// check.cpp
//
// Routines for --check for rddbmgr(8)
//
//   (C) Copyright 2018 Fred Gleason <fredg@paravelsystems.com>
//
//   This program is free software; you can redistribute it and/or modify
//   it under the terms of the GNU General Public License version 2 as
//   published by the Free Software Foundation.
//
//   This program is distributed in the hope that it will be useful,
//   but WITHOUT ANY WARRANTY; without even the implied warranty of
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//   GNU General Public License for more details.
//
//   You should have received a copy of the GNU General Public
//   License along with this program; if not, write to the Free Software
//   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//

#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <qdir.h>
#include <qprocess.h>

#include <dbversion.h>
#include <rdcart.h>
#include <rdclock.h>
#include <rdconf.h>
#include <rdcut.h>
#include <rddb.h>
#include <rdescape_string.h>
#include <rdhash.h>
#include <rdlog.h>
#include <rdwavefile.h>

#include "rddbmgr.h"

bool MainObject::Check(QString *err_msg)
{
  if(GetCurrentSchema()!=RD_VERSION_DATABASE) {
    *err_msg="unsupported schema for checking";
    return false;
  }

  //
  // Recover Audio
  //
  if((db_check_all)&&!db_relink_audio.isEmpty()) {
    RelinkAudio(db_relink_audio);
    return true;
  }

  //
  // Check Table Attributes
  //
  if(db_check_all) {
    printf("Checking DB/table attributes...\n");
    CheckTableAttributes();
    printf("done.\n\n");
  }

  //
  // Check for Orphaned Voice Tracks
  //
  if(db_check_all||db_check_orphaned_tracks) {
    printf("Checking voice tracks...\n");
    CheckOrphanedTracks();
    printf("done.\n\n");
  }

  //
  // Check for stale reservations
  //
  if(db_check_all) {
    printf("Checking for stale cart reservations...\n");
    CheckPendingCarts();
    printf("done.\n\n");
  }

  //
  // Check for orphaned carts
  //
  if(db_check_all||db_check_orphaned_carts) {
    printf("Checking for orphaned carts...\n");
    CheckOrphanedCarts();
    printf("done.\n\n");
  }

  //
  // Check for orphaned cuts
  //
  if(db_check_all||db_check_orphaned_cuts) {
    printf("Checking for orphaned cuts...\n");
    CheckOrphanedCuts();
    printf("done.\n\n");
  }

  //
  // Check Cart->Cut Counts
  //
  if(db_check_all) {
    printf("Checking cart->cuts counters...\n");
    CheckCutCounts();
    printf("done.\n\n");
  }

  //
  // Check Orphaned Audio
  //
  if(db_check_all||db_check_orphaned_audio) {
    printf("Checking for orphaned audio...\n");
    CheckOrphanedAudio();
    printf("done.\n\n");
  }

  //
  // Validating Audio Lengths
  //
  if(db_check_all) {
    printf("Validating audio lengths (this may take some time)...\n");
    ValidateAudioLengths();
    printf("done.\n\n");
  }

  //
  // Rehash
  //
  if((db_check_all)&&!db_rehash.isEmpty()) {
    printf("Checking hashes...\n");
    Rehash(db_rehash);
    printf("done.\n\n");
  }

  *err_msg="ok";
  return true;
}


void MainObject::CheckTableAttributes()
{
  QString sql;
  RDSqlQuery *q;

  //
  // Per-table Attributes
  //
  sql=QString("select ")+
    "TABLE_NAME,"+       // 00
    "ENGINE,"+           // 01
    "TABLE_COLLATION "+  // 02
    "from information_schema.TABLES where "+
    "TABLE_SCHEMA='"+RDEscapeString(db_mysql_database)+"'";
  q=new RDSqlQuery(sql,false);
  while(q->next()) {
    QStringList f0=q->value(2).toString().split("_");
    QString charset=f0.at(0);
    if(q->value(1).toString().toLower()!=db_mysql_engine.toLower()) {
      printf("  Table \"%s\" uses engine type %s, should be %s. Fix? (y/N) ",
	     (const char *)q->value(0).toString().toUtf8(),
	     (const char *)q->value(1).toString().toUtf8(),
	     (const char *)db_mysql_engine.toUtf8());
      fflush(NULL);
      if(UserResponse()) {
	sql=QString("alter table `")+q->value(0).toString()+"` "+
	  "ENGINE="+db_mysql_engine;
	RDSqlQuery::apply(sql);
      }
    }
    if(q->value(2).toString().toLower()!="utf8mb4_general_ci") {
      printf("  Table \"%s\" uses charset/collation %s/%s, should be utf8mb4/utf8mb4_general_ci. Fix? (y/N) ",
	     (const char *)q->value(0).toString().toUtf8(),
	     (const char *)charset.toUtf8(),
	     (const char *)q->value(2).toString().toUtf8());
      fflush(NULL);
      if(UserResponse()) {
	RewriteTable(q->value(0).toString(),
		     charset,q->value(2).toString(),
		     "utf8mb4","utf8mb4_general_ci");
      }
    }
  }
  delete q;

