Merge branch 'main' into seek-support

20 files changed, 422 insertions, 227 deletions

diff --git a/src/app_console/app_console.cpp b/src/app_console/app_console.cpp
index 33f41306..94a48955 100644
--- a/src/app_console/app_console.cpp
+++ b/src/app_console/app_console.cpp
@@ -40,7 +40,7 @@
 #include "freertos/projdefs.h"
 #include "haptics.hpp"
 #include "index.hpp"
-#include "lua_thread.hpp"
+#include "lua_registry.hpp"
 #include "memory_resource.hpp"
 #include "samd.hpp"
 #include "service_locator.hpp"
@@ -628,8 +628,7 @@ static const char kReplMain[] =
     "repl:run()\n";
 
 int CmdLua(int argc, char** argv) {
-  std::unique_ptr<lua::LuaThread> context{
-      lua::LuaThread::Start(*AppConsole::sServices)};
+  auto context = lua::Registry::instance(*AppConsole::sServices).newThread();
   if (!context) {
     return 1;
   }
@@ -652,8 +651,7 @@ int CmdLua(int argc, char** argv) {
 }
 
 int CmdLuaRun(int argc, char** argv) {
-  std::unique_ptr<lua::LuaThread> context{
-      lua::LuaThread::Start(*AppConsole::sServices)};
+  auto context = lua::Registry::instance(*AppConsole::sServices).newThread();
   if (!context) {
     return 1;
   }
diff --git a/src/audio/audio_fsm.cpp b/src/audio/audio_fsm.cpp
index bb7d33dc..b5b6e04b 100644
--- a/src/audio/audio_fsm.cpp
+++ b/src/audio/audio_fsm.cpp
@@ -13,7 +13,9 @@
 
 #include "audio_sink.hpp"
 #include "bluetooth_types.hpp"
+#include "esp_heap_caps.h"
 #include "esp_log.h"
+#include "freertos/FreeRTOS.h"
 #include "freertos/portmacro.h"
 #include "freertos/projdefs.h"
 
@@ -192,20 +194,28 @@ void AudioState::react(const TogglePlayPause& ev) {
 
 namespace states {
 
+// Two seconds of samples for two channels, at a representative sample rate.
+constexpr size_t kDrainBufferSize = sizeof(sample::Sample) * 48000 * 4;
+static StreamBufferHandle_t sDrainBuffer;
+
 void Uninitialised::react(const system_fsm::BootComplete& ev) {
   sServices = ev.services;
 
-  constexpr size_t kDrainBufferSize =
-      drivers::kI2SBufferLengthFrames * sizeof(sample::Sample) * 2 * 8;
   ESP_LOGI(kTag, "allocating drain buffer, size %u KiB",
            kDrainBufferSize / 1024);
-  StreamBufferHandle_t stream = xStreamBufferCreateWithCaps(
-      kDrainBufferSize, sizeof(sample::Sample), MALLOC_CAP_DMA);
+
+  auto meta = reinterpret_cast<StaticStreamBuffer_t*>(
+      heap_caps_malloc(sizeof(StaticStreamBuffer_t), MALLOC_CAP_DMA));
+  auto storage = reinterpret_cast<uint8_t*>(
+      heap_caps_malloc(kDrainBufferSize, MALLOC_CAP_SPIRAM));
+
+  sDrainBuffer = xStreamBufferCreateStatic(
+      kDrainBufferSize, sizeof(sample::Sample), storage, meta);
 
   sFileSource.reset(
       new FatfsAudioInput(sServices->tag_parser(), sServices->bg_worker()));
-  sI2SOutput.reset(new I2SAudioOutput(stream, sServices->gpios()));
-  sBtOutput.reset(new BluetoothAudioOutput(stream, sServices->bluetooth(),
+  sI2SOutput.reset(new I2SAudioOutput(sDrainBuffer, sServices->gpios()));
+  sBtOutput.reset(new BluetoothAudioOutput(sDrainBuffer, sServices->bluetooth(),
                                            sServices->bg_worker()));
 
   auto& nvs = sServices->nvs();
@@ -366,6 +376,12 @@ void Playback::react(const internal::InputFileFinished& ev) {
   ESP_LOGI(kTag, "finished playing file");
   sServices->track_queue().finish();
   if (!sServices->track_queue().current()) {
+    for (int i = 0; i < 20; i++) {
+      if (xStreamBufferIsEmpty(sDrainBuffer)) {
+        break;
+      }
+      vTaskDelay(pdMS_TO_TICKS(200));
+    }
     transit<Standby>();
   }
 }
diff --git a/src/audio/track_queue.cpp b/src/audio/track_queue.cpp
index 534da10c..b75230fc 100644
--- a/src/audio/track_queue.cpp
+++ b/src/audio/track_queue.cpp
@@ -200,39 +200,52 @@ auto TrackQueue::append(Item i) -> void {
 }
 
 auto TrackQueue::next() -> void {
-  const std::unique_lock<std::shared_mutex> lock(mutex_);
-  if (shuffle_) {
-    shuffle_->next();
-    pos_ = shuffle_->current();
-  } else {
-    if (pos_ + 1 >= tracks_.size()) {
-      if (replay_) {
-        pos_ = 0;
-      }
+  bool changed = true;
+
+  {
+    const std::unique_lock<std::shared_mutex> lock(mutex_);
+    if (shuffle_) {
+      shuffle_->next();
+      pos_ = shuffle_->current();
     } else {
-      pos_++;
+      if (pos_ + 1 >= tracks_.size()) {
+        if (replay_) {
+          pos_ = 0;
+        } else {
+          pos_ = tracks_.size();
+          changed = false;
+        }
+      } else {
+        pos_++;
+      }
     }
   }
 
-  notifyChanged(true);
+  notifyChanged(changed);
 }
 
 auto TrackQueue::previous() -> void {
-  const std::unique_lock<std::shared_mutex> lock(mutex_);
-  if (shuffle_) {
-    shuffle_->prev();
-    pos_ = shuffle_->current();
-  } else {
-    if (pos_ == 0) {
-      if (repeat_) {
-        pos_ = tracks_.size() - 1;
-      }
+  bool changed = true;
+
+  {
+    const std::unique_lock<std::shared_mutex> lock(mutex_);
+    if (shuffle_) {
+      shuffle_->prev();
+      pos_ = shuffle_->current();
     } else {
-      pos_--;
+      if (pos_ == 0) {
+        if (repeat_) {
+          pos_ = tracks_.size() - 1;
+        } else {
+          changed = false;
+        }
+      } else {
+        pos_--;
+      }
     }
   }
 
-  notifyChanged(true);
+  notifyChanged(changed);
 }
 
 auto TrackQueue::finish() -> void {
diff --git a/src/database/database.cpp b/src/database/database.cpp
index b596063c..ec11455b 100644
--- a/src/database/database.cpp
+++ b/src/database/database.cpp
@@ -383,8 +383,7 @@ auto Database::updateIndexes() -> void {
   ESP_LOGI(kTag, "scanning for new tracks");
   uint64_t num_processed = 0;
   std::pair<uint16_t, uint16_t> newest_track = last_update;
-  file_gatherer_.FindFiles("", [&](const std::string& path,
-                                   const FILINFO& info) {
+  file_gatherer_.FindFiles("", [&](std::string_view path, const FILINFO& info) {
     num_processed++;
     events::Ui().Dispatch(event::UpdateProgress{
         .stage = event::UpdateProgress::Stage::kScanningForNewTracks,
@@ -456,9 +455,7 @@ auto Database::updateIndexes() -> void {
       dbCreateIndexesForTrack(*t);
     } else if (existing_data->filepath !=
                std::pmr::string{path.data(), path.size()}) {
-      ESP_LOGW(kTag, "tag hash collision for %s and %s",
-               existing_data->filepath.c_str(), path.c_str());
-      ESP_LOGI(kTag, "hash components: %s, %s, %s",
+      ESP_LOGW(kTag, "hash collision: %s, %s, %s",
                tags->title().value_or("no title").c_str(),
                tags->artist().value_or("no artist").c_str(),
                tags->album().value_or("no album").c_str());
diff --git a/src/database/file_gatherer.cpp b/src/database/file_gatherer.cpp
index dde363bd..b7b7271e 100644
--- a/src/database/file_gatherer.cpp
+++ b/src/database/file_gatherer.cpp
@@ -22,12 +22,12 @@ static_assert(sizeof(TCHAR) == sizeof(char), "TCHAR must be CHAR");
 
 auto FileGathererImpl::FindFiles(
     const std::string& root,
-    std::function<void(const std::string&, const FILINFO&)> cb) -> void {
-  std::deque<std::string> to_explore;
-  to_explore.push_back(root);
+    std::function<void(std::string_view, const FILINFO&)> cb) -> void {
+  std::pmr::deque<std::pmr::string> to_explore{&memory::kSpiRamResource};
+  to_explore.push_back({root.data(), root.size()});
 
   while (!to_explore.empty()) {
-    std::string next_path_str = to_explore.front();
+    auto next_path_str = to_explore.front();
     to_explore.pop_front();
 
     const TCHAR* next_path = static_cast<const TCHAR*>(next_path_str.c_str());
@@ -56,7 +56,7 @@ auto FileGathererImpl::FindFiles(
         // System or hidden file. Ignore it and move on.
         continue;
       } else {
-        std::string full_path;
+        std::pmr::string full_path{&memory::kSpiRamResource};
         full_path += next_path_str;
         full_path += "/";
         full_path += info.fname;
diff --git a/src/database/include/file_gatherer.hpp b/src/database/include/file_gatherer.hpp
index 66127bb7..685bdb2c 100644
--- a/src/database/include/file_gatherer.hpp
+++ b/src/database/include/file_gatherer.hpp
@@ -21,7 +21,7 @@ class IFileGatherer {
 
   virtual auto FindFiles(
       const std::string& root,
-      std::function<void(const std::string&, const FILINFO&)> cb)
+      std::function<void(std::string_view, const FILINFO&)> cb)
       -> void = 0;
 };
 
@@ -29,7 +29,7 @@ class FileGathererImpl : public IFileGatherer {
  public:
   virtual auto FindFiles(
       const std::string& root,
-      std::function<void(const std::string&, const FILINFO&)> cb)
+      std::function<void(std::string_view, const FILINFO&)> cb)
       -> void override;
 };
 
diff --git a/src/database/include/tag_parser.hpp b/src/database/include/tag_parser.hpp
index f196c479..966258b5 100644
--- a/src/database/include/tag_parser.hpp
+++ b/src/database/include/tag_parser.hpp
@@ -16,18 +16,18 @@ namespace database {
 class ITagParser {
  public:
   virtual ~ITagParser() {}
-  virtual auto ReadAndParseTags(const std::string& path)
+  virtual auto ReadAndParseTags(std::string_view path)
       -> std::shared_ptr<TrackTags> = 0;
 };
 
 class TagParserImpl : public ITagParser {
  public:
   TagParserImpl();
-  auto ReadAndParseTags(const std::string& path)
+  auto ReadAndParseTags(std::string_view path)
       -> std::shared_ptr<TrackTags> override;
 
  private:
-  auto parseNew(const std::string& path) -> std::shared_ptr<TrackTags>;
+  auto parseNew(std::string_view path) -> std::shared_ptr<TrackTags>;
 
   /*
    * Cache of tags that have already been extracted from files. Ideally this
diff --git a/src/database/tag_parser.cpp b/src/database/tag_parser.cpp
index c247bb7d..cbcbdcb5 100644
--- a/src/database/tag_parser.cpp
+++ b/src/database/tag_parser.cpp
@@ -108,7 +108,7 @@ static const std::size_t kBufSize = 1024;
 
 TagParserImpl::TagParserImpl() {}
 
-auto TagParserImpl::ReadAndParseTags(const std::string& path)
+auto TagParserImpl::ReadAndParseTags(std::string_view path)
     -> std::shared_ptr<TrackTags> {
   {
     std::lock_guard<std::mutex> lock{cache_mutex_};
@@ -130,7 +130,7 @@ auto TagParserImpl::ReadAndParseTags(const std::string& path)
   if (!tags->track()) {
     auto slash_pos = path.find_last_of("/");
     if (slash_pos != std::string::npos && path.size() - slash_pos > 1) {
-      std::string trunc = path.substr(slash_pos + 1);
+      auto trunc = path.substr(slash_pos + 1);
       tags->track({trunc.data(), trunc.size()});
     }
   }
@@ -143,8 +143,8 @@ auto TagParserImpl::ReadAndParseTags(const std::string& path)
   return tags;
 }
 
-auto TagParserImpl::parseNew(const std::string& path)
-    -> std::shared_ptr<TrackTags> {
+auto TagParserImpl::parseNew(std::string_view p) -> std::shared_ptr<TrackTags> {
+  std::string path{p};
   libtags::Aux aux;
   auto out = TrackTags::create();
   aux.tags = out.get();
diff --git a/src/lua/CMakeLists.txt b/src/lua/CMakeLists.txt
index d89b22e8..ff0831c9 100644
--- a/src/lua/CMakeLists.txt
+++ b/src/lua/CMakeLists.txt
@@ -4,7 +4,7 @@
 
 idf_component_register(
   SRCS "lua_thread.cpp" "bridge.cpp" "property.cpp" "lua_database.cpp"
-  "lua_queue.cpp" "lua_version.cpp" "lua_controls.cpp"
+  "lua_queue.cpp" "lua_version.cpp" "lua_controls.cpp" "registry.cpp"
   INCLUDE_DIRS "include"
   REQUIRES "drivers" "lvgl" "tinyfsm" "events" "system_fsm" "database"
   "esp_timer" "battery" "esp-idf-lua" "luavgl" "lua-linenoise" "lua-term"
diff --git a/src/lua/bridge.cpp b/src/lua/bridge.cpp
index a680a521..a26f74bb 100644
--- a/src/lua/bridge.cpp
+++ b/src/lua/bridge.cpp
@@ -22,6 +22,9 @@
 #include "lua_version.hpp"
 #include "lvgl.h"
 
+#include "font/lv_font_loader.h"
+#include "luavgl.h"
+
 #include "event_queue.hpp"
 #include "property.hpp"
 #include "service_locator.hpp"
@@ -32,34 +35,62 @@ int luaopen_linenoise(lua_State* L);
 int luaopen_term_core(lua_State* L);
 }
 
+LV_FONT_DECLARE(font_fusion_12);
+LV_FONT_DECLARE(font_fusion_10);
+
 namespace lua {
 
 [[maybe_unused]] static constexpr char kTag[] = "lua_bridge";
 
 static constexpr char kBridgeKey[] = "bridge";
 
+static auto make_font_cb(const char* name, int size, int weight)
+    -> const lv_font_t* {
+  if (std::string{"fusion"} == name) {
+    if (size == 12) {
+      return &font_fusion_12;
+    }
+    if (size == 10) {
+      return &font_fusion_10;
+    }
+  }
+  return NULL;
+}
+
+static auto delete_font_cb(lv_font_t* font) -> void {}
+
 auto Bridge::Get(lua_State* state) -> Bridge* {
   lua_pushstring(state, kBridgeKey);
   lua_gettable(state, LUA_REGISTRYINDEX);
   return reinterpret_cast<Bridge*>(lua_touserdata(state, -1));
 }
 
-Bridge::Bridge(system_fsm::ServiceLocator& services, lua_State& s)
-    : services_(services), state_(s), bindings_(s) {
-  lua_pushstring(&s, kBridgeKey);
-  lua_pushlightuserdata(&s, this);
-  lua_settable(&s, LUA_REGISTRYINDEX);
+Bridge::Bridge(system_fsm::ServiceLocator& services) : services_(services) {}
+
+auto Bridge::installBaseModules(lua_State* L) -> void {
+  lua_pushstring(L, kBridgeKey);
+  lua_pushlightuserdata(L, this);
+  lua_settable(L, LUA_REGISTRYINDEX);
+
+  bindings_.install(L);
 
-  luaL_requiref(&s, "linenoise", luaopen_linenoise, true);
-  lua_pop(&s, 1);
+  luaL_requiref(L, "linenoise", luaopen_linenoise, true);
+  lua_pop(L, 1);
 
-  luaL_requiref(&s, "term.core", luaopen_term_core, true);
-  lua_pop(&s, 1);
+  luaL_requiref(L, "term.core", luaopen_term_core, true);
+  lua_pop(L, 1);
+
+  RegisterControlsModule(L);
+  RegisterDatabaseModule(L);
+  RegisterQueueModule(L);
+  RegisterVersionModule(L);
+}
 
-  RegisterControlsModule(&s);
-  RegisterDatabaseModule(&s);
-  RegisterQueueModule(&s);
-  RegisterVersionModule(&s);
+auto Bridge::installLvgl(lua_State* L) -> void {
+  luavgl_set_pcall(L, CallProtected);
+  luavgl_set_font_extension(L, make_font_cb, delete_font_cb);
+  luaL_requiref(L, "lvgl", luaopen_lvgl, true);
+  lua_pop(L, 1);
 }
 
 static auto new_property_module(lua_State* state) -> int {
@@ -76,32 +107,33 @@ static auto new_property_module(lua_State* state) -> int {
 template <class... Ts>
 inline constexpr bool always_false_v = false;
 
-auto Bridge::AddPropertyModule(
+auto Bridge::installPropertyModule(
+    lua_State* L,
     const std::string& name,
-    std::vector<std::pair<std::string, std::variant<LuaFunction, Property*>>>
+    std::vector<std::pair<std::string, std::variant<LuaFunction, Property*>>>&
         props) -> void {
   // Create the module (or retrieve it if one with this name already exists)
-  luaL_requiref(&state_, name.c_str(), new_property_module, true);
+  luaL_requiref(L, name.c_str(), new_property_module, true);
 
   for (const auto& prop : props) {
-    lua_pushstring(&state_, prop.first.c_str());
+    lua_pushstring(L, prop.first.c_str());
     std::visit(
         [&](auto&& arg) {
           using T = std::decay_t<decltype(arg)>;
           if constexpr (std::is_same_v<T, LuaFunction>) {
-            bindings_.Register(&state_, arg);
+            bindings_.Register(L, arg);
           } else if constexpr (std::is_same_v<T, Property*>) {
-            bindings_.Register(&state_, arg);
+            bindings_.Register(L, arg);
           } else {
             static_assert(always_false_v<T>, "missing case");
           }
         },
         prop.second);
 
-    lua_settable(&state_, -3);  // metatable.propname = property
+    lua_settable(L, -3);  // metatable.propname = property
   }
 
-  lua_pop(&state_, 1);  // pop the module off the stack
+  lua_pop(L, 1);  // pop the module off the stack
 }
 
 }  // namespace lua
diff --git a/src/lua/include/bridge.hpp b/src/lua/include/bridge.hpp
index 62fbc340..64f14e0e 100644
--- a/src/lua/include/bridge.hpp
+++ b/src/lua/include/bridge.hpp
@@ -16,25 +16,38 @@
 
 namespace lua {
 
+/*
+ * Responsible for adding C/C++ module bindings to Lua threads. This class
+ * keeps no thread-specific internal state, and instead uses the LUA_REGISTRY
+ * table of its host threads to store data.
+ */
 class Bridge {
  public:
+  /*
+   * Utility for retrieving the Bridge from a Lua thread in which the Bridge's
+   * bindings have been installed. Use by Lua's C callbacks to access the rest
+   * of the system.
+   */
   static auto Get(lua_State* state) -> Bridge*;
 
-  Bridge(system_fsm::ServiceLocator&, lua_State& s);
+  Bridge(system_fsm::ServiceLocator& s);
 
-  auto AddPropertyModule(
+  system_fsm::ServiceLocator& services() { return services_; }
+
+  auto installBaseModules(lua_State* L) -> void;
+  auto installLvgl(lua_State* L) -> void;
+  auto installPropertyModule(
+      lua_State* L,
       const std::string&,
       std::vector<
-          std::pair<std::string,
-                    std::variant<LuaFunction, Property*>>>)
+          std::pair<std::string, std::variant<LuaFunction, Property*>>>&)
       -> void;
 
-  system_fsm::ServiceLocator& services() { return services_; }
-  PropertyBindings& bindings() { return bindings_; }
+  Bridge(const Bridge&) = delete;
+  Bridge& operator=(const Bridge&) = delete;
 
  private:
   system_fsm::ServiceLocator& services_;
-  lua_State& state_;
   PropertyBindings bindings_;
 };
 
diff --git a/src/lua/include/lua_registry.hpp b/src/lua/include/lua_registry.hpp
new file mode 100644
index 00000000..abc5063e
--- /dev/null
+++ b/src/lua/include/lua_registry.hpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2023 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#pragma once
+
+#include <memory>
+#include <string>
+
+#include "lua.hpp"
+
+#include "bridge.hpp"
+#include "lua_thread.hpp"
+#include "service_locator.hpp"
+
+namespace lua {
+
+class Registry {
+ public:
+  static auto instance(system_fsm::ServiceLocator&) -> Registry&;
+
+  auto uiThread() -> std::shared_ptr<LuaThread>;
+  auto newThread() -> std::shared_ptr<LuaThread>;
+
+  auto AddPropertyModule(
+      const std::string&,
+      std::vector<std::pair<std::string, std::variant<LuaFunction, Property*>>>)
+      -> void;
+
+  Registry(const Registry&) = delete;
+  Registry& operator=(const Registry&) = delete;
+
+ private:
+  Registry(system_fsm::ServiceLocator&);
+
+  system_fsm::ServiceLocator& services_;
+  std::unique_ptr<Bridge> bridge_;
+
+  std::shared_ptr<LuaThread> ui_thread_;
+  std::list<std::weak_ptr<LuaThread>> threads_;
+
+  std::vector<
+      std::pair<std::string,
+                std::vector<std::pair<std::string,
+                                      std::variant<LuaFunction, Property*>>>>>
+      modules_;
+};
+
+}  // namespace lua
diff --git a/src/lua/include/lua_thread.hpp b/src/lua/include/lua_thread.hpp
index d10dba3a..384de61d 100644
--- a/src/lua/include/lua_thread.hpp
+++ b/src/lua/include/lua_thread.hpp
@@ -10,9 +10,7 @@
 #include <string>
 
