**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*******************************************************************************
**
** File utilities.
**
** Functions named file_* are generic functions that always follow symlinks.
**
** Functions named file_wd_* are to be used for files inside working
** directories. They follow symlinks depending on 'allow-symlinks' setting.
*/
#include "config.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include "file.h"

/*
** The file status information from the most recent stat() call.
**
** Use _stati64 rather than stat on windows, in order to handle files
** larger than 2GB.
*/
#if defined(_WIN32) && defined(__MSVCRT__)
# define stat _stati64
#endif
/*
** On Windows S_ISLNK always returns FALSE.
*/
#if defined(_WIN32)
# define S_ISLNK(x) (0)
#endif
static int fileStatValid = 0;
static struct stat fileStat;

/*
** Fill stat buf with information received from stat() or lstat().
** lstat() is called on Unix if isWd is TRUE and allow-symlinks setting is on.
**
*/
static int fossil_stat(const char *zFilename, struct stat *buf, int isWd){
#if !defined(_WIN32)
  if( isWd && g.allowSymlinks ){
    return lstat(zFilename, buf);
  }else{
    return stat(zFilename, buf);
  }
#else
  int rc = 0;
  char *zMbcs = fossil_utf8_to_mbcs(zFilename);
  rc = stat(zMbcs, buf);
  fossil_mbcs_free(zMbcs);
#endif
}

/*
** Fill in the fileStat variable for the file named zFilename.
** If zFilename==0, then use the previous value of fileStat if
** there is a previous value.
**
** If isWd is TRUE, do lstat() instead of stat() if allow-symlinks is on.
**
** Return the number of errors.  No error messages are generated.
*/
static int getStat(const char *zFilename, int isWd){
  int rc = 0;
  if( zFilename==0 ){
    if( fileStatValid==0 ) rc = 1;
  }else{

    if( fossil_stat(zFilename, &fileStat, isWd)!=0 ){
      fileStatValid = 0;
      rc = 1;
    }else{
      fileStatValid = 1;
      rc = 0;
    }

  }
  return rc;
}


/*
** Return the size of a file in bytes.  Return -1 if the file does not
** exist.  If zFilename is NULL, return the size of the most recently
** stat-ed file.
*/
i64 file_size(const char *zFilename){
  return getStat(zFilename, 0) ? -1 : fileStat.st_size;
}

/*
** Same as file_size(), but takes into account symlinks.
*/
i64 file_wd_size(const char *zFilename){
  return getStat(zFilename, 1) ? -1 : fileStat.st_size;  
}

/*
** Return the modification time for a file.  Return -1 if the file
** does not exist.  If zFilename is NULL return the size of the most
** recently stat-ed file.
*/
i64 file_mtime(const char *zFilename){
  return getStat(zFilename, 0) ? -1 : fileStat.st_mtime;
}

/*
** Same as file_mtime(), but takes into account symlinks.
*/
i64 file_wd_mtime(const char *zFilename){
  return getStat(zFilename, 1) ? -1 : fileStat.st_mtime;
}

/*
** Return TRUE if the named file is an ordinary file or symlink 
** and symlinks are allowed.
** Return false for directories, devices, fifos, etc.
*/
int file_wd_isfile_or_link(const char *zFilename){


  return getStat(zFilename, 1) ? 0 : S_ISREG(fileStat.st_mode) ||


                                     S_ISLNK(fileStat.st_mode);
}

/*
** Return TRUE if the named file is an ordinary file.  Return false
** for directories, devices, fifos, symlinks, etc.
*/
int file_isfile(const char *zFilename){
  return getStat(zFilename, 0) ? 0 : S_ISREG(fileStat.st_mode);
}

int file_wd_isfile(const char *zFilename){
  return getStat(zFilename, 1) ? 0 : S_ISREG(fileStat.st_mode);
}

/*
** Create symlink to file on Unix, or plain-text file with
** symlink target if "allow-symlinks" is off or we're on Windows.
**
** Arguments: target file (symlink will point to it), link file
**/
void symlink_create(const char *zTargetFile, const char *zLinkFile){
#if !defined(_WIN32)
  if( g.allowSymlinks ){
    int i, nName;
    char *zName, zBuf[1000];

    nName = strlen(zLinkFile);
    if( nName>=sizeof(zBuf) ){

  {
    Blob content;
    blob_set(&content, zTargetFile);
    blob_write_to_file(&content, zLinkFile);
    blob_reset(&content);
  }
}

/*
** Copy symbolic link from zFrom to zTo.
*/
void symlink_copy(const char *zFrom, const char *zTo){
  Blob content;
  blob_read_link(&content, zFrom);
  symlink_create(blob_str(&content), zTo);
  blob_reset(&content);
}

