feat: implement cron-based automation task scheduling and update task configuration

domain/tasks/scheduler.py

@@ -0,0 +1,102 @@
+import asyncio
+from dataclasses import dataclass
+from datetime import datetime
+
+from croniter import croniter
+
+from models.database import AutomationTask
+from .task_queue import task_queue_service
+
+
+@dataclass
+class CronTaskItem:
+    task_id: int
+    processor_type: str
+    path: str
+    cron: croniter
+    next_run: datetime
+
+
+class AutomationTaskScheduler:
+    def __init__(self):
+        self._items: list[CronTaskItem] = []
+        self._worker: asyncio.Task | None = None
+        self._reload_event = asyncio.Event()
+        self._stop_event = asyncio.Event()
+
+    async def start(self) -> None:
+        if self._worker and not self._worker.done():
+            return
+        self._stop_event.clear()
+        await self._load_tasks()
+        self._worker = asyncio.create_task(self._run_loop())
+
+    async def stop(self) -> None:
+        if not self._worker:
+            return
+        self._stop_event.set()
+        self._reload_event.set()
+        await self._worker
+        self._worker = None
+
+    def refresh(self) -> None:
+        if self._worker and not self._worker.done():
+            self._reload_event.set()
+
+    async def _load_tasks(self) -> None:
+        tasks = await AutomationTask.filter(event="cron", enabled=True)
+        items: list[CronTaskItem] = []
+        now = datetime.now()
+        for task in tasks:
+            trigger = task.trigger_config or {}
+            if not isinstance(trigger, dict):
+                continue
+            cron_expr = trigger.get("cron_expr")
+            path = trigger.get("path")
+            if not cron_expr or not path:
+                continue
+            cron = self._build_cron(cron_expr, now)
+            if not cron:
+                continue
+            next_run = cron.get_next(datetime)
+            items.append(
+                CronTaskItem(
+                    task_id=task.id,
+                    processor_type=task.processor_type,
+                    path=path,
+                    cron=cron,
+                    next_run=next_run,
+                )
+            )
+        self._items = items
+
+    def _build_cron(self, expr: str, base_time: datetime) -> croniter | None:
+        expr = str(expr or "").strip()
+        if not expr:
+            return None
+        parts = [p for p in expr.split() if p]
+        if len(parts) not in (5, 6):
+            return None
+        second_at_beginning = len(parts) == 6
+        try:
+            return croniter(expr, base_time, second_at_beginning=second_at_beginning)
+        except Exception:
+            return None
+
+    async def _run_loop(self) -> None:
+        while not self._stop_event.is_set():
+            if self._reload_event.is_set():
+                self._reload_event.clear()
+                await self._load_tasks()
+            now = datetime.now()
+            for item in list(self._items):
+                if item.next_run <= now:
+                    await task_queue_service.add_task(
+                        item.processor_type,
+                        {"task_id": item.task_id, "path": item.path},
+                    )
+                    item.next_run = item.cron.get_next(datetime)
+            await asyncio.sleep(1)
+
+
+task_scheduler = AutomationTaskScheduler()