feat(backend): refactor mono repository

This commit is contained in:
2025-08-27 11:04:56 -04:00
parent d0dbba21fb
commit be1c729220
37 changed files with 2534 additions and 452 deletions

3
backend/db/__init__.py Normal file
View File

@@ -0,0 +1,3 @@
# database/__init__.py
from .connection import DatabaseConnection
from .base_repository import BaseRepository

View File

@@ -0,0 +1,109 @@
# backend/db/base_repository.py
from __future__ import annotations
from typing import TypeVar, Generic, List, Sequence, Any, Mapping, Tuple
from .connection import DatabaseConnection
# Generic type for the model (your dataclasses such as Member, Service, …)
T = TypeVar("T")
class BaseRepository(Generic[T]):
"""
Very small generic repository that knows how to:
* INSERT a dataclasslike object (any object that implements ``to_dict`` and
``from_row``)
* SELECT all rows from a table and turn them into model instances
* (optionally) UPDATE or DELETE rows stubs are provided for future use
"""
def __init__(self, db: DatabaseConnection):
self.db = db
# ------------------------------------------------------------------
# INSERT
# ------------------------------------------------------------------
def _insert(self, table: str, obj: T, pk_name: str) -> T:
"""
Insert ``obj`` into ``table`` and populate the autoincrement primarykey
field named ``pk_name`` on the original object.
The model **must** implement:
* ``to_dict() -> Mapping[str, Any]`` returns a mapping of column →
value (including the PK, which we drop here)
* ``from_row(row: sqlite3.Row) -> Model`` classmethod used by
``_select_all``.
"""
# 1⃣ Turn the model into a plain dict and drop the PK column.
data: Mapping[str, Any] = obj.to_dict() # type: ignore[attr-defined]
if pk_name not in data:
raise ValueError(f"Primarykey column '{pk_name}' not found in model data.")
# Remove the autoincrement column SQLite will fill it in.
data_without_pk = {k: v for k, v in data.items() if k != pk_name}
# 2⃣ Build the column list and matching placeholders.
columns = ", ".join(data_without_pk.keys())
placeholders = ", ".join("?" for _ in data_without_pk)
sql = f"INSERT INTO {table} ({columns}) VALUES ({placeholders})"
# 3⃣ Execute the statement with a *tuple* of values that matches the
# number of placeholders.
cursor = self.db.execute(sql, tuple(data_without_pk.values()))
# 4⃣ SQLite gives us the newly generated rowid on the cursor.
setattr(obj, pk_name, cursor.lastrowid) # type: ignore[attr-defined]
return obj
# ------------------------------------------------------------------
# SELECT ALL
# ------------------------------------------------------------------
def _select_all(self, table: str, model_cls: type[T]) -> List[T]:
"""
Return every row from ``table`` as a list of ``model_cls`` instances.
``model_cls`` must provide a ``from_row`` classmethod that accepts a
``sqlite3.Row`` and returns an instantiated model.
"""
rows = self.db.fetchall(f"SELECT * FROM {table}")
return [model_cls.from_row(r) for r in rows] # type: ignore[attr-defined]
# ------------------------------------------------------------------
# OPTIONAL UPDATE helper (you can call it from concrete repos)
# ------------------------------------------------------------------
def _update(
self,
table: str,
pk_name: str,
pk_value: Any,
updates: Mapping[str, Any],
) -> None:
"""
Simple UPDATE helper.
Example:
repo._update(
table="Members",
pk_name="MemberId",
pk_value=42,
updates={"IsActive": 0, "Notes": "temporarily disabled"},
)
"""
if not updates:
return # nothing to do
set_clause = ", ".join(f"{col}=?" for col in updates)
sql = f"UPDATE {table} SET {set_clause} WHERE {pk_name} = ?"
params: Tuple[Any, ...] = tuple(updates.values()) + (pk_value,)
self.db.execute(sql, params)
# ------------------------------------------------------------------
# OPTIONAL DELETE helper
# ------------------------------------------------------------------
def _delete(self, table: str, pk_name: str, pk_value: Any) -> None:
"""
Delete a row by primary key.
"""
sql = f"DELETE FROM {table} WHERE {pk_name} = ?"
self.db.execute(sql, (pk_value,))

