###########################################################################
#
# dbutil::tdb -- utility functions for writing to tdb databases. Should be
#                hauntingly similar to GDBM utility functions.
#
# A component of the Greenstone digital library software
# from the New Zealand Digital Library Project at the
# University of Waikato, New Zealand.
#
# Copyright (C) 2011
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# 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.
#
###########################################################################

package dbutil::tdb;

# Pragma
use strict;

# Libraries/Modules
use dbutil::gdbmtxtgz;

# -----------------------------------------------------------------------------
#   TDB IMPLEMENTATION
# -----------------------------------------------------------------------------

# /**
#  */
sub get_tdb_executable
{
  my $program = shift(@_);
  my $program_exe = &util::filename_cat($program . &util::get_os_exe());
  if (!-x $program_exe)
  {
    die('Fatal Error! File doesn\'t exist or isn\'t executable: ' . $program_exe);
  }
  return $program_exe;
}
# /** get_tdb_executable() **/

# /**
#  */
sub open_infodb_write_handle
{
  my $infodb_file_path = shift(@_);
  my $opt_append = shift(@_);

  my $txt2tdb_exe = &dbutil::tdb::get_tdb_executable('txt2tdb');

  my $cmd = "\"$txt2tdb_exe\"";
  if ((defined $opt_append) && ($opt_append eq "append"))
  {
    $cmd .= " -append";
  }
  $cmd .= " \"$infodb_file_path\"";

  # we're going to pipe the key value pairs, in the appropriate format, from
  # within the buildproc, so we create a piped handle here
  my $infodb_file_handle = undef;
  if(!open($infodb_file_handle, "| $cmd"))
  {
    print STDERR "Error: Failed to open pipe to $cmd\n";
    print STDERR "       $!\n";
    return undef;
  }

  binmode($infodb_file_handle,":utf8");

  return $infodb_file_handle;
}
# /** open_infodb_write_handle() **/

# /**
#  */
sub close_infodb_write_handle
{
  my $infodb_handle = shift(@_);
  close($infodb_handle);
}
# /** close_infodb_write_handle() **/

# /**
#  */
sub get_infodb_file_path
{
  my $collection_name = shift(@_);
  my $infodb_directory_path = shift(@_);

  my $infodb_file_extension = ".tdb";
  my $infodb_file_name = &util::get_dirsep_tail($collection_name) . $infodb_file_extension;

  return &util::filename_cat($infodb_directory_path, $infodb_file_name);
}
# /** get_infodb_file_path() **/

# /**
#  */
sub read_infodb_file
{
  my $infodb_file_path = shift(@_);
  my $infodb_map = shift(@_);

  my $tdb2txt_exe = &dbutil::tdb::get_tdb_executable('tdb2txt');

  if (!open (PIPEIN, "\"$tdb2txt_exe\" \"$infodb_file_path\" |"))
  {
    print STDERR 'Error: Failed to open pipe to ' . $tdb2txt_exe . "\n";
    print STDERR "       $!\n";
    return undef;
  }

  binmode(PIPEIN,":utf8");

  my $infodb_line = "";
  my $infodb_key = "";
  my $infodb_value = "";
  while (defined ($infodb_line = <PIPEIN>))
  {
    if ($infodb_line =~ /^\[([^\]]+)\]$/)
    {
      $infodb_key = $1;
    }
    elsif ($infodb_line =~ /^-{70}$/)
    {
      $infodb_map->{$infodb_key} = $infodb_value;
      $infodb_key = "";
      $infodb_value = "";
    }
    else
    {
      $infodb_value .= $infodb_line;
    }
  }

  close (PIPEIN);
}
# /** read_infodb_file() **/

# /**
#  */
sub read_infodb_keys
{
  my $infodb_file_path = shift(@_);
  my $infodb_map = shift(@_);

  my $tdbkeys_exe = &dbutil::tdb::get_tdb_executable('tdbkeys');

  if (!open (PIPEIN, "\"tdbkeys_exe\" \"$infodb_file_path\" |"))
  {
    die "couldn't open pipe from gdbmkeys \$infodb_file_path\"\n$!\n";
  }

  binmode(PIPEIN,":utf8");

  my $infodb_line = "";
  my $infodb_key = "";
  my $infodb_value = "";
  while (defined ($infodb_line = <PIPEIN>))
  {
    # remove end of line
    chomp $infodb_line;

    $infodb_map->{$infodb_line} = 1;
  }

  close (PIPEIN);
}
# /** read_infodb_keys() **/

# /**
#  */
sub write_infodb_entry
{
  # With infodb_handle already set up, works the same as gdbm and gdbm_txtgz
  # versions
  &dbutil::gdbmtxtgz::write_infodb_entry(@_);
}
# /** write_infodb_entry() **/

# /**
#  */
sub write_infodb_rawentry
{
  # With infodb_handle already set up, works the same as gdbm and gdbm_txtgz
  # versions
  &dbutil::gdbmtxtgz::write_infodb_rawentry(@_);
}
# /** write_infodb_rawentry() **/

# /**
#  */
sub set_infodb_entry
{
  my $infodb_file_path = shift(@_);
  my $infodb_key = shift(@_);
  my $infodb_map = shift(@_);

  # Protect metadata values that go inside quotes for tdbset
  foreach my $k (keys %$infodb_map)
  {
    my @escaped_v = ();
    foreach my $v (@{$infodb_map->{$k}})
    {
      if ($k eq "contains")
      {
        # protect quotes in ".2;".3 etc
        $v =~ s/\"/\\\"/g;
        push(@escaped_v, $v);
      }
      else
      {
        my $ev = &ghtml::unescape_html($v);
        $ev =~ s/\"/\\\"/g;
        push(@escaped_v, $ev);
      }
    }
    $infodb_map->{$k} = \@escaped_v;
  }

  # Generate the record string
  my $serialized_infodb_map = &dbutil::convert_infodb_hash_to_string($infodb_map);
  ## print STDERR "**** ser dr\n$serialized_infodb_map\n\n\n";

  # Store it into GDBM
  my $tdbset_exe = &dbutil::tdb::get_tdb_executable('tdbset');
  my $cmd = "\"tdbset_exe\" \"$infodb_file_path\" \"$infodb_key\" \"$serialized_infodb_map\"";
  my $status = system($cmd);

  return $status;
}
# /** set_infodb_entry() **/

# /**
#  */
sub delete_infodb_entry
{
  # With infodb_handle already set up, works the same as gdbm and gdbm_txtgz
  # versions
  &dbutil::gdbmtxtgz::delete_infodb_entry(@_);
}
# /** delete_infodb_entry() **/

1;
