WIP: Add download feature

src/asyncytmusic.cpp

@@ -10,6 +10,7 @@
 #include <QJsonArray>
 #include <QFutureInterface>
 #include <QCoreApplication>
+#include <QTimer>
 
 #include <pybind11/embed.h>
 
@@ -55,6 +56,17 @@ AsyncYTMusic::AsyncYTMusic(QObject *parent)
     connect(this, &AsyncYTMusic::errorOccurred, this, [](const QString &err) {
         std::cerr << qPrintable(err);
     });
+
+    QTimer::singleShot(0, [this]() {
+        qDebug() << "Downloading album";
+        downloadPlaylist("https://music.youtube.com/watch?v=8rIjsa85UVk&list=RDAMVM8rIjsa85UVk", [](YtDlDownloadStatus status) {
+            if (!status.finished && status.current_track) {
+                std::cout << *status.current_track << std::endl;
+            } else if (status.finished) {
+                std::cout << "Download finished" << std::endl;
+            }
+        });
+    });
 }
 
 //
@@ -148,6 +160,13 @@ QFuture<Lyrics> AsyncYTMusic::fetchLyrics(const QString &browseId)
     });
 }
 
+QFuture<void> AsyncYTMusic::downloadPlaylist(const std::string &url, std::function<void (YtDlDownloadStatus)> progressHook)
+{
+    return invokeAndCatchOnThread([=, this]() {
+        m_ytm->download_playlist(url, progressHook);
+    });
+}
+
 YTMusicThread &YTMusicThread::instance()
 {
     static YTMusicThread thread;

src/asyncytmusic.h

@@ -123,6 +123,8 @@ public:
 
     QFuture<Lyrics> fetchLyrics(const QString &browseId);
 
+    QFuture<void> downloadPlaylist(const std::string &url, std::function<void(YtDlDownloadStatus)> progressHook);
+
     Q_SIGNAL void errorOccurred(const QString &error);
 
 protected:
@@ -136,8 +138,12 @@ private:
         auto interface = std::make_shared<QFutureInterface<ReturnType>>();
         QMetaObject::invokeMethod(this, [=, this]() {
             try {
-                ReturnType val = fun();
-                interface->reportResult(val);
+                if constexpr (!std::is_same_v<std::invoke_result_t<Func>, void>) {
+                    ReturnType val = fun();
+                    interface->reportResult(val);
+                } else {
+                    fun();
+                }
                 interface->reportFinished();
             } catch (const std::exception &err) {
                 interface->reportFinished();

src/ytmusic.cpp

@@ -497,7 +497,6 @@ watch::Playlist YTMusic::get_watch_playlist(const std::optional<std::string> &vi
     };
 }
 
-
 Lyrics YTMusic::get_lyrics(const std::string &browse_id) const
 {
     auto lyrics = d->get_ytmusic().attr("get_lyrics")(browse_id);
@@ -507,3 +506,30 @@ Lyrics YTMusic::get_lyrics(const std::string &browse_id) const
         lyrics["lyrics"].cast<std::string>()
     };
 }
+
+void YTMusic::download_playlist(const std::string &playlist_url, std::function<void (YtDlDownloadStatus)> progress_hook) const
+{
+    py::module::import("ytmx.ytmx").attr("YTMX")(std::vector {playlist_url}, py::cpp_function([=](const py::dict &ytdl_status) {
+        if (ytdl_status["status"].cast<std::string>() == "finished") {
+            int current_track_index = ytdl_status["info_dict"]["playlist_index"].cast<int>();
+            int playlist_length = ytdl_status["info_dict"]["playlist_count"].cast<int>();
+            auto current_track = ytdl_status["info_dict"]["title"].cast<std::string>();
+
+            progress_hook(YtDlDownloadStatus {
+                .finished = true,
+                .playlist_length = playlist_length,
+                .current_track_index = current_track_index,
+            });
+        } else if (ytdl_status["status"].cast<std::string>() == "downloading") {
+            int current_track_index = ytdl_status["info_dict"]["playlist_index"].cast<int>();
+            int playlist_length = ytdl_status["info_dict"]["playlist_count"].cast<int>();
+            auto current_track = ytdl_status["info_dict"]["title"].cast<std::string>();
+
+            progress_hook(YtDlDownloadStatus {
+                  .playlist_length = playlist_length,
+                  .current_track_index = current_track_index,
+                  .current_track = current_track
+              });
+        }
+    }));
+}

src/ytmusic.h

@@ -11,6 +11,7 @@
 #include <variant>
 #include <vector>
 #include <memory>
+#include <functional>
 
 struct YTMusicPrivate;
 
@@ -277,6 +278,13 @@ struct Lyrics {
     std::string lyrics;
 };
 
+struct YtDlDownloadStatus {
+    bool finished = false;
+    int playlist_length;
+    std::optional<int> current_track_index;
+    std::optional<std::string> current_track;
+};
+
 class YTMusic
 {
 public:
@@ -319,6 +327,9 @@ public:
 
     Lyrics get_lyrics(const std::string &browse_id) const;
 
+    void download_playlist(const std::string &playlist_url,
+                           std::function<void(YtDlDownloadStatus)> progress_hook) const;
+
     // TODO wrap more methods
 
 private: