// Copyright (c) 2012-2014 Konstantin Isakov <ikm@zbackup.org> and ZBackup contributors, see CONTRIBUTORS
// Part of ZBackup. Licensed under GNU GPLv2 or later + OpenSSL, see LICENSE

#include "zbackup.hh"
#include "backup_creator.hh"
#include "backup_file.hh"
#include "backup_restorer.hh"
#include "debug.hh"
#include "sha256.hh"
#include "backup_collector.hh"
#include "config.hh"
#include "utils.hh"

using std::vector;
using std::bitset;
using std::iterator;

ZBackup::ZBackup( string const & storageDir, string const & password,
                  Config & configIn ):
  ZBackupBase( storageDir, password, configIn ),
  chunkStorageWriter( config, encryptionkey, tmpMgr, chunkIndex,
                      getBundlesPath(), getIndexPath(), config.runtime.threads )
{
}

void ZBackup::backupFromStdin( string const & outputFileName )
{
  if ( isatty( fileno( stdin ) ) )
    throw exWontReadFromTerminal();

  if ( File::exists( outputFileName ) )
    throw exWontOverwrite( outputFileName );

  Sha256 sha256;
  BackupCreator backupCreator( config, chunkIndex, chunkStorageWriter );

  time_t startTime = time( 0 );
  uint64_t totalDataSize = 0;

  for ( ; ; )
  {
    size_t toRead = backupCreator.getInputBufferSize();
//    dPrintf( "Reading up to %u bytes from stdin\n", toRead );

    void * inputBuffer = backupCreator.getInputBuffer();
    size_t rd = fread( inputBuffer, 1, toRead, stdin );

    if ( !rd )
    {
      if ( feof( stdin ) )
      {
        dPrintf( "No more input on stdin\n" );
        break;
      }
      else
        throw exStdinError();
    }

    sha256.add( inputBuffer, rd );

    backupCreator.handleMoreData( rd );

    totalDataSize += rd;
  }

  // Finish up with the creator
  backupCreator.finish();

  string serialized;
  backupCreator.getBackupData( serialized );

  BackupInfo info;

  info.set_sha256( sha256.finish() );
  info.set_size( totalDataSize );

  // Shrink the serialized data iteratively until it wouldn't shrink anymore
  for ( ; ; )
  {
    BackupCreator backupCreator( config, chunkIndex, chunkStorageWriter );
    char const * ptr = serialized.data();
    size_t left = serialized.size();
    while( left )
    {
      size_t bufferSize = backupCreator.getInputBufferSize();
      size_t toCopy = bufferSize > left ? left : bufferSize;

      memcpy( backupCreator.getInputBuffer(), ptr, toCopy );
      backupCreator.handleMoreData( toCopy );
      ptr += toCopy;
      left -= toCopy;
    }

    backupCreator.finish();

    string newGen;
    backupCreator.getBackupData( newGen );

    if ( newGen.size() < serialized.size() )
    {
      serialized.swap( newGen );
      info.set_iterations( info.iterations() + 1 );
    }
    else
      break;
  }

  dPrintf( "Iterations: %u\n", info.iterations() );

  info.mutable_backup_data()->swap( serialized );

  info.set_time( time( 0 ) - startTime );

  // Commit the bundles to the disk before creating the final output file
  chunkStorageWriter.commit();

  // Now save the resulting BackupInfo

  sptr< TemporaryFile > tmpFile = tmpMgr.makeTemporaryFile();
  BackupFile::save( tmpFile->getFileName(), encryptionkey, info );
  tmpFile->moveOverTo( outputFileName );
}

ZRestore::ZRestore( string const & storageDir, string const & password,
                    Config & configIn ):
  ZBackupBase( storageDir, password, configIn ),
  chunkStorageReader( config, encryptionkey, chunkIndex, getBundlesPath(),
                      config.runtime.cacheSize )
{
}

void ZRestore::restoreToStdin( string const & inputFileName )
{
  if ( isatty( fileno( stdout ) ) )
    throw exWontWriteToTerminal();

  BackupInfo backupInfo;