 #include "lua.hpp"
-#include "lvgl.h"
 
-#include "bridge.hpp"
 #include "service_locator.hpp"
 
 namespace lua {
@@ -23,8 +21,7 @@ auto CallProtected(lua_State*, int nargs, int nresults) -> int;
 
 class LuaThread {
  public:
-  static auto Start(system_fsm::ServiceLocator&, lv_obj_t* lvgl_root = nullptr)
-      -> LuaThread*;
+  static auto Start(system_fsm::ServiceLocator&) -> LuaThread*;
   ~LuaThread();
 
   auto RunScript(const std::string& path) -> bool;
@@ -32,14 +29,15 @@ class LuaThread {
 
   auto DumpStack() -> void;
 
-  auto bridge() -> Bridge& { return *bridge_; }
   auto state() -> lua_State* { return state_; }
 
+  LuaThread(const LuaThread&) = delete;
+  LuaThread& operator=(const LuaThread&) = delete;
+
  private:
-  LuaThread(std::unique_ptr<Allocator>&, std::unique_ptr<Bridge>&, lua_State*);
+  LuaThread(std::unique_ptr<Allocator>&, lua_State*);
 
   std::unique_ptr<Allocator> alloc_;
-  std::unique_ptr<Bridge> bridge_;
   lua_State* state_;
 };
 
diff --git a/src/lua/include/property.hpp b/src/lua/include/property.hpp
index 03229bc1..7d160fba 100644
--- a/src/lua/include/property.hpp
+++ b/src/lua/include/property.hpp
@@ -53,7 +53,9 @@ class Property {
 
 class PropertyBindings {
  public:
-  PropertyBindings(lua_State&);
+  PropertyBindings();
+
+  auto install(lua_State*) -> void;
 
   auto Register(lua_State*, Property*) -> void;
   auto Register(lua_State*, LuaFunction) -> void;
diff --git a/src/lua/lua_queue.cpp b/src/lua/lua_queue.cpp
index 69d3b03d..dfb820c2 100644
--- a/src/lua/lua_queue.cpp
+++ b/src/lua/lua_queue.cpp
@@ -16,6 +16,7 @@
 #include "lua.h"
 #include "lvgl.h"
 
+#include "bridge.hpp"
 #include "database.hpp"
 #include "event_queue.hpp"
 #include "index.hpp"
@@ -70,4 +71,4 @@ auto RegisterQueueModule(lua_State* s) -> void {
   lua_pop(s, 1);
 }
 
-}  // namespace lua
\ No newline at end of file
+}  // namespace lua
diff --git a/src/lua/lua_thread.cpp b/src/lua/lua_thread.cpp
index b94b70ab..dd72e41d 100644
--- a/src/lua/lua_thread.cpp
+++ b/src/lua/lua_thread.cpp
@@ -9,22 +9,16 @@
 #include <iostream>
 #include <memory>
 
-#include "lauxlib.h"
-#include "lua.h"
-#include "lua.hpp"
-
-#include "font/lv_font_loader.h"
-#include "luavgl.h"
-
 #include "esp_heap_caps.h"
 #include "esp_log.h"
+#include "lua.hpp"
+
+#include "bridge.hpp"
 #include "event_queue.hpp"
+#include "memory_resource.hpp"
 #include "service_locator.hpp"
 #include "ui_events.hpp"
 
-LV_FONT_DECLARE(font_fusion_12);
-LV_FONT_DECLARE(font_fusion_10);
-
 namespace lua {
 
 [[maybe_unused]] static constexpr char kTag[] = "lua";
@@ -59,23 +53,7 @@ static int lua_panic(lua_State* L) {
   return 0;
 }
 
-static auto make_font_cb(const char* name, int size, int weight)
-    -> const lv_font_t* {
-  if (std::string{"fusion"} == name) {
-    if (size == 12) {
-      return &font_fusion_12;
-    }
-    if (size == 10) {
-      return &font_fusion_10;
-    }
-  }
-  return NULL;
-}
-
-static auto delete_font_cb(lv_font_t* font) -> void {}
-
-auto LuaThread::Start(system_fsm::ServiceLocator& services, lv_obj_t* lvgl_root)
-    -> LuaThread* {
+auto LuaThread::Start(system_fsm::ServiceLocator& services) -> LuaThread* {
   auto alloc = std::make_unique<Allocator>();
   lua_State* state = lua_newstate(lua_alloc, alloc.get());
   if (!state) {
@@ -85,24 +63,11 @@ auto LuaThread::Start(system_fsm::ServiceLocator& services, lv_obj_t* lvgl_root)
   luaL_openlibs(state);
   lua_atpanic(state, lua_panic);
 
-  auto bridge = std::make_unique<Bridge>(services, *state);
-
-  // FIXME: luavgl init should probably be a part of the bridge.
-  if (lvgl_root) {
-    luavgl_set_pcall(state, CallProtected);
-    luavgl_set_font_extension(state, make_font_cb, delete_font_cb);
-    luavgl_set_root(state, lvgl_root);
-    luaL_requiref(state, "lvgl", luaopen_lvgl, true);
-    lua_pop(state, 1);
-  }
-
-  return new LuaThread(alloc, bridge, state);
+  return new LuaThread(alloc, state);
 }
 
