#include "stderr.h"
#include <assert.h>
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

int main(int argc, char **argv)
{
    err_setarg0(argv[0]);

    if (argc != 2)
        err_usage("directory");

    struct stat sb;
    char *name = argv[1];

    if (stat(name, &sb) != 0)
        err_syserr("Unable to stat directory '%s': ", name);
    if (!S_ISDIR(sb.st_mode))
        err_error("File '%s' is not a directory (mode = %o)\n", name, sb.st_mode);

    size_t bufmax = 4096;
    char  *buffer = malloc(bufmax);
    if (buffer == 0)
        err_syserr("Failed to malloc %zu bytes: ", bufmax);
    strcpy(buffer, name);
    size_t buflen = strlen(buffer);
    assert(buflen < bufmax);
    size_t levels = 0;

    while (buflen < bufmax)
    {
        if (chdir(name) != 0)
        {
            err_sysrem("Failed to chdir into '%s'\n", name);
            err_remark("%3zu (%4zu): %s\n", ++levels, buflen, buffer);
            err_error("Mode = %o\n", sb.st_mode);
        }
        printf("%3zu (%4zu): %s\n", ++levels, buflen, buffer);
        DIR *dp = opendir(".");
        struct dirent *nm;
        while ((nm = readdir(dp)) != 0)
        {
            if (strcmp(nm->d_name, ".") == 0 || strcmp(nm->d_name, "..") == 0)
                continue;
            if (stat(nm->d_name, &sb) != 0)
                err_syserr("Unable to stat name '%s': ", nm->d_name);
            if (!S_ISDIR(sb.st_mode))
            {
                err_sysrem("Name '%s' is not a directory (mode = %o)\n", nm->d_name, sb.st_mode);
                if (unlink(nm->d_name) != 0)
                    err_syserr("Failed to remove non-directory '%s': ", nm->d_name);
                err_remark("Removed '%s' from '%s'\n", nm->d_name, buffer);
                continue;
            }
            size_t namlen = strlen(nm->d_name);
            if (buflen + namlen + 1 >= bufmax)
            {
                err_remark("Allocate space - name is too long: additional name '%s' - (%zu levels) %zu '%s'\n",
                          nm->d_name, levels, buflen, buffer);
                size_t newmax = 2 * bufmax;
                char  *newbuf = realloc(buffer, newmax);
                if (newbuf == 0)
                    err_syserr("Failed to reallocate %zu bytes memory: ", newmax);
                bufmax = newmax;
                buffer = newbuf;
            }
            buffer[buflen++] = '/';
            strcpy(&buffer[buflen], nm->d_name);
            name = &buffer[buflen];
            buflen += namlen;
            break;
        }
        closedir(dp);
    }

    return 0;
}