  //
  // Database Attributes
  //
  sql=QString("select ")+
    "SCHEMA_NAME,"+                 // 00
    "DEFAULT_CHARACTER_SET_NAME,"+  // 01
    "DEFAULT_COLLATION_NAME "+      // 02
    "from information_schema.SCHEMATA";
  q=new RDSqlQuery(sql);
  while(q->next()) {
    if(q->value(0).toString()==db_mysql_database) {
      if((q->value(1).toString().toLower()!="utf8mb4")||
	 (q->value(2).toString().toLower()!="utf8mb4_general_ci")) {
	printf("  Database uses default charset/collation %s/%s, should be utf8mb4/utf8mb4_general_ci. Fix? (y/N) ",
	       (const char *)q->value(1).toString().toUtf8(),
	       (const char *)q->value(2).toString().toUtf8());
	fflush(NULL);
	if(UserResponse()) {
	  sql=QString("alter database `")+db_mysql_database+"` "+
	    "character set utf8mb4 collate utf8mb4_general_ci";
	  RDSqlQuery::apply(sql);	
	}
      }
    }
  }
  delete q;
}


void MainObject::RewriteTable(const QString &tblname,
			      const QString &old_charset,
			      const QString &old_collation,
			      const QString &new_charset,
			      const QString &new_collation)
{
  QProcess *proc=NULL;
  QStringList args;
  QString tempdir=RDTempDir();
  if(tempdir.isEmpty()) {
    return;
  }
  QString filename=tempdir+"/table.sql";
  QString temp_filename=tempdir+"/table-temp.sql";
  QString out_filename=tempdir+"/table-out.sql";
  /*
  printf("table \"%s\" using: %s\n",
	 (const char *)tblname.toUtf8(),
	 (const char *)tempdir.toUtf8());
  */

  //
  // Dump Table
  //
  args.clear();
  args.push_back("--opt");
  args.push_back("-h");
  args.push_back(db_mysql_hostname);
  args.push_back("-u");
  args.push_back(db_mysql_loginname);
  args.push_back("-p"+db_mysql_password);
  args.push_back(db_mysql_database);
  args.push_back(tblname);
  proc=new QProcess(this);
  proc->setStandardOutputFile(filename);
  proc->start("mysqldump",args);
  proc->waitForFinished(-1);
  delete proc;

  //
  // Modify COLLATION
  //
  args.clear();
  args.push_back("s/"+old_collation+"/"+new_collation+"/g");
  args.push_back(filename);
  proc=new QProcess(this);
  proc->setStandardOutputFile(temp_filename);
  proc->start("sed",args);
  proc->waitForFinished(-1);
  delete proc;

  //
  // Modify CHARSET
  //
  args.clear();
  args.push_back("s/"+old_charset+"/"+new_charset+"/g");
  args.push_back(temp_filename);
  proc=new QProcess(this);
  proc->setStandardOutputFile(out_filename);
  proc->start("sed",args);
  proc->waitForFinished(-1);
  delete proc;

  //
  // Push Back Modified Table
  //
  args.clear();
  args.push_back("-h");
  args.push_back(db_mysql_hostname);
  args.push_back("-u");
  args.push_back(db_mysql_loginname);
  args.push_back("-p"+db_mysql_password);
  args.push_back(db_mysql_database);
  proc=new QProcess(this);
  proc->setStandardInputFile(out_filename);
  proc->start("mysql",args);
  proc->waitForFinished(-1);
  delete proc;

