lib/Kalamar/API.pm - KorAP/Kalamar - Gitiles

 package Kalamar::API;
 use Mojo::Base 'Mojolicious::Plugin';
 use Scalar::Util qw/blessed weaken/;
 use strict;
 use warnings;

 # KorAP Search engine for Mojolicious::Plugin::Search

 # TODO: Add fixtures
 # TODO: Support search in corpus and virtualcollection
 # TODO: Support caching everywhere!
 # TODO: Correct use of stash info everywhere!
 # TODO: Alot is now underneath "meta"


 # Register the plugin
 sub register {
   my ($plugin, $mojo, $index_class, $param) = @_;
   $param ||= {};

   # Add attributes to the index class
   $index_class->attr(api => $param->{api});
   $index_class->attr([qw/cutoff
 			 query_language
 			 time_exceeded
 			 api_request
 			 _api_cache
 			 api_response
 			 benchmark
 			 query_jsonld
 			 collection
 			 collection_jsonld/]);
   $index_class->attr(no_cache => 0);
 };


 # Search the index
 sub search {
   my $self = shift;
   my $index = shift;

   # Get controller
   my $c = $index->controller;

   # If there is a callback, do async
   my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';

   # No query defined
   unless ($index->query) {
     return $cb->($index) if $cb;
     return;
   };

   # Get query url
   my $url = _query_url($index, @_);

   # Cache based on URL
   $index->_api_cache('total-' . $url->to_string);
   # TODO: Make this user dependent for collections!!!!

   my %param = @_;

   # Set context based on parameter
   # base/s:p
   $url->query({ context => $param{'context'} // '40-t,40-t' });
   # 'base/s:p'/'paragraph'

   # Set path to search
   $url->path('search');

   # Check cache for total results
   my $total_results;

   if (!$index->no_cache &&
 	defined ($total_results = $c->chi->get($index->_api_cache))) {

     # Set total results from cache
     $index->total_results($total_results);
     $c->app->log->debug('Get total result from cache');

     # Set cutoff unless already set
     $url->query({cutoff => 'true'}) unless defined $index->cutoff;
   };

   # Set api request for debugging
   $index->api_request($url->to_string);

   # Create new user agent and set timeout to 2 minutes
   my $ua = $c->ua;
   $ua->inactivity_timeout(120);

   # Debugging
   $c->app->log->debug('Search for ' . $index->api_request);

   # Search non-blocking
   if ($cb) {

     $ua->get(
       $url => sub {
 	my $tx = pop;
 	$self->_process_response('matches', $index, $tx);
 	weaken $index;
 	return $cb->($index);
       });
   }

   # Search blocking
   else {
     my $tx = $ua->get($url);
     $self->_process_response('matches', $index, $tx);
     return $index;
   };
 };


 # Trace query serialization
 sub trace {
   my $self = shift;
   my $index = shift;

   # Get controller
   my $c = $index->controller;

   # If there is a callback, do async
   my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';

   my %param = @_;

   # No query defined
   unless ($index->query(delete $param{query})) {
     return $cb->($index) if $cb;
     return;
   };

   # Get query url
   my $url = _query_url($index, @_);

   $url->path('search');

   # Create new user agent and set timeout to 30 seconds
   my $ua = $c->ua; # Mojo::UserAgent->new;
   $ua->inactivity_timeout(30);

   # Build transaction
   my $tx = $ua->build_tx(TRACE => $url);

   # non-blocking
   if ($cb) {
     weaken $index;

     # Trace non-blocking
     $ua->start(
       $tx => sub {
 	$self->_process_response('trace', $index, pop);
 	return $cb->($index);
       });
   }
   # Trace blocking
   else {
     my $tx = $ua->start($url);
     return $self->_process_response('trace', $index, $tx);
   };
 };


 # Get match info
 sub match {
   my $self = shift;
   my $index = shift;

   # Get controller
   my $c = $index->controller;

   # If there is a callback, do async
   my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';

   my %param = @_;

   my $url = Mojo::URL->new($index->api);

   # Legacy: In old versions, doc_id contained text_id
   $param{doc_id} .= '.' . $param{text_id} if $param{text_id};

   # Use hash slice to create path
   $url->path(join('/', 'corpus', @param{qw/corpus_id doc_id match_id/}, 'matchInfo'));

   # Build match id
   # $match = 'match-' . $corpus . '!' . $corpus . '_' . $doc . '-' . $match;

   my %query;
   $query{foundry} = $param{foundry};
   $query{layer}   = $param{layer}   if defined $param{layer};
   $query{spans}   = $param{spans} ? 'true' : 'false';

   # Add query
   $url->query(\%query);

   $c->app->log->debug('Match info: ' . $url);

   # Create new user agent and set timeout to 30 seconds
   my $ua = $c->ua; # Mojo::UserAgent->new;
   $ua->inactivity_timeout(30);

   # non-blocking
   if ($cb) {
     weaken $index;
     $ua->get(
       $url => sub {
 	my $tx = pop;
 	$self->_process_response('match', $index, $tx);
 	return $cb->($index);
       });
   }

   # Match info blocking
   else {
     my $tx = $ua->get($url);
     return $self->_process_response('match', $index, $tx);
   };
 };


 # Get resource information
 sub resource {
   my $self = shift;
   my $index = shift;

   # Get controller
   my $c = $index->controller;

   # If there is a callback, do async
   my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';

   my %param = @_;

   # Rename info endpoints regarding resource
   my $type = $param{type} // 'collection';
   $type = 'virtualcollection' if $type eq 'collection';

   # Create resource URL
   my $url = Mojo::URL->new($index->api)->path($type);

   # Debugging
   $c->app->log->debug('Get resource info on '. $url);

   # Check for cached information
   if (my $json = $c->chi->get($url->to_string)) {

     # TODO: That's unfortunate, as it prohibits caching of multiple resources
     $c->app->log->debug('Get resource info from cache');
     $c->stash('search.resource' => $json);
     return $cb->($index) if $cb;
     return $json;
   };

   $c->stash('search._resource_cache' => $url->to_string);

   # Create new user agent and set timeout to 30 seconds
   my $ua = $c->ua; # Mojo::UserAgent->new;
   $ua->inactivity_timeout(30);

   # Get resource information async
   if ($cb) {
     weaken $index;
     $ua->get(
       $url => sub {
 	$self->_process_response('resource', $index, pop);
 	return $cb->($index);
       })
   }

   # Get resource information blocking
   else {
     my $tx = $ua->get($url);
     $self->_process_response('resource', $index, $tx);
   };
 };


 # Process response - especially error messages etc.
 sub _process_response {
   my ($self, $type, $index, $tx) = @_;
   my $c = $index->controller;

   # An error has occurded
   if (my $e = $tx->error) {
     $c->notify(
       error =>
 	($e->{code} ? $e->{code} . ': ' : '') .
 	  $e->{message} . ' for ' . $type . ' (remote)'
 	);
     return;
   };

   # Response was fine
   if (my $res = $tx->success) {

     # Json failure
     my $json;
     unless ($json = $res->json) {
       $c->notify(error => 'JSON response is invalid');
       return;
     };

     # Set api response as jsonld
     $index->api_response($json);

     # expected response for matches
     if ($type eq 'matches') {
       $self->_process_response_matches($index, $json);
     }
     elsif ($type eq 'trace') {
       $self->_process_response_trace($index, $json);
     }
     elsif ($type eq 'match') {
       $self->_process_response_match($index, $json);
     }
     elsif ($type eq 'resource') {
       $self->_process_response_resource($index, $json);
     };

     return 1 if ref $json ne 'HASH';

     $self->_notify_on_warnings($c, $json);
     $self->_notify_on_error($c, 0, $json);
   }

   # Request failed
   else {
     $self->_notify_on_error($c, 1, $tx->res);
   };
   return 1;
 };


 # Handle match results
 sub _process_response_matches {
   my ($self, $index, $json) = @_;

   # Process meta
   my $meta = $json->{meta};

   # Reformat benchmark counter
   my $benchmark = $meta->{benchmark};
   if ($benchmark && $benchmark =~ s/\s+(m)?s$//) {
     $benchmark = sprintf("%.2f", $benchmark) . ($1 ? $1 : '') . 's';
   };

   # Set benchmark
   $index->benchmark($benchmark);

   # Set time exceeded
   if ($meta->{timeExceeded} && $meta->{timeExceeded} eq Mojo::JSON::true) {
     $index->time_exceeded(1);
   };

   # Set result values
   $index->items_per_page($meta->{itemsPerPage});


   # Bouncing query
 #  if ($json->{query}) {
 #    $index->query_jsonld($json->{query});
 #  };

   # Legacy
   # elsif ($json->{request}->{query}) {
   #   $index->query_jsonld($json->{request}->{query});
   # };

   # Bouncing collection query
   if ($json->{collection}) {
     $index->collection_jsonld($json->{collection});
   }

   # Legacy
   # elsif ($json->{request}->{collection}) {
   #  $index->collection_jsonld($json->{request}->{collection});
   # };

