init project

src/lua/loader.cpp

@@ -0,0 +1,154 @@
+#include <cstdlib>
+#include <iostream>
+#include <lua/loader.hpp>
+#include <stdexcept>
+
+LuaLoader::LuaLoader() : L(luaL_newstate()) {
+  luaL_openlibs(L);
+  AddLuaPath("./?.lua");
+  AddCPath("./?.so");
+  AddCPath("./?.dylib");
+}
+
+void LuaLoader::AddLuaPath(const std::string& new_path) {
+  lua_getglobal(L, "package");
+  lua_getfield(L, -1, "path");
+  lua_pushstring(L, (std::string(";") + new_path).data());
+  lua_concat(L, 2);
+  lua_setfield(L, -2, "path");
+  lua_pop(L, 1);
+}
+
+void LuaLoader::AddCPath(const std::string& new_path) {
+  lua_getglobal(L, "package");
+  lua_getfield(L, -1, "cpath");
+  lua_pushstring(L, (std::string(";") + new_path).data());
+  lua_concat(L, 2);
+  lua_setfield(L, -2, "cpath");
+  lua_pop(L, 1);
+}
+
+void LuaLoader::LoadImpl(const std::string& name) {
+  lua_getglobal(L, "require");
+  lua_pushstring(L, name.data());
+
+  if (lua_pcall(L, 1, 1, 0) != LUA_OK) {
+    std::cerr << "Error call script: " << name.data() << std::endl;
+    std::cerr << lua_tostring(L, -1) << std::endl;
+    throw std::logic_error("Error call script: " + name);
+  }
+
+  ParseRequire();
+  ParseImport();
+}
+
+void LuaLoader::LoadToGlobal(const std::string& name) {
+  LoadImpl(name);
+  lua_setglobal(L, name.data());
+}
+
+std::vector<std::string> LuaLoader::GetListScripts(const std::string& lua_module) const {
+  std::vector<std::string> result;
+
+  lua_getglobal(L, lua_module.data());
+  lua_pushnil(L);
+
+  while (lua_next(L, -2) != 0) {
+    if (!lua_isfunction(L, -1)) {
+      lua_pop(L, 1);
+      continue;
+    }
+
+    lua_pop(L, 1);
+    result.push_back(lua_tostring(L, -1));
+  }
+
+  lua_pop(L, 1);
+
+  return result;
+}
+
+void LuaLoader::ForEachByStringArray(std::function<void(const std::string&)> callback) {
+  if (lua_isnil(L, -1)) {
+    lua_pop(L, 1);
+    return;
+  }
+
+  if (lua_isstring(L, -1)) {
+    callback(lua_tostring(L, -1));
+
+    lua_pop(L, 1);
+    return;
+  } else if (lua_istable(L, -1)) {
+    lua_pushnil(L);
+
+    while (lua_next(L, -2) != 0) {
+      if (!lua_isstring(L, -1)) {
+        throw std::logic_error("Error in for each by string array");
+      }
+
+      callback(lua_tostring(L, -1));
+      lua_pop(L, 1);
+    }
+
+    lua_pop(L, 1);
+    return;
+  }
+
+  throw std::logic_error("Error in parse requires ");
+}
+
+void LuaLoader::ParseRequire() {
+  if (!lua_istable(L, -1)) {
+    return;
+  }
+
+  lua_getfield(L, -1, "require");
+
+  ForEachByStringArray(
+      [this](const std::string& new_module_name) { LoadToGlobal(new_module_name); });
+}
+
+void LuaLoader::Import(const std::string& name, const std::string& field, int table) {
+  LoadImpl(name);
+  lua_getfield(L, -1, field.data());
+  lua_setfield(L, table, field.data());
+  lua_pop(L, 1);
+}
+
+void LuaLoader::ParseImport() {
+  if (!lua_istable(L, -1)) {
+    lua_pop(L, 1);
+    return;
+  }
+
+  lua_getfield(L, -1, "import");
+
+  ForEachByStringArray([this, table = lua_absindex(L, -2)](const std::string& new_module_name) {
+    int dot_position = new_module_name.find(".");
+
+    if (dot_position == std::string::npos) {
+      throw std::logic_error("Can't find dot in import");
+    }
+
+    Import(new_module_name.substr(0, dot_position), new_module_name.substr(dot_position + 1),
+           table);
+  });
+}
+
+void LuaLoader::Call(const std::string& lua_module, const std::string& function) {
+  lua_getglobal(L, lua_module.data());
+  lua_getfield(L, -1, function.data());
+
+  if (lua_pcall(L, 0, 0, 0) != LUA_OK) {
+    std::cout << "Error in call " << lua_module << "." << function << std::endl;
+    std::cerr << lua_tostring(L, -1) << std::endl;
+    throw std::logic_error("Error in call " + lua_module + "." + function);
+  }
+
+  lua_pop(L, 1);
+}
+
+LuaLoader::~LuaLoader() {
+  lua_close(L);
+}