"""Database management."""
from os.path import isfile
-from sqlite3 import connect as sql_connect
-from plomtask.misc import HandledException
+from difflib import Differ
+from sqlite3 import connect as sql_connect, Cursor, Row
+from typing import Any, Dict
+from plomtask.exceptions import HandledException
PATH_DB_SCHEMA = 'scripts/init.sql'
-class DatabaseFile:
+class DatabaseFile: # pylint: disable=too-few-public-methods
"""Represents the sqlite3 database's file."""
- def __init__(self, path):
+ def __init__(self, path: str) -> None:
self.path = path
- self.check()
+ self._check()
- def check(self):
- """Check file exists and is of proper schema."""
- self.exists = isfile(self.path)
- if self.exists:
- self.validate_schema()
-
- def remake(self):
+ def remake(self) -> None:
"""Create tables in self.path file as per PATH_DB_SCHEMA sql file."""
with sql_connect(self.path) as conn:
with open(PATH_DB_SCHEMA, 'r', encoding='utf-8') as f:
conn.executescript(f.read())
- self.check()
+ self._check()
- def validate_schema(self):
+ def _check(self) -> None:
+ """Check file exists, and is of proper schema."""
+ self.exists = isfile(self.path)
+ if self.exists:
+ self._validate_schema()
+
+ def _validate_schema(self) -> None:
"""Compare found schema with what's stored at PATH_DB_SCHEMA."""
sql_for_schema = 'SELECT sql FROM sqlite_master ORDER BY sql'
- msg_wrong_schema = 'Database has wrong tables schema.'
+ msg_err = 'Database has wrong tables schema. Diff:\n'
with sql_connect(self.path) as conn:
schema_rows = [r[0] for r in conn.execute(sql_for_schema) if r[0]]
retrieved_schema = ';\n'.join(schema_rows) + ';'
with open(PATH_DB_SCHEMA, 'r', encoding='utf-8') as f:
stored_schema = f.read().rstrip()
if stored_schema != retrieved_schema:
- raise HandledException(msg_wrong_schema)
+ diff_msg = Differ().compare(retrieved_schema.splitlines(),
+ stored_schema.splitlines())
+ raise HandledException(msg_err + '\n'.join(diff_msg))
+
+
+class DatabaseConnection:
+ """A single connection to the database."""
+
+ def __init__(self, db_file: DatabaseFile) -> None:
+ self.file = db_file
+ self.conn = sql_connect(self.file.path)
+ self.cached_todos: Dict[int, Any] = {}
+ self.cached_days: Dict[str, Any] = {}
+ self.cached_process_steps: Dict[int, Any] = {}
+ self.cached_processes: Dict[int, Any] = {}
+ self.cached_conditions: Dict[int, Any] = {}
+
+ def commit(self) -> None:
+ """Commit SQL transaction."""
+ self.conn.commit()
+
+ def exec(self, code: str, inputs: tuple[Any, ...] = tuple()) -> Cursor:
+ """Add commands to SQL transaction."""
+ return self.conn.execute(code, inputs)
+
+ def close(self) -> None:
+ """Close DB connection."""
+ self.conn.close()
+
+
+class BaseModel:
+ """Template for most of the models we use/derive from the DB."""
+ table_name = ''
+ to_save: list[str] = []
+ id_: None | int | str
+ id_type: type[Any] = int
+
+ @classmethod
+ def from_table_row(cls, db_conn: DatabaseConnection, row: Row) -> Any:
+ """Make from DB row, write to DB cache."""
+ obj = cls(*row)
+ assert isinstance(obj.id_, cls.id_type)
+ cache = getattr(db_conn, f'cached_{cls.table_name}')
+ cache[obj.id_] = obj
+ return obj
+
+ def set_int_id(self, id_: int | None) -> None:
+ """Set id_ if >= 1 or None, else fail."""
+ if (id_ is not None) and id_ < 1:
+ msg = f'illegal {self.__class__.__name__} ID, must be >=1: {id_}'
+ raise HandledException(msg)
+ self.id_ = id_
+
+ def save_core(self, db_conn: DatabaseConnection,
+ update_with_lastrowid: bool = True) -> None:
+ """Write bare-bones self (sans connected items), ensuring self.id_."""
+ q_marks = ','.join(['?'] * (len(self.to_save) + 1))
+ values = tuple([self.id_] + [getattr(self, key)
+ for key in self.to_save])
+ table_name = self.table_name
+ cursor = db_conn.exec(f'REPLACE INTO {table_name} VALUES ({q_marks})',
+ values)
+ if update_with_lastrowid:
+ self.id_ = cursor.lastrowid
+ cache = getattr(db_conn, f'cached_{table_name}')
+ cache[self.id_] = self