   $index->results(_map_matches($json->{matches}));

   # Total results not set by stash
   if ($index->total_results == -1) {

     if ($meta->{totalResults} && $meta->{totalResults} > -1) {
       my $c = $index->controller;

       $c->app->log->debug('Cache total result');
       $c->chi->set($index->_api_cache => $meta->{totalResults}, '120min');
       $index->total_results($meta->{totalResults});
     };
   };
 };


 # Process query serialization response
 sub _process_response_match {
   my ($self, $index, $json) = @_;
   $index->results(_map_match($json));
 };


 # Process trace response
 sub _process_response_trace {
   my ($self, $index, $json) = @_;
   $index->query_jsonld($json);
 };


 # Process resource response
 sub _process_response_resource {
   my ($self, $index, $json) = @_;
   my $c = $index->controller;

   # TODO: That's unfortunate, as it prohibits multiple resources
   $c->stash('search.resource' => $json);
   $c->app->log->debug('Cache resource info');
   $c->chi->set($c->stash('search._resource_cache') => $json, '24 hours');
 };


 # Parse error messages and forward them to the user
 sub _notify_on_error {
   my ($self, $c, $failure, $res) = @_;
   my $json = $res;

   my $log = $c->app->log;

   # Check if the response is already json
   if (blessed $res) {
     $json = $res->json if blessed $res ne 'Mojo::JSON';
   };

   # Check json response error message
   if ($json) {

     # Legacy, but still in use by Kustvakt
     if ($json->{error}) {

       # Temp
       $json->{error} =~ s/;\s+null$//;
       $c->notify(error => $json->{error});
       return;
     }

     # New error messages
     elsif ($json->{errstr}) {
       # Temp
       $json->{errstr} =~ s/;\s+null$//;
       $c->notify(error => $json->{errstr});
       return;
     }

     elsif ($json->{errors}) {
       my $errors = $json->{errors};
       # TODO: Check for ref!
       foreach (@$errors) {
 	$c->notify(
 	  error =>
 	    ($_->[0] ? $_->[0] . ': ' : '') .
 	      $_->[1]
 	  );
       };
     }

     # policy service error messages
     elsif ($json->{status}) {
       $c->notify(error => 'Middleware error ' . $json->{status});
       return;
     };
   };

   # Doesn't matter what - there is a failure!
   if ($failure) {
     $c->notify(error => (
       ($res->{code}    ? $res->{code} . ': ' : '') .
       ($res->{message} ? $res->{message}     : 'Unknown error') .
       ' (remote)'
     ));
   };
 };


 sub _notify_on_warnings {
   my ($self, $c, $json) = @_;

   # Add warnings (Legacy)
   if ($json->{warning}) {
     $json->{warning} =~ s/;\s+null$//;
     $c->notify(warn => $json->{warning});
   }

   # Add warnings
   elsif ($json->{warnings}) {

     my $warnings = $json->{warnings};
     # TODO: Check for ref!
     foreach (@$warnings) {
       $c->notify(
 	warn =>
 	  ($_->[0] ? $_->[0] . ': ' : '') .
 	    $_->[1]
 	  );
     };
   };
 };


 # Cleanup array of matches
 sub _map_matches {
   return () unless $_[0];
   map { _map_match($_) } @{ shift() };
 };


 # Cleanup single match
 sub _map_match {
   my $x = shift or return;
   $x->{matchID} =~ s/^match\-(?:[^!]+!|[^_]+_)[^\.]+?\.[^-]+?-//;

   (
     $x->{corpusID},
     $x->{docID},
     $x->{textID}
   ) = ($x->{textSigle} =~ /^([^_]+?)_+([^\.]+?)\.(.+?)$/);

   # $x->{docID} =~ s/^[^_]+_//;
   # Legacy: In old versions the text_id was part of the doc_id
   #  unless ($x->{textID}) {
   #    ($x->{docID}, $x->{textID}) = split '\.', $x->{docID};
   #  };

   $x;
 };