  //
  // Clean Up
  //
  unlink(filename.toUtf8());
  unlink(temp_filename.toUtf8());
  unlink(out_filename.toUtf8());
  rmdir(tempdir);
}


void MainObject::RelinkAudio(const QString &srcdir) const
{
  QString sql;
  RDSqlQuery *q;

  QDir dir(srcdir);
  QStringList files=dir.entryList(QDir::Files|QDir::Readable|QDir::Hidden);
  for(int i=0;i<files.size();i++) {
    QString filename=dir.path()+"/"+files[i];
    QString hash=RDSha1Hash(filename);
    QString firstdest;
    bool delete_source=true;
    sql=QString("select CUTS.CUT_NAME,CART.TITLE from ")+
      "CUTS left join CART "+
      "on CUTS.CART_NUMBER=CART.NUMBER where "+
      "CUTS.SHA1_HASH=\""+RDEscapeString(hash)+"\"";
    q=new RDSqlQuery(sql);
    while(q->next()) {
      printf("  Recovering %06u/%03d [%s]...",
	     RDCut::cartNumber(q->value(0).toString()),
	     RDCut::cutNumber(q->value(0).toString()),
	     (const char *)q->value(1).toString());
      fflush(stdout);
      if(db_relink_audio_move) {
	unlink(RDCut::pathName(q->value(0).toString()));
	if(link(filename,RDCut::pathName(q->value(0).toString()))<0) {
	  if(errno==EXDEV) {
	    if(firstdest.isEmpty()) {
	      if(CopyFile(RDCut::pathName(q->value(0).toString()),filename)) {
		firstdest=RDCut::pathName(q->value(0).toString());
	      }
	      else {
		fprintf(stderr,"unable to copy file \"%s\"\n",
			(const char *)filename);
		delete_source=false;
	      }
	    }
	    else {
	      unlink(RDCut::pathName(q->value(0).toString()));
	      link(firstdest,RDCut::pathName(q->value(0).toString()));
	    }
	  }
	  else {
	    fprintf(stderr,"unable to move file \"%s\" [%s]\n",
		    (const char *)filename,strerror(errno));
	    delete_source=false;
	  }
	}
      }
      else {
	if(firstdest.isEmpty()) {
	  if(CopyFile(RDCut::pathName(q->value(0).toString()),filename)) {
	    firstdest=RDCut::pathName(q->value(0).toString());
	  }
	  else {
	    fprintf(stderr,"unable to copy file \"%s\"\n",
		    (const char *)filename);
	  }
	}
	else {
	  unlink(RDCut::pathName(q->value(0).toString()));
	  link(firstdest,RDCut::pathName(q->value(0).toString()));
	}
      }
      printf("  done.\n");
    }
    if(db_relink_audio_move&&delete_source) {
      unlink(filename);
    }
  }
}


void MainObject::CheckOrphanedTracks() const
{
  QString sql="select NUMBER,TITLE,OWNER from CART where OWNER!=\"\"";
  QSqlQuery *q=new QSqlQuery(sql);
  QSqlQuery *q1;

  while(q->next()) {
    sql=QString("select LINE_ID from LOG_LINES where ")+
      "LOG_NAME=\""+RDEscapeString(q->value(2).toString())+"\" && "+
      QString().sprintf("CART_NUMBER=%u",q->value(0).toUInt());
    q1=new QSqlQuery(sql);
    if(!q1->first()) {
      printf("  Found orphaned track %u - \"%s\".  Delete? (y/N) ",
	     q->value(0).toUInt(),(const char *)q->value(1).toString());
      fflush(NULL);
      if(UserResponse()) {
	RDCart *cart=new RDCart(q->value(0).toUInt());
	cart->remove(NULL,NULL,db_config);
	delete cart;
	RDLog *log=new RDLog(q->value(2).toString());
	if(log->exists()) {
	  log->updateTracks();
	}
	delete log;
      }
    }
    delete q1;
  }
  delete q;
}


void MainObject::CheckCutCounts() const
{
  QString sql;
  QSqlQuery *q;
  QSqlQuery *q1;

