feat(core): implement services for issue #8

- Add BountyService for room bounty operations (group and personal)
- Add TrackingService for tracking bounty operations
- Uses RoomStorage and TrackingStorage ports
- PermissionError raised when non-creator edits/deletes
- ValueError raised when bounty not found in tracking

core/services.py

@@ -0,0 +1,155 @@
+"""Pure business logic services for JIGAIDO."""
+
+import time
+from typing import Optional
+
+from core.models import Bounty, RoomData, TrackedBounty, TrackingData
+from core.ports import RoomStorage, TrackingStorage
+
+
+class BountyService:
+    """Service for bounty operations in a room.
+
+    A room is identified by room_id:
+    - Negative room_id: Telegram group (e.g., -1001)
+    - Positive room_id: DM/personal context (user's Telegram ID)
+
+    This service handles both group and personal bounties through room_id.
+    """
+
+    def __init__(self, storage: RoomStorage):
+        self._storage = storage
+
+    def add_bounty(
+        self,
+        room_id: int,
+        user_id: int,
+        text: Optional[str] = None,
+        link: Optional[str] = None,
+        due_date_ts: Optional[int] = None,
+    ) -> Bounty:
+        """Add a new bounty to the room."""
+        room_data = self._storage.load(room_id)
+        if room_data is None:
+            room_data = RoomData(room_id=room_id, bounties=[], next_id=1)
+        else:
+            room_data.next_id += 1
+
+        bounty = Bounty(
+            id=room_data.next_id,
+            created_by_user_id=user_id,
+            text=text,
+            link=link,
+            due_date_ts=due_date_ts,
+            created_at=int(time.time()),
+        )
+        self._storage.add_bounty(room_id, bounty)
+        return bounty
+
+    def list_bounties(self, room_id: int) -> list[Bounty]:
+        """List all bounties in a room."""
+        room_data = self._storage.load(room_id)
+        if room_data is None:
+            return []
+        return room_data.bounties
+
+    def get_bounty(self, room_id: int, bounty_id: int) -> Bounty | None:
+        """Get a specific bounty by ID."""
+        return self._storage.get_bounty(room_id, bounty_id)
+
+    def update_bounty(
+        self,
+        room_id: int,
+        bounty_id: int,
+        user_id: int,
+        text: Optional[str] = None,
+        link: Optional[str] = None,
+        due_date_ts: Optional[int] = None,
+        clear_link: bool = False,
+        clear_due: bool = False,
+    ) -> bool:
+        """Update a bounty. Only creator can update."""
+        bounty = self._storage.get_bounty(room_id, bounty_id)
+        if not bounty:
+            return False
+        if bounty.created_by_user_id != user_id:
+            raise PermissionError("Only the creator can edit this bounty.")
+
+        updated = Bounty(
+            id=bounty.id,
+            created_by_user_id=bounty.created_by_user_id,
+            text=text if text is not None else bounty.text,
+            link=None if clear_link else (link if link is not None else bounty.link),
+            due_date_ts=None
+            if clear_due
+            else (due_date_ts if due_date_ts is not None else bounty.due_date_ts),
+            created_at=bounty.created_at,
+        )
+        self._storage.update_bounty(room_id, updated)
+        return True
+
+    def delete_bounty(self, room_id: int, bounty_id: int, user_id: int) -> bool:
+        """Delete a bounty. Only creator can delete."""
+        bounty = self._storage.get_bounty(room_id, bounty_id)
+        if not bounty:
+            return False
+        if bounty.created_by_user_id != user_id:
+            raise PermissionError("Only the creator can delete this bounty.")
+
+        self._storage.delete_bounty(room_id, bounty_id)
+        return True
+
+
+class TrackingService:
+    """Service for tracking bounty operations."""
+
+    def __init__(self, tracking_storage: TrackingStorage, room_storage: RoomStorage):
+        self._tracking = tracking_storage
+        self._room = room_storage
+
+    def track_bounty(self, room_id: int, user_id: int, bounty_id: int) -> bool:
+        """Start tracking a bounty. Returns True if newly tracked."""
+        bounty = self._room.get_bounty(room_id, bounty_id)
+        if not bounty:
+            raise ValueError("Bounty not found.")
+
+        tracking_data = self._tracking.load(room_id, user_id)
+        if tracking_data is None:
+            tracking_data = TrackingData(room_id=room_id, user_id=user_id, tracked=[])
+
+        for tracked in tracking_data.tracked:
+            if tracked.bounty_id == bounty_id:
+                return False
+
+        tracked = TrackedBounty(bounty_id=bounty_id, created_at=int(time.time()))
+        self._tracking.track_bounty(room_id, user_id, tracked)
+        return True
+
+    def untrack_bounty(self, room_id: int, user_id: int, bounty_id: int) -> bool:
+        """Stop tracking a bounty. Returns True if was tracking."""
+        tracking_data = self._tracking.load(room_id, user_id)
+        if tracking_data is None:
+            return False
+
+        for tracked in tracking_data.tracked:
+            if tracked.bounty_id == bounty_id:
+                self._tracking.untrack_bounty(room_id, user_id, bounty_id)
+                return True
+        return False
+
+    def get_tracked_bounties(self, room_id: int, user_id: int) -> list[Bounty]:
+        """Get all bounties tracked by a user in a room."""
+        tracking_data = self._tracking.load(room_id, user_id)
+        if tracking_data is None:
+            return []
+
+        room_data = self._room.load(room_id)
+        if room_data is None:
+            return []
+
+        bounty_map = {b.id: b for b in room_data.bounties}
+        return [
+            bounty_map[t.bounty_id]
+            for t in tracking_data.tracked
+            if t.bounty_id in bounty_map
+        ]