmap");

    for (int i = 0; i < length; i++)
    {
        char ch = *(map_addr + i);

        no_bytes++;

        if (fw)
        {
            if (isspace(ch))
            {
                if (last == 1)
                {
                    no_words++;
                }
                last = 2;
            }
            else
                last = 1;
        }

        if (fn)
        {
            if (ch == '\n')
            {
                no_newlines++;
            }
        }

        if (fL)
        {
            if (ch != '\n')
            {
                if (ch == '\t')
                    no_chars_per_line += 8;
                else
                    no_chars_per_line++;
            }
            else
            {
                if (max_length < no_chars_per_line)
                {
                    max_length = no_chars_per_line;
                }
                no_chars_per_line = 0;
            }
        }
    }

    if (fw)
    {
        if (last == 1)
        {
            no_words++;
        }
    }

    printf("Fisierul %s contine: ", nume_fisier);
    if (fc)
        printf("%lu caractere (octeti) , ", no_bytes);
    if (fw)
        printf("%lu cuvinte , ", no_words);
    if (fn)
        printf("%u linii de text (de fapt, newline-uri) , ", no_newlines);
    if (fL)
        printf("%u lungimea maxima a liniilor de text.", max_length);
    printf("\n");

    if (munmap(map_addr, length) == -1)
        perror("Erroare la munmap.");

    if(close(fd) == -1)
        perror("Eroare la inchiderea fisierului.");

    return 0;
}