  sql="select NUMBER,CUT_QUANTITY,TITLE from CART";
  q=new QSqlQuery(sql);
  while(q->next()) {
    sql=QString().sprintf("select CUT_NAME from CUTS \
                           where (CART_NUMBER=%u)&&(LENGTH>0)",
			  q->value(0).toUInt());
    q1=new QSqlQuery(sql);
    if(q1->size()!=q->value(1).toInt()) {
      printf("  Cart %u [%s] has invalid cut count, fix (y/N)?",
	     q->value(0).toUInt(),(const char *)q->value(2).toString());
      if(UserResponse()) {
	RDCart *cart=new RDCart(q->value(0).toUInt());
	cart->updateLength();
	cart->resetRotation();
	delete cart;
      }
    }
    delete q1;
  }
  delete q;
}


void MainObject::CheckPendingCarts() const
{
  QString sql;
  QSqlQuery *q;
  QDateTime now(QDate::currentDate(),QTime::currentTime());

  sql=QString("select NUMBER from CART where ")+
    "(PENDING_STATION is not null)&&"+
    "(PENDING_DATETIME<\""+now.addDays(-1).
    toString("yyyy-MM-dd hh:mm:ss")+"\")";
  q=new QSqlQuery(sql);
  while(q->next()) {
    printf("  Cart %06u has stale reservation, delete cart(y/N)?",
	   q->value(0).toUInt());
    if(UserResponse()) {
      RDCart::removeCart(q->value(0).toUInt(),NULL,NULL,db_config);
    }
  }
  delete q;
}


void MainObject::CheckOrphanedCarts() const
{
  QString sql;
  QSqlQuery *q;
  QSqlQuery *q1;

  sql="select CART.NUMBER,CART.TITLE from CART left join GROUPS \
       on CART.GROUP_NAME=GROUPS.NAME where GROUPS.NAME is null";
  q=new QSqlQuery(sql);
  while(q->next()) {
    printf("  Cart %06u [%s] has missing/invalid group.\n",
	   q->value(0).toUInt(),(const char *)q->value(1).toString());
    if(db_orphan_group_name.isEmpty()) {
      printf("  Rerun rddbcheck with the --orphan-group= switch to fix.\n\n");
    }
    else {
      printf("  Assign to group \"%s\" (y/N)?",(const char *)db_orphan_group_name);
      if(UserResponse()) {
	sql=QString().
	  sprintf("update CART set GROUP_NAME=\"%s\" where NUMBER=%u",
		  (const char *)RDEscapeString(db_orphan_group_name),
		  q->value(0).toUInt());
	q1=new QSqlQuery(sql);
	delete q1;
      }
      printf("\n");
    }
  }
  delete q;
}


void MainObject::CheckOrphanedCuts() const
{
  QString sql;
  QSqlQuery *q;
  QSqlQuery *q1;
  QSqlQuery *q2;
  QFileInfo *file=NULL;

  sql="select CUTS.CUT_NAME,CUTS.DESCRIPTION from CUTS left join CART \
       on CUTS.CART_NUMBER=CART.NUMBER where CART.NUMBER is null";
  q=new QSqlQuery(sql);
  while(q->next()) {
    printf("  Cut %s [%s] is orphaned.\n",
	   (const char *)q->value(0).toString(),
	   (const char *)q->value(1).toString());
    //
    // Try to repair it
    //
    sql=QString().sprintf("select NUMBER from CART where NUMBER=%d",
			  q->value(0).toString().left(6).toUInt());
    q1=new QSqlQuery(sql);
    if(q1->first()) {
      printf("  Repair it (y/N)?");
      if(UserResponse()) {
	//
	// FIXME: Regen Cart Data
	//
	sql=QString().
	  sprintf("update CUTS set CART_NUMBER=%u where CUT_NAME=\"%s\"",
		  q1->value(0).toUInt(),
		  (const char *)q->value(0).toString());
	q2=new QSqlQuery(sql);
	delete q2;
	delete q1;
	printf("\n");
	continue;
      }
    }
    printf("\n");
    delete q1;

