"""OCC 方案 B（常驻进程池）契约测试，见 docs/topics/performance/OCC_THROUGHPUT.md。

覆盖：spawn 子进程 + 管道往返、操作错误回传、超时换新补位、真实 OCC 解析
（盒体 STP 端到端）。OCC（pythonocc）仅 conda 环境提供，无 OCC 环境自动跳过。
"""
import os
from pathlib import Path

import pytest

pytest.importorskip("OCC", reason="需要 pythonocc 运行 OCC 进程池测试")

from moldinsight.services.occ_process_pool import OccProcessPool


@pytest.fixture(scope="module", autouse=True)
def _child_pythonpath():
    """spawn 子进程不继承 pytest 的 sys.path，需经 PYTHONPATH 传递 src 目录。"""
    src_dir = str(Path(__file__).resolve().parent.parent / "src")
    prev = os.environ.get("PYTHONPATH", "")
    os.environ["PYTHONPATH"] = src_dir if not prev else f"{src_dir}{os.pathsep}{prev}"
    yield
    if prev:
        os.environ["PYTHONPATH"] = prev
    else:
        os.environ.pop("PYTHONPATH", None)


@pytest.fixture
async def pool():
    _pool = OccProcessPool()
    try:
        yield _pool
    finally:
        await _pool.shutdown()


async def test_ping_roundtrip(pool):
    result = await pool.run("ping", {})
    assert result == {"pong": True}


async def test_unknown_op_raises(pool):
    with pytest.raises(RuntimeError, match="未知 OCC 操作"):
        await pool.run("no_such_op", {})


async def test_child_error_surfaces(pool):
    # parse_stp 指向不存在的文件：子进程内抛错，父进程应收到 RuntimeError
    with pytest.raises(RuntimeError):
        await pool.run("parse_stp", {"stp_path": "D:/no/such/file.stp"})


async def test_timeout_replaces_worker(pool):
    # 子进程挂 15s，父进程 1s 超时 → 换新补位后池仍可用
    with pytest.raises(Exception, match=".*"):
        await pool.run("sleep", {"seconds": 15}, timeout=1)
    # 新 worker 上 ping 正常
    result = await pool.run("ping", {})
    assert result == {"pong": True}


def _write_box_stp(path: Path) -> Path:
    from OCC.Core.BRepPrimAPI import BRepPrimAPI_MakeBox
    from OCC.Core.IFSelect import IFSelect_RetDone
    from OCC.Core.STEPControl import STEPControl_AsIs, STEPControl_Writer
    from OCC.Core.gp import gp_Pnt

    box = BRepPrimAPI_MakeBox(gp_Pnt(0, 0, 0), 100.0, 60.0, 40.0).Shape()
    writer = STEPControl_Writer()
    writer.Transfer(box, STEPControl_AsIs)
    assert writer.Write(str(path)) == IFSelect_RetDone
    return path


async def test_parse_stp_end_to_end(pool, tmp_path):
    stp_path = _write_box_stp(tmp_path / "box.stp")
    geometry = await pool.run("parse_stp", {"stp_path": str(stp_path)})
    assert geometry["volume"] == pytest.approx(100 * 60 * 40, rel=0.01)
    assert "bounding_box" in geometry


async def test_generate_cavity_persists_export_steps(pool, tmp_path):
    """最复杂的迁移点：分模 + 方案形状 STEP 导出全部在子进程内完成，
    TopoDS 不跨进程传输，export_manifest 携带落盘文件清单。"""
    from moldinsight.services.material_service import MaterialService

    stp_path = _write_box_stp(tmp_path / "box.stp")
    export_dir = tmp_path / "exports"
    result = await pool.run(
        "generate_cavity",
        {
            "stp_path": str(stp_path),
            "task_id": "test-task",
            "material": dict(MaterialService.get_material("ABS")),
            "is_foam_material": False,
            "process_params": None,
            "export_out_dir": str(export_dir),
        },
        timeout=120,
    )

    plan_result = result["plan_result"]
    schemes = plan_result["candidate_schemes"]
    assert 1 <= len(schemes) <= 3
    assert plan_result["best_scheme_id"] == schemes[0]["scheme_id"]
    # TopoDS 形状不得跨进程（子进程已 pop 掉 _export_shapes）
    assert "_export_shapes" not in plan_result

    manifest = result["export_manifest"]
    assert manifest is not None
    assert manifest["schemes"]
    best = manifest["schemes"][plan_result["best_scheme_id"]]
    assert best["total_files"] >= 1
    # 落盘文件真实存在于子进程写入的 export_out_dir
    assert any((export_dir / f.get("relative_path", "")).exists() for f in best["files"])