#ifdef _MSC_VER
#include <windows.h>
#endif

/*
 * dirent.h - dirent API for Microsoft Visual Studio
 *
 * Copyright (C) 2006-2012 Toni Ronkko
 *
 * MIT License
 *
 * Version 1.13, Dec 12 2012, Toni Ronkko
 * Use traditional 8+3 file name if the name cannot be represented in the
 * default ANSI code page.  Now compiles again with MSVC 6.0.  Thanks to
 * Konstantin Khomoutov for testing.
 *
 * Version 1.12.1, Oct 1 2012, Toni Ronkko
 * Bug fix: renamed wide-character DIR structure _wDIR to _WDIR (with
 * capital W) in order to maintain compatibility with MingW.
 *
 * Version 1.12, Sep 30 2012, Toni Ronkko
 * Define PATH_MAX and NAME_MAX.  Added wide-character variants _wDIR,
 * _wdirent, _wopendir(), _wreaddir(), _wclosedir() and _wrewinddir().
 * Thanks to Edgar Buerkle and Jan Nijtmans for ideas and code.
 *
 * Do not include windows.h.  This allows dirent.h to be integrated more
 * easily into programs using winsock.  Thanks to Fernando Azaldegui.
 *
 * Version 1.11, Mar 15, 2011, Toni Ronkko
 * Defined FILE_ATTRIBUTE_DEVICE for MSVC 6.0.
 *
 * Version 1.10, Aug 11, 2010, Toni Ronkko
 * Added d_type and d_namlen fields to dirent structure.  The former is
 * especially useful for determining whether directory entry represents a
 * file or a directory.  For more information, see
 * http://www.delorie.com/gnu/docs/glibc/libc_270.html
 *
 * Improved conformance to the standards.  For example, errno is now set
 * properly on failure and assert() is never used.  Thanks to Peter Brockam
 * for suggestions.
 *
 * Fixed a bug in rewinddir(): when using relative directory names, change
 * of working directory no longer causes rewinddir() to fail.
 *
 * Version 1.9, Dec 15, 2009, John Cunningham
 * Added rewinddir member function
 *
 * Version 1.8, Jan 18, 2008, Toni Ronkko
 * Using FindFirstFileA and WIN32_FIND_DATAA to avoid converting string
 * between multi-byte and unicode representations.  This makes the
 * code simpler and also allows the code to be compiled under MingW.  Thanks
 * to Azriel Fasten for the suggestion.
 *
 * Mar 4, 2007, Toni Ronkko
 * Bug fix: due to the strncpy_s() function this file only compiled in
 * Visual Studio 2005.  Using the new string functions only when the
 * compiler version allows.
 *
 * Nov  2, 2006, Toni Ronkko
 * Major update: removed support for Watcom C, MS-DOS and Turbo C to
 * simplify the file, updated the code to compile cleanly on Visual
 * Studio 2005 with both unicode and multi-byte character strings,
 * removed rewinddir() as it had a bug.
 *
 * Aug 20, 2006, Toni Ronkko
 * Removed all remarks about MSVC 1.0, which is antiqued now.  Simplified
 * comments by removing SGML tags.
 *
 * May 14 2002, Toni Ronkko
 * Embedded the function definitions directly to the header so that no
 * source modules need to be included in the Visual Studio project.  Removed
 * all the dependencies to other projects so that this header file can be
 * used independently.
 *
 * May 28 1998, Toni Ronkko
 * First version.
 *****************************************************************************/
#ifndef DIRENT_H
#define DIRENT_H

/// @cond NEVER

#if !defined(_68K_) && !defined(_MPPC_) && !defined(_X86_) && !defined(_IA64_) && !defined(_AMD64_) && defined(_M_IX86)
#define _X86_
#endif
#include <stdio.h>
#include <stdarg.h>
#include <windef.h>
#include <winbase.h>
#include <wchar.h>
#include <string.h>
#include <stdlib.h>
#include <malloc.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>

/* Indicates that d_type field is available in dirent structure */
#define _DIRENT_HAVE_D_TYPE

/* Indicates that d_namlen field is available in dirent structure */
#define _DIRENT_HAVE_D_NAMLEN