    //
    // Try to recover audio
    //
    file=new QFileInfo(RDCut::pathName(q->value(0).toString()));
    if(!file->exists()) {
      printf("  Clear it (y/N)?");
      if(UserResponse()) {
	sql=QString().sprintf("delete from CUTS where CUT_NAME=\"%s\"",
			      (const char *)q->value(0).toString());
	q1=new QSqlQuery(sql);
	delete q1;
      }
    }
    else {
      if(db_dump_cuts_dir.isEmpty()) {
	printf("  Rerun rddbcheck with the --dump-cuts-dir= switch to fix.\n");
      }
      else {
	printf("  Clear it (y/N)?");
	if(UserResponse()) {
	  system("mv "+file->filePath()+" "+db_dump_cuts_dir+"/");
	  sql=QString().sprintf("delete from CUTS where CUT_NAME=\"%s\"",
				(const char *)q->value(0).toString());
	  q1=new QSqlQuery(sql);
	  delete q1;
	  printf("  Saved audio in \"%s/%s\"\n",(const char *)db_dump_cuts_dir,
		 (const char *)file->fileName());
	}
      }
    }
    printf("\n");
    delete file;
    file=NULL;
  }
  delete q;
}


void MainObject::CheckOrphanedAudio() const
{
  QDir dir(db_config->audioRoot());
  QStringList list=dir.entryList("??????_???.wav",QDir::Files);
  for(int i=0;i<list.size();i++) {
    bool ok=false;
    list[i].left(6).toUInt(&ok);
    if(ok) {
      list[i].mid(7,3).toInt(&ok);
      if(ok) {
	QString sql=QString().sprintf("select CUT_NAME from CUTS \
                                       where CUT_NAME=\"%s\"",
				      (const char *)list[i].left(10));
	QSqlQuery *q=new QSqlQuery(sql);
	if(!q->first()) {
	  printf("  File \"%s/%s\" is orphaned.\n",
		 (const char *)db_config->audioRoot(),(const char *)list[i]);
	  if(db_dump_cuts_dir.isEmpty()) {
	    printf(
	     "  Rerun rddbcheck with the --dump-cuts-dir= switch to fix.\n\n");
	  }
	  else {
	    printf("  Move to \"%s\" (y/N)? ",(const char *)db_dump_cuts_dir);
	    if(UserResponse()) {
	      system(QString().sprintf("mv %s/%s %s/",
				       (const char *)db_config->audioRoot(),
				       (const char *)list[i],
				       (const char *)db_dump_cuts_dir));
	      printf("  Saved audio in \"%s/%s\"\n",(const char *)db_dump_cuts_dir,
		     (const char *)list[i]);
	    }
	  }
	}
	delete q;
      }
    }
  }
}


void MainObject::ValidateAudioLengths() const
{
  QString sql;
  QSqlQuery *q;
  RDWaveFile *wave=NULL;

  sql="select CUT_NAME,CART_NUMBER,LENGTH from CUTS order by CART_NUMBER";
  q=new QSqlQuery(sql);
  while(q->next()) {
    if(q->value(2).toInt()>0) {
      wave=new RDWaveFile(RDCut::pathName(q->value(0).toString()));
      if(wave->openWave()) {
	if((int)wave->getExtTimeLength()<(q->value(2).toInt()-100)) {
	  SetCutLength(q->value(0).toString(),wave->getExtTimeLength());
	}
      }
      else {
	SetCutLength(q->value(0).toString(),0);
      }
      delete wave;
    }
  }
  delete q;
}


void MainObject::Rehash(const QString &arg) const
{
  QString sql;
  QSqlQuery *q;
  unsigned cartnum;
  bool ok=false;

  if(arg.lower()=="all") {
    sql=QString("select NUMBER from CART where ")+
      QString().sprintf("TYPE=%d ",RDCart::Audio)+
      "order by NUMBER";
    q=new QSqlQuery(sql);
    while(q->next()) {
      RehashCart(q->value(0).toUInt());
    }
    delete q;
    return;
  }
  cartnum=arg.toUInt(&ok);
  if(ok&&(cartnum>0)&&(cartnum<=RD_MAX_CART_NUMBER)) {
    RehashCart(cartnum);
    return;
  }
  RDCut *cut=new RDCut(arg);
  if(cut->exists()) {
    RehashCut(arg);
  }
  delete cut;
}


void MainObject::RehashCart(unsigned cartnum) const
{
  RDCart *cart=new RDCart(cartnum);
  if(cart->exists()) {
    if(cart->type()==RDCart::Audio) {
      QString sql=QString("select CUT_NAME from CUTS where ")+
	QString().sprintf("CART_NUMBER=%u ",cartnum)+
	"order by CUT_NAME";
      QSqlQuery *q=new QSqlQuery(sql);
      while(q->next()) {
	RehashCut(q->value(0).toString());
      }
      delete q;
    }
  }
  else {
    printf("  Cart %06u does not exist.\n",cartnum);
  }
}


