#!/usr/bin/perl
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use strict;
use warnings;
use 5.010;

# fix lib paths, some may be relative
BEGIN { # BEGIN RT CMD BOILERPLATE
    require File::Spec;
    require Cwd;
    my @libs = ("lib", "local/lib");
    my $bin_path;

    for my $lib (@libs) {
        unless ( File::Spec->file_name_is_absolute($lib) ) {
            $bin_path ||= ( File::Spec->splitpath(Cwd::abs_path(__FILE__)) )[1];
            $lib = File::Spec->catfile( $bin_path, File::Spec->updir, $lib );
        }
        unshift @INC, $lib;
    }

}

use RT -init;
use RT::Interface::CLI ();
use HTML::Entities;

use Getopt::Long qw(GetOptions);
my %OPT = ( memory => '2M', limit => 0 );
GetOptions( \%OPT,
    "help|h!",
    "debug!",
    "quiet!",

    "all!",
    "limit=i",

    "memory=s",
);
$OPT{limit} ||= 200;

RT::Interface::CLI->ShowHelp if $OPT{help};

use Fcntl ':flock';
if ( !flock main::DATA, LOCK_EX | LOCK_NB ) {
    if ( $OPT{quiet} ) {
        RT::Logger->info("$0 is already running; aborting silently, as requested");
        exit;
    }
    else {
        print STDERR "$0 is already running\n";
        exit 1;
    }
}

my $db_type = RT->Config->Get('DatabaseType');
my $fts_config = $ENV{RT_FTS_CONFIG} ? JSON::from_json($ENV{RT_FTS_CONFIG})
    : RT->Config->Get('FullTextSearch') || {};
unless ( $fts_config->{'Enable'} ) {
    print STDERR <<EOT;

Full text search is disabled in your RT configuration.  Run
/opt/rt4/sbin/rt-setup-fulltext-index to configure and enable it.

EOT
    exit 1;
}
unless ( $fts_config->{'Indexed'} ) {
    print STDERR <<EOT;

Full text search is enabled in your RT configuration, but not with any
full-text database indexing -- hence this tool is not required.  Read
the documentation for %FullTextSearch in your RT_Config for more details.

EOT
    exit 1;
}

if ( $db_type eq 'Oracle' ) {
    my $index = $fts_config->{'IndexName'} || 'rt_fts_index';
    $RT::Handle->dbh->do(
        "begin ctx_ddl.sync_index(?, ?); end;", undef,
        $index, $OPT{'memory'}
    );
    exit;
} elsif ( $fts_config->{Sphinx} ) {
    print STDERR <<EOT;

Updates to the external Sphinx index are done via running the sphinx
`indexer` tool:

    indexer rt

EOT
    exit 1;
}

# Skip ACL checks.  This saves a large number of unnecessary queries
# (for tickets, ACLs, and users) which are unnecessary, as we are
# running as the system user.
{
    no warnings 'redefine';
    no warnings 'once';
    *RT::Attachment::_Value = \&DBIx::SearchBuilder::Record::_Value;
    *RT::Attachments::Next  = \&DBIx::SearchBuilder::Next;
}

my $LAST;
if ($db_type eq 'mysql') {
    process_mysql();
} elsif ($db_type eq 'Pg') {
    process_pg();
}

sub attachment_loop {
    my $subref = shift;
    my $table = $fts_config->{'Table'};
    $LAST //= 0;

    # Fetch in batches of size --limit
    {
        # Indexes all text/plain and text/html attachments
        my $attachments = RT::Attachments->new( RT->SystemUser );
        $attachments->Limit(
            FIELD    => 'ContentType',
            OPERATOR => 'IN',
            VALUE    => ['text/plain', 'text/html'],
        );
        $attachments->Limit( FIELD => 'id', OPERATOR => '>', VALUE => $LAST );
        $attachments->OrderBy( FIELD => 'id', ORDER => 'asc' );
        $attachments->RowsPerPage( $OPT{'limit'} );

        # Call back to the DB-specific part
        $subref->($attachments);

        $LAST = $attachments->Last->id if $attachments->Count;

        redo if $OPT{'all'} and $attachments->Count == $OPT{'limit'};
    }
}

sub process_bulk_insert {
    my $dbh = $RT::Handle->dbh;
    my ($statement, $error) = @_;

    # Doing large inserts is faster than individual statements, but
    # comes at a parsing cost; cache the statement handles (99% of which
    # will be the same size) for a notable (2x) speed gain.
    my %sthandles;

    $sthandles{1} =
        $dbh->prepare($statement->(1));

    attachment_loop( sub {
        my ($attachments) = @_;
        my @insert;
        my $found = 0;
        while ( my $a = $attachments->Next ) {
            debug("Found attachment #". $a->id );
            my $text = $a->Content // "";
            HTML::Entities::decode_entities($text) if $a->ContentType eq "text/html";
            push @insert, $text, $a->id;
            $found++;
        }
        return unless $found;

        # $found should be the limit size on all but the last go-around.
        $sthandles{$found} ||= $dbh->prepare($statement->($found));

        return if eval { $sthandles{$found}->execute(@insert); };