/*
** Return file permissions (normal, executable, or symlink):
**   - PERM_EXE if file is executable;
**   - PERM_LNK on Unix if file is symlink and allow-symlinks option is on;
**   - PERM_REG for all other cases (regular file, directory, fifo, etc).
*/
int file_wd_perm(const char *zFilename){
  if( getStat(zFilename, 1) ) return PERM_REG;
#if defined(_WIN32)
#  if defined(__DMC__) || defined(_MSC_VER)
#    define S_IXUSR  _S_IEXEC
#  endif
  if( S_ISREG(fileStat.st_mode) && ((S_IXUSR)&fileStat.st_mode)!=0 )
    return PERM_EXE;
  else

#endif
}

/*
** Return TRUE if the named file is an executable.  Return false
** for directories, devices, fifos, symlinks, etc.
*/
int file_wd_isexe(const char *zFilename){
  return file_wd_perm(zFilename)==PERM_EXE;
}

/*
** Return TRUE if the named file is a symlink and symlinks are allowed.
** Return false for all other cases.
**
** On Windows, always return False.
*/
int file_wd_islink(const char *zFilename){
  return file_wd_perm(zFilename)==PERM_LNK;
}

/*
** Return 1 if zFilename is a directory.  Return 0 if zFilename
** does not exist.  Return 2 if zFilename exists but is something
** other than a directory.
*/
int file_isdir(const char *zFilename){
  int rc;

  if( zFilename ){
    char *zFN = mprintf("%s", zFilename);
    file_simplify_name(zFN, -1);
    rc = getStat(zFN, 0);
    free(zFN);
  }else{
    rc = getStat(0, 0);
  }


  return rc ? 0 : (S_ISDIR(fileStat.st_mode) ? 1 : 2);
}

/*
** Same as file_isdir(), but takes into account symlinks.
*/
int file_wd_isdir(const char *zFilename){
  int rc;

  if( zFilename ){
    char *zFN = mprintf("%s", zFilename);
    file_simplify_name(zFN, -1);
    rc = getStat(zFN, 1);
    free(zFN);
  }else{
    rc = getStat(0, 1);
  }
  return rc ? 0 : (S_ISDIR(fileStat.st_mode) ? 1 : 2);

}


/*
** Wrapper around the access() system call.
*/
int file_access(const char *zFilename, int flags){
  char *zMbcs = fossil_utf8_to_mbcs(zFilename);
  int rc = access(zMbcs, flags);

  fclose(out);
}

/*
** Set or clear the execute bit on a file.  Return true if a change
** occurred and false if this routine is a no-op.
*/
int file_wd_setexe(const char *zFilename, int onoff){
  int rc = 0;
#if !defined(_WIN32)
  struct stat buf;
  if( fossil_stat(zFilename, &buf, 1)!=0 || S_ISLNK(buf.st_mode) ) return 0;
  if( onoff ){
    int targetMode = (buf.st_mode & 0444)>>2;
    if( (buf.st_mode & 0111)!=targetMode ){
      chmod(zFilename, buf.st_mode | targetMode);
      rc = 1;
    }
  }else{

  blob_zero(&x);
  for(i=2; i<g.argc; i++){
    char zBuf[100];
    const char *zName = g.argv[i];
    file_canonical_name(zName, &x);
    fossil_print("[%s] -> [%s]\n", zName, blob_buffer(&x));
    blob_reset(&x);
    sqlite3_snprintf(sizeof(zBuf), zBuf, "%lld", file_wd_size(zName));
    fossil_print("  file_size   = %s\n", zBuf);
    sqlite3_snprintf(sizeof(zBuf), zBuf, "%lld", file_wd_mtime(zName));
    fossil_print("  file_mtime  = %s\n", zBuf);
    fossil_print("  file_isfile = %d\n", file_wd_isfile(zName));
    fossil_print("  file_isfile_or_link = %d\n",file_wd_isfile_or_link(zName));
    fossil_print("  file_islink = %d\n", file_wd_islink(zName));
    fossil_print("  file_isexe  = %d\n", file_wd_isexe(zName));
    fossil_print("  file_isdir  = %d\n", file_wd_isdir(zName));
  }
}

/*
** Return TRUE if the given filename is canonical.
**
** Canonical names are full pathnames using "/" not "\" and which

  i64 iSize;
  int rc;
  Blob onDisk;

  iSize = file_size(zName);
  if( iSize<0 ) return 0;
  if( iSize!=blob_size(pContent) ) return 0;
  if( file_wd_islink(zName) ){
    blob_read_link(&onDisk, zName);
  }else{
    blob_read_from_file(&onDisk, zName);
  }
  rc = blob_compare(&onDisk, pContent);
  blob_reset(&onDisk);
  return rc==0;