Isolate Stemweb calls into own controller; guard against server being down. #29
[scpubgit/stemmaweb.git] / lib / stemmaweb / Controller / Stemweb.pm
CommitLineData
532cc23b 1package stemmaweb::Controller::Stemweb;
2use Moose;
3use namespace::autoclean;
ed0ce314 4use Encode qw/ decode_utf8 /;
c2b80bba 5use JSON;
70744367 6use LWP::UserAgent;
532cc23b 7use Safe::Isa;
8use TryCatch;
70744367 9use URI;
532cc23b 10
11BEGIN { extends 'Catalyst::Controller' }
12
70744367 13## TODO Move the /algorithms/available function to the Stemweb module
14my $STEMWEB_BASE_URL = 'http://slinkola.users.cs.helsinki.fi';
15
532cc23b 16=head1 NAME
17
18stemmaweb::Controller::Stemweb - Client listener for Stemweb results
19
20=head1 DESCRIPTION
21
22This is a client listener for the Stemweb API as implemented by the protocol defined at
23L<https://docs.google.com/document/d/1aNYGAo1v1WPDZi6LXZ30FJSMJwF8RQPYbOkKqHdCZEc/pub>.
24
25=head1 METHODS
26
27=head2 result
28
29 POST stemweb/result
30 Content-Type: application/json
31 (On success):
67b2a665 32 { jobid: <ID number>
532cc23b 33 status: 0
34 format: <format>
35 result: <data> }
36 (On failure):
37 { jobid: <ID number>
38 status: >1
39 result: <error message> }
40
41Used by the Stemweb server to notify us that one or more stemma graphs
42has been calculated in response to an earlier request.
43
44=cut
45
46sub result :Local :Args(0) {
47 my( $self, $c ) = @_;
48 if( $c->request->method eq 'POST' ) {
49 # TODO: Verify the sender!
50 my $answer;
51 if( ref( $c->request->body ) eq 'File::Temp' ) {
52 # Read in the file and parse that.
67b2a665 53 $c->log->debug( "Request body is in a temp file" );
54 open( POSTDATA, $c->request->body )
c0292f64 55 or return _json_error( $c, 500, "Failed to open post data file" );
532cc23b 56 binmode( POSTDATA, ':utf8' );
57 # JSON should be all one line
58 my $pdata = <POSTDATA>;
59 chomp $pdata;
60 close POSTDATA;
c2b80bba 61 try {
62 $answer = from_json( $pdata );
63 } catch {
64 return _json_error( $c, 400,
65 "Could not parse POST request '' $pdata '' as JSON: $@" );
66 }
532cc23b 67 } else {
68 $answer = from_json( $c->request->body );
69 }
67b2a665 70 $c->log->debug( "Received push notification from Stemweb: "
71 . to_json( $answer ) );
c2b80bba 72 return _process_stemweb_result( $c, $answer );
73 } else {
74 return _json_error( $c, 403, 'Please use POST!' );
75 }
76}
77
66458003 78=head2 available
79
80 GET algorithms/available
81
82Queries the Stemweb server for available stemma generation algorithms and their
83parameters. Returns the JSON answer as obtained from Stemweb.
84
85=cut
86
87sub available :Local :Args(0) {
88 my( $self, $c ) = @_;
89 my $ua = LWP::UserAgent->new();
90 my $resp = $ua->get( $STEMWEB_BASE_URL . '/algorithms/available' );
91 if( $resp->is_success ) {
92 $c->stash->{'result'} = $resp->content;
93 } else {
94 $c->stash->{'result'} = '{}';
95 }
96 $c->forward('View::JSON');
97}
98
c2b80bba 99=head2 query
100
101 GET stemweb/query/<jobid>
102
103A backup method to query the stemweb server to check a particular job status.
104Returns a result as in /stemweb/result above, but status can also be -1 to
105indicate that the job is still running.
106
107=cut
108
109sub query :Local :Args(1) {
110 my( $self, $c, $jobid ) = @_;
111 my $ua = LWP::UserAgent->new();
2c514a6f 112 my $resp = $ua->get( $STEMWEB_BASE_URL . "/algorithms/jobstatus/$jobid" );
c2b80bba 113 if( $resp->is_success ) {
114 # Process it
115 my $response = decode_utf8( $resp->content );
116 $c->log->debug( "Got a response from the server: $response" );
117 my $answer;
118 try {
119 $answer = from_json( $response );
120 } catch {
532cc23b 121 return _json_error( $c, 500,
c2b80bba 122 "Could not parse stemweb response '' $response '' as JSON: $@" );
123 }
124 return _process_stemweb_result( $c, $answer );
125 } elsif( $resp->code == 500 && $resp->header('Client-Warning')
126 && $resp->header('Client-Warning') eq 'Internal response' ) {
127 # The server was unavailable.
128 return _json_error( $c, 503, "The Stemweb server is currently unreachable." );
129 } else {
130 return _json_error( $c, 500, "Stemweb error: " . $resp->code . " / "
131 . $resp->content );
132 }
133}
134
135
136## Helper function for parsing Stemweb result data either by push or by pull
137sub _process_stemweb_result {
138 my( $c, $answer ) = @_;
c0292f64 139 # Find the specified tradition and check its job ID.
c2b80bba 140 my $m = $c->model('Directory');
c0292f64 141 my $tradition = $m->tradition( $answer->{textid} );
142 unless( $tradition ) {
143 return _json_error( $c, 400, "No tradition found with ID "
144 . $answer->{textid} );
145 }
146 if( $answer->{status} == 0 ) {
147 my $stemmata;
148 if( $tradition->has_stemweb_jobid
149 && $tradition->stemweb_jobid eq $answer->{jobid} ) {
c2b80bba 150 try {
151 $stemmata = $tradition->record_stemweb_result( $answer );
152 $m->save( $tradition );
153 } catch( Text::Tradition::Error $e ) {
154 return _json_error( $c, 500, $e->message );
155 } catch {
156 return _json_error( $c, 500, $@ );
157 }
c0292f64 158 } else {
159 # It may be that we already received a callback meanwhile.