 # Build query url
 sub _query_url {
   my ($index, %param) = @_;

   # Set cutoff from param
   $index->cutoff(delete $param{cutoff});

   # Set collection from param
   $index->collection(delete $param{collection});

   # Set query language
   $index->query_language(delete $param{query_language} // 'poliqarp');

   # Should results be cached? Defaults to "yes"
   $index->no_cache(1) if $param{no_cache};

   # Init the query with stuff coming from the index
   my %query;
   $query{q}      = $index->query;
   $query{ql}     = $index->query_language;
   $query{page}   = $index->start_page if $index->start_page;
   $query{count}  = $index->items_per_page if $index->items_per_page;
   $query{cq}     = $index->collection if $index->collection;
   $query{cutoff} = 'true' if $index->cutoff;

   # Create query url
   my $url = Mojo::URL->new($index->api);
   $url->query(\%query);
   return $url;
 };


 1;


 __END__

 =pod

 =encoding utf8

 =head1 NAME

 Kalamar::API

 =head1 DESCRIPTION

 L<Kalamar::API> is a search engine class for L<Mojolicious::Plugin::Search>
 that uses the KorAP Web API.

 B<The Web API as well as L<Mojolicious::Plugin::Search> are not stable yet,
 so this class is expected to change in the near future. Do not rely on its API!>


 =head1 METHODS

 L<Kalamar::API> inherits all methods from L<Mojolicious::Plugin> and
 implements the following new ones.


 =head2 register

 See L<Mojolicious::Plugin::Search> for registering search engines.
 In addition to the mentioned query parameters, the following parameters are supported:


 =over 2

 =item B<query_language>

 One of the supported query languages, like C<poliqarp> or C<annis>.


 =item B<cutoff>

 Cut off results following the current page (i.e. don't count the number of results).


 =item B<no_cache>

 Do not cache search results. Defaults to C<0>.


 =back

 In addition to the mentioned index attributes, the following attributes are supported:

 =over 2

 =item B<api>

 The API address.


 =item B<time_exceeded>

 Report on time outs, that may mean, not all results were retrieved.


 =item B<api_request>

 Report the whole API request.


 =item B<api_response>

 Report the whole API response (a KoralQuery object).


 =item B<benchmarks>

 Report on processing time for benchmarking.


 =item B<query_jsonld>

 The KoralQuery realization of the C<query> object.

 =back

 =head2 search

 Search the index.

 =head2 trace

 Trace query serializations.

 =head2 match

 Get match information.

 =head2 resource

 Get resource information.


 =head1 COPYRIGHT AND LICENSE

 Copyright (C) 2015, L<IDS Mannheim|http://www.ids-mannheim.de/>
 Author: L<Nils Diewald|http://nils-diewald.de/>

 Kalamar is developed as part of the L<KorAP|http://korap.ids-mannheim.de/>
 Corpus Analysis Platform at the
 L<Institute for the German Language (IDS)|http://ids-mannheim.de/>,
 member of the
 L<Leibniz-Gemeinschaft|http://www.leibniz-gemeinschaft.de/en/about-us/leibniz-competition/projekte-2011/2011-funding-line-2/>
 and supported by the L<KobRA|http://www.kobra.tu-dortmund.de> project,
 funded by the
 L<Federal Ministry of Education and Research (BMBF)|http://www.bmbf.de/en/>.

 Kalamar is free software published under the
 L<BSD-2 License|https://raw.githubusercontent.com/KorAP/Kalamar/master/LICENSE>.

 =cut

   # Temporary:
   my $collection_query = {
     '@type' => "koral:docGroup",
     "operation" => "operation:or",
     "operands" => [
       {
 	'@type' => "koral:docGroup",
 	"operation" => "operation:and",
 	"operands" => [
 	  {
 	    '@type' => "koral:doc",
 	    "key" => "title",
 	    "match" => "match:eq",
 	    "value" => "Der Birnbaum",
 	    "type" => "type:string"
 	  },
 	  {
 	    '@type' => "koral:doc",
 	    "key" => "pubPlace",
 	    "match" => "match:eq",
 	    "value" => "Mannheim",
 	    "type" => "type:string"
 	  },
 	  {
 	    '@type' => "koral:docGroup",
 	    "operation" => "operation:or",
 	    "operands" => [
 	      {
 		'@type' => "koral:doc",
 		"key" => "subTitle",
 		"match" => "match:eq",
 		"value" => "Aufzucht oder Pflege",
 		"type" => "type:string"
 	      },
 	      {
 		'@type' => "koral:doc",
 		"key" => "subTitle",
 		"match" => "match:eq",
 		"value" => "Gedichte",
 		"type" => "type:string"
 	      }
 	    ]
 	  }
 	]
       },
       {
 	'@type' => "koral:doc",
 	"key" => "pubDate",
 	"match" => "match:geq",
 	"value" => "2015-03-05",
 	"type" => "type:date"
       }
     ]
   };
	package Kalamar::API;
	use Mojo::Base 'Mojolicious::Plugin';
	use Scalar::Util qw/blessed weaken/;
	use strict;
	use warnings;