  BackupFile::load( inputFileName, encryptionkey, backupInfo );

  string backupData;

  // Perform the iterations needed to get to the actual user backup data
  BackupRestorer::restoreIterations( chunkStorageReader, backupInfo, backupData, NULL );

  struct StdoutWriter: public DataSink
  {
    Sha256 sha256;

    virtual void saveData( void const * data, size_t size )
    {
      sha256.add( data, size );
      if ( fwrite( data, size, 1, stdout ) != 1 )
        throw exStdoutError();
    }
  } stdoutWriter;

  BackupRestorer::restore( chunkStorageReader, backupData, &stdoutWriter, NULL );

  if ( stdoutWriter.sha256.finish() != backupInfo.sha256() )
    throw exChecksumError();
}

ZExchange::ZExchange( string const & srcStorageDir, string const & srcPassword,
                      string const & dstStorageDir, string const & dstPassword,
                      Config & configIn ):
  srcZBackupBase( srcStorageDir, srcPassword, configIn, true ),
  dstZBackupBase( dstStorageDir, dstPassword, configIn, true ),
  config( configIn )
{
}

void ZExchange::exchange()
{
  vector< BackupExchanger::PendingExchangeRename > pendingExchangeRenames;

  if ( config.runtime.exchange.test( BackupExchanger::bundles ) )
  {
    verbosePrintf( "Searching for bundles...\n" );

    vector< string > bundles = BackupExchanger::recreateDirectories(
        srcZBackupBase.getBundlesPath(), dstZBackupBase.getBundlesPath() );

    for ( std::vector< string >::iterator it = bundles.begin(); it != bundles.end(); ++it )
    {
      verbosePrintf( "Processing bundle file %s... ", it->c_str() );
      string outputFileName ( Dir::addPath( dstZBackupBase.getBundlesPath(), *it ) );
      if ( !File::exists( outputFileName ) )
      {
        sptr< Bundle::Reader > reader = new Bundle::Reader( Dir::addPath (
              srcZBackupBase.getBundlesPath(), *it ), srcZBackupBase.encryptionkey, true );
        sptr< Bundle::Creator > creator = new Bundle::Creator;
        sptr< TemporaryFile > bundleTempFile = dstZBackupBase.tmpMgr.makeTemporaryFile();
        creator->write( bundleTempFile->getFileName(), dstZBackupBase.encryptionkey, *reader );

        if ( creator.get() && reader.get() )
        {
          creator.reset();
          reader.reset();
          pendingExchangeRenames.push_back( BackupExchanger::PendingExchangeRename(
                bundleTempFile, outputFileName ) );
          verbosePrintf( "done.\n" );
        }
      }
      else
      {
        verbosePrintf( "file exists - skipped.\n" );
      }
    }

    verbosePrintf( "Bundle exchange completed.\n" );
  }

  if ( config.runtime.exchange.test( BackupExchanger::index ) )
  {
    verbosePrintf( "Searching for indicies...\n" );
    vector< string > indicies = BackupExchanger::recreateDirectories(
        srcZBackupBase.getIndexPath(), dstZBackupBase.getIndexPath() );

    for ( std::vector< string >::iterator it = indicies.begin(); it != indicies.end(); ++it )
    {
      verbosePrintf( "Processing index file %s... ", it->c_str() );
      string outputFileName ( Dir::addPath( dstZBackupBase.getIndexPath(), *it ) );
      if ( !File::exists( outputFileName ) )
      {
        sptr< IndexFile::Reader > reader = new IndexFile::Reader( srcZBackupBase.encryptionkey,
                                 Dir::addPath( srcZBackupBase.getIndexPath(), *it ) );
        sptr< TemporaryFile > indexTempFile = dstZBackupBase.tmpMgr.makeTemporaryFile();
        sptr< IndexFile::Writer > writer = new IndexFile::Writer( dstZBackupBase.encryptionkey,
            indexTempFile->getFileName() );