        # We can catch and recover from some errors; re-do row-by-row to
        # know which row had which errors
        while (@insert) {
            my ($content, $id) = splice(@insert,0,2);
            next if eval { $sthandles{1}->execute($content, $id); };
            $error->($id, $content);

            # If this was a semi-expected error, insert an empty
            # tsvector, so we count this row as "indexed" for
            # purposes of knowing where to pick up
            eval { $sthandles{1}->execute( "", $id ) }
                or die "Failed to insert empty row for attachment $id: " . $dbh->errstr;
        }
    });
}

sub process_mysql {
    my $dbh = $RT::Handle->dbh;
    my $table = $fts_config->{'Table'};

    ($LAST) = $dbh->selectrow_array("SELECT MAX(id) FROM $table");

    my $insert = $fts_config->{Engine} eq "MyISAM" ? "INSERT DELAYED" : "INSERT";

    process_bulk_insert(
        sub {
            my ($n) = @_;
            return "$insert INTO $table(Content, id) VALUES "
                . join(", ", ("(?,?)") x $n);
        },
        sub {
            my ($id) = @_;
            if ($dbh->err == 1366 and $dbh->state eq "HY000") {
                warn "Attachment $id cannot be indexed. Most probably it contains invalid UTF8 bytes. ".
                    "Error: ". $dbh->errstr;
            } else {
                die "Attachment $id cannot be indexed: " . $dbh->errstr;
            }
        }
    );
}


sub process_pg {
    if ( $fts_config->{'Table'} ne 'Attachments' ) {
        process_pg_insert();
    } else {
        process_pg_update();
    }
}

sub process_pg_insert {
    my $dbh = $RT::Handle->dbh;
    my $table = $fts_config->{'Table'};
    my $column = $fts_config->{'Column'};
    ($LAST) = $dbh->selectrow_array("SELECT MAX(id) FROM $table");

    process_bulk_insert(
        sub {
            my ($n) = @_;
            return "INSERT INTO $table($column, id) VALUES "
                . join(", ", ("(TO_TSVECTOR(?),?)") x $n);
        },
        sub {
            my ($id) = @_;
            if ( $dbh->err == 7 && $dbh->state eq '54000' ) {
                warn "Attachment $id cannot be indexed. Most probably it contains too many unique words. ".
                  "Error: ". $dbh->errstr;
            } elsif ( $dbh->err == 7 && $dbh->state eq '22021' ) {
                warn "Attachment $id cannot be indexed. Most probably it contains invalid UTF8 bytes. ".
                  "Error: ". $dbh->errstr;
            } else {
                die "Attachment $id cannot be indexed: " . $dbh->errstr;
            }
        }
    );
}

sub process_pg_update {
    my $dbh = $RT::Handle->dbh;
    my $column = $fts_config->{'Column'};

    ($LAST) = $dbh->selectrow_array("SELECT MAX(id) FROM Attachments WHERE $column IS NOT NULL");

    my $sth = $dbh->prepare("UPDATE Attachments SET $column = TO_TSVECTOR(?) WHERE id = ?");

    attachment_loop( sub {
        my ($attachments) = @_;
        my @insert;
        while ( my $a = $attachments->Next ) {
            debug("Found attachment #". $a->id );

            my $text = $a->Content // "";
            HTML::Entities::decode_entities($text) if $a->ContentType eq "text/html";

            push @insert, [$text, $a->id];
        }

        # Try in one database transaction; if it fails, we roll it back
        # and try one statement at a time.
        $dbh->begin_work;
        my $ok = 1;
        for (@insert) {
            $ok = eval { $sth->execute( $_->[0], $_->[1] ) };
            last unless $ok;
        }
        if ($ok) {
            $dbh->commit;
            return;
        }
        $dbh->rollback;

        # Things didn't go well.  Retry the UPDATE statements one row at
        # a time, outside of the transaction.
        for (@insert) {
            my ($content, $id) = ($_->[0], $_->[1]);
            next if eval { $sth->execute( $content, $id ) };
            if ( $dbh->err == 7  && $dbh->state eq '54000' ) {
                warn "Attachment $id cannot be indexed. Most probably it contains too many unique words. ".
                  "Error: ". $dbh->errstr;
            } elsif ( $dbh->err == 7 && $dbh->state eq '22021' ) {
                warn "Attachment $id cannot be indexed. Most probably it contains invalid UTF8 bytes. ".
                  "Error: ". $dbh->errstr;
            } else {
                die "Attachment $id cannot be indexed: " . $dbh->errstr;
            }

            # If this was a semi-expected error, insert an empty
            # tsvector, so we count this row as "indexed" for
            # purposes of knowing where to pick up
            eval { $sth->execute( "", $id ) }
                or die "Failed to insert empty row for attachment $id: " . $dbh->errstr;
        }
    });
}


# helper functions
sub debug    { print @_, "\n" if $OPT{debug}; 1 }
sub error    { $RT::Logger->error(_(@_)); 1 }
sub warning  { $RT::Logger->warn(_(@_)); 1 }

=head1 NAME

rt-fulltext-indexer - Indexer for full text search

=head1 DESCRIPTION

This is a helper script to keep full text indexes in sync with data.
Read F<docs/full_text_indexing.pod> for complete details on how and when
to run it.

=cut

__DATA__