160 # Check all stemmata for the given jobid and return them.
161 @$stemmata = grep { $_->came_from_jobid && $_->from_jobid eq $answer->{jobid} } $tradition->stemmata;
162 }
163 $DB::single = 1;
164 if( @$stemmata ) {
c2b80bba 165 # If we got here, success!
166 my @steminfo = map { {
167 name => $_->identifier,
168 directed => _json_bool( !$_->is_undirected ),
169 svg => $_->as_svg() } }
2c514a6f 170 @$stemmata;
c2b80bba 171 $c->stash->{'result'} = {
172 'status' => 'success',
173 'stemmata' => \@steminfo };
c2b80bba 174 } else {
c0292f64 175 # Hm, no stemmata found on this tradition with this jobid.
176 # Clear the tradition jobid so that the user can try again.
177 if( $tradition->has_stemweb_jobid ) {
178 $tradition->_clear_stemweb_jobid;
179 $m->save( $tradition );
180 }
181 $c->stash->{'result'} = { status => 'notfound' };
c2b80bba 182 }
c0292f64 183 } elsif( $answer->{status} < 1 ) {
184 $c->stash->{'result'} = { 'status' => 'running' };
c2b80bba 185 } else {
c0292f64 186 return _json_error( $c, 500,
187 "Stemweb failure not handled: " . $answer->{result} );
532cc23b 188 }
c2b80bba 189 $c->forward('View::JSON');
532cc23b 190}
191
70744367 192=head2 request
193
194 GET stemweb/request/?
195 tradition=<tradition ID> &
196 algorithm=<algorithm ID> &
197 [<algorithm parameters>]
198
199Send a request for the given tradition with the given parameters to Stemweb.
200Processes and returns the JSON response given by the Stemweb server.
201
202=cut
203
204sub request :Local :Args(0) {
205 my( $self, $c ) = @_;
206 # Look up the relevant tradition and check permissions.
207 my $reqparams = $c->req->params;
208 my $tid = delete $reqparams->{tradition};
209 my $t = $c->model('Directory')->tradition( $tid );
210 my $ok = _check_permission( $c, $t );
211 return unless $ok;
212 return( _json_error( $c, 403,
213 'You do not have permission to update stemmata for this tradition' ) )
214 unless $ok eq 'full';
215
216 # Form the request for Stemweb.
217 my $algorithm = delete $reqparams->{algorithm};
218 my $return_uri = URI->new( $c->uri_for( '/stemweb/result' ) );
219 my $stemweb_request = {
220 return_path => $return_uri->path,
221 return_host => $return_uri->host_port,
67b2a665 222 data => $t->collation->as_tsv({noac => 1}),
c2b80bba 223 userid => $c->user->get_object->email,
67b2a665 224 textid => $tid,
70744367 225 parameters => $reqparams };
226
227 # Call to the appropriate URL with the request parameters.
228 my $ua = LWP::UserAgent->new();
c2b80bba 229 $c->log->debug( 'Sending request to Stemweb: ' . to_json( $stemweb_request ) );
70744367 230 my $resp = $ua->post( $STEMWEB_BASE_URL . "/algorithms/process/$algorithm/",
231 'Content-Type' => 'application/json; charset=utf-8',
232 'Content' => encode_json( $stemweb_request ) );
233 if( $resp->is_success ) {
234 # Process it
ed0ce314 235 $c->log->debug( 'Got a response from the server: '
c2b80bba 236 . decode_utf8( $resp->content ) );
70744367 237 my $stemweb_response = decode_json( $resp->content );
238 try {
239 $t->set_stemweb_jobid( $stemweb_response->{jobid} );
240 } catch( Text::Tradition::Error $e ) {
241 return _json_error( $c, 429, $e->message );
242 }
243 $c->model('Directory')->save( $t );
244 $c->stash->{'result'} = $stemweb_response;
245 $c->forward('View::JSON');
246 } elsif( $resp->code == 500 && $resp->header('Client-Warning')
247 && $resp->header('Client-Warning') eq 'Internal response' ) {
248 # The server was unavailable.
249 return _json_error( $c, 503, "The Stemweb server is currently unreachable." );
250 } else {
ed0ce314 251 return _json_error( $c, 500, "Stemweb error: " . $resp->code . " / "
70744367 252 . $resp->content );
253 }
254}
255
256# Helper to check what permission, if any, the active user has for
257# the given tradition
258sub _check_permission {
259 my( $c, $tradition ) = @_;
260 my $user = $c->user_exists ? $c->user->get_object : undef;
261 if( $user ) {
262 return 'full' if ( $user->is_admin ||
263 ( $tradition->has_user && $tradition->user->id eq $user->id ) );
264 }
265 # Text doesn't belong to us, so maybe it's public?
266 return 'readonly' if $tradition->public;
267
268 # ...nope. Forbidden!
269 return _json_error( $c, 403, 'You do not have permission to view this tradition.' );
270}
271
532cc23b 272# Helper to throw a JSON exception
273sub _json_error {
274 my( $c, $code, $errmsg ) = @_;
275 $c->response->status( $code );
276 $c->stash->{'result'} = { 'error' => $errmsg };
277 $c->forward('View::JSON');
278 return 0;
279}
280
c2b80bba 281sub _json_bool {
282 return $_[0] ? JSON::true : JSON::false;
283}
284
285
ed0ce314 2861;