	# KorAP Search engine for Mojolicious::Plugin::Search

	# TODO: Add fixtures
	# TODO: Support search in corpus and virtualcollection
	# TODO: Support caching everywhere!
	# TODO: Correct use of stash info everywhere!
	# TODO: Alot is now underneath "meta"


	# Register the plugin
	sub register {
	my ($plugin, $mojo, $index_class, $param) = @_;
	$param \|\|= {};

	# Add attributes to the index class
	$index_class->attr(api => $param->{api});
	$index_class->attr([qw/cutoff
	query_language
	time_exceeded
	api_request
	_api_cache
	api_response
	benchmark
	query_jsonld
	collection
	collection_jsonld/]);
	$index_class->attr(no_cache => 0);
	};


	# Search the index
	sub search {
	my $self = shift;
	my $index = shift;

	# Get controller
	my $c = $index->controller;

	# If there is a callback, do async
	my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';

	# No query defined
	unless ($index->query) {
	return $cb->($index) if $cb;
	return;
	};

	# Get query url
	my $url = _query_url($index, @_);

	# Cache based on URL
	$index->_api_cache('total-' . $url->to_string);
	# TODO: Make this user dependent for collections!!!!

	my %param = @_;

	# Set context based on parameter
	# base/s:p
	$url->query({ context => $param{'context'} // '40-t,40-t' });
	# 'base/s:p'/'paragraph'

	# Set path to search
	$url->path('search');

	# Check cache for total results
	my $total_results;

	if (!$index->no_cache &&
	defined ($total_results = $c->chi->get($index->_api_cache))) {

	# Set total results from cache
	$index->total_results($total_results);
	$c->app->log->debug('Get total result from cache');

	# Set cutoff unless already set
	$url->query({cutoff => 'true'}) unless defined $index->cutoff;
	};

	# Set api request for debugging
	$index->api_request($url->to_string);

	# Create new user agent and set timeout to 2 minutes
	my $ua = $c->ua;
	$ua->inactivity_timeout(120);

	# Debugging
	$c->app->log->debug('Search for ' . $index->api_request);

	# Search non-blocking
	if ($cb) {

	$ua->get(
	$url => sub {
	my $tx = pop;
	$self->_process_response('matches', $index, $tx);
	weaken $index;
	return $cb->($index);
	});
	}

	# Search blocking
	else {
	my $tx = $ua->get($url);
	$self->_process_response('matches', $index, $tx);
	return $index;
	};
	};


	# Trace query serialization
	sub trace {
	my $self = shift;
	my $index = shift;

	# Get controller
	my $c = $index->controller;

	# If there is a callback, do async
	my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';

	my %param = @_;

	# No query defined
	unless ($index->query(delete $param{query})) {
	return $cb->($index) if $cb;
	return;
	};

	# Get query url
	my $url = _query_url($index, @_);

	$url->path('search');

	# Create new user agent and set timeout to 30 seconds
	my $ua = $c->ua; # Mojo::UserAgent->new;
	$ua->inactivity_timeout(30);

	# Build transaction
	my $tx = $ua->build_tx(TRACE => $url);

	# non-blocking
	if ($cb) {
	weaken $index;

	# Trace non-blocking
	$ua->start(
	$tx => sub {
	$self->_process_response('trace', $index, pop);
	return $cb->($index);
	});
	}
	# Trace blocking
	else {
	my $tx = $ua->start($url);
	return $self->_process_response('trace', $index, $tx);
	};
	};


	# Get match info
	sub match {
	my $self = shift;
	my $index = shift;

	# Get controller
	my $c = $index->controller;

	# If there is a callback, do async
	my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';

	my %param = @_;

	my $url = Mojo::URL->new($index->api);

	# Legacy: In old versions, doc_id contained text_id
	$param{doc_id} .= '.' . $param{text_id} if $param{text_id};

	# Use hash slice to create path
	$url->path(join('/', 'corpus', @param{qw/corpus_id doc_id match_id/}, 'matchInfo'));

	# Build match id
	# $match = 'match-' . $corpus . '!' . $corpus . '_' . $doc . '-' . $match;

	my %query;
	$query{foundry} = $param{foundry};
	$query{layer} = $param{layer} if defined $param{layer};
	$query{spans} = $param{spans} ? 'true' : 'false';