void MainObject::RehashCut(const QString &cutnum) const
{
  QString hash=RDSha1Hash(RDCut::pathName(cutnum),true);
  if(hash.isEmpty()) {
    printf("  Unable to generate hash for \"%s\"\n",
	    (const char *)RDCut::pathName(cutnum));
  }
  else {
    RDCut *cut=new RDCut(cutnum);
    if(cut->exists()) {
      if(cut->sha1Hash().isEmpty()) {
	cut->setSha1Hash(hash);
      }
      else {
	if(cut->sha1Hash()!=hash) {
	  RDCart *cart=new RDCart(RDCut::cartNumber(cutnum));
	  printf("  Cut %d [%s] in cart %06u [%s] has inconsistent SHA1 hash.  Fix? (y/N) ",
		 cut->cutNumber(),
		 (const char *)cut->description(),
		 cart->number(),
		 (const char *)cart->title());
	  fflush(NULL);
	  if(UserResponse()) {
	    cut->setSha1Hash(hash);
	  }
	  delete cart;
	}
      }
    }
    else {
      printf("  Cut \"%s\" does not exist.\n",(const char *)cutnum);
    }
    delete cut;
  }
}


void MainObject::SetCutLength(const QString &cutname,int len) const
{
  QString sql;
  QSqlQuery *q;
  RDCut *cut=new RDCut(cutname);
  RDCart *cart=new RDCart(cut->cartNumber());

  printf("  Cut %d [%s] in cart %06u [%s] has invalid length.  Correct? (y/N) ",
	 cut->cutNumber(),
	 (const char *)cut->description(),
	 cart->number(),
	 (const char *)cart->title());
  fflush(NULL);
  if(UserResponse()) {
    fflush(NULL);
    sql=QString("update CUTS set ")+
      "START_POINT=0,"+
      QString().sprintf("END_POINT=%d,",len)+
      "FADEUP_POINT=-1,"+
      "FADEDOWN_POINT=-1,"+
      "SEGUE_START_POINT=-1,"+
      "SEGUE_END_POINT=-1,"+
      "TALK_START_POINT=-1,"+
      "TALK_END_POINT=-1,"+
      "HOOK_START_POINT=-1,"+
      "HOOK_END_POINT=-1,"+
      "PLAY_GAIN=0,"+
      QString().sprintf("LENGTH=%d where ",len)+
      "CUT_NAME=\""+RDEscapeString(cutname)+"\"";
    q=new QSqlQuery(sql);
    delete q;
    cart->updateLength();
    cart->resetRotation();
  }
  delete cart;
  delete cut;
}


bool MainObject::UserResponse() const
{
  char c=0;

  if(db_yes) {
    printf("y\n");
    return true;
  }
  if(db_no) {
    printf("n\n");
    return false;
  }
  while((c!='y')&&(c!='Y')&&(c!='n')&&(c!='N')) {
    scanf("%c",&c);
    if((c=='y')||(c=='Y')) {
      scanf("%c",&c);
      return true;
    }
    if(c=='\n') {
      return false;
    }
  }
  scanf("%c",&c);
  return false;
}


bool MainObject::CopyFile(const QString &destfile,const QString &srcfile) const
{
  int src_fd=-1;
  struct stat src_stat;
  int dest_fd=-1;
  struct stat dest_stat;
  int n;
  int blksize;
  char *data=NULL;

  if((src_fd=open(srcfile,O_RDONLY))<0) {
    return false;
  }
  fstat(src_fd,&src_stat);
  mode_t mask=umask(S_IRWXO);
  if((dest_fd=open(destfile,O_WRONLY|O_CREAT|O_TRUNC,
		   S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP))<0) {
    close(src_fd);
    return false;
  }
  umask(mask);
  fstat(dest_fd,&dest_stat);
  blksize=src_stat.st_blksize;
  if(dest_stat.st_blksize<blksize) {
    blksize=dest_stat.st_blksize;
  }
  data=(char *)malloc(blksize);
  while((n=read(src_fd,data,blksize))!=0) {
    write(dest_fd,data,n);
  }
  free(data);
  fchown(dest_fd,150,150);  // FIXME: do name lookup!
  close(dest_fd);
  close(src_fd);
  

  return true;
}