#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<dirent.h>
#include<errno.h>
#include<limits.h>
#include<libgen.h>

char *AppName;

int ProcessFolder(FILE *outfile, char *path)
{
    DIR *curDir;
    curDir = opendir(path);

    if (curDir == NULL)
    {
        fprintf(stderr, "%s: %s %s\n", AppName, path, strerror(errno));
        errno = 0;

        return -1;
    }

    struct dirent *dent;
    struct stat buf;
    char *file = alloca(strlen(path) + NAME_MAX + 2);

    if (file==NULL)
    {
        fprintf(stderr,"%s: %s.", AppName, strerror(errno));

        return -1;
    }

    long int sum = 0;
    int count = 0;
    int maxSize = -1;
    char *maxFile = alloca(NAME_MAX);

    if (maxFile==NULL)
    {
        fprintf(stderr, "%s: %s.", AppName, strerror(errno));

        return -1;
    }

    maxFile[0] = 0;
    errno = 0;

    while (dent = readdir(curDir))
    {
        if (strcmp(".", dent->d_name) && strcmp("..", dent->d_name))
        {
            strcpy(file, path);
            strcat(file, "/");
            strcat(file, dent->d_name);

            if (lstat(file,&buf) == -1)
            {
                fprintf(stderr, "%s: %s %s\n", AppName, path, strerror(errno));

                return -1;
            }

            if (!S_ISDIR(buf.st_mode))
            {
                if (buf.st_size > maxSize)
                {
                    maxSize = buf.st_size;
                    strcpy(maxFile, basename(file));
                }

                sum += buf.st_size;
                count++;
            }

            if (S_ISDIR(buf.st_mode))
            {
                ProcessFolder(outfile, file);
            }
        }
    }

    if (errno != 0)
    {
        fprintf(stderr, "%s: %s %s\n", AppName, path, strerror(errno));

        return -1;
    }

    printf("%s %d %ld %s\n", path, count, sum, maxFile);
    fprintf(outfile, "%s %d %ld %s\n", path, count, sum, maxFile);

    if (closedir(curDir) == -1)
    {
        fprintf(stderr, "%s: %s %s\n", AppName, path, strerror(errno));

        return -1;
    }

    return 0;
}

int main(int argc, char **argv)
{
    AppName = alloca(strlen(basename(argv[0])));
    strcpy(AppName, basename(argv[0]));

    if (argc < 3)
    {
        fprintf(stderr, "%s: Enter two arguments.\n", AppName);

        return -1;
    }

    FILE *file;

    if ((file = fopen(argv[2], "w")) == NULL)
    {
        fprintf(stderr, "%s: %s %s\n", AppName, argv[2], strerror(errno));

        return -1;
    }

    if (realpath(argv[1], NULL) == NULL)
    {
        fprintf(stderr, "%s: %s %s\n", AppName, argv[1], strerror(errno));

        return -1;
    }

    ProcessFolder(file, realpath(argv[1], NULL));

    if (fclose(file) != 0)
    {
        fprintf(stderr,"%s: %s %s\n", AppName, argv[2], strerror(errno));

        return -1;
    }

    return 0;
}