feat: add share calendar API

backend/src/v1/schedule_items/service.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
+import json
+from typing import TYPE_CHECKING, Protocol
 from uuid import UUID
 
 from fastapi import HTTPException
@@ -9,13 +10,17 @@ from sqlalchemy.exc import SQLAlchemyError
 from core.auth.models import CurrentUser
 from core.db.base_service import BaseService
 from core.logging import get_logger
+from models.inbox_messages import InboxMessage, InboxMessageType
 from models.schedule_items import ScheduleItem
+from v1.auth.gateway import SupabaseAuthGateway
 from v1.schedule_items.repository import ScheduleItemRepository
 from v1.schedule_items.schemas import (
     ScheduleItemCreateRequest,
     ScheduleItemListRequest,
     ScheduleItemMetadata,
     ScheduleItemResponse,
+    ScheduleItemShareRequest,
+    ScheduleItemShareResponse,
     ScheduleItemUpdateRequest,
     ScheduleItemSourceType,
     ScheduleItemStatus,
@@ -24,22 +29,31 @@ from v1.schedule_items.schemas import (
 if TYPE_CHECKING:
     from sqlalchemy.ext.asyncio import AsyncSession
 
+    from v1.auth.schemas import UserByEmailResponse
+
 logger = get_logger("v1.schedule_items.service")
 
 
+class AuthByEmailGateway(Protocol):
+    async def get_user_by_email(self, email: str) -> "UserByEmailResponse": ...
+
+
 class ScheduleItemService(BaseService):
     _repository: ScheduleItemRepository
     _session: AsyncSession
+    _auth_gateway: AuthByEmailGateway
 
     def __init__(
         self,
         repository: ScheduleItemRepository,
         session: AsyncSession,
         current_user: CurrentUser | None,
+        auth_gateway: AuthByEmailGateway | None = None,
     ) -> None:
         super().__init__(current_user=current_user)
         self._repository = repository
         self._session = session
+        self._auth_gateway = auth_gateway or SupabaseAuthGateway()
 
     async def create(self, request: ScheduleItemCreateRequest) -> ScheduleItemResponse:
         user_id = self.require_user_id()
@@ -179,6 +193,50 @@ class ScheduleItemService(BaseService):
 
         return [self._to_response(item) for item in items]
 
+    async def share(
+        self, item_id: UUID, request: ScheduleItemShareRequest
+    ) -> ScheduleItemShareResponse:
+        user_id = self.require_user_id()
+
+        try:
+            item = await self._repository.get_by_id(item_id)
+            if item is None:
+                raise HTTPException(status_code=404, detail="Schedule item not found")
+            if item.owner_id != user_id:
+                raise HTTPException(
+                    status_code=403,
+                    detail="Only owner can share this schedule item",
+                )
+
+            target_user = await self._auth_gateway.get_user_by_email(request.email)
+            recipient_id = UUID(target_user.id)
+            message = InboxMessage(
+                recipient_id=recipient_id,
+                sender_id=user_id,
+                message_type=InboxMessageType.CALENDAR,
+                schedule_item_id=item.id,
+                content=json.dumps({"permission": request._permission_value()}),
+                created_by=user_id,
+            )
+            self._session.add(message)
+            await self._session.commit()
+        except HTTPException:
+            raise
+        except SQLAlchemyError:
+            await self._session.rollback()
+            logger.exception("Failed to share schedule item", item_id=str(item_id))
+            raise HTTPException(
+                status_code=503, detail="Schedule item store unavailable"
+            )
+        except ValueError:
+            await self._session.rollback()
+            logger.exception(
+                "Auth lookup returned invalid user id", email=request.email
+            )
+            raise HTTPException(status_code=503, detail="Auth lookup unavailable")
+
+        return ScheduleItemShareResponse(message="Calendar invitation sent")
+
     def _to_response(self, item: ScheduleItem) -> ScheduleItemResponse:
         return ScheduleItemResponse(
             id=item.id,