refactor: enhance type hinting and casting for improved type safety across multiple files

app/core/cache.py

@@ -6,7 +6,7 @@ import asyncio
 import json
 import logging
 from collections.abc import Awaitable, Callable
-from typing import Any
+from typing import Any, cast
 
 import redis.asyncio as redis
 from app.core.config import settings
@@ -45,10 +45,13 @@ class RedisCacheManager:
         async with self._lock:
             if self._client is not None:
                 return
-            self._client = redis.from_url(
-                settings.redis_url,
-                encoding="utf-8",
-                decode_responses=False,
+            self._client = cast(
+                Redis,
+                redis.from_url(  # type: ignore[no-untyped-call]
+                    settings.redis_url,
+                    encoding="utf-8",
+                    decode_responses=False,
+                ),
             )
             await self._refresh_availability()
 
@@ -64,10 +67,13 @@ class RedisCacheManager:
             return
         async with self._lock:
             if self._client is None:
-                self._client = redis.from_url(
-                    settings.redis_url,
-                    encoding="utf-8",
-                    decode_responses=False,
+                self._client = cast(
+                    Redis,
+                    redis.from_url(  # type: ignore[no-untyped-call]
+                        settings.redis_url,
+                        encoding="utf-8",
+                        decode_responses=False,
+                    ),
                 )
             await self._refresh_availability()
 
@@ -76,7 +82,7 @@ class RedisCacheManager:
             self._available = False
             return
         try:
-            await self._client.ping()
+            await cast(Awaitable[Any], self._client.ping())
         except RedisError as exc:  # pragma: no cover - logging only
             self._available = False
             logger.warning("Redis ping failed: %s", exc)
@@ -140,8 +146,8 @@ async def write_json(
     """Serialize data to JSON and store it with TTL using retry/backoff."""
     payload = json.dumps(value, separators=(",", ":"), ensure_ascii=True).encode("utf-8")
 
-    async def _operation() -> Any:
-        return await client.set(name=key, value=payload, ex=ttl_seconds)
+    async def _operation() -> None:
+        await client.set(name=key, value=payload, ex=ttl_seconds)
 
     await _run_with_retry(_operation, backoff_ms)
 
@@ -151,8 +157,8 @@ async def delete_keys(client: Redis, keys: list[str], backoff_ms: int) -> None:
     if not keys:
         return
 
-    async def _operation() -> Any:
-        return await client.delete(*keys)
+    async def _operation() -> None:
+        await client.delete(*keys)
 
     await _run_with_retry(_operation, backoff_ms)
 

app/core/security.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 
 from collections.abc import Mapping
 from datetime import datetime, timedelta, timezone
-from typing import Any
+from typing import Any, cast
 
 import jwt
 from app.core.config import settings
@@ -18,10 +18,10 @@ class PasswordHasher:
         self._context = CryptContext(schemes=["pbkdf2_sha256"], deprecated="auto")
 
     def hash(self, password: str) -> str:
-        return self._context.hash(password)
+        return cast(str, self._context.hash(password))
 
     def verify(self, password: str, hashed_password: str) -> bool:
-        return self._context.verify(password, hashed_password)
+        return bool(self._context.verify(password, hashed_password))
 
 
 class JWTService:
@@ -45,10 +45,10 @@ class JWTService:
         }
         if claims:
             payload.update(claims)
-        return jwt.encode(payload, self._secret_key, algorithm=self._algorithm)
+        return cast(str, jwt.encode(payload, self._secret_key, algorithm=self._algorithm))
 
     def decode(self, token: str) -> dict[str, Any]:
-        return jwt.decode(token, self._secret_key, algorithms=[self._algorithm])
+        return cast(dict[str, Any], jwt.decode(token, self._secret_key, algorithms=[self._algorithm]))
 
 
 password_hasher = PasswordHasher()

app/models/activity.py

@@ -10,9 +10,11 @@ from pydantic import BaseModel, ConfigDict, Field
 from sqlalchemy import DateTime, ForeignKey, Integer, func, text
 from sqlalchemy import Enum as SqlEnum
 from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.engine import Dialect
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 from sqlalchemy.types import JSON as SA_JSON
 from sqlalchemy.types import TypeDecorator
+from sqlalchemy.sql.type_api import TypeEngine
 
 from app.models.base import Base, enum_values
 
@@ -31,7 +33,7 @@ class JSONBCompat(TypeDecorator):
     impl = JSONB
     cache_ok = True
 
-    def load_dialect_impl(self, dialect):  # type: ignore[override]
+    def load_dialect_impl(self, dialect: Dialect) -> TypeEngine[Any]:
         if dialect.name == "sqlite":
             from sqlalchemy.dialects.sqlite import JSON as SQLITE_JSON  # local import
 

app/models/base.py

@@ -14,7 +14,7 @@ class Base(DeclarativeBase):
     """Base class that configures naming conventions."""
 
     @declared_attr.directive
-    def __tablename__(cls) -> str:  # type: ignore[misc]  # noqa: N805 - SQLAlchemy expects cls
+    def __tablename__(cls) -> str:  # noqa: N805 - SQLAlchemy expects cls
         return cls.__name__.lower()
 
 

app/repositories/task_repo.py

@@ -5,7 +5,7 @@ from __future__ import annotations
 from collections.abc import Mapping, Sequence
 from dataclasses import dataclass
 from datetime import datetime
-from typing import Any
+from typing import Any, cast
 
 from sqlalchemy import Select, select
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -123,6 +123,9 @@ class TaskRepository:
 
     async def _resolve_task_owner(self, task: Task) -> int | None:
         if task.deal is not None:
-            return task.deal.owner_id
+            return int(task.deal.owner_id)
         stmt = select(Deal.owner_id).where(Deal.id == task.deal_id)
-        return await self._session.scalar(stmt)
+        owner_id_raw: Any = await self._session.scalar(stmt)
+        if owner_id_raw is None:
+            return None
+        return cast(int, owner_id_raw)

app/services/contact_service.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 from collections.abc import Sequence
 from dataclasses import dataclass
+from typing import cast
 
 from sqlalchemy import select
 
@@ -151,11 +152,11 @@ class ContactService:
     def _build_update_mapping(self, updates: ContactUpdateData) -> dict[str, str | None]:
         payload: dict[str, str | None] = {}
         if updates.name is not UNSET:
-            payload["name"] = updates.name
+            payload["name"] = cast(str | None, updates.name)
         if updates.email is not UNSET:
-            payload["email"] = updates.email
+            payload["email"] = cast(str | None, updates.email)
         if updates.phone is not UNSET:
-            payload["phone"] = updates.phone
+            payload["phone"] = cast(str | None, updates.phone)
         return payload
 
     async def _ensure_no_related_deals(self, contact_id: int) -> None: