Reorganized and cleaned up the solution.

Include/Database/Database.hpp

@@ -0,0 +1,92 @@
+#pragma once
+
+#include <memory>
+#include <mutex>
+#include <string>
+#include <tuple>
+#include <chrono>
+#include <map>
+
+#include <sqlite3.h>
+#include "Transaction.hpp"
+#include "Game/RealmCharacter.hpp"
+#include "Game/RealmCharacterMetaKV.hpp"
+
+enum class QueryID {
+	CreateAccount,
+	VerifyAccount,
+	LoadAccount,
+
+	LoadCharacterSlots,
+	CreateNewCharacter,
+	SaveCharacter,
+	LoadCharacter,
+
+	SaveFriend,
+	RemoveFriend,
+	LoadFriendList,
+
+	SaveIgnore,
+	RemoveIgnore,
+	LoadIgnoreList,
+};
+
+class Database {
+private:
+	static inline std::unique_ptr<Database> m_instance;
+	static inline std::mutex m_mutex;
+
+	sqlite3 *m_db = nullptr;
+	std::unordered_map< QueryID, sqlite3_stmt * > m_statements;
+
+public:
+	static Database &Get()
+	{
+		std::lock_guard<std::mutex> lock( m_mutex );
+		if( !m_instance )
+			m_instance.reset( new Database() );
+		return *m_instance;
+	}
+
+	Database( const Database & ) = delete;
+	Database &operator=( const Database & ) = delete;
+
+	Database();
+	~Database();
+
+public:
+	int64_t CreateNewAccount( const std::string &username,
+							  const std::string &password,
+							  const std::string &email_address,
+							  const std::string &date_of_birth,
+							  const std::string &chat_handle );
+
+	std::tuple< bool, int64_t, std::wstring > VerifyAccount( const std::wstring &username, const std::wstring &password );
+
+	uint32_t CreateNewCharacter( const int64_t account_id,
+								 const CharacterSlotData meta,
+								 const std::vector< uint8_t > &blob );
+
+	bool SaveCharacter( const int64_t account_id,
+						const int32_t character_id,
+						const CharacterSlotData meta,
+						const std::vector< uint8_t > &blob );
+
+	std::map< uint32_t, CharacterSlotData > LoadCharacterSlots( const int64_t account_id );
+
+	sptr_realm_character LoadCharacterData( const int64_t account_id, const int32_t character_id );
+
+	bool SaveFriend( const int64_t account_id, const std::wstring &friend_handle );
+	bool RemoveFriend( const int64_t account_id, const std::wstring &friend_handle );
+	std::vector< std::wstring > LoadFriends( const int64_t account_id );
+
+	bool SaveIgnore( const int64_t account_id, const std::wstring &ignore_handle );
+	bool RemoveIgnore( const int64_t account_id, const std::wstring &ignore_handle );
+	std::vector< std::wstring > LoadIgnores( const int64_t account_id );
+
+private:
+	void CreateTables();
+	void PrepareStatements();
+	void FinalizeStatements();
+	void Execute( const char *sql );
+};

Include/Database/Transaction.hpp

@@ -0,0 +1,68 @@
+#pragma once
+
+#include <sqlite3.h>
+#include <stdexcept>
+
+class SQLiteTransaction {
+	sqlite3 *m_db = nullptr;
+	bool m_committed = false;
+
+public:
+	explicit SQLiteTransaction( sqlite3 *db )
+		: m_db( db )
+	{
+		if( !m_db )
+			throw std::invalid_argument( "Null SQLite database pointer" );
+
+		if( sqlite3_exec( m_db, "BEGIN TRANSACTION;", nullptr, nullptr, nullptr ) != SQLITE_OK )
+			throw std::runtime_error( "Failed to begin transaction: " + std::string( sqlite3_errmsg( m_db ) ) );
+	}
+
+	~SQLiteTransaction()
+	{
+		if( m_committed || !m_db )
+			return;
+
+		sqlite3_exec( m_db, "ROLLBACK;", nullptr, nullptr, nullptr );
+	}
+
+	SQLiteTransaction( const SQLiteTransaction & ) = delete;
+	SQLiteTransaction &operator=( const SQLiteTransaction & ) = delete;
+
+	SQLiteTransaction( SQLiteTransaction &&other ) noexcept
+		: m_db( other.m_db ), m_committed( other.m_committed )
+	{
+		other.m_db = nullptr;
+	}
+
+	SQLiteTransaction &operator=( SQLiteTransaction &&other ) noexcept
+	{
+		if( this != &other )
+		{
+			rollbackOnError();
+			m_db = other.m_db;
+			m_committed = other.m_committed;
+			other.m_db = nullptr;
+		}
+		return *this;
+	}
+
+	void commit()
+	{
+		if( m_committed || !m_db )
+			return;
+
+		if( sqlite3_exec( m_db, "COMMIT;", nullptr, nullptr, nullptr ) != SQLITE_OK )
+			throw std::runtime_error( "Failed to commit transaction: " + std::string( sqlite3_errmsg( m_db ) ) );
+		m_committed = true;
+	}
+
+private:
+	void rollbackOnError()
+	{
+		if( m_committed || !m_db )
+			return;
+
+		sqlite3_exec( m_db, "ROLLBACK;", nullptr, nullptr, nullptr );
+	}
+};