        BundleInfo bundleInfo;
        Bundle::Id bundleId;
        while( reader->readNextRecord( bundleInfo, bundleId ) )
        {
          writer->add( bundleInfo, bundleId );
        }

        if ( writer.get() && reader.get() )
        {
          writer.reset();
          reader.reset();
          pendingExchangeRenames.push_back( BackupExchanger::PendingExchangeRename(
                indexTempFile, outputFileName ) );
          verbosePrintf( "done.\n" );
        }
      }
      else
      {
        verbosePrintf( "file exists - skipped.\n" );
      }
    }

    verbosePrintf( "Index exchange completed.\n" );
  }

  if ( config.runtime.exchange.test( BackupExchanger::backups ) )
  {
    BackupInfo backupInfo;

    verbosePrintf( "Searching for backups...\n" );
    vector< string > backups = BackupExchanger::recreateDirectories(
        srcZBackupBase.getBackupsPath(), dstZBackupBase.getBackupsPath() );

    for ( std::vector< string >::iterator it = backups.begin(); it != backups.end(); ++it )
    {
      verbosePrintf( "Processing backup file %s... ", it->c_str() );
      string outputFileName ( Dir::addPath( dstZBackupBase.getBackupsPath(), *it ) );
      if ( !File::exists( outputFileName ) )
      {
        BackupFile::load( Dir::addPath( srcZBackupBase.getBackupsPath(), *it ),
            srcZBackupBase.encryptionkey, backupInfo );
        sptr< TemporaryFile > tmpFile = dstZBackupBase.tmpMgr.makeTemporaryFile();
        BackupFile::save( tmpFile->getFileName(), dstZBackupBase.encryptionkey,
            backupInfo );
        pendingExchangeRenames.push_back( BackupExchanger::PendingExchangeRename(
                tmpFile, outputFileName ) );
        verbosePrintf( "done.\n" );
      }
      else
      {
        verbosePrintf( "file exists - skipped.\n" );
      }
    }

    verbosePrintf( "Backup exchange completed.\n" );
  }

  if ( pendingExchangeRenames.size() > 0 )
  {
    verbosePrintf( "Moving files from temp directory to appropriate places... " );
    for ( size_t x = pendingExchangeRenames.size(); x--; )
    {
      BackupExchanger::PendingExchangeRename & r = pendingExchangeRenames[ x ];
      r.first->moveOverTo( r.second );
      if ( r.first.get() )
      {
        r.first.reset();
      }
    }
    pendingExchangeRenames.clear();
    verbosePrintf( "done.\n" );
  }
}

DEF_EX( exSpecifyTwoKeys, "Specify password flag (--non-encrypted or --password-file)"
  " for import/export/passwd operation twice (first for source and second for destination)", std::exception )
DEF_EX( exNonEncryptedWithKey, "--non-encrypted and --password-file are incompatible", std::exception )
DEF_EX( exSpecifyEncryptionOptions, "Specify either --password-file or --non-encrypted", std::exception )

int main( int argc, char *argv[] )
{
  try
  {
    bool printHelp = false;
    vector< char const * > args;
    vector< string > passwords;
    Config config;

    for( int x = 1; x < argc; ++x )
    {
      char const * option;
      string deprecated;
      Config::OptionType optionType = Config::Runtime;

      if ( strcmp( argv[ x ], "--password-file" ) == 0 && x + 1 < argc )
      {
        // Read the password
        char const * passwordFile = argv[ x + 1 ];
        string passwordData;
        if ( passwordFile )
        {
          File f( passwordFile, File::ReadOnly );
          passwordData.resize( f.size() );
          f.read( &passwordData[ 0 ], passwordData.size() );

          // If the password ends with \n, remove that last \n. Many editors will
          // add \n there even if a user doesn't want them to
          if ( !passwordData.empty() &&
               passwordData[ passwordData.size() - 1 ] == '\n' )
            passwordData.resize( passwordData.size() - 1 );
          passwords.push_back( passwordData );
        }
        ++x;
      }
      else
      if ( strcmp( argv[ x ], "--non-encrypted" ) == 0 )
      {
          passwords.push_back( "" );
      }
      else
      if ( strcmp( argv[ x ], "--silent" ) == 0 )
        verboseMode = false;
      else
      if ( strcmp( argv[ x ], "--exchange" ) == 0 && x + 1 < argc )
      {
        fprintf( stderr, "%s is deprecated, use -O exchange instead\n", argv[ x ] );
        deprecated = argv[ x ] + 2;//; + "=" + argv[ x + 1 ];
        deprecated += "=";
        deprecated += argv[ x + 1 ];
        option = deprecated.c_str();
        goto parse_option;
      }
      else
      if ( strcmp( argv[ x ], "--threads" ) == 0 && x + 1 < argc )
      {
        fprintf( stderr, "%s is deprecated, use -O threads instead\n", argv[ x ] );
        deprecated = argv[ x ] + 2;
        deprecated += "=";
        deprecated += argv[ x + 1 ];
        option = deprecated.c_str();
        goto parse_option;
      }
      else
      if ( strcmp( argv[ x ], "--cache-size" ) == 0 && x + 1 < argc )
      {
        fprintf( stderr, "%s is deprecated, use -O cache-size instead\n", argv[ x ] );
        size_t cacheSizeMb;
        char suffix[ 16 ];
        int n;
        if ( sscanf( argv[ x + 1 ], "%zu %15s %n",
              &cacheSizeMb, suffix, &n ) == 2 && !argv[ x + 1][ n ] )

        deprecated = argv[ x ] + 2;
        deprecated += "=" + Utils::numberToString( cacheSizeMb ) + "MiB";
        option = deprecated.c_str();
        goto parse_option;
      }
      else
      if ( strcmp( argv[ x ], "--compression" ) == 0 && x + 1 < argc )
      {
        fprintf( stderr, "%s is deprecated, use -o bundle.compression_method instead\n", argv[ x ] );
        deprecated = argv[ x ] + 2;
        deprecated += "=";
        deprecated += argv[ x + 1 ];
        option = deprecated.c_str();
        optionType = Config::Storable;
        goto parse_option;
      }
      else
      if ( strcmp( argv[ x ], "--help" ) == 0 || strcmp( argv[ x ], "-h" ) == 0 )
      {
        printHelp = true;
      }
      else
      if ( ( strcmp( argv[ x ], "-o" ) == 0 || strcmp( argv[ x ], "-O" ) == 0 )
          && x + 1 < argc )
      {
        option = argv[ x + 1 ];
        if ( option )
        {
          if ( strcmp( argv[ x ], "-O" ) == 0 )
            optionType = Config::Runtime;
          else
          if ( strcmp( argv[ x ], "-o" ) == 0 )
            optionType = Config::Storable;

          if ( strcmp( option, "help" ) == 0 )
          {
            Config::showHelp( optionType );
            return EXIT_SUCCESS;
          }
          else
          {
parse_option:
            if ( !config.parseOrValidate( option, optionType ) )
              goto invalid_option;
          }
        }
        else
        {
invalid_option:
          fprintf( stderr, "Invalid option specified: %s\n",
                   option );
          return EXIT_FAILURE;
        }
        ++x;
      }
      else
        args.push_back( argv[ x ] );
    }

    if ( args.size() < 1 || printHelp )
    {
      fprintf( stderr,
"ZBackup, a versatile deduplicating backup tool, version 1.4\n"
"Copyright (c) 2012-2014 Konstantin Isakov <ikm@zbackup.org> and\n"
"ZBackup contributors\n"
"Comes with no warranty. Licensed under GNU GPLv2 or later + OpenSSL.\n"
"Visit the project's home page at http://zbackup.org/\n\n"

