Start on audio FSM playback. needs more thought.

src/audio/audio_fsm.cpp

@@ -6,6 +6,7 @@
 
 #include "audio_fsm.hpp"
 #include "audio_decoder.hpp"
+#include "audio_events.hpp"
 #include "audio_task.hpp"
 #include "dac.hpp"
 #include "fatfs_audio_input.hpp"
@@ -50,6 +51,12 @@ void Uninitialised::react(const system_fsm::BootComplete&) {
   });
 }
 
+void Standby::react(const PlayFile &ev) {
+  if (sFileSource->OpenFile(ev.filename)) {
+    transit<Playback>();
+  }
+}
+
 }  // namespace states
 
 }  // namespace audio

src/audio/audio_task.cpp

@@ -21,6 +21,7 @@
 #include "esp_err.h"
 #include "esp_heap_caps.h"
 #include "esp_log.h"
+#include "event_queue.hpp"
 #include "freertos/portmacro.h"
 #include "freertos/projdefs.h"
 #include "freertos/queue.h"
@@ -44,10 +45,14 @@ static const char* kTag = "task";
 
 void AudioTaskMain(std::unique_ptr<Pipeline> pipeline, IAudioSink* sink) {
   std::optional<StreamInfo::Format> output_format;
+  uint_fast16_t delay_ticks = pdMS_TO_TICKS(5);
 
   std::vector<Pipeline*> elements = pipeline->GetIterationOrder();
 
+  events::EventQueue &event_queue = events::EventQueue::GetInstance();
   while (1) {
+    event_queue.ServiceAudio(delay_ticks);
+
     for (int i = 0; i < elements.size(); i++) {
       std::vector<RawStream> raw_in_streams;
       elements.at(i)->InStreams(&raw_in_streams);

src/audio/fatfs_audio_input.cpp

@@ -35,7 +35,7 @@ FatfsAudioInput::FatfsAudioInput()
 
 FatfsAudioInput::~FatfsAudioInput() {}
 
-auto FatfsAudioInput::OpenFile(const std::string& path) -> void {
+auto FatfsAudioInput::OpenFile(const std::string& path) -> bool {
   if (is_file_open_) {
     f_close(&current_file_);
     is_file_open_ = false;
@@ -44,11 +44,11 @@ auto FatfsAudioInput::OpenFile(const std::string& path) -> void {
   FRESULT res = f_open(&current_file_, path.c_str(), FA_READ);
   if (res != FR_OK) {
     ESP_LOGE(kTag, "failed to open file! res: %i", res);
-    // TODO(jacqueline): Handle errors.
-    return;
+    return false;
   }
 
   is_file_open_ = true;
+  return true;
 }
 
 auto FatfsAudioInput::Process(const std::vector<InputStream>& inputs,

src/audio/include/audio_events.hpp

@@ -6,14 +6,22 @@
 
 #pragma once
 
+#include <string>
+
 #include "tinyfsm.hpp"
 
 #include "song.hpp"
 
 namespace audio {
 
+struct PlayFile : tinyfsm::Event {
+  std::string filename;
+};
+
 struct PlaySong : tinyfsm::Event {
   database::SongId id;
+  std::optional<database::SongData> data;
+  std::optional<database::SongTags> tags;
 };
 
 }  // namespace audio

src/audio/include/audio_fsm.hpp

@@ -37,6 +37,7 @@ class AudioState : public tinyfsm::Fsm<AudioState> {
 
   virtual void react(const system_fsm::BootComplete&) {}
   virtual void react(const PlaySong&) {}
+  virtual void react(const PlayFile&) {}
 
  protected:
   static drivers::GpioExpander* sGpioExpander;
@@ -59,6 +60,12 @@ class Uninitialised : public AudioState {
 class Standby : public AudioState {
  public:
   void react(const PlaySong&) override {}
+  void react(const PlayFile&) override;
+  using AudioState::react;
+};
+
+class Playback : public AudioState {
+ public:
   using AudioState::react;
 };
 

src/audio/include/fatfs_audio_input.hpp

@@ -28,10 +28,10 @@ namespace audio {
 
 class FatfsAudioInput : public IAudioElement {
  public:
-  explicit FatfsAudioInput();
+  FatfsAudioInput();
   ~FatfsAudioInput();
 
-  auto OpenFile(const std::string& path) -> void;
+  auto OpenFile(const std::string& path) -> bool;
 
   auto Process(const std::vector<InputStream>& inputs, OutputStream* output)
       -> void override;