	# Add query
	$url->query(\%query);

	$c->app->log->debug('Match info: ' . $url);

	# Create new user agent and set timeout to 30 seconds
	my $ua = $c->ua; # Mojo::UserAgent->new;
	$ua->inactivity_timeout(30);

	# non-blocking
	if ($cb) {
	weaken $index;
	$ua->get(
	$url => sub {
	my $tx = pop;
	$self->_process_response('match', $index, $tx);
	return $cb->($index);
	});
	}

	# Match info blocking
	else {
	my $tx = $ua->get($url);
	return $self->_process_response('match', $index, $tx);
	};
	};


	# Get resource information
	sub resource {
	my $self = shift;
	my $index = shift;

	# Get controller
	my $c = $index->controller;

	# If there is a callback, do async
	my $cb = pop if ref $_[-1] && ref $_[-1] eq 'CODE';

	my %param = @_;

	# Rename info endpoints regarding resource
	my $type = $param{type} // 'collection';
	$type = 'virtualcollection' if $type eq 'collection';

	# Create resource URL
	my $url = Mojo::URL->new($index->api)->path($type);

	# Debugging
	$c->app->log->debug('Get resource info on '. $url);

	# Check for cached information
	if (my $json = $c->chi->get($url->to_string)) {

	# TODO: That's unfortunate, as it prohibits caching of multiple resources
	$c->app->log->debug('Get resource info from cache');
	$c->stash('search.resource' => $json);
	return $cb->($index) if $cb;
	return $json;
	};

	$c->stash('search._resource_cache' => $url->to_string);

	# Create new user agent and set timeout to 30 seconds
	my $ua = $c->ua; # Mojo::UserAgent->new;
	$ua->inactivity_timeout(30);

	# Get resource information async
	if ($cb) {
	weaken $index;
	$ua->get(
	$url => sub {
	$self->_process_response('resource', $index, pop);
	return $cb->($index);
	})
	}

	# Get resource information blocking
	else {
	my $tx = $ua->get($url);
	$self->_process_response('resource', $index, $tx);
	};
	};


	# Process response - especially error messages etc.
	sub _process_response {
	my ($self, $type, $index, $tx) = @_;
	my $c = $index->controller;

	# An error has occurded
	if (my $e = $tx->error) {
	$c->notify(
	error =>
	($e->{code} ? $e->{code} . ': ' : '') .
	$e->{message} . ' for ' . $type . ' (remote)'
	);
	return;
	};

	# Response was fine
	if (my $res = $tx->success) {

	# Json failure
	my $json;
	unless ($json = $res->json) {
	$c->notify(error => 'JSON response is invalid');
	return;
	};

	# Set api response as jsonld
	$index->api_response($json);

	# expected response for matches
	if ($type eq 'matches') {
	$self->_process_response_matches($index, $json);
	}
	elsif ($type eq 'trace') {
	$self->_process_response_trace($index, $json);
	}
	elsif ($type eq 'match') {
	$self->_process_response_match($index, $json);
	}
	elsif ($type eq 'resource') {
	$self->_process_response_resource($index, $json);
	};

	return 1 if ref $json ne 'HASH';

	$self->_notify_on_warnings($c, $json);
	$self->_notify_on_error($c, 0, $json);
	}

	# Request failed
	else {
	$self->_notify_on_error($c, 1, $tx->res);
	};
	return 1;
	};


	# Handle match results
	sub _process_response_matches {
	my ($self, $index, $json) = @_;

	# Process meta
	my $meta = $json->{meta};

	# Reformat benchmark counter
	my $benchmark = $meta->{benchmark};
	if ($benchmark && $benchmark =~ s/\s+(m)?s$//) {
	$benchmark = sprintf("%.2f", $benchmark) . ($1 ? $1 : '') . 's';
	};

	# Set benchmark
	$index->benchmark($benchmark);

	# Set time exceeded
	if ($meta->{timeExceeded} && $meta->{timeExceeded} eq Mojo::JSON::true) {
	$index->time_exceeded(1);
	};

