Subsonic API: added getLyrics/getLyricsBySongId support, ref #379

src/libs/subsonic/impl/SubsonicResource.cpp

@@ -200,7 +200,8 @@ namespace lms::api::subsonic
             // Media retrieval
             { "/hls", { handleNotImplemented } },
             { "/getCaptions", { handleNotImplemented } },
-            { "/getLyrics", { handleNotImplemented } },
+            { "/getLyrics", { handleGetLyrics } },
+            { "/getLyricsBySongId", { handleGetLyricsBySongId } },
             { "/getAvatar", { handleNotImplemented } },
 
             // Media annotation

src/libs/subsonic/impl/SubsonicResponse.cpp

@@ -196,7 +196,11 @@ namespace lms::api::subsonic
             auto valueToPropertyTree = [](const Node::ValueType& value) {
                 boost::property_tree::ptree res;
                 std::visit([&](const auto& rawValue) {
-                    res.put_value(rawValue);
+                    using RawValueType = std::decay_t<decltype(rawValue)>;
+                    if constexpr (std::is_same_v<RawValueType, Node::string>)
+                        res.put_value(core::stringUtils::replaceInString(rawValue, "\n", "\\n"));
+                    else
+                        res.put_value(rawValue);
                 },
                     value);
 

src/libs/subsonic/impl/entrypoints/MediaRetrieval.cpp

@@ -31,11 +31,13 @@
 #include "core/Utils.hpp"
 #include "database/Session.hpp"
 #include "database/Track.hpp"
+#include "database/TrackLyrics.hpp"
 #include "database/User.hpp"
 #include "services/artwork/IArtworkService.hpp"
 
 #include "ParameterParsing.hpp"
 #include "SubsonicId.hpp"
+#include "responses/Lyrics.hpp"
 
 namespace lms::api::subsonic
 {
@@ -189,6 +191,59 @@ namespace lms::api::subsonic
         }
     } // namespace
 
+    Response handleGetLyrics(RequestContext& context)
+    {
+        std::string artistName{ getParameterAs<std::string>(context.parameters, "artist").value_or("") };
+        std::string titleName{ getParameterAs<std::string>(context.parameters, "title").value_or("") };
+
+        Response response{ Response::createOkResponse(context.serverProtocolVersion) };
+
+        // best effort search, as this API is really limited
+        auto transaction{ context.dbSession.createReadTransaction() };
+
+        db::Track::FindParameters params;
+        params.name = titleName;
+        params.artistName = artistName;
+        params.range = Range{ 0, 2 };
+
+        // Choice: we return nothing if there are too many results
+        const auto tracks{ db::Track::findIds(context.dbSession, params) };
+        if (tracks.results.size() == 1)
+        {
+            // Choice: we return only the first lyrics if the track has many lyrics
+            bool lyricsSet{};
+            db::TrackLyrics::find(context.dbSession, tracks.results[0], [&](const db::TrackLyrics::pointer& lyrics) {
+                if (lyricsSet)
+                    return;
+                response.addNode("lyrics", createLyricsNode(context, lyrics));
+                lyricsSet = true;
+            });
+        }
+
+        return response;
+    }
+
+    Response handleGetLyricsBySongId(RequestContext& context)
+    {
+        // mandatory params
+        db::TrackId id{ getMandatoryParameterAs<db::TrackId>(context.parameters, "id") };
+
+        Response response{ Response::createOkResponse(context.serverProtocolVersion) };
+        Response::Node& lyricsList{ response.createNode("lyricsList") };
+        lyricsList.createEmptyArrayChild("structuredLyrics");
+
+        auto transaction{ context.dbSession.createReadTransaction() };
+        const db::Track::pointer track{ db::Track::find(context.dbSession, id) };
+        if (track)
+        {
+            db::TrackLyrics::find(context.dbSession, track->getId(), [&](const db::TrackLyrics::pointer& lyrics) {
+                lyricsList.addArrayChild("structuredLyrics", createStructuredLyricsNode(context, lyrics));
+            });
+        }
+
+        return response;
+    }
+
     void handleDownload(RequestContext& context, const Wt::Http::Request& request, Wt::Http::Response& response)
     {
         std::shared_ptr<IResourceHandler> resourceHandler;

src/libs/subsonic/impl/entrypoints/MediaRetrieval.hpp

@@ -26,6 +26,9 @@
 
 namespace lms::api::subsonic
 {
+    Response handleGetLyrics(RequestContext& context);
+    Response handleGetLyricsBySongId(RequestContext& context);
+
     void handleDownload(RequestContext& context, const Wt::Http::Request& request, Wt::Http::Response& response);
     void handleStream(RequestContext& context, const Wt::Http::Request& request, Wt::Http::Response& response);
     void handleGetCoverArt(RequestContext& context, const Wt::Http::Request& request, Wt::Http::Response& response);

src/libs/subsonic/impl/entrypoints/System.cpp

@@ -35,6 +35,12 @@ namespace lms::api::subsonic
             formPostNode.addArrayValue("versions", 1);
         }
 
