Add an Encyclopaedia Metallum lyrics provider. Fixes issue 3568

data/lyrics/ultimate_providers.xml

@@ -43,6 +43,14 @@
     </exclude>
     <invalidIndicator value="Page not Found"/>
   </provider>
+  <provider name="Encyclopaedia Metallum" title="{title Lyrics - {artist}" charset="utf-8" url="http://www.metal-archives.com/search/ajax-advanced/searching/songs/?songTitle={title}&amp;bandName={artist}&amp;ExactBandMatch=1">
+    <extract>
+      <item url="http://www.metal-archives.com/release/ajax-view-lyrics/id/{id}"/>
+      <item begin="id=\&quot;lyricsLink_" end="&quot;"/>
+    </extract>
+    <invalidIndicator value="&quot;iTotalRecords&quot;: 0"/>
+    <invalidIndicator value="lyrics not available"/>
+  </provider>
   <provider name="letras.mus.br" title="" charset="iso-8859-1" url="http://letras.terra.com.br/winamp.php?musica={title}&amp;artista={artist}">
     <urlFormat replace="_@,;&amp;\/&quot;" with="_"/>
     <urlFormat replace=" " with="+"/>

src/songinfo/ultimatelyricsprovider.cpp

@@ -34,7 +34,8 @@ const int UltimateLyricsProvider::kRedirectLimit = 5;
 UltimateLyricsProvider::UltimateLyricsProvider()
   : network_(new NetworkAccessManager(this)),
     relevance_(0),
-    redirect_count_(0)
+    redirect_count_(0),
+    url_hop_(false)
 {
 }
 
@@ -64,13 +65,16 @@ void UltimateLyricsProvider::FetchInfo(int id, const Song& metadata) {
 
 void UltimateLyricsProvider::LyricsFetched() {
   QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
-  if (!reply)
+  if (!reply) {
+    url_hop_ = false;
     return;
+  }
 
   int id = requests_.take(reply);
   reply->deleteLater();
 
   if (reply->error() != QNetworkReply::NoError) {
+    url_hop_ = false;
     emit Finished(id);
     return;
   }
@@ -79,6 +83,7 @@ void UltimateLyricsProvider::LyricsFetched() {
   QVariant redirect_target = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
   if (redirect_target.isValid()) {
     if (redirect_count_ >= kRedirectLimit) {
+      url_hop_ = false;
       emit Finished(id);
       return;
     }
@@ -105,11 +110,13 @@ void UltimateLyricsProvider::LyricsFetched() {
   foreach (const QString& indicator, invalid_indicators_) {
     if (original_content.contains(indicator)) {
       qLog(Debug) << "Found invalid indicator" << indicator;
+      url_hop_ = false;
       emit Finished(id);
       return;
     }
   }
 
+  if (!url_hop_) {
     // Apply extract rules
     foreach (const Rule& rule, extract_rules_) {
       // Modify the rule for this request's metadata
@@ -119,18 +126,28 @@ void UltimateLyricsProvider::LyricsFetched() {
       }
 
       QString content = original_content;
-    ApplyExtractRule(rule_copy, &content);
+      if (ApplyExtractRule(rule_copy, &content)) {
-    qLog(Debug) << "Extract rule" << rule_copy << "matched" << content.length();
+        url_hop_ = true;
+        QUrl url(content);
+        qLog(Debug) << "Next url hop: " << url;
+        QNetworkReply* reply = network_->get(QNetworkRequest(url));
+        requests_[reply] = id;
+        connect(reply, SIGNAL(finished()), SLOT(LyricsFetched()));
+        return;
+      }
+
+      // Apply exclude rules
+      foreach (const Rule& rule, exclude_rules_) {
+        ApplyExcludeRule(rule, &lyrics);
+      }
 
       if (!content.isEmpty()) {
         lyrics = content;
         break;
       }
     }
-
+  } else {
-  // Apply exclude rules
+    lyrics = original_content;
-  foreach (const Rule& rule, exclude_rules_) {
-    ApplyExcludeRule(rule, &lyrics);
   }
 
   if (!lyrics.isEmpty()) {
@@ -152,17 +169,40 @@ void UltimateLyricsProvider::LyricsFetched() {
 
     emit InfoReady(id, data);
   }
+  url_hop_ = false;
   emit Finished(id);
 }
 
-void UltimateLyricsProvider::ApplyExtractRule(const Rule& rule, QString* content) const {
+bool UltimateLyricsProvider::ApplyExtractRule(const Rule& rule, QString* content) const {
   foreach (const RuleItem& item, rule) {
     if (item.second.isNull()) {
+      if (item.first.startsWith("http://") && item.second.isNull()) {
+        *content = ExtractUrl(*content, rule);
+        return true;
+      } else {
         *content = ExtractXmlTag(*content, item.first);        
+      }
     } else {
       *content = Extract(*content, item.first, item.second);
     }
   }
+  return false;
+}
+
+QString UltimateLyricsProvider::ExtractUrl(const QString& source, const Rule& rule) {
+  QString url;
+  QString id;
+
+  foreach(const RuleItem& item, rule) {
+    if (item.first.startsWith("http://") && item.second.isNull())
+      url = item.first;
+    else
+      id = Extract(source, item.first,item.second);
+  }
+
+  url.replace("{id}", id);
+
+  return url;
 }
 
 QString UltimateLyricsProvider::ExtractXmlTag(const QString& source, const QString& tag) {

src/songinfo/ultimatelyricsprovider.h

@@ -62,9 +62,10 @@ private slots:
   void LyricsFetched();
 
 private:
-  void ApplyExtractRule(const Rule& rule, QString* content) const;
+  bool ApplyExtractRule(const Rule& rule, QString* content) const;
   void ApplyExcludeRule(const Rule& rule, QString* content) const;
 
+  static QString ExtractUrl(const QString& source, const Rule& rule);
   static QString ExtractXmlTag(const QString& source, const QString& tag);
   static QString Extract(const QString& source, const QString& begin, const QString& end);
   static QString ExcludeXmlTag(const QString& source, const QString& tag);
@@ -93,6 +94,7 @@ private:
 
   Song metadata_;
   int redirect_count_;
+  bool url_hop_;
 };
 
 #endif // ULTIMATELYRICSPROVIDER_H

src/songinfo/ultimatelyricsreader.cpp

@@ -110,6 +110,8 @@ UltimateLyricsProvider::Rule UltimateLyricsReader::ParseRule(QXmlStreamReader* r
         QXmlStreamAttributes attr = reader->attributes();
         if (attr.hasAttribute("tag"))
           ret << UltimateLyricsProvider::RuleItem(attr.value("tag").toString(), QString());
+        else if (attr.hasAttribute("url"))
+          ret << UltimateLyricsProvider::RuleItem(attr.value("url").toString(), QString());
         else if (attr.hasAttribute("begin"))
           ret << UltimateLyricsProvider::RuleItem(attr.value("begin").toString(),
                                                   attr.value("end").toString());