-LuaThread::LuaThread(std::unique_ptr<Allocator>& alloc,
-                     std::unique_ptr<Bridge>& bridge,
-                     lua_State* state)
-    : alloc_(std::move(alloc)), bridge_(std::move(bridge)), state_(state) {}
+LuaThread::LuaThread(std::unique_ptr<Allocator>& alloc, lua_State* state)
+    : alloc_(std::move(alloc)), state_(state) {}
 
 LuaThread::~LuaThread() {
   lua_close(state_);
diff --git a/src/lua/property.cpp b/src/lua/property.cpp
index 5357ccc5..f721f9ce 100644
--- a/src/lua/property.cpp
+++ b/src/lua/property.cpp
@@ -10,10 +10,12 @@
 #include <cmath>
 #include <memory>
 #include <memory_resource>
+#include <sstream>
 #include <string>
 #include <variant>
 
 #include "bluetooth_types.hpp"
+#include "lauxlib.h"
 #include "lua.h"
 #include "lua.hpp"
 #include "lua_thread.hpp"
@@ -76,10 +78,30 @@ static auto property_bind(lua_State* state) -> int {
   return 1;
 }
 
-static const struct luaL_Reg kPropertyBindingFuncs[] = {{"get", property_get},
-                                                        {"set", property_set},
-                                                        {"bind", property_bind},
-                                                        {NULL, NULL}};
+static auto property_tostring(lua_State* state) -> int {
+  Property* p = check_property(state);
+  p->PushValue(*state);
+
+  std::stringstream str{};
+  str << "property { " << luaL_tolstring(state, -1, NULL);
+  if (!p->IsTwoWay()) {
+    str << ", read-only";
+  }
+  str << " }";
+
+  lua_settop(state, 0);
+
+  std::string res = str.str();
+  lua_pushlstring(state, res.data(), res.size());
+  return 1;
+}
+
+static const struct luaL_Reg kPropertyBindingFuncs[] = {
+    {"get", property_get},
+    {"set", property_set},
+    {"bind", property_bind},
+    {"__tostring", property_tostring},
+    {NULL, NULL}};
 
 static auto generic_function_cb(lua_State* state) -> int {
   lua_pushstring(state, kBinderKey);
@@ -98,45 +120,47 @@ static auto generic_function_cb(lua_State* state) -> int {
   return std::invoke(fn, state);
 }
 
-PropertyBindings::PropertyBindings(lua_State& s) {
-  lua_pushstring(&s, kBinderKey);
-  lua_pushlightuserdata(&s, this);
-  lua_settable(&s, LUA_REGISTRYINDEX);
+PropertyBindings::PropertyBindings() : functions_(&memory::kSpiRamResource) {}
+
+auto PropertyBindings::install(lua_State* L) -> void {
+  lua_pushstring(L, kBinderKey);
+  lua_pushlightuserdata(L, this);
+  lua_settable(L, LUA_REGISTRYINDEX);
 
   // Create the metatable responsible for the Property API.
-  luaL_newmetatable(&s, kPropertyMetatable);
+  luaL_newmetatable(L, kPropertyMetatable);
 
-  lua_pushliteral(&s, "__index");
-  lua_pushvalue(&s, -2);
-  lua_settable(&s, -3);  // metatable.__index = metatable
+  lua_pushliteral(L, "__index");
+  lua_pushvalue(L, -2);
+  lua_settable(L, -3);  // metatable.__index = metatable
 
   // Add our binding funcs (get, set, bind) to the metatable.
-  luaL_setfuncs(&s, kPropertyBindingFuncs, 0);
+  luaL_setfuncs(L, kPropertyBindingFuncs, 0);
 
   // We've finished setting up the metatable, so pop it.
-  lua_pop(&s, 1);
+  lua_pop(L, 1);
 
   // Create a weak table in the registry to hold live bindings.
-  lua_pushstring(&s, kBindingsTable);
-  lua_newtable(&s);  // bindings = {}
+  lua_pushstring(L, kBindingsTable);
+  lua_newtable(L);  // bindings = {}
 
   // Metatable for the weak table. Values are weak.
-  lua_newtable(&s);  // meta = {}
-  lua_pushliteral(&s, "__mode");
-  lua_pushliteral(&s, "v");
-  lua_settable(&s, -3);      // meta.__mode='v'
-  lua_setmetatable(&s, -2);  // setmetatable(bindings, meta)
+  lua_newtable(L);  // meta = {}
+  lua_pushliteral(L, "__mode");
+  lua_pushliteral(L, "v");
+  lua_settable(L, -3);      // meta.__mode='v'
+  lua_setmetatable(L, -2);  // setmetatable(bindings, meta)
 
-  lua_settable(&s, LUA_REGISTRYINDEX);  // REGISTRY[kBindingsTable] = bindings
+  lua_settable(L, LUA_REGISTRYINDEX);  // REGISTRY[kBindingsTable] = bindings
 
   // Create the metatable for C++ functions.
-  luaL_newmetatable(&s, kFunctionMetatable);
+  luaL_newmetatable(L, kFunctionMetatable);
 
-  lua_pushliteral(&s, "__call");
-  lua_pushcfunction(&s, generic_function_cb);
-  lua_settable(&s, -3);  // metatable.__call = metatable
+  lua_pushliteral(L, "__call");
+  lua_pushcfunction(L, generic_function_cb);
+  lua_settable(L, -3);  // metatable.__call = metatable
 
