Add image fetching from wikipedia

#5416

ext/libclementine-common/CMakeLists.txt

@@ -7,6 +7,7 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} --std=c++0x")
 
 set(SOURCES
   core/closure.cpp
+  core/latch.cpp
   core/logging.cpp
   core/messagehandler.cpp
   core/messagereply.cpp
@@ -16,6 +17,7 @@ set(SOURCES
 
 set(HEADERS
   core/closure.h
+  core/latch.h
   core/messagehandler.h
   core/messagereply.h
   core/workerpool.h

ext/libclementine-common/core/latch.cpp

@@ -0,0 +1,36 @@
+/* This file is part of Clementine.
+   Copyright 2016, John Maguire <john.maguire@gmail.com>
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+#include "latch.h"
+
+#include "core/logging.h"
+
+CountdownLatch::CountdownLatch() : count_(0) {}
+
+void CountdownLatch::Wait() {
+  QMutexLocker l(&mutex_);
+  ++count_;
+}
+
+void CountdownLatch::CountDown() {
+  QMutexLocker l(&mutex_);
+  Q_ASSERT(count_ > 0);
+  --count_;
+  qLog(Debug) << "Decrement:" << count_;
+  if (count_ == 0) {
+    emit Done();
+  }
+}

ext/libclementine-common/core/latch.h

@@ -0,0 +1,38 @@
+/* This file is part of Clementine.
+   Copyright 2016, John Maguire <john.maguire@gmail.com>
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+#ifndef CORE_LATCH_H
+#define CORE_LATCH_H
+
+#include <QMutex>
+#include <QObject>
+
+class CountdownLatch : public QObject {
+  Q_OBJECT
+ public:
+  CountdownLatch();
+  void Wait();
+  void CountDown();
+
+signals:
+  void Done();
+
+ private:
+  QMutex mutex_;
+  int count_;
+};
+
+#endif  // CORE_LATCH_H

src/songinfo/artistbiography.cpp

@@ -22,11 +22,18 @@
 #include <qjson/parser.h>
 
 #include "core/closure.h"
+#include "core/latch.h"
+#include "core/logging.h"
 #include "core/network.h"
 #include "songinfo/songinfotextview.h"
 
 namespace {
 const char* kArtistBioUrl = "https://data.clementine-player.org/fetchbio";
+const char* kWikipediaImageListUrl =
+    "https://en.wikipedia.org/w/api.php?action=query&prop=images&format=json";
+const char* kWikipediaImageInfoUrl =
+    "https://en.wikipedia.org/w/"
+    "api.php?action=query&prop=imageinfo&iiprop=url&format=json";
 
 QString GetLocale() {
   QLocale locale;
@@ -75,6 +82,105 @@ void ArtistBiography::FetchInfo(int id, const Song& metadata) {
     editor->SetHtml(text);
     data.contents_ = editor;
     emit InfoReady(id, data);
-    emit Finished(id);
+
+    if (url.contains("wikipedia.org")) {
+      FetchWikipediaImages(id, url);
+    } else {
+      emit Finished(id);
+    }
+  });
+}
+
+namespace {
+
+QStringList ExtractImageTitles(const QVariantMap& json) {
+  QStringList ret;
+  for (auto it = json.constBegin(); it != json.constEnd(); ++it) {
+    if (it.value().type() == QVariant::Map) {
+      ret.append(ExtractImageTitles(it.value().toMap()));
+    } else if (it.key() == "images" && it.value().type() == QVariant::List) {
+      QVariantList images = it.value().toList();
+      for (QVariant i : images) {
+        QVariantMap image = i.toMap();
+        QString image_title = image["title"].toString();
+        if (!image_title.isEmpty() &&
+            (
+                // SVGs tend to be irrelevant icons.
+                image_title.endsWith(".jpg", Qt::CaseInsensitive) ||
+                image_title.endsWith(".png", Qt::CaseInsensitive))) {
+          ret.append(image_title);
+        }
+      }
+    }
+  }
+  return ret;
+}
+
+QString ExtractImageUrl(const QVariantMap& json) {
+  for (auto it = json.constBegin(); it != json.constEnd(); ++it) {
+    if (it.value().type() == QVariant::Map) {
+      QString r = ExtractImageUrl(it.value().toMap());
+      if (!r.isEmpty()) {
+        return r;
+      }
+    } else if (it.key() == "imageinfo") {
+      QVariantList imageinfos = it.value().toList();
+      QVariantMap imageinfo = imageinfos.first().toMap();
+      return imageinfo["url"].toString();
+    }
+  }
+  return QString::null;
+}
+
+}  // namespace
+
+void ArtistBiography::FetchWikipediaImages(int id,
+                                           const QString& wikipedia_url) {
+  QRegExp regex("/wiki/(.*)");
+  if (regex.indexIn(wikipedia_url) == -1) {
+    emit Finished(id);
+    return;
+  }
+  QString wiki_title = regex.cap(1);
+  QUrl url(kWikipediaImageListUrl);
+  url.addQueryItem("titles", wiki_title);
+
+  qLog(Debug) << "Wikipedia images:" << url;
+
+  QNetworkRequest request(url);
+  QNetworkReply* reply = network_->get(request);
+  NewClosure(reply, SIGNAL(finished()), [this, id, reply]() {
+    reply->deleteLater();
+
+    QJson::Parser parser;
+    QVariantMap response = parser.parse(reply).toMap();
+
+    QStringList image_titles = ExtractImageTitles(response);
+
+    CountdownLatch* latch = new CountdownLatch;
+    NewClosure(latch, SIGNAL(Done()), [this, latch, id]() {
+      latch->deleteLater();
+      emit Finished(id);
+    });
+
+    for (const QString& image_title : image_titles) {
+      latch->Wait();
+      QUrl url(kWikipediaImageInfoUrl);
+      url.addQueryItem("titles", image_title);
+
+      QNetworkRequest request(url);
+      QNetworkReply* reply = network_->get(request);
+      NewClosure(reply, SIGNAL(finished()), [this, id, reply, latch]() {
+        reply->deleteLater();
+        QJson::Parser parser;
+        QVariantMap json = parser.parse(reply).toMap();
+        QString url = ExtractImageUrl(json);
+        qLog(Debug) << "Found wikipedia image url:" << url;
+        if (!url.isEmpty()) {
+          emit ImageReady(id, QUrl(url));
+        }
+        latch->CountDown();
+      });
+    }
   });
 }

src/songinfo/artistbiography.h

@@ -34,6 +34,8 @@ class ArtistBiography : public SongInfoProvider {
   void FetchInfo(int id, const Song& metadata) override;
 
  private:
+  void FetchWikipediaImages(int id, const QString& title);
+
   std::unique_ptr<NetworkAccessManager> network_;
 };
 

src/widgets/prettyimage.cpp

@@ -88,7 +88,8 @@ void PrettyImage::ImageFetched(RedirectFollower* follower) {
 
   QImage image = QImage::fromData(reply->readAll());
   if (image.isNull()) {
-    qLog(Debug) << "Image failed to load" << reply->request().url();
+    qLog(Debug) << "Image failed to load" << reply->request().url()
+                << reply->error();
     deleteLater();
   } else {
     state_ = State_CreatingThumbnail;