#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>

#include "listdir.h"

void listDir (char *thisDir, int level)
{
  int pass;         // Used to mark what pass we are on.
  struct stat statBuff;  // Made static so it doesn't have to be re-allocated every call.
  DIR *dir;
  struct dirent *dirSlot;

  char path [100];     // Can get large.

  strcpy (path, thisDir);
  dir = opendir (".");         // Open this dir.

  if (dir == NULL)
  {
    perror ("Could not open directory!");
    return;     // Fail.
  }

  // Pass 1:
  while ((dirSlot = readdir (dir)) != NULL)  // Keep reading until this directory ends 
  {
    stat (dirSlot->d_name, &statBuff);  // Get details.

    spaces (level);  // Print spaces according to recursion level (give a slight indentation effect).
    printEntryDetails (&statBuff, dirSlot->d_name);
  }

  rewinddir (dir);

  // Pass 2:
  while ((dirSlot = readdir (dir)) != NULL)  // Keep reading until this directory ends:
  {
     stat (dirSlot->d_name, &statBuff);  // Get details.

     if (S_ISDIR (statBuff.st_mode)) // Determine directory...
     {
	if ((strcmp ("..", dirSlot->d_name) != 0) && (strcmp (".", dirSlot->d_name) != 0))  // ... but not ".." or "." !!!
	{
	  strcat (path, "/");  // Concatenate the path and new dir together, along with '/'.
	  strcat (path, dirSlot->d_name);

	  spaces (level);
	  printf ("Entering directory %s - level %d:\n",path, level + 1);

          chdir (dirSlot->d_name);
          listDir (path, level + 1);
          printf ("Leaving directory %s.\n", path);
        }
      }
   
  }

  closedir (dir);
}

void spaces (int number)
{
  int i;

  for (i = 0; i <= number; i++)
    printf (" ");
}

void printPermissions (unsigned int st_mode_word)
{
  int i;
  unsigned int permMask = 0x0100;
  char permChar [4] = { 'r', 'w', 'x' };

  for (i = 0; i < 9; i++)
  {
    if (st_mode_word & permMask)
      printf ("%c", permChar [i % 3]);

    else
      printf ("_");

    permMask >>= 1;
  }

  printf (" ");  // Not a tab as all strings of the permissions will be 9 chars in length.
}

void printEntryDetails (struct stat *statBuff, char *name)
{
  if (S_ISDIR (statBuff->st_mode))
    printf ("d");

  else
    printf ("_");

  printPermissions (statBuff->st_mode);
  printUserName (statBuff->st_uid);

  printf ("%s\t", name);

  if (strlen (name) < 4 )
    printf ("\t\t");   // Extra tab.

  printf ("%d\t", statBuff->st_size);
  printf ("%d\t", statBuff->st_uid);
  
  printf ("\n");
}

void printUserName (uid_t uid)
{
  struct passwd *userDetails = getpwuid (uid);

  if (userDetails != NULL)
    printf ("%s\t", userDetails->pw_name);
}