Add basics of last.fm suggester and library resolver.

src/CMakeLists.txt

@@ -185,6 +185,8 @@ set(SOURCES
   radio/somafmservice.cpp
   radio/somafmurlhandler.cpp
 
+  resolvers/libraryresolver.cpp
+
   scripting/installscriptdialog.cpp
   scripting/languageengine.cpp
   scripting/script.cpp
@@ -222,6 +224,8 @@ set(SOURCES
   songinfo/ultimatelyricsprovider.cpp
   songinfo/ultimatelyricsreader.cpp
 
+  suggesters/lastfmsuggester.cpp
+
   transcoder/transcodedialog.cpp
   transcoder/transcoder.cpp
   transcoder/transcoderoptionsaac.cpp
@@ -397,6 +401,8 @@ set(HEADERS
   radio/somafmservice.h
   radio/somafmurlhandler.h
 
+  resolvers/libraryresolver.h
+
   scripting/installscriptdialog.h
   scripting/languageengine.h
   scripting/scriptdialog.h
@@ -428,6 +434,8 @@ set(HEADERS
   songinfo/ultimatelyricsprovider.h
   songinfo/ultimatelyricsreader.h
 
+  suggesters/lastfmsuggester.h
+
   transcoder/transcodedialog.h
   transcoder/transcoder.h
   transcoder/transcoderoptionsdialog.h

src/resolvers/libraryresolver.cpp

@@ -0,0 +1,62 @@
+#include "libraryresolver.h"
+
+#include <QtConcurrentRun>
+
+#include <boost/scoped_ptr.hpp>
+
+#include "core/boundfuturewatcher.h"
+#include "core/song.h"
+#include "library/librarybackend.h"
+#include "library/libraryquery.h"
+#include "library/sqlrow.h"
+
+using boost::scoped_ptr;
+
+LibraryResolver::LibraryResolver(LibraryBackendInterface* backend, QObject* parent)
+    : QObject(parent),
+      backend_(backend) {
+}
+
+int LibraryResolver::ResolveSong(const Song& song) {
+  LibraryQuery* query = new LibraryQuery;
+  query->AddWhere("artist", song.artist());
+  query->AddWhere("title", song.title());
+
+  QFuture<bool> future = QtConcurrent::run(
+      backend_, &LibraryBackendInterface::ExecQuery, query);
+  BoundFutureWatcher<bool, LibraryQuery*>* watcher =
+      new BoundFutureWatcher<bool, LibraryQuery*>(query);
+  watcher->setFuture(future);
+  connect(watcher, SIGNAL(finished()), SLOT(QueryFinished()));
+
+  int id = next_id_++;
+  queries_[query] = id;
+
+  return id;
+}
+
+void LibraryResolver::QueryFinished() {
+  BoundFutureWatcher<bool, LibraryQuery*>* watcher =
+      static_cast<BoundFutureWatcher<bool, LibraryQuery*>*>(sender());
+  scoped_ptr<LibraryQuery> query(watcher->data());
+  watcher->deleteLater();
+
+  QMap<LibraryQuery*, int>::iterator it = queries_.find(query.get());
+  if (it == queries_.end()) {
+    return;
+  }
+
+  int id = it.value();
+  queries_.erase(it);
+
+  SongList songs;
+  if (watcher->result() && query->Next()) {
+    do {
+      Song song;
+      song.InitFromQuery(*query);
+      songs << song;
+    } while (query->Next());
+  }
+
+  emit ResolveFinished(id, songs);
+}

src/resolvers/libraryresolver.h

@@ -0,0 +1,32 @@
+#ifndef LIBRARYRESOLVER_H
+#define LIBRARYRESOLVER_H
+
+#include <QMap>
+#include <QObject>
+
+#include "core/song.h"
+
+class QNetworkReply;
+
+class LibraryBackendInterface;
+class LibraryQuery;
+
+class LibraryResolver : public QObject {
+  Q_OBJECT
+ public:
+  LibraryResolver(LibraryBackendInterface* backend, QObject* parent = 0);
+  int ResolveSong(const Song& song);
+
+ signals:
+  void ResolveFinished(int id, SongList songs);
+
+ private slots:
+  void QueryFinished();
+
+ private:
+  LibraryBackendInterface* backend_;
+  QMap<LibraryQuery*, int> queries_;
+  int next_id_;
+};
+
+#endif  // LIBRARYRESOLVER_H

src/suggesters/lastfmsuggester.cpp

@@ -0,0 +1,66 @@
+#include "lastfmsuggester.h"
+
+#include <lastfm/XmlQuery>
+
+#include "core/logging.h"
+#include "core/timeconstants.h"
+
+using lastfm::XmlQuery;
+
+LastFMSuggester::LastFMSuggester(QObject* parent)
+  : QObject(parent),
+    next_id_(0) {
+}
+
+int LastFMSuggester::SuggestSongs(const Song& song) {
+  QMap<QString, QString> params;
+  params["method"] = "track.getsimilar";
+  params["track"] = song.title();
+  params["artist"] = song.artist();
+  params["limit"] = "25";
+  QNetworkReply* reply = lastfm::ws::get(params);
+  connect(reply, SIGNAL(finished()), SLOT(RequestFinished()));
+
+  int id = next_id_++;
+  replies_[reply] = id;
+
+  return id;
+}
+
+void LastFMSuggester::RequestFinished() {
+  QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
+  Q_ASSERT(reply);
+  reply->deleteLater();
+
+  QMap<QNetworkReply*, int>::iterator it = replies_.find(reply);
+  if (it == replies_.end()) {
+    return;
+  }
+  int id = it.value();
+  replies_.erase(it);
+
+  try {
+    lastfm::XmlQuery const lfm = lastfm::ws::parse(reply);
+#ifdef Q_OS_WIN32
+    if (lastfm::ws::last_parse_error != lastfm::ws::NoError)
+      throw std::runtime_error("");
+#endif
+
+    const QList<XmlQuery> tracks = lfm["similartracks"].children("track");
+    SongList songs;
+    foreach (const XmlQuery& q, tracks) {
+      Song song;
+      song.Init(
+          q["name"].text(),
+          q["artist"]["name"].text(),
+          QString::null,
+          QString(q["duration"].text()).toInt() * kNsecPerMsec);
+      songs << song;
+    }
+    qLog(Debug) << songs.length() << "suggested songs from Last.fm";
+    emit SuggestSongsFinished(id, songs);
+  } catch (std::runtime_error& e) {
+    qLog(Error) << e.what();
+    emit SuggestSongsFinished(id, SongList());
+  }
+}

src/suggesters/lastfmsuggester.h

@@ -0,0 +1,30 @@
+#ifndef LASTFMSUGGESTER_H
+#define LASTFMSUGGESTER_H
+
+#include <QMap>
+#include <QObject>
+
+#include <lastfm/ws.h>
+
+#include "core/song.h"
+
+class LastFMSuggester : public QObject {
+  Q_OBJECT
+ public:
+  LastFMSuggester(QObject* parent = 0);
+
+ public slots:
+  int SuggestSongs(const Song& song);
+
+ signals:
+  void SuggestSongsFinished(int id, const SongList& songs);
+
+ private slots:
+  void RequestFinished();
+
+ private:
+  QMap<QNetworkReply*, int> replies_;
+  int next_id_;
+};
+
+#endif  // LASTFMSUGGESTER_H