Play basic wav files in response to tts prompts

It's currently quite limited (no stereo or sample rate conversion,
multiple messages clobber each other, only plays if music is playing),
but we're getting there!

src/tangara/audio/audio_fsm.cpp

@@ -226,7 +226,7 @@ void AudioState::react(const internal::StreamStarted& ev) {
   }
 
   sStreamCues.addCue(ev.track, ev.cue_at_sample);
-  sStreamCues.update(sDrainBuffer->totalReceived());
+  sStreamCues.update(sDrainBuffers->first.totalReceived());
 
   if (!sIsPaused && !is_in_state<states::Playback>()) {
     transit<states::Playback>();

src/tangara/tts/player.cpp

@@ -6,7 +6,10 @@
 
 #include "tts/player.hpp"
 
+#include "codec.hpp"
 #include "esp_log.h"
+#include "sample.hpp"
+#include "types.hpp"
 
 namespace tts {
 
@@ -19,6 +22,53 @@ Player::Player(tasks::WorkerPool& worker,
 
 auto Player::playFile(const std::string& path) -> void {
   ESP_LOGI(kTag, "playing '%s'", path.c_str());
+  bg_.Dispatch<void>([=]() {
+    auto stream = stream_factory_.create(path);
+    if (!stream) {
+      ESP_LOGE(kTag, "creating stream failed");
+      return;
+    }
+    if (stream->type() != codecs::StreamType::kWav) {
+      ESP_LOGE(kTag, "stream was unsupported type");
+      return;
+    }
+    auto decoder = codecs::CreateCodecForType(stream->type());
+    if (!decoder) {
+      ESP_LOGE(kTag, "creating decoder failed");
+      return;
+    }
+    std::unique_ptr<codecs::ICodec> codec{*decoder};
+    auto open_res = codec->OpenStream(stream, 0);
+    if (open_res.has_error()) {
+      ESP_LOGE(kTag, "opening stream failed");
+      return;
+    }
+    // if (open_res->sample_rate_hz != 48000 || open_res->num_channels != 2) {
+    // ESP_LOGE(kTag, "stream format is wrong (was %u channels @ %lu hz)",
+    // open_res->num_channels, open_res->sample_rate_hz);
+    // return;
+    // }
+    sample::Sample decode_buf[4096];
+    for (;;) {
+      auto decode_res = codec->DecodeTo(decode_buf);
+      if (decode_res.has_error()) {
+        ESP_LOGE(kTag, "decoding error");
+        return;
+      }
+      if (decode_res->is_stream_finished) {
+        break;
+      }
+
+      std::span<sample::Sample> decode_span{decode_buf,
+                                            decode_res->samples_written};
+      while (!decode_span.empty()) {
+        size_t sent = output_.send(decode_span);
+        decode_span = decode_span.subspan(sent);
+      }
+    }
+
+    ESP_LOGI(kTag, "finished playing okay");
+  });
 }
 
 }  // namespace tts

src/tangara/tts/provider.cpp

@@ -28,8 +28,7 @@ static const char* kTtsPath = "/.tangara-tts/";
 static auto textToFile(const std::string& text) -> std::optional<std::string> {
   uint64_t hash = komihash(text.data(), text.size(), 0);
   std::stringstream stream;
-  stream << drivers::kStoragePath << kTtsPath;
-  stream << std::hex << hash;
+  stream << kTtsPath << std::hex << hash << ".wav";
   return stream.str();
 }