feat: add repeating tasks

backend/main.py

@@ -3,7 +3,7 @@ import json
 import time
 from collections import defaultdict, deque
 from contextlib import asynccontextmanager
-from datetime import datetime
+from datetime import datetime, timedelta
 from pathlib import Path
 from uuid import UUID
 
@@ -26,8 +26,8 @@ from .auth import (
     verify_password,
 )
 from .db import create_schema, get_db
-from .models import AppState, Folder, Session, Task, TaskList, User, utcnow
-from .mvp import audit
+from .models import AppState, Folder, RecurrenceTemplate, Session, Task, TaskList, User, utcnow
+from .mvp import audit, occurrences
 from .mvp import router as mvp_router
 from .schemas import (
     BatchResult,
@@ -624,16 +624,33 @@ async def update_task(
     user: User = Depends(current_user),
     db: AsyncSession = Depends(get_db),
 ):
+    task = await db.scalar(select(Task).where(Task.id == task_id, Task.user_id == user.id, Task.deleted_at.is_(None)))
+    if task is None:
+        raise HTTPException(status_code=404, detail="任务不存在")
     data = payload.model_dump(exclude_unset=True)
     expected_version = data.pop("version")
+    recurrence = None
+    if data.get("completed") is True:
+        recurrence = await db.scalar(select(RecurrenceTemplate).where(
+            RecurrenceTemplate.task_id == task_id, RecurrenceTemplate.user_id == user.id
+        ))
+        if recurrence:
+            next_items = occurrences(
+                recurrence.rrule,
+                recurrence.starts_at,
+                recurrence.starts_at + timedelta(microseconds=1),
+                recurrence.starts_at + timedelta(days=3660),
+                recurrence.ends_at,
+            )
+            if next_items:
+                data["completed"] = False
+                data["due_at"] = next_items[0]
+                recurrence.starts_at = next_items[0]
     if "list_id" in data:
         await _owned_list(db, user.id, data["list_id"])
-        parent_id = await db.scalar(
-            select(Task.parent_id).where(Task.id == task_id, Task.user_id == user.id)
-        )
-        if parent_id:
+        if task.parent_id:
             parent_list = await db.scalar(
-                select(Task.list_id).where(Task.id == parent_id, Task.user_id == user.id)
+                select(Task.list_id).where(Task.id == task.parent_id, Task.user_id == user.id)
             )
             if parent_list != data["list_id"]:
                 raise HTTPException(status_code=400, detail="子任务必须与父任务属于同一清单")