/**************************************************************************
 * Copyright (c)   2001    Southeastern Universities Research Association,
 *                         Thomas Jefferson National Accelerator Facility
 *
 * This software was developed under a United States Government license
 * described in the NOTICE file included as part of this distribution.
 *
 * Jefferson Lab HPC Group, 12000 Jefferson Ave., Newport News, VA 23606
 **************************************************************************
 *
 * Description:
 *      File utility to handle some functionalities that are missing
 *      from java.io.File
 *
 * Author:  
 *      Jie Chen
 *      Jefferson Lab HPC Group
 *
 *
 *
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pwd.h>
#include <grp.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <linux/quota.h>
#include <sys/vfs.h>

#define UNKNOWN "UNKNOWN"

/* Generated header file from javah */
#include "JFile.h"

/**
 * Get group count for a user with username
 */
static int getugroups (int maxcount, gid_t grouplist[], 
		       char *username, gid_t gid)
{
  struct group *grp;
  register char **cp;
  register int count = 0;

  if (gid != -1) {
    if (maxcount != 0)
      grouplist[count] = gid;
    ++count;
  }

  setgrent ();
  while ((grp = getgrent ()) != 0) {
    for (cp = grp->gr_mem; *cp; ++cp) {
      int n;
      
      if ( strcmp (username, *cp) != 0)
	continue;

      /* See if this group number is already on the list.  */
      for (n = 0; n < count; ++n)
	if (grouplist && grouplist[n] == grp->gr_gid)
	  break;

      /* If it's a new group number, then try to add it to the list.  */
      if (n == count) {
	if (maxcount != 0) {
	  if (count >= maxcount) {
	    endgrent ();
	    return count;
	  }
	  grouplist[count] = grp->gr_gid;
	}
	count++;
      }
    }
  }
  endgrent ();
  
  return count;
}

/**
 * Set supplemental groups to a user id and a group id 
 *
 * On success 0 is returned.
 * On error, -1 is returned
 */
static int setsupgroups (const char* username, gid_t gid)
{
  int maxcount, count;
  gid_t sgrps[32];
  
  maxcount = 32;
  count = getugroups (maxcount, sgrps, username, gid);
  if (count <= 0)
    return -1;
  
  if (setgroups (count, sgrps) != 0) {
    printf ("Set groups failed, errno is %d\n", errno);
    perror (" Set groups: ");
    return -1;
  }
  return 0;

}


jboolean Java_jlab_hpc_util_JFile_isLink
  (JNIEnv * env, jclass cl, jstring fname)
{
  struct stat st;
  char*   filename;

  /* Obtain a C-copy of the Java string */
  filename = strdup((*env)->GetStringUTFChars(env, fname, 0));

  if(filename[strlen(filename)-1]=='/' && strlen(filename)>1)
    filename[strlen(filename)-1] = 0;
  if (lstat (filename, &st) == 0) {
   free(filename);
   return ((st.st_mode & (S_IFLNK | S_IFREG)) == S_IFLNK);
   }
  else {
   free(filename);
   return 0;
 }
}


jstring Java_jlab_hpc_util_JFile_getLinkTarget
  (JNIEnv *env, jclass cl, jstring fname)
{
  char buf[1024];
  char*   filename;
  char * ptr;
  int len = 0;

  /* Obtain a C-copy of the Java string */
  filename = strdup((*env)->GetStringUTFChars(env, fname, 0));
  if(filename[strlen(filename)-1]=='/' && strlen(filename)>1)
    filename[strlen(filename)-1] = 0;

  if ((len=readlink(filename, buf, 1024)) <= 0) 
    {
    free(filename);
    return NULL;
    }
  else {    
    buf[len]=0;
    if (*buf != '/' && (ptr=strrchr(filename, '/'))!=NULL)
      {
	*(ptr+1)=0;
        memmove(buf+strlen(filename), buf, strlen(buf)+1);
	memmove(buf, filename, strlen(filename));
      }
    free(filename);  
    return (*env)->NewStringUTF(env, buf);
  }
}


jboolean Java_jlab_hpc_util_JFile_allocate
  (JNIEnv * env, jclass cl, jstring fname, jstring user, jlong bytes)
{
  const  char*   filename; 
  const  char*   username;  
  struct passwd* pwsd = 0;
  uid_t  userid;
  long   size;
  struct mem_dqblk mb;

  return 1;