/* Entries missing from MSVC 6.0 */
#if !defined(FILE_ATTRIBUTE_DEVICE)
#define FILE_ATTRIBUTE_DEVICE 0x40
#endif

/* File type and permission flags for stat() */
#if !defined(S_IFMT)
#define S_IFMT _S_IFMT /* File type mask */
#endif
#if !defined(S_IFDIR)
#define S_IFDIR _S_IFDIR /* Directory */
#endif
#if !defined(S_IFCHR)
#define S_IFCHR _S_IFCHR /* Character device */
#endif
#if !defined(S_IFFIFO)
#define S_IFFIFO _S_IFFIFO /* Pipe */
#endif
#if !defined(S_IFREG)
#define S_IFREG _S_IFREG /* Regular file */
#endif
#if !defined(S_IREAD)
#define S_IREAD _S_IREAD /* Read permission */
#endif
#if !defined(S_IWRITE)
#define S_IWRITE _S_IWRITE /* Write permission */
#endif
#if !defined(S_IEXEC)
#define S_IEXEC _S_IEXEC /* Execute permission */
#endif
#if !defined(S_IFIFO)
#define S_IFIFO _S_IFIFO /* Pipe */
#endif
#if !defined(S_IFBLK)
#define S_IFBLK 0 /* Block device */
#endif
#if !defined(S_IFLNK)
#define S_IFLNK 0 /* Link */
#endif
#if !defined(S_IFSOCK)
#define S_IFSOCK 0 /* Socket */
#endif

#if defined(_MSC_VER)
#define S_IRUSR S_IREAD  /* Read user */
#define S_IWUSR S_IWRITE /* Write user */
#define S_IXUSR 0        /* Execute user */
#define S_IRGRP 0        /* Read group */
#define S_IWGRP 0        /* Write group */
#define S_IXGRP 0        /* Execute group */
#define S_IROTH 0        /* Read others */
#define S_IWOTH 0        /* Write others */
#define S_IXOTH 0        /* Execute others */
#endif

/* Maximum length of file name */
#if !defined(PATH_MAX)
#define PATH_MAX MAX_PATH
#endif
#if !defined(FILENAME_MAX)
#define FILENAME_MAX MAX_PATH
#endif
#if !defined(NAME_MAX)
#define NAME_MAX FILENAME_MAX
#endif

/* File type flags for d_type */
#define DT_UNKNOWN 0
#define DT_REG S_IFREG
#define DT_DIR S_IFDIR
#define DT_FIFO S_IFIFO
#define DT_SOCK S_IFSOCK
#define DT_CHR S_IFCHR
#define DT_BLK S_IFBLK

/* Macros for converting between st_mode and d_type */
#define IFTODT(mode) ((mode)&S_IFMT)
#define DTTOIF(type) (type)

/*
 * File type macros.  Note that block devices, sockets and links cannot be
 * distinguished on Windows and the macros S_ISBLK, S_ISSOCK and S_ISLNK are
 * only defined for compatibility.  These macros should always return false
 * on Windows.
 */
#define S_ISFIFO(mode) (((mode)&S_IFMT) == S_IFIFO)
#define S_ISDIR(mode) (((mode)&S_IFMT) == S_IFDIR)
#define S_ISREG(mode) (((mode)&S_IFMT) == S_IFREG)
#define S_ISLNK(mode) (((mode)&S_IFMT) == S_IFLNK)
#define S_ISSOCK(mode) (((mode)&S_IFMT) == S_IFSOCK)
#define S_ISCHR(mode) (((mode)&S_IFMT) == S_IFCHR)
#define S_ISBLK(mode) (((mode)&S_IFMT) == S_IFBLK)

/* Return the exact length of d_namlen without zero terminator */
#define _D_EXACT_NAMLEN(p) ((p)->d_namlen)

/* Return number of bytes needed to store d_namlen */
#define _D_ALLOC_NAMLEN(p) (PATH_MAX + 1)