	# Set result values
	$index->items_per_page($meta->{itemsPerPage});


	# Bouncing query
	# if ($json->{query}) {
	# $index->query_jsonld($json->{query});
	# };

	# Legacy
	# elsif ($json->{request}->{query}) {
	# $index->query_jsonld($json->{request}->{query});
	# };

	# Bouncing collection query
	if ($json->{collection}) {
	$index->collection_jsonld($json->{collection});
	}

	# Legacy
	# elsif ($json->{request}->{collection}) {
	# $index->collection_jsonld($json->{request}->{collection});
	# };

	$index->results(_map_matches($json->{matches}));

	# Total results not set by stash
	if ($index->total_results == -1) {

	if ($meta->{totalResults} && $meta->{totalResults} > -1) {
	my $c = $index->controller;

	$c->app->log->debug('Cache total result');
	$c->chi->set($index->_api_cache => $meta->{totalResults}, '120min');
	$index->total_results($meta->{totalResults});
	};
	};
	};


	# Process query serialization response
	sub _process_response_match {
	my ($self, $index, $json) = @_;
	$index->results(_map_match($json));
	};


	# Process trace response
	sub _process_response_trace {
	my ($self, $index, $json) = @_;
	$index->query_jsonld($json);
	};


	# Process resource response
	sub _process_response_resource {
	my ($self, $index, $json) = @_;
	my $c = $index->controller;

	# TODO: That's unfortunate, as it prohibits multiple resources
	$c->stash('search.resource' => $json);
	$c->app->log->debug('Cache resource info');
	$c->chi->set($c->stash('search._resource_cache') => $json, '24 hours');
	};


	# Parse error messages and forward them to the user
	sub _notify_on_error {
	my ($self, $c, $failure, $res) = @_;
	my $json = $res;

	my $log = $c->app->log;

	# Check if the response is already json
	if (blessed $res) {
	$json = $res->json if blessed $res ne 'Mojo::JSON';
	};

	# Check json response error message
	if ($json) {

	# Legacy, but still in use by Kustvakt
	if ($json->{error}) {

	# Temp
	$json->{error} =~ s/;\s+null$//;
	$c->notify(error => $json->{error});
	return;
	}

	# New error messages
	elsif ($json->{errstr}) {
	# Temp
	$json->{errstr} =~ s/;\s+null$//;
	$c->notify(error => $json->{errstr});
	return;
	}

	elsif ($json->{errors}) {
	my $errors = $json->{errors};
	# TODO: Check for ref!
	foreach (@$errors) {
	$c->notify(
	error =>
	($_->[0] ? $_->[0] . ': ' : '') .
	$_->[1]
	);
	};
	}

	# policy service error messages
	elsif ($json->{status}) {
	$c->notify(error => 'Middleware error ' . $json->{status});
	return;
	};
	};

	# Doesn't matter what - there is a failure!
	if ($failure) {
	$c->notify(error => (
	($res->{code} ? $res->{code} . ': ' : '') .
	($res->{message} ? $res->{message} : 'Unknown error') .
	' (remote)'
	));
	};
	};


	sub _notify_on_warnings {
	my ($self, $c, $json) = @_;

	# Add warnings (Legacy)
	if ($json->{warning}) {
	$json->{warning} =~ s/;\s+null$//;
	$c->notify(warn => $json->{warning});
	}

	# Add warnings
	elsif ($json->{warnings}) {

	my $warnings = $json->{warnings};
	# TODO: Check for ref!
	foreach (@$warnings) {
	$c->notify(
	warn =>
	($_->[0] ? $_->[0] . ': ' : '') .
	$_->[1]
	);
	};
	};
	};


	# Cleanup array of matches
	sub _map_matches {
	return () unless $_[0];
	map { _map_match($_) } @{ shift() };
	};


	# Cleanup single match
	sub _map_match {
	my $x = shift or return;
	$x->{matchID} =~ s/^match\-(?:[^!]+!\|[^_]+_)[^\.]+?\.[^-]+?-//;

	(
	$x->{corpusID},
	$x->{docID},
	$x->{textID}
	) = ($x->{textSigle} =~ /^([^_]+?)_+([^\.]+?)\.(.+?)$/);

	# $x->{docID} =~ s/^[^_]+_//;
	# Legacy: In old versions the text_id was part of the doc_id
	# unless ($x->{textID}) {
	# ($x->{docID}, $x->{textID}) = split '\.', $x->{docID};
	# };

	$x;
	};