186
backend/db/connection.py Normal file
View File

@@ -0,0 +1,186 @@
"""
Thin convenience layer over the builtin ``sqlite3`` module.
Why we need a wrapper
---------------------
* The repository (`repository.py`) expects the following public API:
- ``execute`` run an INSERT/UPDATE/DELETE.
- ``fetchone`` / ``fetchall`` run a SELECT and get the result(s).
- ``lastrowid`` primarykey of the most recent INSERT.
- ``close`` close the DB connection.
* A wrapper lets us:
• Set a sensible ``row_factory`` (``sqlite3.Row``) so column names are
accessible as ``row["ColumnName"]``.
• Centralise ``commit``/``rollback`` handling.
• Provide type hints and a contextmanager interface
(``with DatabaseConnection(...):``) which is handy for tests.
* No external dependencies everything stays purePython/SQLite.
The implementation below is deliberately tiny: it only does what the
application needs while remaining easy to extend later (e.g. add
connectionpooling or logging).
"""
from __future__ import annotations
import sqlite3
from pathlib import Path
from typing import Any, Iterable, Tuple, List, Optional, Union
class DatabaseConnection:
"""
Simple wrapper around a SQLite connection.
Core behaviour
---------------
* ``row_factory`` is set to :class:`sqlite3.Row` callers can use
``row["col_name"]`` or treat the row like a mapping.
* All ``execute`` calls are automatically committed.
If an exception bubbles out, the transaction is rolled back.
* ``execute`` returns the cursor so callers can chain
``cursor.lastrowid`` if they need the autogenerated PK.
* Implements the contextmanager protocol (``with ... as db:``).
The public API matches what ``Repository`` expects:
- execute(sql, params=None) → None
- fetchone(sql, params=None) → Optional[sqlite3.Row]
- fetchall(sql, params=None) → List[sqlite3.Row]
- lastrowid → int
- close()
"""
# -----------------------------------------------------------------
# Construction / contextmanager protocol
# -----------------------------------------------------------------
def __init__(
self,
db_path: Union[str, Path],
*,
timeout: float = 5.0,
detect_types: int = sqlite3.PARSE_DECLTYPES | sqlite3.PARSE_COLNAMES,
) -> None:
"""
Parameters
----------
db_path
Path to the SQLite file. ``":memory:"`` works for tests.
timeout
Seconds to wait for a lock before raising ``sqlite3.OperationalError``.
detect_types
Enable type conversion (so DATE/DATETIME are returned as ``datetime``).
"""
self._conn: sqlite3.Connection = sqlite3.connect(
str(db_path), timeout=timeout, detect_types=detect_types
)
# ``Row`` makes column access dictionarylike and preserves order.
self._conn.row_factory = sqlite3.Row
self._cursor: sqlite3.Cursor = self._conn.cursor()
def __enter__(self) -> "DatabaseConnection":
"""Allow ``with DatabaseConnection(...) as db:`` usage."""
return self
def __exit__(self, exc_type, exc_val, exc_tb) -> Optional[bool]:
"""
On normal exit commit the transaction, otherwise roll back.
Returning ``False`` propagates any exception.
"""
if exc_type is None:
try:
self._conn.commit()
finally:
self.close()
else:
# Something went wrong roll back to keep the DB clean.
self._conn.rollback()
self.close()
# ``None`` means “dont suppress exceptions”
return None
# -----------------------------------------------------------------
# Lowlevel helpers used by the repository
# -----------------------------------------------------------------
@property
def cursor(self) -> sqlite3.Cursor:
"""Expose the underlying cursor rarely needed outside the repo."""
return self._cursor
@property
def lastrowid(self) -> int:
"""PK of the most recent ``INSERT`` executed on this connection."""
return self._cursor.lastrowid
# -----------------------------------------------------------------
# Public API the four methods used throughout the code base
# -----------------------------------------------------------------
def execute(self, sql: str, params: Optional[Tuple[Any, ...]] = None) -> sqlite3.Cursor:
"""
Run an INSERT/UPDATE/DELETE statement and commit immediately.
Returns the underlying ``sqlite3.Cursor`` so callers can inspect
``lastrowid``, ``rowcount`` etc. This mirrors the behaviour of the
standard ``sqlite3.Connection.execute`` method.
"""
try:
if params is None:
cursor = self._cursor.execute(sql) # ← capture cursor
else:
cursor = self._cursor.execute(sql, params) # ← capture cursor
self._conn.commit()
return cursor # ← **return it**
except sqlite3.Error as exc:
# Keep the original error handling but reraise after logging.
# self._logger.error(
# "SQL execution error: %s SQL: %s Params: %s",
# exc,
# sql,
# params,
# )
raise
def fetchone(
self, sql: str, params: Optional[Tuple[Any, ...]] = None
) -> Optional[sqlite3.Row]:
"""
Execute a SELECT that returns at most one row.
Returns ``None`` when the result set is empty.
"""
if params is None:
self._cursor.execute(sql)
else:
self._cursor.execute(sql, params)
return self._cursor.fetchone()
def fetchall(
self, sql: str, params: Optional[Tuple[Any, ...]] = None
) -> List[sqlite3.Row]:
"""
Execute a SELECT and return **all** rows as a list.
The rows are ``sqlite3.Row`` instances, which behave like dicts.
"""
if params is None:
self._cursor.execute(sql)
else:
self._cursor.execute(sql, params)
return self._cursor.fetchall()
def executescript(self, script: str) -> None:
"""Convenient wrapper for sqlite3.Connection.executescript."""
try:
self._conn.executescript(script)
self._conn.commit()
except Exception:
self._conn.rollback()
raise
def close(self) -> None:
"""Close the underlying SQLite connection."""
# ``cursor`` is automatically closed when the connection closes,
# but we explicitly close it for clarity.
try:
self._cursor.close()
finally:
self._conn.close()