From c479d699d059bc58e6850d43b14f2e91c2076e12 Mon Sep 17 00:00:00 2001
From: ailurux <ailuruxx@gmail.com>
Date: Tue, 17 Sep 2024 14:13:05 +1000
Subject: [PATCH] Implements seeking to saved position for tracks

---
 lua/browser.lua                    |  4 +++-
 src/tangara/audio/audio_events.hpp |  2 ++
 src/tangara/audio/audio_fsm.cpp    |  2 +-
 src/tangara/audio/track_queue.cpp  | 23 ++++++++++++++++++++++-
 src/tangara/audio/track_queue.hpp  |  1 +
 src/tangara/lua/lua_queue.cpp      | 14 ++++++++++++++
 6 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/lua/browser.lua b/lua/browser.lua
index 731c1dc6..3d7e3e9d 100644
--- a/lua/browser.lua
+++ b/lua/browser.lua
@@ -105,8 +105,10 @@ return screen:new{
                         local track = database.track_by_id(contents)
                         if (track) then
                             print("Track saved position: ", track.saved_position)
+                            queue.play_from(track.filepath, track.saved_position)
+                        else 
+                            queue.add(contents)
                         end
-                        queue.add(contents)
                         playback.playing:set(true)
                         backstack.push(playing:new())
                     end
diff --git a/src/tangara/audio/audio_events.hpp b/src/tangara/audio/audio_events.hpp
index 56d150b2..89dc28ff 100644
--- a/src/tangara/audio/audio_events.hpp
+++ b/src/tangara/audio/audio_events.hpp
@@ -106,6 +106,8 @@ struct QueueUpdate : tinyfsm::Event {
     kBulkLoadingUpdate,
   };
   Reason reason;
+
+  std::optional<uint32_t> seek_to_second;
 };
 
 struct StepUpVolume : tinyfsm::Event {};
diff --git a/src/tangara/audio/audio_fsm.cpp b/src/tangara/audio/audio_fsm.cpp
index 71decd48..dd9f2fde 100644
--- a/src/tangara/audio/audio_fsm.cpp
+++ b/src/tangara/audio/audio_fsm.cpp
@@ -113,7 +113,7 @@ auto AudioState::emitPlaybackUpdate(bool paused) -> void {
 void AudioState::react(const QueueUpdate& ev) {
   SetTrack cmd{
       .new_track = std::monostate{},
-      .seek_to_second = {},
+      .seek_to_second = ev.seek_to_second,
   };
 
   auto current = sServices->track_queue().current();
diff --git a/src/tangara/audio/track_queue.cpp b/src/tangara/audio/track_queue.cpp
index 2c1faf96..ff24637b 100644
--- a/src/tangara/audio/track_queue.cpp
+++ b/src/tangara/audio/track_queue.cpp
@@ -85,6 +85,16 @@ auto notifyChanged(bool current_changed, Reason reason) -> void {
   events::Audio().Dispatch(ev);
 }
 
+auto notifyPlayFrom(uint32_t start_from_position) -> void {
+  QueueUpdate ev{
+      .current_changed = true,
+      .reason = Reason::kExplicitUpdate,
+      .seek_to_second = start_from_position,
+  };
+  events::Ui().Dispatch(ev);
+  events::Audio().Dispatch(ev);
+}
+
 TrackQueue::TrackQueue(tasks::WorkerPool& bg_worker, database::Handle db)
     : mutex_(),
       bg_worker_(bg_worker),
@@ -109,6 +119,17 @@ auto TrackQueue::current() const -> TrackItem {
   return val;
 }
 
+auto TrackQueue::playFromPosition(const std::string& filepath,
+                                  uint32_t position) -> void {
+  clear();
+  {
+    const std::unique_lock<std::shared_mutex> lock(mutex_);
+    playlist_.append(filepath);
+    updateShuffler(true);
+  }
+  notifyPlayFrom(position);
+}
+
 auto TrackQueue::currentPosition() const -> size_t {
   const std::shared_lock<std::shared_mutex> lock(mutex_);
   return position_;
@@ -245,7 +266,7 @@ auto TrackQueue::currentPosition(size_t position) -> bool {
     goTo(position);
   }
 
-  // If we're explicitly setting the position, we want to treat it as though 
+  // If we're explicitly setting the position, we want to treat it as though
   // the current track has changed, even if the position was the same
   notifyChanged(true, Reason::kExplicitUpdate);
   return true;
diff --git a/src/tangara/audio/track_queue.hpp b/src/tangara/audio/track_queue.hpp
index a8d1dc3a..727b4be0 100644
--- a/src/tangara/audio/track_queue.hpp
+++ b/src/tangara/audio/track_queue.hpp
@@ -78,6 +78,7 @@ class TrackQueue {
   auto open() -> bool;
   auto openPlaylist(const std::string& playlist_file, bool notify = true)
       -> bool;
+  auto playFromPosition(const std::string& filepath, uint32_t position) -> void;
 
   using Item =
       std::variant<database::TrackId, database::TrackIterator, std::string>;
diff --git a/src/tangara/lua/lua_queue.cpp b/src/tangara/lua/lua_queue.cpp
index 7eb32c62..07093390 100644
--- a/src/tangara/lua/lua_queue.cpp
+++ b/src/tangara/lua/lua_queue.cpp
@@ -79,10 +79,24 @@ static auto queue_open_playlist(lua_State* state) -> int {
   return 0;
 }
 
+static auto queue_play_from(lua_State* state) -> int {
+  Bridge* instance = Bridge::Get(state);
+  audio::TrackQueue& queue = instance->services().track_queue();
+  size_t len = 0;
+  const char* str = luaL_checklstring(state, 1, &len);
+  if (!str) {
+    return 0;
+  }
+  auto pos = luaL_checkinteger(state, 2);
+  queue.playFromPosition(str, pos);
+  return 0;
+}
+
 static const struct luaL_Reg kQueueFuncs[] = {
     {"add", queue_add},
     {"clear", queue_clear},
     {"open_playlist", queue_open_playlist},
+    {"play_from", queue_play_from},
     {NULL, NULL}};
 
 static auto lua_queue(lua_State* state) -> int {