/*
  Copyright (c) 2005 Tom Albers <tomalbers@kde.nl>
  Copyright (c) 1997-1999 Stefan Taferner <taferner@kde.org>

  This library is free software; you can redistribute it and/or modify it
  under the terms of the GNU Library General Public License as published by
  the Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  This library 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 Library General Public
  License for more details.

  You should have received a copy of the GNU Library General Public License
  along with this library; see the file COPYING.LIB.  If not, write to the
  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  02110-1301, USA.
*/

#include "kfileio.h"
#include "kpimutils_export.h"

#include <kdebug.h>
#include <kde_file.h>
#include <klocale.h>
#include <kmessagebox.h>
#include <KStandardGuiItem>

#include <QDir>
#include <QByteArray>
#include <QWidget>
#include <QFile>
#include <QFileInfo>

#include <sys/stat.h>
#include <sys/types.h>
#include <assert.h>

namespace KPIMUtils {

//-----------------------------------------------------------------------------
static void msgDialog( const QString &msg )
{
  KMessageBox::sorry( 0, msg, i18n( "File I/O Error" ) );
}

//-----------------------------------------------------------------------------
QByteArray kFileToByteArray( const QString &aFileName, bool aEnsureNL,
                             bool aVerbose )
{
  QByteArray result;
  QFileInfo info( aFileName );
  unsigned int readLen;
  unsigned int len = info.size();
  QFile file( aFileName );

  //assert(aFileName!=0);
  if( aFileName.isEmpty() ) {
    return "";
  }

  if ( !info.exists() ) {
    if ( aVerbose ) {
      msgDialog( i18n( "The specified file does not exist:\n%1", aFileName ) );
    }
    return QByteArray();
  }
  if ( info.isDir() ) {
    if ( aVerbose ) {
      msgDialog( i18n( "This is a folder and not a file:\n%1", aFileName ) );
    }
    return QByteArray();
  }
  if ( !info.isReadable() ) {
    if ( aVerbose ) {
      msgDialog( i18n( "You do not have read permissions to the file:\n%1", aFileName ) );
    }
    return QByteArray();
  }
  if ( len <= 0 ) {
    return QByteArray();
  }

  if ( !file.open( QIODevice::Unbuffered|QIODevice::ReadOnly ) ) {
    if ( aVerbose ) {
      switch( file.error() ) {
      case QFile::ReadError:
        msgDialog( i18n( "Could not read file:\n%1", aFileName ) );
        break;
      case QFile::OpenError:
        msgDialog( i18n( "Could not open file:\n%1", aFileName ) );
        break;
      default:
        msgDialog( i18n( "Error while reading file:\n%1", aFileName ) );
      }
    }
    return QByteArray();
  }

  result.resize( len + int( aEnsureNL ) );
  readLen = file.read( result.data(), len );
  if ( aEnsureNL ) {
    if ( result[readLen-1] != '\n' ) {
      result[readLen++] = '\n';
      len++;
    } else {
      result.truncate( len );
    }
  }

  if ( readLen < len ) {
    QString msg = i18np( "Could only read 1 byte of %2.",
                         "Could only read %1 bytes of %2.",
                         readLen, len );
    msgDialog( msg );
    result.truncate( readLen );
  }

  return result;
}

//-----------------------------------------------------------------------------
bool kByteArrayToFile( const QByteArray &aBuffer, const QString &aFileName,
                       bool aAskIfExists, bool aBackup, bool aVerbose )
{
  // TODO: use KSaveFile
  QFile file( aFileName );

  //assert(aFileName!=0);
  if( aFileName.isEmpty() ) {
    return false;
  }

  if ( file.exists() ) {
    if ( aAskIfExists ) {
      QString str;
      str = i18n( "File %1 exists.\nDo you want to replace it?", aFileName );
      const int rc =
        KMessageBox::warningContinueCancel( 0, str, i18n( "Save to File" ),
                                            KGuiItem( i18n( "&Replace" ) ) );
      if ( rc != KMessageBox::Continue ) {
        return false;
      }
    }
    if ( aBackup ) {
      // make a backup copy
      // TODO: use KSaveFile::backupFile()
      QString bakName = aFileName;
      bakName += '~';
      QFile::remove(bakName);
      if ( !QDir::current().rename( aFileName, bakName ) ) {
	// failed to rename file
        if ( !aVerbose ) {
          return false;
        }
        const int rc =
          KMessageBox::warningContinueCancel(
            0,
            i18n( "Failed to make a backup copy of %1.\nContinue anyway?", aFileName ),
            i18n( "Save to File" ), KStandardGuiItem::save() );

        if ( rc != KMessageBox::Continue ) {
          return false;
        }
      }
    }
  }

  if ( !file.open( QIODevice::Unbuffered|QIODevice::WriteOnly|QIODevice::Truncate ) ) {
    if ( aVerbose ) {
      switch( file.error() ) {
      case QFile::WriteError:
        msgDialog( i18n( "Could not write to file:\n%1", aFileName ) );
        break;
      case QFile::OpenError:
        msgDialog( i18n( "Could not open file for writing:\n%1", aFileName ) );
        break;
      default:
        msgDialog( i18n( "Error while writing file:\n%1", aFileName ) );
      }
    }
    return false;
  }

  const int writeLen = file.write( aBuffer.data(), aBuffer.size() );

