"""FastAPI 应用工厂。

路由概览：
    GET  /              -> 仅返回版本号
    GET  /docs          -> Swagger UI（Basic Auth）
    GET  /redoc         -> ReDoc       （Basic Auth）
    GET  /openapi.json  -> OpenAPI 文档（Basic Auth）
    GET  /health        -> 存活探针（公开）
    GET  /api/...       -> 业务接口
"""

from __future__ import annotations

import logging
from contextlib import asynccontextmanager

from fastapi import Depends, FastAPI
from fastapi.openapi.docs import get_redoc_html, get_swagger_ui_html
from fastapi.responses import JSONResponse, PlainTextResponse

from .controllers import file_router, system_router
from .database import init_db_schema
from .security import require_docs_auth

logger = logging.getLogger("zikai")


@asynccontextmanager
async def lifespan(app: FastAPI):
    try:
        init_db_schema()
        logger.info("数据库表已就绪。")
    except Exception as exc:  # pragma: no cover
        logger.error("初始化数据库失败：%s", exc)
    yield


def create_app() -> FastAPI:
    app = FastAPI(
        title="zikai file service",
        description=(
            "f.zikai.wang 的文件上传与主机监控服务。\n\n"
            "- `GET /api/system/status` — CPU / 内存 / 磁盘（HTML 或 JSON）\n"
            "- `POST /api/files/upload` — 大文件流式上传\n"
            "- 内置 SFTP 服务（详见 README）\n\n"
            "/docs 等接口需 Basic Auth，凭据见 config.yaml 的 docs 段。"
        ),
        version="1.0.0",
        docs_url=None,
        redoc_url=None,
        openapi_url=None,
        lifespan=lifespan,
    )

    app.include_router(system_router)
    app.include_router(file_router)

    # 受 Basic Auth 保护的文档接口
    @app.get("/openapi.json", include_in_schema=False)
    def protected_openapi(_: str = Depends(require_docs_auth)) -> JSONResponse:
        return JSONResponse(app.openapi())

    @app.get("/docs", include_in_schema=False)
    def protected_docs(_: str = Depends(require_docs_auth)):
        return get_swagger_ui_html(
            openapi_url="/openapi.json", title="zikai docs", swagger_favicon_url=""
        )

    @app.get("/redoc", include_in_schema=False)
    def protected_redoc(_: str = Depends(require_docs_auth)):
        return get_redoc_html(
            openapi_url="/openapi.json", title="zikai docs", redoc_favicon_url=""
        )

    # 公开元信息（不暴露接口列表）
    @app.get("/", include_in_schema=False, response_class=PlainTextResponse)
    def root() -> PlainTextResponse:
        return PlainTextResponse(f"zikai {app.version}\n")

    @app.get("/health", include_in_schema=False)
    def health() -> dict:
        return {"status": "ok"}

    return app


app = create_app()