  /* Obtain a C-copy of the Java string */
  filename = (*env)->GetStringUTFChars(env, fname, 0);
  username = (*env)->GetStringUTFChars(env, user,  0);

  /* Find user id information for username */
  if ((pwsd = getpwnam (username)) != 0) 
    userid = pwsd->pw_uid;

  if (quotactl(Q_GETQUOTA, filename, userid, (caddr_t)&mb) == 0) {
    size = mb.dqb_bsoftlimit - mb.dqb_curspace;
    if (size >= bytes) return 1;
  }
  return 0;
}


jint Java_jlab_hpc_util_JFile_createFile
(JNIEnv *env, jclass cl, jstring fname, jstring user)
{
  const  char*   filename;
  const  char*   username;
  struct passwd* pwsd = 0;
   uid_t          userid;
  gid_t          grpid;
  int            ok = 1;
  int            fd = 0;

  /* Obtain a C-copy of the Java string */
  filename = (*env)->GetStringUTFChars(env, fname, 0);
  username = (*env)->GetStringUTFChars(env, user,  0);

  /* Find user id information for username */
  if ((pwsd = getpwnam (username)) != 0) {
    userid = pwsd->pw_uid;
    grpid  = pwsd->pw_gid;
    /* do seteuid: cannot setuid since we have to switch back to root */
    if (setsupgroups (username, grpid) != 0 || 
	setegid (grpid) != 0 || seteuid (userid) != 0) 
      ok = 0;
  }
  else 
    ok = 0;
  
  if (ok) {
    if ((fd = creat (filename, 0644)) == -1) 
      ok = 0;
    else 
      close (fd);
    
    /* set uid back to root */
    if (seteuid (0) != 0 || setegid (0) != 0 
	|| setsupgroups ("root", 0) != 0) {
      ok = 0;
    }
  }

  /* Now we are done with str */
  (*env)->ReleaseStringUTFChars(env, fname, filename);
  (*env)->ReleaseStringUTFChars(env, user,  username);
  return ok;
}

jint Java_jlab_hpc_util_JFile_deleteFile
(JNIEnv *env, jclass cl, jstring fname, jstring user)
{
  const  char*   filename;
  const  char*   username;
  struct passwd* pwsd = 0;
  struct stat    st;
  uid_t          userid;
  gid_t          grpid;
  int            ok = 1;

  /* Obtain a C-copy of the Java string */
  filename = (*env)->GetStringUTFChars(env, fname, 0);
  username = (*env)->GetStringUTFChars(env, user,  0);

  /* Find user id information for username */
  if ((pwsd = getpwnam (username)) != 0) {
    userid = pwsd->pw_uid;
    grpid  = pwsd->pw_gid;
    if (stat (filename, &st) != 0) 
      ok = 0;
    else {
      if (st.st_uid != userid) 
	ok = 0;
    }
  }
  else 
    ok = 0;

  if (ok) {
    if (setsupgroups (username, grpid) != 0 ||
	setegid (grpid) != 0 || seteuid (userid) != 0) 
      ok = 0;
    else if (remove (filename) == -1)
      ok = 0;
    /* set uid back to root */
    if (seteuid (0) != 0 || setegid (0) != 0 || setsupgroups ("root", 0) != 0) 
      ok = 0;    
  }
        
  /* Now we are done with str */
  (*env)->ReleaseStringUTFChars(env, fname, filename);
  (*env)->ReleaseStringUTFChars(env, user,  username);
  return ok;
}


jstring Java_jlab_hpc_util_JFile_getOwner
(JNIEnv *env, jclass cl, jstring fname)
{  
  const  char*   filename;
  struct stat    st;
  struct passwd* pwst;
  const  char*   username = NULL;

  /* Obtain a C-copy of the Java string */
  filename = (*env)->GetStringUTFChars(env, fname, 0);
  if (stat (filename, &st) == 0) { 
    pwst = getpwuid(st.st_uid);  
    if (pwst != NULL) username = pwst->pw_name;
  }
  return (*env)->NewStringUTF(env, username);
}


jstring Java_jlab_hpc_util_JFile_getGroup
(JNIEnv *env, jclass cl, jstring fname)
{  
  const  char*   filename;
  struct stat    st;
  struct group*   gst;
  const  char*   grname = NULL;

