| 1 |  |  | import logging | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  | import os | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  | from typing import Final | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  | from sqlalchemy import Engine, create_engine, URL, inspect | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  | from sqlalchemy.sql.ddl import CreateSchema | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  | from src.kalauz.singleton import Singleton | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  | # future: swith to SQLAlchemy ORM when https://youtrack.jetbrains.com/issue/PY-4536 is fixed | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  | class Database(metaclass=Singleton): | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  |     def __init__(self) -> None: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  |         self.logger = logging.getLogger(__name__) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  |         self._DRIVERNAME: Final = "mysql+mysqlconnector" | 
            
                                                                                                            
                            
            
                                    
            
            
                | 18 |  |  |         self._HOST: Final = "localhost" | 
            
                                                                                                            
                            
            
                                    
            
            
                | 19 |  |  |         self._PORT: Final = 3306 | 
            
                                                                                                            
                            
            
                                    
            
            
                | 20 |  |  |         self._USERNAME: Final = "root" | 
            
                                                                                                            
                            
            
                                    
            
            
                | 21 |  |  |         self._PASSWORD: Final = self.get_password() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 22 |  |  |         self.DATABASE_NAME: Final = "kalauz" | 
            
                                                                                                            
                            
            
                                    
            
            
                | 23 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 |  |  |         self.engine = self.connect_to_database_server() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 |  |  |         self.engine = self.connect_to_database() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 |  |  |         self.logger.info(f"{self.__class__.__name__} initialized!") | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 28 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 29 |  |  |     def get_password(self) -> str: | 
            
                                                                        
                            
            
                                    
            
            
                | 30 |  |  |         try: | 
            
                                                                        
                            
            
                                    
            
            
                | 31 |  |  |             database_password = os.getenv("DATABASE_PASSWORD") | 
            
                                                                        
                            
            
                                    
            
            
                | 32 |  |  |             if not database_password: | 
            
                                                                        
                            
            
                                    
            
            
                | 33 |  |  |                 raise ValueError( | 
            
                                                                        
                            
            
                                    
            
            
                | 34 |  |  |                     "No password found in the .env file for the database server!" | 
            
                                                                        
                            
            
                                    
            
            
                | 35 |  |  |                 ) | 
            
                                                                        
                            
            
                                    
            
            
                | 36 |  |  |         except ValueError as error: | 
            
                                                                        
                            
            
                                    
            
            
                | 37 |  |  |             self.logger.critical(error) | 
            
                                                                        
                            
            
                                    
            
            
                | 38 |  |  |             raise | 
            
                                                                        
                            
            
                                    
            
            
                | 39 |  |  |         return database_password | 
            
                                                                                                            
                            
            
                                    
            
            
                | 40 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 41 |  |  |     def connect_to_database_server(self) -> Engine: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 42 |  |  |         try: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 43 |  |  |             database_url = URL.create( | 
            
                                                                                                            
                            
            
                                    
            
            
                | 44 |  |  |                 drivername=self._DRIVERNAME, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 45 |  |  |                 host=self._HOST, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 46 |  |  |                 port=self._PORT, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 47 |  |  |                 username=self._USERNAME, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 48 |  |  |                 password=self._PASSWORD, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 49 |  |  |             ) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 50 |  |  |             return create_engine(database_url) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 51 |  |  |         finally: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 52 |  |  |             self.logger.debug("Successfully connected to the database server!") | 
            
                                                                                                            
                            
            
                                    
            
            
                | 53 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 54 |  |  |     def connect_to_database(self) -> Engine: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 55 |  |  |         if not inspect(self.engine).has_schema(self.DATABASE_NAME): | 
            
                                                                                                            
                            
            
                                    
            
            
                | 56 |  |  |             with self.engine.begin() as connection: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 57 |  |  |                 connection.execute(CreateSchema(self.DATABASE_NAME)) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 58 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 59 |  |  |         return self.connect_to_created_database() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 60 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 61 |  |  |     def connect_to_created_database(self) -> Engine: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 62 |  |  |         try: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 63 |  |  |             database_url = URL.create( | 
            
                                                                                                            
                            
            
                                    
            
            
                | 64 |  |  |                 drivername=self._DRIVERNAME, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 65 |  |  |                 host=self._HOST, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 66 |  |  |                 port=self._PORT, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 67 |  |  |                 username=self._USERNAME, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 68 |  |  |                 password=self._PASSWORD, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 69 |  |  |                 database=self.DATABASE_NAME, | 
            
                                                                                                            
                            
            
                                    
            
            
                | 70 |  |  |             ) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 71 |  |  |             return create_engine(database_url) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 72 |  |  |         finally: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 73 |  |  |             self.logger.debug( | 
            
                                                                                                            
                            
            
                                    
            
            
                | 74 |  |  |                 f"Successfully connected to the {self.DATABASE_NAME} database of the server!" | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 75 |  |  |             ) | 
            
                                                        
            
                                    
            
            
                | 76 |  |  |  |