pokemon-radar-api/pokemon_radar_api.py

import json
import os
import sys
import threading
import time
from typing import Any, Dict, List, Optional

import redis
from dotenv import load_dotenv
from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from loguru import logger
from pydantic import BaseModel, Field

# 載入環境變數（要在 import radar_fetcher 之前，讓它 module-level 讀到）
load_dotenv()

import radar_fetcher
from pokemon_location_fetcher import PokemonRadarClient

# ========= 設定 =========
REDIS_HOST = os.getenv("REDIS_HOST", "192.168.42.211")
REDIS_PORT = int(os.getenv("REDIS_PORT", 6379))
REDIS_DB = int(os.getenv("REDIS_DB", 0))
REDIS_PASSWORD = os.getenv("REDIS_PASSWORD", None)
REDIS_KEY = "pokemon:radar:latest"

# Stale-while-revalidate：快取剩餘 TTL 低於此值時，在背景觸發 fetcher 更新
STALE_THRESHOLD = int(os.getenv("STALE_THRESHOLD", 120))
# 互斥 lock，避免同時多個 fetcher；FETCH_LOCK_TTL 要 >= fetcher 最長執行時間
FETCH_LOCK_KEY = os.getenv("FETCH_LOCK_KEY", "pokemon:radar:fetching")
FETCH_LOCK_TTL = int(os.getenv("FETCH_LOCK_TTL", 180))

# ========= FastAPI 初始化 =========
app = FastAPI(title="Pokemon Radar API (Redis Backed)", version="2.0.0")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# ========= Redis 連線池 =========
try:
    redis_pool = redis.ConnectionPool(
        host=REDIS_HOST,
        port=REDIS_PORT,
        db=REDIS_DB,
        password=REDIS_PASSWORD,
        decode_responses=True,
        socket_connect_timeout=5
    )
except Exception as e:
    print(f"❌ Redis 設定錯誤: {e}")
    sys.exit(1)


# ========= Models (保持與原本相容) =========
class ScanRequest(BaseModel):
    # 雖然改用 Redis，但保留這些欄位讓前端/n8n 不用改
    # 實際上 lat, lng, zoom, shot, state_path, ua... 在此模式下會被忽略
    lat: float = Field(..., description="(已忽略) 緯度")
    lng: float = Field(..., description="(已忽略) 經度")
    zoom: int = Field(16, description="(已忽略) 地圖縮放")
    shot: bool = Field(False, description="(已忽略) 是否擷取畫面")
    state_path: Optional[str] = Field(None, description="(已忽略)")
    ua_from_state: bool = Field(True, description="(已忽略)")
    
    # === 這些篩選參數依然有效 ===
    min_remaining: Optional[int] = Field(None, ge=0, description="只保留 剩餘秒數 ≥ 此值")
    min_iv: Optional[int] = Field(None, ge=0, le=100, description="只保留 IV% ≥ 此值")
    perfect_only: bool = Field(False, description="只保留 100% IV")
    species: Optional[str] = Field("", description="dex id 或關鍵字，例如 '133,伊布'")
    
    save_files: bool = Field(False, description="(已忽略) API 不再負責存檔")


class Item(BaseModel):
    id: Optional[int]
    name: Optional[str]
    gender: Optional[str]
    remaining: Optional[int]
    expire_time: Optional[int] = None
    expire_at: Optional[str] = None
    latitude: Optional[float]
    longitude: Optional[float]
    iv_pct: Optional[int]
    iv_atk: Optional[int]
    iv_def: Optional[int]
    iv_sta: Optional[int]
    cp: Optional[int]
    level: Optional[int]
    is_perfect: bool
    fast_move: Optional[str] = None
    charge_move: Optional[str] = None


class ScanResponse(BaseModel):
    source: str = "redis"
    ttl: int
    count_raw: int
    count_filtered: int
    items: List[Item]
    debug: Dict[str, Any]


# ========= 工具：Redis Helper =========
def get_data_from_redis():
    try:
        r = redis.Redis(connection_pool=redis_pool)
        if not r.exists(REDIS_KEY):
            return None, 0, None
        ttl = r.ttl(REDIS_KEY)
        raw_json = r.get(REDIS_KEY)
    except redis.exceptions.RedisError as e:
        return None, 0, f"redis unreachable: {e}"

    try:
        return json.loads(raw_json), ttl, None
    except json.JSONDecodeError:
        return None, 0, "redis payload not json"


# ========= 依賴：Client (只用來做 postprocess) =========
# 我們不需要傳入真實的 url/token，因為不會用到 fetch
_filter_helper = PokemonRadarClient(url="", token="")


# ========= Stale-while-revalidate 背景刷新 =========
def _trigger_background_refresh() -> None:
    """若沒有其他 fetcher 在跑，開一個 daemon thread 更新 Redis 快取。非阻塞。"""
    try:
        r = redis.Redis(connection_pool=redis_pool)
        acquired = r.set(FETCH_LOCK_KEY, str(time.time()), nx=True, ex=FETCH_LOCK_TTL)
    except redis.exceptions.RedisError as e:
        logger.warning(f"refresh lock check failed: {e}")
        return
    if not acquired:
        return  # 有其他 fetcher 正在跑

    def _run() -> None:
        try:
            logger.info("background refresh: start")
            radar_fetcher.main()
            logger.info("background refresh: done")
        except Exception as e:
            logger.exception(f"background refresh failed: {e}")
        finally:
            try:
                redis.Redis(connection_pool=redis_pool).delete(FETCH_LOCK_KEY)
            except redis.exceptions.RedisError:
                pass

    threading.Thread(target=_run, daemon=True, name="radar-refresh").start()


# ========= 路由 =========
@app.get("/ping")
def ping():
    return {"status": "ok", "backend": "redis"}


@app.post("/scan", response_model=ScanResponse)
def scan(req: ScanRequest) -> Any:
    # 1. 從 Redis 讀取資料
    data, ttl, err = get_data_from_redis()

    # Stale-while-revalidate：Redis 可達且（key 不存在 or TTL 快過期）時在背景觸發更新
    if err is None and (data is None or (0 < ttl < STALE_THRESHOLD)):
        _trigger_background_refresh()

    if not data:
        # Redis 沒資料或連不上，都回傳空結果而不是 500，避免前端炸掉
        return {
            "source": "redis (unreachable)" if err else "redis (empty)",
            "ttl": 0,
            "count_raw": 0,
            "count_filtered": 0,
            "items": [],
            "debug": {"note": err or "Redis key not found or expired"}
        }

    # 2. 取得原始列表
    # 根據你的 twpk_radar.mjs 結構，items 可能在 'results' 或 'items' 欄位
    items_raw = data.get("results", data.get("items", []))
    
    # 3. 使用 Helper 進行篩選 (Process & Filter)
    # 這一步很重要，因為 Redis 存的是 raw data，我們要根據 API 請求即時篩選
    try:
        items_filtered = _filter_helper.postprocess(
            items_raw,
            min_remaining=req.min_remaining,
            min_iv=req.min_iv,
            perfect_only=req.perfect_only,
            species=req.species or "",
        )
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Filtering error: {e}")

    # 4. 準備 Debug 資訊
    debug_info = data.get("debug", {})
    # 可以在這裡加入來源資訊
    debug_info["api_source"] = "Cached from Redis"
    debug_info["redis_ttl"] = ttl

    # 5. 回傳結果
    return {
        "source": "redis",
        "ttl": ttl,
        "count_raw": len(items_raw),
        "count_filtered": len(items_filtered),
        "items": items_filtered,
        "debug": debug_info
    }