WIP: Lua filesystem starting point

src/lua/CMakeLists.txt

@@ -5,9 +5,9 @@
 idf_component_register(
   SRCS "lua_theme.cpp" "lua_thread.cpp" "bridge.cpp" "property.cpp" "lua_database.cpp"
   "lua_queue.cpp" "lua_version.cpp" "lua_theme.cpp" "lua_controls.cpp" "registry.cpp"
-  "lua_screen.cpp"
+  "lua_screen.cpp" "lua_filesystem.cpp" "file_iterator.cpp"
   INCLUDE_DIRS "include"
-  REQUIRES "drivers" "lvgl" "tinyfsm" "events" "system_fsm" "database"
+  REQUIRES "drivers" "lvgl" "tinyfsm" "events" "system_fsm" "database" "fatfs"
   "esp_timer" "battery" "esp-idf-lua" "luavgl" "lua-linenoise" "lua-term"
   "esp_app_format")
 target_compile_options(${COMPONENT_LIB} PRIVATE ${EXTRA_WARNINGS})

src/lua/bridge.cpp

@@ -18,6 +18,7 @@
 #include "lua.hpp"
 #include "lua_controls.hpp"
 #include "lua_database.hpp"
+#include "lua_filesystem.hpp"
 #include "lua_queue.hpp"
 #include "lua_screen.hpp"
 #include "lua_version.hpp"
@@ -84,6 +85,7 @@ auto Bridge::installBaseModules(lua_State* L) -> void {
 
   RegisterControlsModule(L);
   RegisterDatabaseModule(L);
+  RegisterFileSystemModule(L);
   RegisterQueueModule(L);
   RegisterVersionModule(L);
   RegisterThemeModule(L);

src/lua/file_iterator.cpp

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2023 ailurux <ailuruxx@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+#include "file_iterator.hpp"
+#include "esp_log.h"
+
+#include <string>
+
+#include "ff.h"
+#include "spi.hpp"
+
+namespace database {
+
+[[maybe_unused]] static const char* kTag = "FileIterator";
+
+FileIterator::FileIterator(std::string filepath) 
+: original_path_(filepath),
+  current_()
+ {
+  auto lock = drivers::acquire_spi();
+
+  const TCHAR* next_path = static_cast<const TCHAR*>(filepath.c_str());
+  FRESULT res = f_opendir(&dir_, next_path);
+  if (res != FR_OK) {
+    ESP_LOGE(kTag, "Error opening directory: %s", filepath.c_str());
+  }
+}
+
+auto FileIterator::value() const -> const std::optional<FileEntry>& {
+  return current_;
+}
+
+auto FileIterator::next() -> void {
+  iterate(false);
+}
+
+auto FileIterator::prev() -> void {
+  iterate(true);
+}
+
+auto FileIterator::iterate(bool reverse) -> bool {
+    FILINFO info;
+    if (reverse) {
+      f_rewinddir(&dir_);
+    }
+    {
+      auto lock = drivers::acquire_spi();
+      auto res = f_readdir(&dir_, &info);
+      if (res != FR_OK) {
+        ESP_LOGI(kTag, "AAAAAAAAAAAAAAAAAAA");
+        ESP_LOGI(kTag, "%d", res);
+        return false;
+      }
+    }
+    if (info.fname[0] == 0) {
+      // End of directory
+      current_.reset();
+      ESP_LOGI(kTag, "End of dir");
+
+    } else {
+      // Update current value
+      ESP_LOGI(kTag, "File: %s", info.fname);
+      current_ = FileEntry{
+        .isHidden = (info.fattrib & AM_HID) > 0,
+        .isDirectory = (info.fattrib & AM_DIR) > 0,
+        .isTrack = false, // TODO
+        .filepath = original_path_ + info.fname,
+
+      };
+    }
+    return true;
+}
+
+}  // namespace database

src/lua/include/file_iterator.hpp

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2023 ailurux <ailuruxx@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#pragma once 
+
+#include <string>
+#include <optional>
+
+#include "ff.h"
+
+namespace database {
+
+// Note for when reading FILINFO, that we are in LFN mode:
+// http://elm-chan.org/fsw/ff/doc/sfileinfo.html
+struct FileEntry {
+    bool isHidden;
+    bool isDirectory;
+    bool isTrack;
+    std::string filepath;
+};
+
+class FileIterator {
+ public:
+  FileIterator(std::string filepath);
+
+  auto value() const -> const std::optional<FileEntry>&;
+  auto next() -> void;
+  auto prev() -> void;
+
+ private: 
+  FF_DIR dir_;
+  std::string original_path_;
+
+  std::optional<FileEntry> current_;
+
+  auto iterate(bool reverse = false) -> bool;
+};
+
+} // namespace database

src/lua/include/lua_filesystem.hpp

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2023 ailurux <ailuruxx@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+#pragma once
+
+#include "lua.hpp"
+#include "file_iterator.hpp"
+
+namespace lua {
+
+auto check_file_iterator(lua_State*, int stack_pos) -> database::FileIterator*;
+
+auto RegisterFileSystemModule(lua_State*) -> void;
+
+}  // namespace lua

