feat: implement db provider

CMakeLists.txt

@@ -3,12 +3,15 @@ project(magic_scrolls)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
+find_package(SQLite3 REQUIRED)
+
 file(GLOB_RECURSE sources
   "${CMAKE_SOURCE_DIR}/src/*.cpp")
 
 add_executable(magic_scrolls ${sources})
 
 target_include_directories(magic_scrolls PUBLIC "${CMAKE_SOURCE_DIR}/include")
+target_link_libraries(magic_scrolls PRIVATE SQLite::SQLite3)
 
 # -------
 enable_testing()
@@ -17,10 +20,23 @@ add_executable(event_bus_test
   tests/engine/event_bus_test.cpp
   src/engine/core/event_bus.cpp
 )
+add_executable(db_provider_test
+  tests/engine/db_provider_test.cpp
+  src/engine/core/engine.cpp
+  src/engine/core/engine_db_provider.cpp
+)
 
 target_include_directories(event_bus_test PUBLIC "${CMAKE_SOURCE_DIR}/include")
+target_link_libraries(event_bus_test PRIVATE SQLite::SQLite3)
+
+target_include_directories(db_provider_test PUBLIC "${CMAKE_SOURCE_DIR}/include")
+target_link_libraries(db_provider_test PRIVATE SQLite::SQLite3)
 
 add_test(
   NAME "Event Bus"
   COMMAND event_bus_test
 )
+add_test(
+  NAME "Database Provider"
+  COMMAND db_provider_test
+)

include/engine/core/engine.hpp

@@ -1,8 +1,9 @@
 #ifndef __MCS_ENGINE_HPP__
 #define __MCS_ENGINE_HPP__
 
-#include "engine/core/engine_module.hpp"
+#include <engine/core/engine_module.hpp>
-#include "engine/core/engine_module_api.hpp"
+#include <engine/core/engine_module_api.hpp>
+#include <engine/core/engine_db_provider.hpp>
 #include <cstdint>
 #include <memory>
 #include <vector>
@@ -24,6 +25,8 @@ public:
   MscEventBus &getBus() override;
   std::unordered_map<std::string, std::uint16_t> getLoadedModules() const override;
   MscEngineModule &getModule(const std::string &name) override;
+  std::unique_ptr<MscEngineDBProvider> createDBProvider() override;
+  std::unique_ptr<MscEngineDBProvider> createDBProvider(const std::string &filepath) override;
 };
 
 #endif // __MCS_ENGINE_HPP__

include/engine/core/engine_db_provider.hpp

@@ -0,0 +1,30 @@
+#ifndef __MSC_ENGINE_DB_PROVIDER_HPP__
+#define __MSC_ENGINE_DB_PROVIDER_HPP__
+
+#include <sqlite3.h>
+#include <string>
+
+/// @brief Engine database provider
+class MscEngineDBProvider
+{
+public:
+    ~MscEngineDBProvider();
+
+    /// @brief Create inmemory database
+    MscEngineDBProvider();
+
+    /// @brief Create file database
+    explicit MscEngineDBProvider(const std::string &filepath);
+
+    /// @brief Execute SQL statement
+    /// @param sql statement
+    void execute(const std::string &sql);
+
+    MscEngineDBProvider(const MscEngineDBProvider &) = delete;
+    MscEngineDBProvider &operator=(const MscEngineDBProvider &) = delete;
+
+private:
+    sqlite3 *_db = nullptr;
+};
+
+#endif // __MSC_ENGINE_DB_PROVIDER_HPP__

include/engine/core/engine_module_api.hpp

@@ -2,24 +2,33 @@
 #define __MSC_ENGINE_MODULE_API_HPP__
 
 #include <engine/core/engine_bus.hpp>
-#include <engine/core/engine_module.hpp>
+#include <engine/core/engine_db_provider.hpp>
 #include <cstdint>
 #include <string>
 #include <unordered_map>
+#include <memory>
+
+class MscEngineModule;
 
 class IMscEngineModuleAPI
 {
 public:
   virtual ~IMscEngineModuleAPI() = default;
 
-  /// Get access to engine event bus
+  /// @brief Get access to engine event bus
   virtual MscEventBus &getBus() = 0;
 