#ifdef __cplusplus
extern "C" {
#endif

/* Wide-character version */
struct _wdirent {
  long d_ino;                   /* Always zero */
  unsigned short d_reclen;      /* Structure size */
  size_t d_namlen;              /* Length of name without \0 */
  int d_type;                   /* File type */
  wchar_t d_name[PATH_MAX + 1]; /* File name */
};
typedef struct _wdirent _wdirent;

struct _WDIR {
  struct _wdirent ent;   /* Current directory entry */
  WIN32_FIND_DATAW data; /* Private file data */
  int cached;            /* True if data is valid */
  HANDLE handle;         /* Win32 search handle */
  wchar_t *patt;         /* Initial directory name */
};
typedef struct _WDIR _WDIR;

static _WDIR *_wopendir(const wchar_t *dirname);
static struct _wdirent *_wreaddir(_WDIR *dirp);
static int _wclosedir(_WDIR *dirp);
static void _wrewinddir(_WDIR *dirp);

/* For compatibility with Symbian */
#define wdirent _wdirent
#define WDIR _WDIR
#define wopendir _wopendir
#define wreaddir _wreaddir
#define wclosedir _wclosedir
#define wrewinddir _wrewinddir

/* Multi-byte character versions */
struct dirent {
  long d_ino;                /* Always zero */
  unsigned short d_reclen;   /* Structure size */
  size_t d_namlen;           /* Length of name without \0 */
  int d_type;                /* File type */
  char d_name[PATH_MAX + 1]; /* File name */
};
typedef struct dirent dirent;

struct DIR {
  struct dirent ent;
  struct _WDIR *wdirp;
};
typedef struct DIR DIR;

static DIR *opendir(const char *dirname);
static struct dirent *readdir(DIR *dirp);
static int closedir(DIR *dirp);
static void rewinddir(DIR *dirp);

/* Internal utility functions */
static WIN32_FIND_DATAW *dirent_first(_WDIR *dirp);
static WIN32_FIND_DATAW *dirent_next(_WDIR *dirp);

static int dirent_mbstowcs_s(size_t *pReturnValue, wchar_t *wcstr, size_t sizeInWords, const char *mbstr, size_t count);

static int dirent_wcstombs_s(size_t *pReturnValue, char *mbstr, size_t sizeInBytes, const wchar_t *wcstr, size_t count);

static void dirent_set_errno(int error);

/*
 * Open directory stream DIRNAME for read and return a pointer to the
 * internal working area that is used to retrieve individual directory
 * entries.
 */
static _WDIR *_wopendir(const wchar_t *dirname) {
  _WDIR *dirp = NULL;
  int error;

  /* Must have directory name */
  if (dirname == NULL || dirname[0] == '\0') {
    dirent_set_errno(ENOENT);
    return NULL;
  }

  /* Allocate new _WDIR structure */
  dirp = (_WDIR *)malloc(sizeof(struct _WDIR));
  if (dirp != NULL) {
    DWORD n;

    /* Reset _WDIR structure */
    dirp->handle = INVALID_HANDLE_VALUE;
    dirp->patt = NULL;
    dirp->cached = 0;

    /* Compute the length of full path plus zero terminator */
    n = GetFullPathNameW(dirname, 0, NULL, NULL);

    /* Allocate room for absolute directory name and search pattern */
    dirp->patt = (wchar_t *)malloc(sizeof(wchar_t) * n + 16);
    if (dirp->patt) {
      /*
       * Convert relative directory name to an absolute one.  This
       * allows rewinddir() to function correctly even when current
       * working directory is changed between opendir() and rewinddir().
       */
      n = GetFullPathNameW(dirname, n, dirp->patt, NULL);
      if (n > 0) {
        wchar_t *p;

        /* Append search pattern \* to the directory name */
        p = dirp->patt + n;
        if (dirp->patt < p) {
          switch (p[-1]) {
            case '\\':
            case '/':
            case ':':
                /* Directory ends in path separator, e.g. c:\temp\ */
                /*NOP*/;
              break;

            default:
              /* Directory name doesn't end in path separator */
              *p++ = '\\';
          }
        }
        *p++ = '*';
        *p = '\0';