src/lua/lua_filesystem.cpp

@@ -0,0 +1,155 @@
+/*
+ * Copyright 2023 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#include "lua_filesystem.hpp"
+#include <string>
+#include <cstring>
+#include "lauxlib.h"
+
+namespace lua {
+
+[[maybe_unused]] static constexpr char kTag[] = "lua_fs";
+
+static constexpr char kFileEntryMetatable[] = "fs_file_entry";
+static constexpr char kFileIteratorMetatable[] = "fs_iterator";
+
+// Todo: Use std::pmr::string for paths/dirs
+struct LuaFileEntry {
+  bool isHidden;
+  bool isDirectory;
+  bool isTrack;
+  size_t path_size;
+  char path[];
+};
+
+static_assert(std::is_trivially_destructible<LuaFileEntry>());
+static_assert(std::is_trivially_copy_assignable<LuaFileEntry>());
+
+static auto push_lua_file_entry(lua_State* L, const database::FileEntry& r) -> void {
+  // Create and init the userdata.
+  LuaFileEntry* file_entry = reinterpret_cast<LuaFileEntry*>(
+      lua_newuserdata(L, sizeof(LuaFileEntry) + r.filepath.size()));
+  luaL_setmetatable(L, kFileEntryMetatable);
+
+  // Init all the fields
+  *file_entry = {
+      .isHidden = r.isHidden,
+      .isDirectory = r.isDirectory,
+      .isTrack = r.isTrack,
+      .path_size = r.filepath.size(),
+  };
+
+  // Copy the string data across.
+  std::memcpy(file_entry->path, r.filepath.data(), r.filepath.size());
+}
+
+auto check_file_iterator(lua_State* L, int stack_pos) -> database::FileIterator* {
+  database::FileIterator* it = *reinterpret_cast<database::FileIterator**>(
+      luaL_checkudata(L, stack_pos, kFileIteratorMetatable));
+  return it;
+}
+
+static auto push_iterator(lua_State* state, const database::FileIterator& it)
+    -> void {
+  database::FileIterator** data = reinterpret_cast<database::FileIterator**>(
+      lua_newuserdata(state, sizeof(uintptr_t)));
+  *data = new database::FileIterator(it); // TODO...
+  luaL_setmetatable(state, kFileIteratorMetatable);
+}
+
+static auto fs_iterate_prev(lua_State* state) -> int {
+  database::FileIterator* it = check_file_iterator(state, 1);
+  it->prev();
+  std::optional<database::FileEntry> res = it->value();
+
+  if (res) {
+    push_lua_file_entry(state, *res);
+  } else {
+    lua_pushnil(state);
+  }
+
+  return 1;
+}
+
+static auto fs_iterate(lua_State* state) -> int {
+  database::FileIterator* it = check_file_iterator(state, 1);
+  it->next();
+  std::optional<database::FileEntry> res = it->value();
+
+  if (res) {
+    push_lua_file_entry(state, *res);
+  } else {
+    lua_pushnil(state);
+  }
+
+  return 1;
+}
+
+// static auto db_iterator_clone(lua_State* state) -> int {
+//   database::Iterator* it = db_check_iterator(state, 1);
+//   push_iterator(state, *it);
+//   return 1;
+// }
+
+static auto fs_iterator_gc(lua_State* state) -> int {
+  database::FileIterator* it = check_file_iterator(state, 1);
+  delete it;
+  return 0;
+}
+
+static const struct luaL_Reg kFileIteratorFuncs[] = {{"next", fs_iterate},
+                                                   {"prev", fs_iterate_prev},
+                                                  //  {"clone", db_iterator_clone},
+                                                   {"__call", fs_iterate},
+                                                   {"__gc", fs_iterator_gc},
+                                                   {NULL, NULL}};
+
+static auto file_entry_path(lua_State* state) -> int {
+  LuaFileEntry* data = reinterpret_cast<LuaFileEntry*>(
+      luaL_checkudata(state, 1, kFileEntryMetatable));
+  lua_pushlstring(state, data->path, data->path_size);
+  return 1;
+}
+
+static const struct luaL_Reg kFileEntryFuncs[] = {{"filepath", file_entry_path},
+                                                 {"__tostring", file_entry_path},
+                                                 {NULL, NULL}};
+
+static auto fs_new_iterator(lua_State* state) -> int {
+  // Takes a filepath as a string and returns a new FileIterator
+  // on that directory
+  std::string filepath = luaL_checkstring(state, -1);
+  database::FileIterator iter(filepath);
+   push_iterator(state, iter);
+  return 1;
+}
+
+static const struct luaL_Reg kDatabaseFuncs[] = {{"iterator", fs_new_iterator},
+                                                 {NULL, NULL}};
+
+static auto lua_filesystem(lua_State* state) -> int {
+  luaL_newmetatable(state, kFileIteratorMetatable);
+  lua_pushliteral(state, "__index");
+  lua_pushvalue(state, -2);
+  lua_settable(state, -3);  // metatable.__index = metatable
+  luaL_setfuncs(state, kFileIteratorFuncs, 0);
+
+  luaL_newmetatable(state, kFileEntryMetatable);
+  lua_pushliteral(state, "__index");
+  lua_pushvalue(state, -2);
+  lua_settable(state, -3);  // metatable.__index = metatable
+  luaL_setfuncs(state, kFileEntryFuncs, 0);
+
+  luaL_newlib(state, kDatabaseFuncs);
+  return 1;
+}
+
+auto RegisterFileSystemModule(lua_State* s) -> void {
+  luaL_requiref(s, "filesystem", lua_filesystem, true);
+  lua_pop(s, 1);
+}
+
+}  // namespace lua