-  lua_pop(&s, 1);  // Clean up the function metatable
+  lua_pop(L, 1);  // Clean up the function metatable
 }
 
 auto PropertyBindings::Register(lua_State* s, Property* prop) -> void {
diff --git a/src/lua/registry.cpp b/src/lua/registry.cpp
new file mode 100644
index 00000000..a6487858
--- /dev/null
+++ b/src/lua/registry.cpp
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2023 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#include "lua_registry.hpp"
+
+#include <iostream>
+#include <memory>
+
+#include "esp_heap_caps.h"
+#include "esp_log.h"
+#include "lua.hpp"
+
+#include "bridge.hpp"
+#include "event_queue.hpp"
+#include "memory_resource.hpp"
+#include "service_locator.hpp"
+#include "ui_events.hpp"
+
+namespace lua {
+
+[[maybe_unused]] static constexpr char kTag[] = "lua";
+
+auto Registry::instance(system_fsm::ServiceLocator& s) -> Registry& {
+  static Registry sRegistry{s};
+  return sRegistry;
+}
+
+Registry::Registry(system_fsm::ServiceLocator& services)
+    : services_(services), bridge_(new Bridge(services)) {}
+
+auto Registry::uiThread() -> std::shared_ptr<LuaThread> {
+  if (!ui_thread_) {
+    ui_thread_ = newThread();
+    bridge_->installLvgl(ui_thread_->state());
+  }
+  return ui_thread_;
+}
+
+auto Registry::newThread() -> std::shared_ptr<LuaThread> {
+  std::shared_ptr<LuaThread> thread{LuaThread::Start(services_)};
+  bridge_->installBaseModules(thread->state());
+  for (auto& module : modules_) {
+    bridge_->installPropertyModule(thread->state(), module.first,
+                                   module.second);
+  }
+  threads_.push_back(thread);
+  return thread;
+}
+
+auto Registry::AddPropertyModule(
+    const std::string& name,
+    std::vector<std::pair<std::string, std::variant<LuaFunction, Property*>>>
+        properties) -> void {
+  modules_.push_back(std::make_pair(name, properties));
+
+  // Any live threads will need to be updated to include the new module.
+  auto it = threads_.begin();
+  while (it != threads_.end()) {
+    auto thread = it->lock();
+    if (!thread) {
+      // Thread has been destroyed; stop tracking it.
+      it = threads_.erase(it);
+    } else {
+      bridge_->installPropertyModule(thread->state(), name, properties);
+      it++;
+    }
+  }
+}
+
+}  // namespace lua
diff --git a/src/ui/include/ui_fsm.hpp b/src/ui/include/ui_fsm.hpp
index ffaff0bb..6cf2ba4c 100644
--- a/src/ui/include/ui_fsm.hpp
+++ b/src/ui/include/ui_fsm.hpp
@@ -163,6 +163,8 @@ class Lua : public UiState {
   auto ShowAlert(lua_State*) -> int;
   auto HideAlert(lua_State*) -> int;
 
+  auto Ticks(lua_State*) -> int;
+
   auto SetPlaying(const lua::LuaValue&) -> bool;
   auto SetRandom(const lua::LuaValue&) -> bool;
   auto SetRepeat(const lua::LuaValue&) -> bool;
diff --git a/src/ui/ui_fsm.cpp b/src/ui/ui_fsm.cpp
index 3e85c36e..d98e435d 100644
--- a/src/ui/ui_fsm.cpp
+++ b/src/ui/ui_fsm.cpp
@@ -24,6 +24,7 @@
 #include "core/lv_obj_tree.h"
 #include "database.hpp"
 #include "esp_heap_caps.h"
+#include "esp_timer.h"
 #include "haptics.hpp"
 #include "lauxlib.h"
 #include "lua_thread.hpp"
@@ -36,6 +37,7 @@
 #include "encoder_input.hpp"
 #include "event_queue.hpp"
 #include "gpios.hpp"
+#include "lua_registry.hpp"
 #include "lvgl_task.hpp"
 #include "nvs.hpp"
 #include "property.hpp"
@@ -142,29 +144,29 @@ lua::Property UiState::sPlaybackPosition{0, [](const lua::LuaValue& val) {
 lua::Property UiState::sQueuePosition{0};
 lua::Property UiState::sQueueSize{0};
 lua::Property UiState::sQueueRepeat{false, [](const lua::LuaValue& val) {
-      if (!std::holds_alternative<bool>(val)) {
-        return false;
-      }
-      bool new_val = std::get<bool>(val);
-      sServices->track_queue().repeat(new_val);
-      return true;
-}};
+                                      if (!std::holds_alternative<bool>(val)) {
+                                        return false;
+                                      }
+                                      bool new_val = std::get<bool>(val);
+                                      sServices->track_queue().repeat(new_val);
+                                      return true;
+                                    }};
 lua::Property UiState::sQueueReplay{false, [](const lua::LuaValue& val) {
-      if (!std::holds_alternative<bool>(val)) {
-        return false;
-      }
-      bool new_val = std::get<bool>(val);
-      sServices->track_queue().replay(new_val);
-      return true;
-}};
+                                      if (!std::holds_alternative<bool>(val)) {
+                                        return false;
+                                      }
+                                      bool new_val = std::get<bool>(val);
+                                      sServices->track_queue().replay(new_val);
+                                      return true;
+                                    }};
 lua::Property UiState::sQueueRandom{false, [](const lua::LuaValue& val) {
-      if (!std::holds_alternative<bool>(val)) {
-        return false;
-      }
-      bool new_val = std::get<bool>(val);
-      sServices->track_queue().random(new_val);
-      return true;
-}};
+                                      if (!std::holds_alternative<bool>(val)) {
+                                        return false;
+                                      }
+                                      bool new_val = std::get<bool>(val);
+                                      sServices->track_queue().random(new_val);
+                                      return true;
+                                    }};
 
 lua::Property UiState::sVolumeCurrentPct{
     0, [](const lua::LuaValue& val) {
@@ -456,27 +458,26 @@ void Lua::entry() {
                                alert_timer_callback);
     sAlertContainer = lv_obj_create(sCurrentScreen->alert());
 
