import multiprocessing as mp
from fastapi import APIRouter

router = APIRouter()


@router.get("/info")
async def get_system_info():
    """Return system info: CPU cores, GPU availability, parallel backend."""
    cpu_cores = mp.cpu_count() or 1

    # Check Ray
    ray_available = False
    ray_initialized = False
    try:
        from app.services.parallel_coverage_service import RAY_AVAILABLE
        ray_available = RAY_AVAILABLE
        if ray_available:
            import ray
            ray_initialized = ray.is_initialized()
    except Exception:
        pass

    # Check GPU
    gpu_info = None
    try:
        import cupy as cp
        if cp.cuda.runtime.getDeviceCount() > 0:
            props = cp.cuda.runtime.getDeviceProperties(0)
            gpu_info = {
                "name": props["name"].decode(),
                "memory_mb": props["totalGlobalMem"] // (1024 * 1024),
            }
    except Exception:
        pass

    return {
        "cpu_cores": cpu_cores,
        "parallel_workers": min(cpu_cores, 14),
        "parallel_backend": "ray" if ray_available else "sequential",
        "ray_available": ray_available,
        "ray_initialized": ray_initialized,
        "gpu": gpu_info,
        "gpu_enabled": gpu_info is not None,
    }