Flesh out audio state machine for playback

Also fix mono playback

5 files changed, 25 insertions, 0 deletions

diff --git a/src/audio/include/audio_events.hpp b/src/audio/include/audio_events.hpp
index 765e0899..920b134e 100644
--- a/src/audio/include/audio_events.hpp
+++ b/src/audio/include/audio_events.hpp
@@ -24,4 +24,7 @@ struct PlaySong : tinyfsm::Event {
   std::optional<database::SongTags> tags;
 };
 
+struct InputFileFinished : tinyfsm::Event {};
+struct AudioPipelineIdle : tinyfsm::Event {};
+
 }  // namespace audio
diff --git a/src/audio/include/audio_fsm.hpp b/src/audio/include/audio_fsm.hpp
index 6274041c..5dad87c0 100644
--- a/src/audio/include/audio_fsm.hpp
+++ b/src/audio/include/audio_fsm.hpp
@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <deque>
 #include <memory>
 #include <vector>
 
@@ -16,6 +17,7 @@
 #include "gpio_expander.hpp"
 #include "i2s_audio_output.hpp"
 #include "i2s_dac.hpp"
+#include "song.hpp"
 #include "storage.hpp"
 #include "tinyfsm.hpp"
 
@@ -40,6 +42,9 @@ class AudioState : public tinyfsm::Fsm<AudioState> {
   virtual void react(const PlaySong&) {}
   virtual void react(const PlayFile&) {}
 
+  virtual void react(const InputFileFinished&) {}
+  virtual void react(const AudioPipelineIdle&) {}
+
  protected:
   static drivers::GpioExpander* sGpioExpander;
   static std::shared_ptr<drivers::I2SDac> sDac;
@@ -49,6 +54,9 @@ class AudioState : public tinyfsm::Fsm<AudioState> {
   static std::unique_ptr<FatfsAudioInput> sFileSource;
   static std::unique_ptr<I2SAudioOutput> sI2SOutput;
   static std::vector<std::unique_ptr<IAudioElement>> sPipeline;
+
+  typedef std::variant<database::SongId, std::string> EnqueuedItem;
+  static std::deque<EnqueuedItem> sSongQueue;
 };
 
 namespace states {
@@ -68,6 +76,12 @@ class Standby : public AudioState {
 
 class Playback : public AudioState {
  public:
+  void entry() override;
+  void exit() override;
+
+  void react(const InputFileFinished&) override;
+  void react(const AudioPipelineIdle&) override;
+
   using AudioState::react;
 };
 
diff --git a/src/audio/include/audio_sink.hpp b/src/audio/include/audio_sink.hpp
index 2cc706ff..e6538bda 100644
--- a/src/audio/include/audio_sink.hpp
+++ b/src/audio/include/audio_sink.hpp
@@ -40,6 +40,8 @@ class IAudioSink {
     free(metadata_);
   }
 
+  virtual auto SetInUse(bool) -> void {}
+
   virtual auto SetVolumeImbalance(int_fast8_t balance) -> void = 0;
   virtual auto SetVolume(uint_fast8_t percent) -> void = 0;
   virtual auto GetVolume() -> uint_fast8_t = 0;
diff --git a/src/audio/include/i2s_audio_output.hpp b/src/audio/include/i2s_audio_output.hpp
index 20980573..7c125476 100644
--- a/src/audio/include/i2s_audio_output.hpp
+++ b/src/audio/include/i2s_audio_output.hpp
@@ -29,6 +29,8 @@ class I2SAudioOutput : public IAudioSink {
                  std::weak_ptr<drivers::DigitalPot> pots);
   ~I2SAudioOutput();
 
+  auto SetInUse(bool) -> void override;
+
   auto SetVolumeImbalance(int_fast8_t balance) -> void override;
   auto SetVolume(uint_fast8_t percent) -> void override;
   auto GetVolume() -> uint_fast8_t override;
diff --git a/src/audio/include/pipeline.hpp b/src/audio/include/pipeline.hpp
index c1f6bf59..bb773006 100644
--- a/src/audio/include/pipeline.hpp
+++ b/src/audio/include/pipeline.hpp
@@ -36,6 +36,10 @@ class Pipeline {
 
   auto GetIterationOrder() -> std::vector<Pipeline*>;
 
+  // Not copyable or movable.
+  Pipeline(const Pipeline&) = delete;
+  Pipeline& operator=(const Pipeline&) = delete;
+
  private:
   IAudioElement* root_;
   std::vector<std::unique_ptr<Pipeline>> subtrees_;