feat: add SQLite persistence models

app/db/repositories.py

@@ -0,0 +1,69 @@
+from datetime import datetime
+
+from sqlalchemy import select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.orm import Session
+
+from app.db.models import Activity, ActivityStatus, HealthState, SyncUser
+
+
+class UserRepository:
+    def __init__(self, session: Session) -> None:
+        self.session = session
+
+    def create(self, **values) -> SyncUser:
+        user = SyncUser(**values)
+        self.session.add(user)
+        self.session.commit()
+        return user
+
+    def get(self, user_id: int) -> SyncUser | None:
+        return self.session.get(SyncUser, user_id)
+
+    def list_enabled(self) -> list[SyncUser]:
+        return list(self.session.scalars(select(SyncUser).where(SyncUser.enabled.is_(True)).order_by(SyncUser.id)))
+
+
+class ActivityRepository:
+    def __init__(self, session: Session) -> None:
+        self.session = session
+
+    def get_or_create_discovered(
+        self,
+        *,
+        user_id: int,
+        mywhoosh_activity_id: str,
+        activity_name: str,
+        activity_timestamp: datetime | None,
+    ) -> tuple[Activity, bool]:
+        existing = self.session.scalar(
+            select(Activity).where(
+                Activity.user_id == user_id,
+                Activity.mywhoosh_activity_id == mywhoosh_activity_id,
+            )
+        )
+        if existing is not None:
+            return existing, False
+        activity = Activity(
+            user_id=user_id,
+            mywhoosh_activity_id=mywhoosh_activity_id,
+            activity_name=activity_name,
+            activity_timestamp=activity_timestamp,
+            status=ActivityStatus.DISCOVERED,
+            last_completed_stage=ActivityStatus.DISCOVERED,
+        )
+        self.session.add(activity)
+        try:
+            self.session.commit()
+        except IntegrityError:
+            self.session.rollback()
+            existing = self.session.scalar(
+                select(Activity).where(
+                    Activity.user_id == user_id,
+                    Activity.mywhoosh_activity_id == mywhoosh_activity_id,
+                )
+            )
+            if existing is None:
+                raise
+            return existing, False
+        return activity, True