"""
任务持久化存储
使用 JSON 文件存储任务数据
"""
import os
import json
import time
from typing import Dict, List, Optional


class TaskStore:
    def __init__(self, store_dir: str):
        self.store_dir = os.path.abspath(store_dir)
        os.makedirs(self.store_dir, exist_ok=True)

    def _task_path(self, task_id: str) -> str:
        return os.path.join(self.store_dir, f"{task_id}.json")

    def save(self, task: dict) -> None:
        task["updated_at"] = time.time()
        path = self._task_path(task["id"])
        with open(path, "w", encoding="utf-8") as f:
            json.dump(task, f, ensure_ascii=False, indent=2)

    def load(self, task_id: str) -> Optional[dict]:
        path = self._task_path(task_id)
        if not os.path.exists(path):
            return None
        with open(path, "r", encoding="utf-8") as f:
            return json.load(f)

    def list_all(self) -> List[dict]:
        tasks = []
        for filename in os.listdir(self.store_dir):
            if filename.endswith(".json"):
                task_id = filename[:-5]
                task = self.load(task_id)
                if task:
                    tasks.append(task)
        tasks.sort(key=lambda t: t.get("created_at", 0), reverse=True)
        return tasks

    def append_log(self, task_id: str, log_line: str) -> None:
        task = self.load(task_id)
        if not task:
            return
        if "logs" not in task:
            task["logs"] = []
        task["logs"].append({
            "time": time.strftime("%Y-%m-%d %H:%M:%S"),
            "message": log_line,
        })
        # 日志最多保留 500 条
        if len(task["logs"]) > 500:
            task["logs"] = task["logs"][-500:]
        self.save(task)