#include<stdio.h>
#include<fcntl.h>
#include<pwd.h>
#include<grp.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/stat.h>
#include<sys/types.h>
#include<dirent.h>
#include<libgen.h>
#include<string.h>
#include<errno.h>
void printAttributes(struct stat st)
{
    char atr[10] = "----------";
    if (S_ISLNK(st.st_mode)) atr[0] = 'l';
    if (S_ISREG(st.st_mode)) atr[0] = '-';
    if (S_ISDIR(st.st_mode)) atr[0] = 'd';
    if (S_ISBLK(st.st_mode)) atr[0] = 'b';
    if (S_ISCHR(st.st_mode)) atr[0] = 'c';
    if (S_ISFIFO(st.st_mode)) atr[0] = 'p';
    if (S_ISSOCK(st.st_mode)) atr[0] = 's';
    if (S_IRUSR & st.st_mode) atr[1] = 'r';
    if (S_IWUSR & st.st_mode) atr[2] = 'w';
    if (S_IXUSR & st.st_mode) atr[3] = 'x';
    if (S_IRGRP & st.st_mode) atr[4] = 'r';
    if (S_IWGRP & st.st_mode) atr[5] = 'w';
    if (S_IXGRP & st.st_mode) atr[6] = 'x';
    if (S_IROTH & st.st_mode) atr[7] = 'r';
    if (S_IWOTH & st.st_mode) atr[8] = 'w';
    if (S_IXOTH & st.st_mode) atr[9] = 'x';
    printf("%s ", atr);
}

void printUsr(const struct stat* st)
{
    struct passwd* pw = getpwuid(st->st_uid);
    if (pw == NULL) printf("%d ", st->st_uid);
    else printf("%s ", pw->pw_name);
}
void printGroup(const struct stat* st)
{
    struct group* gr = getgrgid(st->st_gid);
    if (gr == NULL) printf("%d ", st->st_uid);
    else printf("%s ", gr->gr_name);
}



void printStat(struct stat* st, char* filename)
{
    if (strcmp(basename(filename), ".") == 0 || strcmp(basename(filename), "..") == 0)
    {
        return;
    }
    if (!S_ISLNK(st->st_mode))
    {
        printAttributes(*st);
        printf("%ld ", st->st_nlink);
        printGroup(st);
        printGroup(st);
        printf("%ld ", st->st_size);
        printf("%s\n", basename(filename));
    }
    if (S_ISLNK(st->st_mode))
    {
        printAttributes(*st);
        printf("%ld ", st->st_nlink);
        printGroup(st);
        printGroup(st);
        printf("%ld ", st->st_size);
        char tmp[PATH_MAX] = "";
        ssize_t r = readlink(filename, tmp, sizeof(tmp));
        if (r == -1)
        {
            fprintf(stderr, "%s\n", strerror(errno));
            exit(1);
        }

        tmp[r] = '\0';
        printf("%s -> ", basename(filename));
        printf("%s\n", tmp);
    }
}

int main(int argc, char* argv[])
{
    struct stat st;
    if(lstat(argv[1], &st) == -1)
    {
        fprintf(stderr, "%s\n", strerror(errno));
        exit(1);
    }
    if (!S_ISDIR(st.st_mode))
    {
        if (!S_ISLNK(st.st_mode))
        {
            printAttributes(st);
            printf("%ld ", st.st_nlink);
            printGroup(&st);
            printGroup(&st);
            printf("%ld ", st.st_size);
            printf("%s\n", argv[1]);
        }
        if (S_ISLNK(st.st_mode))
        {
            printAttributes(st);
            printf("%ld ", st.st_nlink);
            printGroup(&st);
            printGroup(&st);
            printf("%ld ", st.st_size);
            char tmp[PATH_MAX] = "";
            ssize_t r = readlink(argv[1], tmp, sizeof(tmp));
            if (r == -1)
            {
                fprintf(stderr, "%s\n", strerror(errno));
                exit(1);
            }

            tmp[r] = '\0';
            printf("%s -> ", argv[1]);
            printf("%s\n", tmp);
        }
    }
    else
    {
        int dir_fd = open(argv[1], O_RDONLY | O_DIRECTORY);
        if (dir_fd == -1)
        {
            fprintf(stderr, "%s\n", strerror(errno));
            exit(1);

        }
        DIR* dir = fdopendir(dir_fd);
        if (dir == NULL)
        {
            fprintf(stderr, "%s\n", strerror(errno));
            exit(1);

        }
        struct dirent* file;
        while(file = readdir(dir))
        {
            char path[PATH_MAX] = "";
            strcat(path, argv[1]);
            strcat(path, "/");
            strcat(path, file->d_name);
            if (lstat(path, &st) != -1)
            {
                printStat(&st, path);//file->d_name);
            }
            else
            {
                fprintf(stderr, "%s\n", strerror(errno));
                exit(1);
            }

        }
        closedir(dir);
    }
    return 0;

}