  if ( writeLen < 0 ) {
    if ( aVerbose ) {
      msgDialog( i18n( "Could not write to file:\n%1", aFileName ) );
    }
    return false;
  } else if ( writeLen < aBuffer.size() ) {
    QString msg = i18np( "Could only write 1 byte of %2.",
                         "Could only write %1 bytes of %2.",
                         writeLen, aBuffer.size() );
    if ( aVerbose ) {
      msgDialog( msg );
    }
    return false;
  }

  return true;
}

QString checkAndCorrectPermissionsIfPossible( const QString &toCheck,
                                              const bool recursive,
                                              const bool wantItReadable,
                                              const bool wantItWritable )
{
  // First we have to find out which type the toCheck is. This can be
  // a directory (follow if recursive) or a file (check permissions).
  // Symlinks are followed as expected.
  QFileInfo fiToCheck(toCheck);
  fiToCheck.setCaching(false);
  QByteArray toCheckEnc = QFile::encodeName( toCheck );
  QString error;
  KDE_struct_stat statbuffer;

  if ( !fiToCheck.exists() ) {
    error.append( i18n( "%1 does not exist", toCheck ) + '\n' );
  }

  // check the access bit of a folder.
  if ( fiToCheck.isDir() ) {
    if ( KDE_stat( toCheckEnc,&statbuffer ) != 0 ) {
      kDebug() << "wantItA: Can't read perms of" << toCheck;
    }
    QDir g( toCheck );
    if ( !g.isReadable() ) {
      if ( chmod( toCheckEnc, statbuffer.st_mode + S_IXUSR ) != 0 ) {
        error.append( i18n( "%1 is not accessible and that is "
                            "unchangeable.", toCheck ) + '\n' );
      } else {
        kDebug() << "Changed access bit for" << toCheck;
      }
    }
  }

  // For each file or folder  we can check if the file is readable
  // and writable, as requested.
  if ( fiToCheck.isFile() || fiToCheck.isDir() ) {

    if ( !fiToCheck.isReadable() && wantItReadable ) {
      // Get the current permissions. No need to do anything with an
      // error, it will het added to errors anyhow, later on.
      if ( KDE_stat( toCheckEnc,&statbuffer ) != 0 ) {
        kDebug() << "wantItR: Can't read perms of" << toCheck;
      }

      // Lets try changing it.
      if ( chmod( toCheckEnc, statbuffer.st_mode + S_IRUSR ) != 0 ) {
        error.append( i18n( "%1 is not readable and that is unchangeable.",
                            toCheck ) + '\n' );
      } else {
        kDebug() << "Changed the read bit for" << toCheck;
      }
    }

    if ( !fiToCheck.isWritable() && wantItWritable ) {
      // Gets the current persmissions. Needed because it can be changed
      // curing previous operation.
      if ( KDE_stat( toCheckEnc,&statbuffer ) != 0 ) {
        kDebug() << "wantItW: Can't read perms of" << toCheck;
      }

      // Lets try changing it.
      if ( chmod ( toCheckEnc, statbuffer.st_mode + S_IWUSR ) != 0 ) {
        error.append( i18n( "%1 is not writable and that is unchangeable.", toCheck ) + '\n' );
      } else {
        kDebug() << "Changed the write bit for" << toCheck;
      }
    }
  }

  // If it is a folder and recursive is true, then we check the contents of
  // the folder.
  if ( fiToCheck.isDir() && recursive ){
    QDir g( toCheck );
    // First check if the folder is readable for us. If not, we get
    // some ugly crashes.
    if ( !g.isReadable() ){
      error.append( i18n( "Folder %1 is inaccessible.", toCheck ) + '\n' );
    } else {
      foreach ( const QFileInfo &fi, g.entryInfoList() ) {
        QString newToCheck = toCheck + '/' + fi.fileName();
        QFileInfo fiNewToCheck(newToCheck);
        if ( fi.fileName() != "." && fi.fileName() != ".." ) {
          error.append (
            checkAndCorrectPermissionsIfPossible( newToCheck, recursive,
                                                  wantItReadable, wantItWritable ) );
        }
      }
    }
  }
  return error;
}

bool checkAndCorrectPermissionsIfPossibleWithErrorHandling( QWidget *parent,
                                                            const QString &toCheck,
                                                            const bool recursive,
                                                            const bool wantItReadable,
                                                            const bool wantItWritable )
{
  QString error =
    checkAndCorrectPermissionsIfPossible( toCheck, recursive, wantItReadable, wantItWritable );

  // There is no KMessageBox with Retry, Cancel and Details.
  // so, I can't provide a functionality to recheck. So it now
  // it is just a warning.
  if ( !error.isEmpty() ) {
    kDebug() << "checkPermissions found:" << error;
    KMessageBox::detailedSorry( parent,
                                i18n( "Some files or folders do not have the "
                                      "necessary permissions, please correct "
                                      "them manually." ),
                                error, i18n( "Permissions Check" ), false );
    return false;
  } else {
    return true;
  }
}

bool removeDirAndContentsRecursively( const QString & path )
{
  bool success = true;

  QDir d;
  d.setPath( path );
  d.setFilter( QDir::Files | QDir::Dirs | QDir::Hidden | QDir::NoSymLinks );

  QFileInfoList list = d.entryInfoList();

  Q_FOREACH( const QFileInfo &fi, list ) {
    if ( fi.isDir() ) {
      if ( fi.fileName() != "." && fi.fileName() != ".." ) {
        success = success && removeDirAndContentsRecursively( fi.absoluteFilePath() );
      }
    } else {
      success = success && d.remove( fi.absoluteFilePath() );
    }
  }

  if ( success ) {
    success = success && d.rmdir( path ); // nuke ourselves, we should be empty now
  }
  return success;
}

}