        /* Open directory stream and retrieve the first entry */
        if (dirent_first(dirp)) {
          /* Directory stream opened successfully */
          error = 0;
        } else {
          /* Cannot retrieve first entry */
          error = 1;
          dirent_set_errno(ENOENT);
        }

      } else {
        /* Cannot retrieve full path name */
        dirent_set_errno(ENOENT);
        error = 1;
      }

    } else {
      /* Cannot allocate memory for search pattern */
      error = 1;
    }

  } else {
    /* Cannot allocate _WDIR structure */
    error = 1;
  }

  /* Clean up in case of error */
  if (error && dirp) {
    _wclosedir(dirp);
    dirp = NULL;
  }

  return dirp;
}

/*
 * Read next directory entry.  The directory entry is returned in dirent
 * structure in the d_name field.  Individual directory entries returned by
 * this function include regular files, sub-directories, pseudo-directories
 * "." and ".." as well as volume labels, hidden files and system files.
 */
static struct _wdirent *_wreaddir(_WDIR *dirp) {
  WIN32_FIND_DATAW *datap;
  struct _wdirent *entp;

  /* Read next directory entry */
  datap = dirent_next(dirp);
  if (datap) {
    size_t n;
    DWORD attr;

    /* Pointer to directory entry to return */
    entp = &dirp->ent;

    /*
     * Copy file name as wide-character string.  If the file name is too
     * long to fit in to the destination buffer, then truncate file name
     * to PATH_MAX characters and zero-terminate the buffer.
     */
    n = 0;
    while (n < PATH_MAX && datap->cFileName[n] != 0) {
      entp->d_name[n] = datap->cFileName[n];
      n++;
    }
    dirp->ent.d_name[n] = 0;

    /* Length of file name excluding zero terminator */
    entp->d_namlen = n;

    /* File type */
    attr = datap->dwFileAttributes;
    if ((attr & FILE_ATTRIBUTE_DEVICE) != 0) {
      entp->d_type = DT_CHR;
    } else if ((attr & FILE_ATTRIBUTE_DIRECTORY) != 0) {
      entp->d_type = DT_DIR;
    } else {
      entp->d_type = DT_REG;
    }

    /* Reset dummy fields */
    entp->d_ino = 0;
    entp->d_reclen = sizeof(struct _wdirent);

  } else {
    /* Last directory entry read */
    entp = NULL;
  }

  return entp;
}

/*
 * Close directory stream opened by opendir() function.  This invalidates the
 * DIR structure as well as any directory entry read previously by
 * _wreaddir().
 */
static int _wclosedir(_WDIR *dirp) {
  int ok;
  if (dirp) {
    /* Release search handle */
    if (dirp->handle != INVALID_HANDLE_VALUE) {
      FindClose(dirp->handle);
      dirp->handle = INVALID_HANDLE_VALUE;
    }

    /* Release search pattern */
    if (dirp->patt) {
      free(dirp->patt);
      dirp->patt = NULL;
    }

    /* Release directory structure */
    free(dirp);
    ok = /*success*/ 0;

  } else {
    /* Invalid directory stream */
    dirent_set_errno(EBADF);
    ok = /*failure*/ -1;
  }
  return ok;
}

/*
 * Rewind directory stream such that _wreaddir() returns the very first
 * file name again.
 */
static void _wrewinddir(_WDIR *dirp) {
  if (dirp) {
    /* Release existing search handle */
    if (dirp->handle != INVALID_HANDLE_VALUE) {
      FindClose(dirp->handle);
    }

    /* Open new search handle */
    dirent_first(dirp);
  }
}

/* Get first directory entry (internal) */
static WIN32_FIND_DATAW *dirent_first(_WDIR *dirp) {
  WIN32_FIND_DATAW *datap;

  /* Open directory and retrieve the first entry */
  dirp->handle = FindFirstFileW(dirp->patt, &dirp->data);
  if (dirp->handle != INVALID_HANDLE_VALUE) {
    /* a directory entry is now waiting in memory */
    datap = &dirp->data;
    dirp->cached = 1;

  } else {
    /* Failed to re-open directory: no directory entry in memory */
    dirp->cached = 0;
    datap = NULL;
  }
  return datap;
}