"Usage: %s [flags] <command [action]> [command args]\n"
"  Flags: --non-encrypted|--password-file <file>\n"
"          password flag should be specified twice if import/export/passwd\n"
"          command specified\n"
"         --silent (default is verbose)\n"
"         --help|-h show this message\n"
"         -O <Option[=Value]> (overrides runtime configuration,\n"
"          can be specified multiple times,\n"
"          for detailed runtime options overview run with -O help)\n"
"         -o <Option[=Value]> (overrides storable repository\n"
"          configuration, can be specified multiple times,\n"
"          for detailed storable options overview run with -o help)\n"
"  Commands:\n"
"    init <storage path> - initializes new storage\n"
"    backup <backup file name> - performs a backup from stdin\n"
"    restore <backup file name> - restores a backup to stdout\n"
"    export <source storage path> <destination storage path> -\n"
"            performs export from source to destination storage\n"
"    import <source storage path> <destination storage path> -\n"
"            performs import from source to destination storage\n"
"    gc <storage path> - performs chunk garbage collection\n"
"    passwd <storage path> - changes repo info file passphrase\n"
//"    info <storage path> - shows repo information\n"
"    config [show|edit|set] <storage path> - performs configuration\n"
"            manipulations (default is show)\n"
"  For export/import storage path must be a valid (initialized) storage\n"
"", *argv );
      return EXIT_FAILURE;
    }

    if ( passwords.size() > 1 &&
        ( ( passwords[ 0 ].empty() && !passwords[ 1 ].empty() ) ||
          ( !passwords[ 0 ].empty() && passwords[ 1 ].empty() ) ) &&
        ( strcmp( args[ 0 ], "export" ) != 0 &&
	  strcmp( args[ 0 ], "import" ) != 0 &&
	  strcmp( args[ 0 ], "passwd" )	) )
      throw exNonEncryptedWithKey();
    else
      if ( passwords.size() != 2 &&
          ( strcmp( args[ 0 ], "export" ) == 0 ||
	    strcmp( args[ 0 ], "import" ) == 0 ||
	    strcmp( args[ 0 ], "passwd" ) == 0 ) )
        throw exSpecifyTwoKeys();
    else
      if ( passwords.size() < 1 )
        throw exSpecifyEncryptionOptions();

    if ( strcmp( args[ 0 ], "init" ) == 0 )
    {
      // Perform the init
      if ( args.size() != 2 )
      {
        fprintf( stderr, "Usage: %s %s <storage path>\n", *argv, args[ 0 ] );
        return EXIT_FAILURE;
      }

      ZBackup::initStorage( args[ 1 ], passwords[ 0 ], !passwords[ 0 ].empty() );
    }
    else
    if ( strcmp( args[ 0 ], "backup" ) == 0 )
    {
      // Perform the backup
      if ( args.size() != 2 )
      {
        fprintf( stderr, "Usage: %s %s <backup file name>\n",
                 *argv, args[ 0 ] );
        return EXIT_FAILURE;
      }
      ZBackup zb( ZBackup::deriveStorageDirFromBackupsFile( args[ 1 ] ),
                  passwords[ 0 ], config );
      zb.backupFromStdin( args[ 1 ] );
    }
    else
    if ( strcmp( args[ 0 ], "restore" ) == 0 )
    {
      // Perform the restore
      if ( args.size() != 2 )
      {
        fprintf( stderr, "Usage: %s %s <backup file name>\n",
                 *argv , args[ 0 ] );
        return EXIT_FAILURE;
      }
      ZRestore zr( ZRestore::deriveStorageDirFromBackupsFile( args[ 1 ] ),
                   passwords[ 0 ], config );
      zr.restoreToStdin( args[ 1 ] );
    }
    else
    if ( strcmp( args[ 0 ], "export" ) == 0 || strcmp( args[ 0 ], "import" ) == 0 )
    {
      if ( args.size() != 3 )
      {
        fprintf( stderr, "Usage: %s %s <source storage path> <destination storage path>\n",
                 *argv, args[ 0 ] );
        return EXIT_FAILURE;
      }
      if ( config.runtime.exchange.none() )
      {
        fprintf( stderr, "Specify any --exchange flag\n" );
        return EXIT_FAILURE;
      }

      int src, dst;
      if ( strcmp( args[ 0 ], "export" ) == 0 )
      {
        src = 1;
        dst = 2;
      }
      else
      if ( strcmp( args[ 0 ], "import" ) == 0 )
      {
        src = 2;
        dst = 1;
      }
      dPrintf( "%s src: %s\n", args[ 0 ], args[ src ] );
      dPrintf( "%s dst: %s\n", args[ 0 ], args[ dst ] );

