# --- routers/leaf_options.py ---
from fastapi import APIRouter, BackgroundTasks, HTTPException, Body
from fastapi.responses import StreamingResponse
from pydantic import BaseModel
from typing import List
import json, os, asyncio, time, re

# 🌟 引入新的 asyncssh 版本爬蟲
from cmts_scraper import sync_cmts_leaves_async
from shared import CMTS_DEVICE

# 🌟 移除原本硬寫的 prefix="/api/v1"，只留下 tags
router = APIRouter(tags=["Options"])
CACHE_FILE = "cmts_leaf_options_cache.json"

# 🌟 1. 改用全域布林變數，狀態切換更即時，消滅非同步時間差
IS_SCANNING = False

class SyncOptionsRequest(BaseModel):
    leaf_paths: List[str]

@router.get("/cmts-leaf-options")
async def get_leaf_options():
    if not os.path.exists(CACHE_FILE): return {}
    with open(CACHE_FILE, "r", encoding="utf-8") as f:
        return json.load(f)

@router.post("/cmts-leaf-options/sync")
async def sync_leaf_options(request: SyncOptionsRequest):
    global IS_SCANNING # 宣告我們要修改全域變數

    if not request.leaf_paths: 
        raise HTTPException(status_code=400)

    # 🌟 2. 第一時間檢查並「立即」阻擋
    if IS_SCANNING:
        async def busy_stream():
            yield json.dumps({"event": "error", "message": "⚠️ 掃描任務正在執行中，請勿重複點擊！"}) + "\n"
        return StreamingResponse(busy_stream(), media_type="text/event-stream")
    
    # 如果沒人掃描，立刻把狀態改為 True (在建立串流之前就上鎖)
    IS_SCANNING = True

    async def event_generator():
        global IS_SCANNING
        try:
            cmts_query_paths = []
            for p in request.leaf_paths:
                clean_p = p.replace("::", " ")
                clean_p = re.sub(r"\s*\[\d+\]", "", clean_p)
                cmts_query_paths.append(clean_p)
            
            cmts_query_paths = list(dict.fromkeys(cmts_query_paths))
            
            # 🌟 因為爬蟲自己會存檔，我們只要專心把進度轉發給前端就好！
            async for chunk in sync_cmts_leaves_async(
                host=CMTS_DEVICE.get("host"),
                username=CMTS_DEVICE.get("username"),
                password=CMTS_DEVICE.get("password"),
                leaf_paths=cmts_query_paths
            ):
                yield chunk 

        except Exception as e:
            yield json.dumps({"event": "error", "message": str(e)}) + "\n"
            
        finally:
            # 🌟 3. 無論成功、失敗、或使用者提早關閉網頁，都確保會解鎖
            IS_SCANNING = False

    return StreamingResponse(event_generator(), media_type="text/event-stream")

# 🌟 新增：清除特定選項快取的 API (使用您原本定義的 CACHE_FILE)
@router.post("/clear_cache")
async def clear_specific_cache(paths_to_clear: list = Body(...)):
    cleared_count = 0
    
    # 1. 檢查快取檔案是否存在
    if not os.path.exists(CACHE_FILE):
        return {"status": "success", "cleared_count": 0, "message": "快取檔案不存在"}

    try:
        # 2. 讀取現有的 JSON 快取資料
        with open(CACHE_FILE, "r", encoding="utf-8") as f:
            cache_data = json.load(f)
            
        # 3. 逐一比對並刪除指定的路徑
        for path in paths_to_clear:
            if path in cache_data:
                del cache_data[path]
                cleared_count += 1
                
        # 4. 如果有刪除資料，將更新後的內容寫回 JSON 檔案
        if cleared_count > 0:
            with open(CACHE_FILE, "w", encoding="utf-8") as f:
                json.dump(cache_data, f, ensure_ascii=False, indent=4)
                
        return {"status": "success", "cleared_count": cleared_count}
        
    except Exception as e:
        return {"status": "error", "message": f"清除快取時發生錯誤: {str(e)}"}