/* Get next directory entry (internal) */
static WIN32_FIND_DATAW *dirent_next(_WDIR *dirp) {
  WIN32_FIND_DATAW *p;

  /* Get next directory entry */
  if (dirp->cached != 0) {
    /* A valid directory entry already in memory */
    p = &dirp->data;
    dirp->cached = 0;

  } else if (dirp->handle != INVALID_HANDLE_VALUE) {
    /* Get the next directory entry from stream */
    if (FindNextFileW(dirp->handle, &dirp->data) != FALSE) {
      /* Got a file */
      p = &dirp->data;
    } else {
      /* The very last entry has been processed or an error occured */
      FindClose(dirp->handle);
      dirp->handle = INVALID_HANDLE_VALUE;
      p = NULL;
    }

  } else {
    /* End of directory stream reached */
    p = NULL;
  }

  return p;
}

/*
 * Open directory stream using plain old C-string.
 */
static DIR *opendir(const char *dirname) {
  struct DIR *dirp;
  int error;

  /* Must have directory name */
  if (dirname == NULL || dirname[0] == '\0') {
    dirent_set_errno(ENOENT);
    return NULL;
  }

  /* Allocate memory for DIR structure */
  dirp = (DIR *)malloc(sizeof(struct DIR));
  if (dirp) {
    wchar_t wname[PATH_MAX + 1];
    size_t n;

    /* Convert directory name to wide-character string */
    error = dirent_mbstowcs_s(&n, wname, PATH_MAX + 1, dirname, PATH_MAX);
    if (!error) {
      /* Open directory stream using wide-character name */
      dirp->wdirp = _wopendir(wname);
      if (dirp->wdirp) {
        /* Directory stream opened */
        error = 0;
      } else {
        /* Failed to open directory stream */
        error = 1;
      }

    } else {
      /*
       * Cannot convert file name to wide-character string.  This
       * occurs if the string contains invalid multi-byte sequences or
       * the output buffer is too small to contain the resulting
       * string.
       */
      error = 1;
    }

  } else {
    /* Cannot allocate DIR structure */
    error = 1;
  }

  /* Clean up in case of error */
  if (error && dirp) {
    free(dirp);
    dirp = NULL;
  }

  return dirp;
}

/*
 * Read next directory entry.
 *
 * When working with text consoles, please note that file names returned by
 * readdir() are represented in the default ANSI code page while any output to
 * console is typically formatted on another code page.  Thus, non-ASCII
 * characters in file names will not usually display correctly on console.  The
 * problem can be fixed in two ways: (1) change the character set of console
 * to 1252 using chcp utility and use Lucida Console font, or (2) use
 * _cprintf function when writing to console.  The _cprinf() will re-encode
 * ANSI strings to the console code page so many non-ASCII characters will
 * display correcly.
 */
static struct dirent *readdir(DIR *dirp) {
  WIN32_FIND_DATAW *datap;
  struct dirent *entp;

  /* Read next directory entry */
  datap = dirent_next(dirp->wdirp);
  if (datap) {
    size_t n;
    int error;

    /* Attempt to convert file name to multi-byte string */
    error = dirent_wcstombs_s(&n, dirp->ent.d_name, MAX_PATH + 1, datap->cFileName, MAX_PATH);

    /*
     * If the file name cannot be represented by a multi-byte string,
     * then attempt to use old 8+3 file name.  This allows traditional
     * Unix-code to access some file names despite of unicode
     * characters, although file names may seem unfamiliar to the user.
     *
     * Be ware that the code below cannot come up with a short file
     * name unless the file system provides one.  At least
     * VirtualBox shared folders fail to do this.
     */
    if (error && datap->cAlternateFileName[0] != '\0') {
      error = dirent_wcstombs_s(&n, dirp->ent.d_name, MAX_PATH + 1, datap->cAlternateFileName,
                                sizeof(datap->cAlternateFileName) / sizeof(datap->cAlternateFileName[0]));
    }

    if (!error) {
      DWORD attr;

      /* Initialize directory entry for return */
      entp = &dirp->ent;

      /* Length of file name excluding zero terminator */
      entp->d_namlen = n - 1;