-    sLua.reset(lua::LuaThread::Start(*sServices, sCurrentScreen->content()));
-    sLua->bridge().AddPropertyModule("power",
-                                     {
-                                         {"battery_pct", &sBatteryPct},
-                                         {"battery_millivolts", &sBatteryMv},
-                                         {"plugged_in", &sBatteryCharging},
-                                     });
-    sLua->bridge().AddPropertyModule(
-        "bluetooth", {
-                         {"enabled", &sBluetoothEnabled},
-                         {"connected", &sBluetoothConnected},
-                         {"paired_device", &sBluetoothPairedDevice},
-                         {"devices", &sBluetoothDevices},
-                     });
-    sLua->bridge().AddPropertyModule("playback",
-                                     {
-                                         {"playing", &sPlaybackPlaying},
-                                         {"track", &sPlaybackTrack},
-                                         {"position", &sPlaybackPosition},
-                                     });
-    sLua->bridge().AddPropertyModule(
+    auto& registry = lua::Registry::instance(*sServices);
+    sLua = registry.uiThread();
+    registry.AddPropertyModule("power", {
+                                            {"battery_pct", &sBatteryPct},
+                                            {"battery_millivolts", &sBatteryMv},
+                                            {"plugged_in", &sBatteryCharging},
+                                        });
+    registry.AddPropertyModule("bluetooth",
+                               {
+                                   {"enabled", &sBluetoothEnabled},
+                                   {"connected", &sBluetoothConnected},
+                                   {"paired_device", &sBluetoothPairedDevice},
+                                   {"devices", &sBluetoothDevices},
+                               });
+    registry.AddPropertyModule("playback", {
+                                               {"playing", &sPlaybackPlaying},
+                                               {"track", &sPlaybackTrack},
+                                               {"position", &sPlaybackPosition},
+                                           });
+    registry.AddPropertyModule(
         "queue",
         {
             {"next", [&](lua_State* s) { return QueueNext(s); }},
@@ -487,40 +488,44 @@ void Lua::entry() {
             {"repeat_track", &sQueueRepeat},
             {"random", &sQueueRandom},
         });
-    sLua->bridge().AddPropertyModule("volume",
-                                     {
-                                         {"current_pct", &sVolumeCurrentPct},
-                                         {"current_db", &sVolumeCurrentDb},
-                                         {"left_bias", &sVolumeLeftBias},
-                                         {"limit_db", &sVolumeLimit},
-                                     });
-
-    sLua->bridge().AddPropertyModule("display",
-                                     {
-                                         {"brightness", &sDisplayBrightness},
-                                     });
-
-    sLua->bridge().AddPropertyModule("controls",
-                                     {
-                                         {"scheme", &sControlsScheme},
-                                         {"scroll_sensitivity", &sScrollSensitivity},
-                                     });
-
-    sLua->bridge().AddPropertyModule(
+    registry.AddPropertyModule("volume",
+                               {
+                                   {"current_pct", &sVolumeCurrentPct},
+                                   {"current_db", &sVolumeCurrentDb},
+                                   {"left_bias", &sVolumeLeftBias},
+                                   {"limit_db", &sVolumeLimit},
+                               });
+
+    registry.AddPropertyModule("display",
+                               {
+                                   {"brightness", &sDisplayBrightness},
+                               });
+
+    registry.AddPropertyModule("controls",
+                               {
+                                   {"scheme", &sControlsScheme},
+                                   {"scroll_sensitivity", &sScrollSensitivity},
+                               });
+
+    registry.AddPropertyModule(
         "backstack",
         {
             {"push", [&](lua_State* s) { return PushLuaScreen(s); }},
             {"pop", [&](lua_State* s) { return PopLuaScreen(s); }},
         });
-    sLua->bridge().AddPropertyModule(
+    registry.AddPropertyModule(
         "alerts", {
                       {"show", [&](lua_State* s) { return ShowAlert(s); }},
                       {"hide", [&](lua_State* s) { return HideAlert(s); }},
                   });
-    sLua->bridge().AddPropertyModule("database",
-                                     {
-                                         {"updating", &sDatabaseUpdating},
-                                     });
+
+    registry.AddPropertyModule(
+        "time", {
+                    {"ticks", [&](lua_State* s) { return Ticks(s); }},
+                });
+    registry.AddPropertyModule("database", {
+                                               {"updating", &sDatabaseUpdating},
+                                           });
 
     auto bt = sServices->bluetooth();
     sBluetoothEnabled.Update(bt.IsEnabled());
@@ -579,6 +584,11 @@ auto Lua::PopLuaScreen(lua_State* s) -> int {
   return 0;
 }
 
+auto Lua::Ticks(lua_State* s) -> int {
+  lua_pushinteger(s, esp_timer_get_time()/1000);
+  return 1;
+}
+
 auto Lua::ShowAlert(lua_State* s) -> int {
   if (!sCurrentScreen) {
     return 0;