      ZExchange ze( ZBackupBase::deriveStorageDirFromBackupsFile( args[ src ], true ),
                    passwords[ src - 1 ],
                    ZBackupBase::deriveStorageDirFromBackupsFile( args[ dst ], true ),
                    passwords[ dst - 1 ],
                    config );
      ze.exchange();
    }
    else
    if ( strcmp( args[ 0 ], "gc" ) == 0 )
    {
      // Perform the restore
      if ( args.size() != 2 )
      {
        fprintf( stderr, "Usage: %s %s <storage path>\n",
                 *argv, args[ 0 ] );
        return EXIT_FAILURE;
      }
      ZCollector zc( args[ 1 ], passwords[ 0 ], config );
      zc.gc();
    }
    else
    if ( strcmp( args[ 0 ], "passwd" ) == 0 )
    {
      // Perform the password change
      if ( args.size() != 2 )
      {
        fprintf( stderr, "Usage: %s %s <storage path>\n",
                 *argv, args[ 0 ] );
        return EXIT_FAILURE;
      }

      ZBackupBase zbb( ZBackupBase::deriveStorageDirFromBackupsFile( args[ 1 ], true ),
          passwords[ 0 ], true );

      if ( passwords[ 0 ].empty() != passwords[ 1 ].empty() )
      {
        fprintf( stderr,
"Changing repo encryption type (non-encrypted to encrypted and vice versa) is possible "
"only via import/export operations.\n"
"Current repo type: %s.\n", zbb.encryptionkey.hasKey() ? "encrypted" : "non-encrypted" );
        return EXIT_FAILURE;
      }
      zbb.setPassword( passwords[ 1 ] );
    }
    else
    if ( strcmp( args[ 0 ], "info" ) == 0 )
    {
      // Show repo info
      if ( args.size() != 2 )
      {
        fprintf( stderr, "Usage: %s %s <storage path>\n",
                 *argv, args[ 0 ] );
        return EXIT_FAILURE;
      }

      // TODO: implementation in ZBackupBase
      ZBackupBase zbb( ZBackupBase::deriveStorageDirFromBackupsFile( args[ 1 ], true ),
          passwords[ 0 ], true );
      fprintf( stderr, "NOT IMPLEMENTED YET!\n" );
      return EXIT_FAILURE;
    }
    else
    if ( strcmp( args[ 0 ], "config" ) == 0 )
    {
      if ( args.size() < 2 || args.size() > 3 )
      {
        fprintf( stderr, "Usage: %s %s [show|edit|set] <storage path>\n",
                 *argv, args[ 0 ] );
        return EXIT_FAILURE;
      }

      int fieldStorage = 1;
      int fieldAction = 2;

      if ( args.size() == 3 )
      {
        fieldStorage = 2;
        fieldAction = 1;
      }

      if ( args.size() > 2 && strcmp( args[ fieldAction ], "edit" ) == 0 )
      {
        ZBackupBase zbb( ZBackupBase::deriveStorageDirFromBackupsFile( args[ fieldStorage ], true ),
            passwords[ 0 ], true );
        if ( zbb.editConfigInteractively() )
          zbb.saveExtendedStorageInfo();
      }
      else
      if ( args.size() > 2 && strcmp( args[ fieldAction ], "set" ) == 0 )
      {
        ZBackupBase zbb( ZBackupBase::deriveStorageDirFromBackupsFile( args[ fieldStorage ], true ),
            passwords[ 0 ], config, true );
        zbb.config.show();
        zbb.saveExtendedStorageInfo();
      }
      else
      {
        ZBackupBase zbb( ZBackupBase::deriveStorageDirFromBackupsFile( args[ fieldStorage ], true ),
            passwords[ 0 ], true );
        zbb.config.show();
      }
    }
    else
    {
      fprintf( stderr, "Error: unknown command line option: %s\n", args[ 0 ] );
      return EXIT_FAILURE;
    }
  }
  catch( std::exception & e )
  {
    fprintf( stderr, "%s\n", e.what() );
    return EXIT_FAILURE;
  }
  return EXIT_SUCCESS;
}