	# Build query url
	sub _query_url {
	my ($index, %param) = @_;

	# Set cutoff from param
	$index->cutoff(delete $param{cutoff});

	# Set collection from param
	$index->collection(delete $param{collection});

	# Set query language
	$index->query_language(delete $param{query_language} // 'poliqarp');

	# Should results be cached? Defaults to "yes"
	$index->no_cache(1) if $param{no_cache};

	# Init the query with stuff coming from the index
	my %query;
	$query{q} = $index->query;
	$query{ql} = $index->query_language;
	$query{page} = $index->start_page if $index->start_page;
	$query{count} = $index->items_per_page if $index->items_per_page;
	$query{cq} = $index->collection if $index->collection;
	$query{cutoff} = 'true' if $index->cutoff;

	# Create query url
	my $url = Mojo::URL->new($index->api);
	$url->query(\%query);
	return $url;
	};


	1;


	__END__

	=pod

	=encoding utf8

	=head1 NAME

	Kalamar::API

	=head1 DESCRIPTION

	L<Kalamar::API> is a search engine class for L<Mojolicious::Plugin::Search>
	that uses the KorAP Web API.

	B<The Web API as well as L<Mojolicious::Plugin::Search> are not stable yet,
	so this class is expected to change in the near future. Do not rely on its API!>


	=head1 METHODS

	L<Kalamar::API> inherits all methods from L<Mojolicious::Plugin> and
	implements the following new ones.


	=head2 register

	See L<Mojolicious::Plugin::Search> for registering search engines.
	In addition to the mentioned query parameters, the following parameters are supported:


	=over 2

	=item B<query_language>

	One of the supported query languages, like C<poliqarp> or C<annis>.


	=item B<cutoff>

	Cut off results following the current page (i.e. don't count the number of results).


	=item B<no_cache>

	Do not cache search results. Defaults to C<0>.


	=back

	In addition to the mentioned index attributes, the following attributes are supported:

	=over 2

	=item B<api>

	The API address.


	=item B<time_exceeded>

	Report on time outs, that may mean, not all results were retrieved.


	=item B<api_request>

	Report the whole API request.


	=item B<api_response>

	Report the whole API response (a KoralQuery object).


	=item B<benchmarks>

	Report on processing time for benchmarking.


	=item B<query_jsonld>

	The KoralQuery realization of the C<query> object.

	=back

	=head2 search

	Search the index.

	=head2 trace

	Trace query serializations.

	=head2 match

	Get match information.

	=head2 resource

	Get resource information.


	=head1 COPYRIGHT AND LICENSE

	Copyright (C) 2015, L<IDS Mannheim\|http://www.ids-mannheim.de/>
	Author: L<Nils Diewald\|http://nils-diewald.de/>

	Kalamar is developed as part of the L<KorAP\|http://korap.ids-mannheim.de/>
	Corpus Analysis Platform at the
	L<Institute for the German Language (IDS)\|http://ids-mannheim.de/>,
	member of the
	L<Leibniz-Gemeinschaft\|http://www.leibniz-gemeinschaft.de/en/about-us/leibniz-competition/projekte-2011/2011-funding-line-2/>
	and supported by the L<KobRA\|http://www.kobra.tu-dortmund.de> project,
	funded by the
	L<Federal Ministry of Education and Research (BMBF)\|http://www.bmbf.de/en/>.

	Kalamar is free software published under the
	L<BSD-2 License\|https://raw.githubusercontent.com/KorAP/Kalamar/master/LICENSE>.

	=cut

	# Temporary:
	my $collection_query = {
	'@type' => "koral:docGroup",
	"operation" => "operation:or",
	"operands" => [
	{
	'@type' => "koral:docGroup",
	"operation" => "operation:and",
	"operands" => [
	{
	'@type' => "koral:doc",
	"key" => "title",
	"match" => "match:eq",
	"value" => "Der Birnbaum",
	"type" => "type:string"
	},
	{
	'@type' => "koral:doc",
	"key" => "pubPlace",
	"match" => "match:eq",
	"value" => "Mannheim",
	"type" => "type:string"
	},
	{
	'@type' => "koral:docGroup",
	"operation" => "operation:or",
	"operands" => [
	{
	'@type' => "koral:doc",
	"key" => "subTitle",
	"match" => "match:eq",
	"value" => "Aufzucht oder Pflege",
	"type" => "type:string"
	},
	{
	'@type' => "koral:doc",
	"key" => "subTitle",
	"match" => "match:eq",
	"value" => "Gedichte",
	"type" => "type:string"
	}
	]
	}
	]
	},
	{
	'@type' => "koral:doc",
	"key" => "pubDate",
	"match" => "match:geq",
	"value" => "2015-03-05",
	"type" => "type:date"
	}
	]
	};