  /* Obtain a C-copy of the Java string */
  filename = (*env)->GetStringUTFChars(env, fname, 0);
  if (stat (filename, &st) == 0) { 
    gst = getgrgid(st.st_gid);  
    if (gst != NULL)   grname = gst->gr_name;
  } 
  return (*env)->NewStringUTF(env, grname);
}


/**
 * change owner of a given file.
 * return 1: success.
 * return 0: failure.
 */
jint Java_jlab_hpc_util_JFile_changeOwner
  (JNIEnv *env, jclass cl, jstring fname, jstring owner)
{
  
  const  char*   filename;
  const  char*   username;
  struct passwd* pwsd = 0;
  uid_t          userid;
  gid_t          grpid;
  int            ok = 1;
  
  /* Obtain a C-copy of the Java string */
  filename = (*env)->GetStringUTFChars(env, fname, 0);
  username = (*env)->GetStringUTFChars(env, owner,  0);

  /* Find user id information for username */
  if ((pwsd = getpwnam (username)) != 0) {
    userid = pwsd->pw_uid;
    grpid  = pwsd->pw_gid;
    if (chown (filename, userid, grpid) != 0)
      ok = 0;
  }
  return ok;
}




/**
 * Create directory 'path' amd make parent directory when needed.
 * return 1: success.
 * return 0: failure.
 */
static int createUserDirs (const char* path)
{
  /* This code is for unix only */
  int    done = 0;
  int    ok = 1;
  struct stat st;
  char*  slash = 0;
  char   tmp[1024];
  char   *q, *p;
  
  /* if there is separator, this is a relative path */
  slash = strchr (path, '/');
  if (!slash)
    return mkdir (path, 0755);
  
  while (!done && slash) {
    slash = slash + 1;
    if (!slash || !*slash)
      done = 1;
    else {
      /* find out each individual path leading to the final path 'path' */
      q = tmp;
      p = (char *)path;
      
      slash = strchr (slash + 1, '/');
      if (!slash) {  /* this is last segment of file path */
	  strcpy (tmp, path);
	  done = 1;
      }
      else {
	  while (p != slash) {
	      *q = *p;
	      q++; p++;
	  }
	  *q = '\0';
      }

      /* now tmp should a path */
      if (stat (tmp, &st) == 0) {
	if (!S_ISDIR (st.st_mode)) {
	  /* this path exisits but it is not a directory  */
	  done = 1;
	  ok = 0;
	}
      }
      else {
	/* now try to create a new directory */
	if (mkdir (tmp, 0755) == -1) { /* failed to create new directory */
	  done = 1;
	  ok = 0;
	}
      }
    }
  }
  return ok;
}


jint Java_jlab_hpc_util_JFile_createDir
(JNIEnv *env, jclass cls, jstring fname, jstring user)
{
  const  char*   filename;
  const  char*   username;
  struct passwd* pwsd = 0;
  struct stat    st;
  uid_t          userid;
  gid_t          grpid;
  int            ok = 1;

  /* Obtain a C-copy of the Java string */
  filename = (*env)->GetStringUTFChars(env, fname, 0);
  username = (*env)->GetStringUTFChars(env, user,  0);
  /* Find user id information for username */
  if ((pwsd = getpwnam (username)) != 0) {
    userid = pwsd->pw_uid;
    grpid  = pwsd->pw_gid;
    if (setsupgroups (username, grpid) != 0 ||
	setegid (grpid) != 0 || seteuid (userid) != 0) 
      ok = 0;
    else {
      if (mkdir (filename, 0755) == 0) ok = 1;
    }
   /* set uid back to root */
    if (seteuid (0) != 0 || setegid (0) != 0 || setsupgroups ("root", 0) != 0) 
      ok = 0;
  }
   /* Now we are done with str */
  (*env)->ReleaseStringUTFChars(env, fname, filename);
  (*env)->ReleaseStringUTFChars(env, user,  username);
  return ok;
}

jint Java_jlab_hpc_util_JFile_createDirs
(JNIEnv *env, jclass cls, jstring fname, jstring user)
{
  const  char*   filename;
  const  char*   username;
  struct passwd* pwsd = 0;
  struct stat    st;
  uid_t          userid;
  gid_t          grpid;
  int            ok = 1;

  /* Obtain a C-copy of the Java string */
  filename = (*env)->GetStringUTFChars(env, fname, 0);
  username = (*env)->GetStringUTFChars(env, user,  0);