-  /// Get access to loaded module list
+  /// @brief Get access to loaded module list
   virtual std::unordered_map<std::string, std::uint16_t> getLoadedModules() const = 0;
 
-  /// Access module by its name
+  /// @brief Access module by its name
   virtual MscEngineModule &getModule(const std::string &name) = 0;
+
+  /// @brief Create database provider with in-memory database
+  virtual std::unique_ptr<MscEngineDBProvider> createDBProvider() = 0;
+
+  /// @brief Create database provider with file database
+  virtual std::unique_ptr<MscEngineDBProvider> createDBProvider(const std::string &filepath) = 0;
 };
 
 #endif // __MSC_ENGINE_MODULE_API_HPP__

src/engine/core/engine.cpp

@@ -84,3 +84,13 @@ MscEngineModule &MscEngine::getModule(const std::string &name)
 
   throw std::runtime_error("Module not found: " + name);
 }
+
+std::unique_ptr<MscEngineDBProvider> MscEngine::createDBProvider()
+{
+  return std::make_unique<MscEngineDBProvider>();
+}
+
+std::unique_ptr<MscEngineDBProvider> MscEngine::createDBProvider(const std::string &filepath)
+{
+  return std::make_unique<MscEngineDBProvider>(filepath);
+}

src/engine/core/engine_db_provider.cpp

@@ -0,0 +1,45 @@
+#include <engine/core/engine_db_provider.hpp>
+#include <stdexcept>
+
+MscEngineDBProvider::MscEngineDBProvider() : MscEngineDBProvider(":memory:")
+{
+}
+
+MscEngineDBProvider::MscEngineDBProvider(const std::string &filepath)
+{
+    const int result = sqlite3_open(filepath.c_str(), &_db);
+    if (result != SQLITE_OK)
+    {
+        const std::string message = _db != nullptr
+                                        ? sqlite3_errmsg(_db)
+                                        : "unknown SQLite error";
+
+        if (_db != nullptr)
+        {
+            sqlite3_close(_db);
+            _db = nullptr;
+        }
+
+        throw std::runtime_error("Failed to open SQLite database: " + message);
+    }
+}
+
+MscEngineDBProvider::~MscEngineDBProvider()
+{
+    if (_db != nullptr)
+        sqlite3_close(_db);
+}
+
+void MscEngineDBProvider::execute(const std::string &sql)
+{
+    char *errorMessage = nullptr;
+    const int result = sqlite3_exec(_db, sql.c_str(), nullptr, nullptr, &errorMessage);
+
+    if (result == SQLITE_OK)
+        return;
+
+    std::string message(errorMessage);
+    sqlite3_free(errorMessage);
+
+    throw std::runtime_error("Failed to execute SQL: " + message);
+}

tests/engine/db_provider_test.cpp

@@ -0,0 +1,62 @@
+#include <cassert>
+#include <vector>
+#include <stdexcept>
+#include <engine/core/engine.hpp>
+#include <engine/core/engine_db_provider.hpp>
+
+/// @brief Проверка на создание экземпляра
+void testProviderCreation()
+{
+    MscEngine engine({});
+
+    auto dbp1 = engine.createDBProvider();
+    assert(dbp1.get() != nullptr);
+}
+
+/// @brief Проверка на создание экземпляра с некорректным путём файла
+void testIncorrectFilePath()
+{
+    MscEngine engine({});
+
+    try
+    {
+        engine.createDBProvider("/i/am/an/incorrect/path/to/file.txt");
+        assert(false);
+    }
+    catch (const std::runtime_error &error)
+    {
+    }
+}
+
+/// @brief Проверка на успешное выполнение корректного выражения
+void testValidStatement()
+{
+    MscEngine engine({});
+    auto dbp = engine.createDBProvider();
+    dbp.get()->execute("SELECT 'hello, world' AS message;");
+}
+
+void testInvalidStatement()
+{
+    MscEngine engine({});
+    auto dbp = engine.createDBProvider();
+
+    try
+    {
+        dbp.get()->execute("SELECT * FROM nonexistentdatabase ABC");
+        assert(false);
+    }
+    catch (const std::runtime_error &error)
+    {
+    }
+}
+
+int main()
+{
+    testProviderCreation();
+    testIncorrectFilePath();
+    testValidStatement();
+    testInvalidStatement();
+
+    return 0;
+}