+        {
+            Response::Node& songLyricsNode{ response.createArrayNode("openSubsonicExtensions") };
+            songLyricsNode.setAttribute("name", "songLyrics");
+            songLyricsNode.addArrayValue("versions", 1);
+        }
+
         return response;
     };
 } // namespace lms::api::subsonic

src/libs/subsonic/impl/responses/Lyrics.cpp

@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2024 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "responses/Lyrics.hpp"
+
+#include "database/TrackLyrics.hpp"
+
+#include "RequestContext.hpp"
+
+namespace lms::api::subsonic
+{
+    Response::Node createLyricsNode(RequestContext& context, const db::TrackLyrics::pointer& lyrics)
+    {
+        Response::Node lyricsNode;
+
+        if (!lyrics->getDisplayArtist().empty())
+            lyricsNode.setAttribute("artist", lyrics->getDisplayArtist());
+
+        if (!lyrics->getDisplayTitle().empty())
+            lyricsNode.setAttribute("title", lyrics->getDisplayTitle());
+
+        std::string lyricsText;
+        auto addLine{ [&](std::string&& line) {
+            if (!lyricsText.empty())
+                lyricsText += "\n";
+            lyricsText += std::move(line);
+        } };
+        if (!lyrics->isSynchronized())
+        {
+            std::vector<std::string> lines{ lyrics->getUnsynchronizedLines() };
+            for (std::string& line : lines)
+                addLine(std::move(line));
+        }
+        else
+        {
+            // Reconstruct the lyrics without timestamp if needed
+            db::TrackLyrics::SynchronizedLines lines{ lyrics->getSynchronizedLines() };
+            for (auto& [timestamp, line] : lines)
+                addLine(std::move(line));
+        }
+
+        switch (context.responseFormat)
+        {
+        case ResponseFormat::json:
+            lyricsNode.setAttribute("value", lyricsText);
+            break;
+        case ResponseFormat::xml:
+            lyricsNode.setValue(lyricsText);
+            break;
+        }
+
+        return lyricsNode;
+    }
+
+    Response::Node createStructuredLyricsNode(RequestContext& context, const db::ObjectPtr<db::TrackLyrics>& lyrics)
+    {
+        Response::Node lyricsNode;
+
+        if (!lyrics->getDisplayArtist().empty())
+            lyricsNode.setAttribute("artist", lyrics->getDisplayArtist());
+
+        if (!lyrics->getDisplayTitle().empty())
+            lyricsNode.setAttribute("title", lyrics->getDisplayTitle());
+
+        lyricsNode.setAttribute("lang", lyrics->getLanguage());
+        lyricsNode.setAttribute("synced", lyrics->isSynchronized());
+        if (lyrics->getOffset() != std::chrono::milliseconds{})
+            lyricsNode.setAttribute("offset", lyrics->getOffset().count());
+
+        lyricsNode.createEmptyArrayChild("lines");
+        auto addLine{ [&](std::string&& line, std::optional<std::chrono::milliseconds> timestamp = std::nullopt) {
+            Response::Node lineNode;
+            if (timestamp)
+                lineNode.setAttribute("start", std::chrono::duration_cast<std::chrono::milliseconds>(*timestamp).count());
+
+            switch (context.responseFormat)
+            {
+            case ResponseFormat::json:
+                lineNode.setAttribute("value", std::move(line));
+                break;
+            case ResponseFormat::xml:
+                lineNode.setValue(std::move(line));
+                break;
+            }
+            lyricsNode.addArrayChild("lines", std::move(lineNode));
+        } };
+
+        if (!lyrics->isSynchronized())
+        {
+            std::vector<std::string> lines{ lyrics->getUnsynchronizedLines() };
+
+            for (std::string& line : lines)
+                addLine(std::move(line));
+        }
+        else
+        {
+            db::TrackLyrics::SynchronizedLines lines{ lyrics->getSynchronizedLines() };
+            for (auto& [timestamp, line] : lines)
+                addLine(std::move(line), timestamp);
+        }
+
+        return lyricsNode;
+    }
+
+} // namespace lms::api::subsonic

src/libs/subsonic/impl/responses/Lyrics.hpp

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2024 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "database/Object.hpp"
+
+#include "SubsonicResponse.hpp"
+
+namespace lms::db
+{
+    class TrackLyrics;
+}
+
+namespace lms::api::subsonic
+{
+    struct RequestContext;
+
+    Response::Node createLyricsNode(RequestContext& context, const db::ObjectPtr<db::TrackLyrics>& lyrics);
+    Response::Node createStructuredLyricsNode(RequestContext& context, const db::ObjectPtr<db::TrackLyrics>& lyrics);
+} // namespace lms::api::subsonic