=encoding utf8

=head1 NAME

Mail::Box::Search - select messages within a mail box

=head1 INHERITANCE

 Mail::Box::Search
   is a Mail::Reporter

 Mail::Box::Search is extended by
   Mail::Box::Search::Grep
   Mail::Box::Search::SpamAssassin
   Mail::Server::IMAP4::Search

=head1 SYNOPSIS

 use Mail::Box::Manager;
 my $mgr    = Mail::Box::Manager->new;
 my $folder = $mgr->open('Inbox');

 my $filter = Mail::Box::Search::[something]->new;
 my @msgs   = $filter->search($folder, ...);
 if($filter->search($message)) {...}

=head1 DESCRIPTION

This C<Mail::Box::Search> class is the base class for various message scan
algorithms.  The selected messages can be labeled.  Boolean operations on
messages are supported.

Currently implemented searches:

=over 4

=item L<Mail::Box::Search::Grep|Mail::Box::Search::Grep>

Match header or body against a regular expression in a UNIX C<grep> like
fashion.

=item L<Mail::Box::Search::SpamAssassin|Mail::Box::Search::SpamAssassin>

Try to detect spam, using Mail::SpamAssassin.

=item Mail::Box::Search::IMAP

Search an IMAP folder for special interface IMAP folders provide for it.
UNDER CONSTRUCTION till L<Mail::Transport::IMAP4|Mail::Transport::IMAP4> is complete.

=back

Extends L<"DESCRIPTION" in Mail::Reporter|Mail::Reporter/"DESCRIPTION">.
 
=head1 METHODS

Extends L<"METHODS" in Mail::Reporter|Mail::Reporter/"METHODS">.
 
=head2 Constructors

Extends L<"Constructors" in Mail::Reporter|Mail::Reporter/"Constructors">.
 
=over 4

=item Mail::Box::Search-E<gt>B<new>(%options)

Create a filter.

 -Option    --Defined in     --Default
  binaries                     <false>
  decode                       <true>
  delayed                      <true>
  deleted                      <false>
  deliver                      undef
  in                           'BODY'
  label                        undef
  limit                        0
  log         Mail::Reporter   'WARNINGS'
  logical                      'REPLACE'
  multiparts                   <true>
  trace       Mail::Reporter   'WARNINGS'

=over 2

=item binaries => BOOLEAN

Whether to include binary bodies in the search.

=item decode => BOOLEAN

Decode the messages before the search takes place.  Even plain text messages
can be encoded, for instance as C<quoted-printable>, which may disturb the
results.  However, decoding will slow-down the search.

=item delayed => BOOLEAN

Include the delayed messages (which will be parsed) in the search.  If you
set this to false, you may find fewer hits.

=item deleted => BOOLEAN

In most cases, you will not be interested in results which are
found in messages flagged to be deleted.  However, with this option
you can specify you want them to be searched too.

=item deliver => undef|CODE|'DELETE'

The exact functionality of this parameter differs per search method, so
read the applicable man-page.  In any case C<undef> means that details
are not collected for this search, which is the fastest search.

C<DELETE> will flag the message to be flagged for deletion.
You may also specify your own CODE reference.  With an reference
to an array, the information about the matches is collected as a list
of hashes, one hash per match.

=item in => 'HEAD'|'BODY'|'MESSAGE'

Where to look for the match.

=item label => STRING

Mark all selected messages with the specified STRING.  If this field is
not specified, the message will not get a label; search() also returns
a list of selected messages.

=item limit => NUMBER

Limit the search to the specified NUMBER of messages.  When the NUMBER
is positive, the search starts at the first message in the folder or
thread.  A negative NUMBER starts at the end of the folder.  If the limit
is set to zero, there is no limit.

=item log => LEVEL

=item logical => 'REPLACE'|'AND'|'OR'|'NOT'|'AND NOT'|'OR NOT'

Only applicable in combination with a C<label>.
How to handle the existing labels.  In case of C<REPLACE>, messages
which already are carrying the label are stripped from their
selection (unless they match again).  With C<AND>, the message must
be selected by this search and already carry the label, otherwise the
label will not be set.  Specify C<OR> to have newly selected messages
added to the set of already selected messages.

C<NOT> is true for messages which do not fulfil the search.  The
details output will still contain the places where the match was
found, however those messages will complementary set of messages will
be labeled and returned.

=item multiparts => BOOLEAN

Are multiparts to be included in the search results?  Some MUA have
problems handling details received from the search.  When this flag
is turned off, the body of multiparts will be ignored.  The parts
search will include the preamble and epilogue.

=item trace => LEVEL

=back

=back

=head2 Searching

=over 4

=item $obj-E<gt>B<inBody>($part, $body)

Tests whether body contains the requesting information.  See the
specific search module for its parameters.

=item $obj-E<gt>B<inHead>($part, $head)

Tests whether header contains the requesting information.  See the
specific search module for its parameters.

=item $obj-E<gt>B<search>($folder|$thread|$message|ARRAY)

Check which messages from the $folder (Mail::Box) match the
search parameters.  The matched messages are returned as list.  You
can also specify a $thread (a L<Mail::Box::Thread::Node|Mail::Box::Thread::Node>), one single
$message (a L<Mail::Message|Mail::Message>), or an ARRAY of messages.

Sometimes we know how only one match is needed.  In this case, this
searching will stop at the first match.  For instance, when C<limit> is C<-1>
or C<1>, or when the search in done in scalar context.

example: 

 my $grep = Mail::Box::Search::Grep->new
  ( match   => 'My Name Is Nobody'
  , deliver => 'PRINT'
  );

 $grep->search($folder);

 my $message = $folder->message(3);
 $grep->search($message);

 my $thread  = $message->threadStart;
 $grep->search($thread);

=item $obj-E<gt>B<searchPart>($part)

Search this message $part for matches.

=back

=head2 The Results

=over 4

=item $obj-E<gt>B<printMatch>( [$fh], HASH )

Print the information about the match (see L<new(deliver)|Mail::Box::Search/"METHODS">) in
some understandable way.  If no file handle
is specified, the output will go to the selected filehandle (see
C<perldoc -f select>).

=back

=head2 Error handling

Extends L<"Error handling" in Mail::Reporter|Mail::Reporter/"Error handling">.
 
=over 4

=item $obj-E<gt>B<AUTOLOAD>()

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<addReport>($object)

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<defaultTrace>( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )

=item Mail::Box::Search-E<gt>B<defaultTrace>( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<errors>()

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<log>( [$level, [$strings]] )

=item Mail::Box::Search-E<gt>B<log>( [$level, [$strings]] )

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<logPriority>($level)

=item Mail::Box::Search-E<gt>B<logPriority>($level)

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<logSettings>()

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<notImplemented>()

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<report>( [$level] )

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<reportAll>( [$level] )

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<trace>( [$level] )

Inherited, see L<Mail::Reporter/"Error handling">

=item $obj-E<gt>B<warnings>()

Inherited, see L<Mail::Reporter/"Error handling">

=back

=head2 Cleanup

Extends L<"Cleanup" in Mail::Reporter|Mail::Reporter/"Cleanup">.
 
=over 4

=item $obj-E<gt>B<DESTROY>()

Inherited, see L<Mail::Reporter/"Cleanup">

=back

=head1 DIAGNOSTICS

=over 4

=item Error: Cannot search in body.

Th search object does not implement L<inBody()|Mail::Box::Search/"Searching">, and can therefore
not search a message body.

=item Error: Cannot search in header.

Th search object does not implement L<inHead()|Mail::Box::Search/"Searching">, and can therefore
not search a message header.

=item Error: Don't know how to deliver via results in $way.

The search results cannot be delivered in the specific way, because that is
not a defined alternative.

=item Error: Package $package does not implement $method.

Fatal error: the specific package (or one of its superclasses) does not
implement this method where it should. This message means that some other
related classes do implement this method however the class at hand does
not.  Probably you should investigate this and probably inform the author
of the package.

=item Error: Search in BODY, HEAD or MESSAGE not $in.

The C<in> option defines only three names.

=back

=head1 SEE ALSO

This module is part of Mail-Box distribution version 3.009,
built on August 18, 2020. Website: F<http://perl.overmeer.net/CPAN/>

=head1 LICENSE

Copyrights 2001-2020 by [Mark Overmeer]. For other contributors see ChangeLog.

This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See F<http://dev.perl.org/licenses/>