  /* Find user id information for username */
  if ((pwsd = getpwnam (username)) != 0) {
    userid = pwsd->pw_uid;
    grpid  = pwsd->pw_gid;
    if (setsupgroups (username, grpid) != 0 || 
	setegid (grpid) != 0 || seteuid (userid) != 0) 
      ok = 0;
    else
      ok = createUserDirs (filename);

    /* set uid back to root */
    if (seteuid (0) != 0 || setegid (0) != 0 || setsupgroups ("root", 0) != 0) 
      ok = 0;
  }
   /* Now we are done with str */
  (*env)->ReleaseStringUTFChars(env, fname, filename);
  (*env)->ReleaseStringUTFChars(env, user,  username);
  return ok;
}

/**
 * Remove a user directory recursively.
 * return 1: success.
 * return 0: failure.
 */
static int deleteUserDirs (const char* path)
{
  struct stat    st;
  DIR*           dir;
  struct dirent* ent;
  char           fname[1024];

  if (stat (path, &st) == 0) {
    if (!S_ISLNK(st.st_mode) && S_ISDIR (st.st_mode)) {
      /* open this directory */
      dir = opendir (path);
      if (!dir)
	return 0;
      while ((ent = readdir(dir))) {
	/* do not count the following directories */
	if (strcmp (ent->d_name, ".") == 0 || strcmp (ent->d_name, "..") == 0)
	  continue;
	sprintf (fname, "%s/%s", path, ent->d_name);
	if (deleteUserDirs (fname) == 0)
	  return 0;
      }
      closedir (dir);
      /* delete this directory */
      if (rmdir(path) == -1)
	return 0;
    }
    if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode))
      if (unlink (path) == -1)
	return 0;
  }
  return 1;
}
	

jint Java_jlab_hpc_util_JFile_deleteDirs
(JNIEnv *env, jclass cls, jstring fname, jstring user)
{
  const  char*   filename;
  const  char*   username;
  struct passwd* pwsd = 0;
  uid_t          userid;
  gid_t          grpid;
  int            ok = 1;

  /* Obtain a C-copy of the Java string */
  filename = (*env)->GetStringUTFChars(env, fname, 0);
  username = (*env)->GetStringUTFChars(env, user,  0);

  /* Find user id information for username */
  if ((pwsd = getpwnam (username)) != 0) {
    userid = pwsd->pw_uid;
    grpid  = pwsd->pw_gid;
    if (setsupgroups (username, grpid) != 0 || 
	setegid (grpid) != 0 || seteuid (userid) != 0) 
      ok = 0;
    else
      ok = deleteUserDirs (filename);

    /* set uid back to root */
    if (seteuid (0) != 0 || setegid (0) != 0 || setsupgroups ("root", 0) != 0) 
      ok = 0;
  }
   /* Now we are done with str */
  (*env)->ReleaseStringUTFChars(env, fname, filename);
  (*env)->ReleaseStringUTFChars(env, user,  username);
  return ok;
}  


jstring Java_jlab_hpc_util_JFile_homeDir
(JNIEnv *env, jclass cls, jstring user)
{
  const  char*   username;
  struct passwd* pwsd = 0;


  /* Obtain a C-copy of the Java string */
  username = (*env)->GetStringUTFChars(env, user,  0); 

  /* Find user id information for username */
  if ((pwsd = getpwnam (username)) != 0) 
    return (*env)->NewStringUTF(env, pwsd->pw_dir);
  return (*env)->NewStringUTF(env, UNKNOWN);
}    

jlong Java_jlab_hpc_util_JFile_getTotalSpace
(JNIEnv *env, jclass cls, jstring path)
{
  const  char*   disk;
  struct statfs  buff;
  long size;

  /* Obtain a C-copy of the Java string */
  disk = (*env)->GetStringUTFChars(env, path,  0);

  if (statfs (disk, &buff) == 0) {
    size = buff.f_bsize/1024;
    return buff.f_blocks*size;
  }
  else  {
    printf ("statfs failed, errno is %d\n", errno);
    return -1;
  }
}

jlong Java_jlab_hpc_util_JFile_getAvailableSpace
(JNIEnv *env, jclass cls, jstring path)
{
  const  char*   disk;
  struct statfs  buff;
  long size;

  /* Obtain a C-copy of the Java string */
  disk = (*env)->GetStringUTFChars(env, path,  0);

  if (statfs (disk, &buff) == 0) {
    size = buff.f_bsize/1024;
    return buff.f_bavail*size;
  }
  else
    return -1;
}