from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from contextlib import asynccontextmanager
from app.config import settings

@asynccontextmanager
async def lifespan(app: FastAPI):
    # 启动时：初始化 DB 连接池、Redis 事件总线与外部适配器
    print(f"Starting {settings.PROJECT_NAME} in [{settings.ENVIRONMENT}] mode...")
    yield
    # 关闭时：优雅断开连接
    print(f"Shutting down {settings.PROJECT_NAME}...")

app = FastAPI(
    title=settings.PROJECT_NAME,
    version=settings.VERSION,
    lifespan=lifespan,
    docs_url="/docs" if settings.ENVIRONMENT != "production" else None,
    redoc_url="/redoc" if settings.ENVIRONMENT != "production" else None
)

# CORS 配置
app.add_middleware(
    CORSMiddleware,
    allow_origins=settings.CORS_ORIGINS,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

@app.get("/health", tags=["System"])
async def health_check():
    """生产探活与健康检查端点 (Blue-Green Probe)"""
    return {
        "status": "ok",
        "service": "wtfx-backend",
        "version": settings.VERSION,
        "environment": settings.ENVIRONMENT
    }