      /* File attributes */
      attr = datap->dwFileAttributes;
      if ((attr & FILE_ATTRIBUTE_DEVICE) != 0) {
        entp->d_type = DT_CHR;
      } else if ((attr & FILE_ATTRIBUTE_DIRECTORY) != 0) {
        entp->d_type = DT_DIR;
      } else {
        entp->d_type = DT_REG;
      }

      /* Reset dummy fields */
      entp->d_ino = 0;
      entp->d_reclen = sizeof(struct dirent);

    } else {
      /*
       * Cannot convert file name to multi-byte string so construct
       * an errornous directory entry and return that.  Note that
       * we cannot return NULL as that would stop the processing
       * of directory entries completely.
       */
      entp = &dirp->ent;
      entp->d_name[0] = '?';
      entp->d_name[1] = '\0';
      entp->d_namlen = 1;
      entp->d_type = DT_UNKNOWN;
      entp->d_ino = 0;
      entp->d_reclen = 0;
    }

  } else {
    /* No more directory entries */
    entp = NULL;
  }

  return entp;
}

/*
 * Close directory stream.
 */
static int closedir(DIR *dirp) {
  int ok;
  if (dirp) {
    /* Close wide-character directory stream */
    ok = _wclosedir(dirp->wdirp);
    dirp->wdirp = NULL;

    /* Release multi-byte character version */
    free(dirp);

  } else {
    /* Invalid directory stream */
    dirent_set_errno(EBADF);
    ok = /*failure*/ -1;
  }
  return ok;
}

/*
 * Rewind directory stream to beginning.
 */
static void rewinddir(DIR *dirp) {
  /* Rewind wide-character string directory stream */
  _wrewinddir(dirp->wdirp);
}

/* Convert multi-byte string to wide character string */
static int dirent_mbstowcs_s(size_t *pReturnValue, wchar_t *wcstr, size_t sizeInWords, const char *mbstr,
                             size_t count) {
  int error;

#if defined(_MSC_VER) && _MSC_VER >= 1400

  /* Microsoft Visual Studio 2005 or later */
  error = mbstowcs_s(pReturnValue, wcstr, sizeInWords, mbstr, count);

#else

  /* Older Visual Studio or non-Microsoft compiler */
  size_t n;

  /* Convert to wide-character string */
  n = mbstowcs(wcstr, mbstr, count);
  if (n < sizeInWords) {
    /* Zero-terminate output buffer */
    if (wcstr) {
      wcstr[n] = 0;
    }

    /* Length of resuting multi-byte string WITH zero terminator */
    if (pReturnValue) {
      *pReturnValue = n + 1;
    }

    /* Success */
    error = 0;

  } else {
    /* Could not convert string */
    error = 1;
  }

#endif

  return error;
}

/* Convert wide-character string to multi-byte string */
static int dirent_wcstombs_s(size_t *pReturnValue, char *mbstr, size_t sizeInBytes, const wchar_t *wcstr,
                             size_t count) {
  int error;

#if defined(_MSC_VER) && _MSC_VER >= 1400

  /* Microsoft Visual Studio 2005 or later */
  error = wcstombs_s(pReturnValue, mbstr, sizeInBytes, wcstr, count);

#else

  /* Older Visual Studio or non-Microsoft compiler */
  size_t n;

  /* Convert to multi-byte string */
  n = wcstombs(mbstr, wcstr, count);
  if (n < sizeInBytes) {
    /* Zero-terminate output buffer */
    if (mbstr) {
      mbstr[n] = '\0';
    }

    /* Lenght of resulting multi-bytes string WITH zero-terminator */
    if (pReturnValue) {
      *pReturnValue = n + 1;
    }

    /* Success */
    error = 0;

  } else {
    /* Cannot convert string */
    error = 1;
  }

#endif

  return error;
}

/* Set errno variable */
static void dirent_set_errno(int error) {
#if defined(_MSC_VER)

  /* Microsoft Visual Studio */
  _set_errno(error);

#else

  /* Non-Microsoft compiler */
  errno = error;

#endif
}

#ifdef __cplusplus
}
#endif

/// @endcond

#endif /*DIRENT_H*/
