"""基础业务路由（仿真/设备/文件下载等）。

该文件保留项目早期的示例接口与基础能力：
- 健康检查
- 设备连接状态（示例）
- 启停仿真
- 文件下载（带目录穿越保护）
"""

from __future__ import annotations

from pathlib import Path

from fastapi import APIRouter, Depends, HTTPException
from fastapi.responses import FileResponse

from backend.api.schemas import HealthResponse, SimulationStartRequest, SimulationStartResponse, SimulationStopResponse
from backend.services.simulation_manager import SimulationManager
from backend.utils import safe_join


def get_router(simulation_manager: SimulationManager, file_root: Path) -> APIRouter:
    """构造基础业务路由。

    说明：此项目采用“router 工厂函数”风格，通过参数注入 service/配置，而不是全局依赖容器。
    """
    router = APIRouter()

    @router.get("/health", response_model=HealthResponse)
    async def health() -> HealthResponse:
        """健康检查（用于容器编排/负载均衡探活）。"""
        return HealthResponse()

    @router.get("/api/devices")
    async def devices():
        """返回设备列表（当前为示例数据，反映仿真运行时状态）。"""
        runtime = simulation_manager.current()
        return {
            "data": [
                {
                    "device_id": "controlbox_01",
                    "device_type": "mock_vehicle",
                    "connected": bool(runtime and runtime.status == "running"),
                }
            ]
        }

    @router.post("/api/simulation/start", response_model=SimulationStartResponse)
    async def start_simulation(body: SimulationStartRequest) -> SimulationStartResponse:
        """启动仿真。"""
        simulation_id = await simulation_manager.start(body.model_dump())
        return SimulationStartResponse(simulation_id=simulation_id)

    @router.post("/api/simulation/{simulation_id}/stop", response_model=SimulationStopResponse)
    async def stop_simulation(simulation_id: str) -> SimulationStopResponse:
        """停止仿真。"""
        await simulation_manager.stop(simulation_id)
        return SimulationStopResponse(simulation_id=simulation_id, status="stopped")

    @router.get("/files/{file_path:path}")
    async def files(file_path: str):
        """下载文件（相对 file_root），并校验路径合法性。"""
        try:
            resolved = safe_join(file_root, file_path)
        except ValueError:
            raise HTTPException(status_code=400, detail="invalid path")
        if not resolved.exists() or not resolved.is_file():
            raise HTTPException(status_code=404, detail="not found")
        return FileResponse(str(resolved))

    return router