"""Exercise the example's SDK boundary without opening a camera or display."""

import importlib.util
import sys
from pathlib import Path
from types import SimpleNamespace

import pytest


@pytest.fixture
def example(monkeypatch):
    path = Path(__file__).resolve().parents[1] / "examples" / "finger_pipeline.py"
    monkeypatch.syspath_prepend(str(path.parent))
    spec = importlib.util.spec_from_file_location("finger_pipeline_example", path)
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    return module


@pytest.mark.parametrize("zero_mode", ["raw", "measure", "none"])
def test_schema3_reference_is_applied_after_warmup_before_pipeline(example, monkeypatch, capsys, zero_mode):
    events = []
    options = {}
    snapshot = SimpleNamespace(fps=20., normal_force=1., shear_x=2., shear_y=3., age_ms=1.,
                               force_units=("N", "raw", "raw"), calibration_status={"fn": "ok"},
                               image=None, flow=None)

    class Pipe:
        def __enter__(self):
            events.append("pipeline")
            self.frames = iter([snapshot, None])
            return self

        def __exit__(self, *args):
            pass

        def wait(self):
            return next(self.frames)

    runtime = SimpleNamespace(
        tactile=SimpleNamespace(raw_sensor=SimpleNamespace(calibration=SimpleNamespace(schema_version=3)),
                                mask_stats={}, force_units=("wrong",) * 3),
        warmup=lambda **kwargs: events.append("warmup"),
        set_calibration_reference=lambda raw, **kwargs: events.append(("reference", raw, kwargs)),
        pipeline=lambda **kwargs: Pipe(), close=lambda: events.append("close"))

    def open_runtime(**kwargs):
        options.update(kwargs)
        return runtime

    monkeypatch.setattr(example.FingerRuntime, "open", open_runtime)
    monkeypatch.setattr(example, "measure_unloaded_reference",
                        lambda runtime: events.append("measure"))
    monkeypatch.setattr(example.cv2, "waitKey", lambda *args: pytest.fail("headless must not call GUI"))
    zero_args = {"raw": ["--zero-fn-raw", "1765.1"], "measure": ["--zero"], "none": []}[zero_mode]
    monkeypatch.setattr(sys, "argv", ["finger_pipeline.py", "--video", "test.mp4", "--no-show",
                                    "--cal-path", "model.json", "--device-id", "dd02-gl",
                                    "--export-dir", "assets", "--map-cache", "map", *zero_args])
    assert example.main() == 0
    assert options["cal_path"] == "model.json" and options["device_id"] == "dd02-gl"
    assert options["export_dir"] == "assets" and options["map_cache"] == "map"
    reference_events = {"raw": [("reference", {"fn": 1765.1}, {"reference_id": "cli-unloaded-reference"})],
                        "measure": ["measure"], "none": []}[zero_mode]
    assert events == ["warmup", *reference_events, "pipeline", "close"]
    output = capsys.readouterr().out
    assert "calibration=fn:ok" in output and "wrong" not in output


def test_selected_calibration_error_is_reported_without_fallback(example, monkeypatch, capsys):
    def fail(**kwargs):
        raise ValueError("calibration identity mismatch")

    monkeypatch.setattr(example.FingerRuntime, "open", fail)
    monkeypatch.setattr(sys, "argv", ["finger_pipeline.py", "--no-show", "--cal_path", "bad.json"])
    assert example.main() == 1
    assert "calibration identity mismatch" in capsys.readouterr().err


@pytest.mark.parametrize("arguments", [["--zero-fn-raw", "nan"], ["--calibration-dir", "calibrations"],
                                      ["--device-id", "SN1"], ["--cal-path", "a", "--calibration-dir", "b"]])
def test_invalid_selection_fails_before_capture(example, monkeypatch, arguments):
    monkeypatch.setattr(example.FingerRuntime, "open", lambda **kwargs: pytest.fail("must not open capture"))
    monkeypatch.setattr(sys, "argv", ["finger_pipeline.py", *arguments])
    with pytest.raises(SystemExit) as exc:
        example.main()
    assert exc.value.code == 2


def test_bundle_geometry_follows_explicit_config(example, tmp_path, monkeypatch):
    bundle = tmp_path / "custom"
    bundle.mkdir()
    (bundle / "sensor.json").write_text('{}')
    (bundle / "manifest.json").write_text('{"assets_dir": "geometry"}')
    (bundle / "geometry").mkdir()
    monkeypatch.chdir(tmp_path)
    assert Path(example.configured_export_dir("custom/sensor.json")) == bundle / "geometry"


def test_missing_declared_geometry_does_not_use_default_bundle(example, tmp_path):
    (tmp_path / "sensor.json").write_text('{}')
    (tmp_path / "manifest.json").write_text('{"assets_dir": "missing"}')
    with pytest.raises(ValueError, match="assets_dir"):
        example.configured_export_dir(str(tmp_path / "sensor.json"))


@pytest.mark.parametrize("advanced", [False, True])
def test_help_separates_debug_overrides(example, monkeypatch, capsys, advanced):
    monkeypatch.setattr(sys, "argv", ["finger_pipeline.py", "--help-advanced" if advanced else "--help"])
    with pytest.raises(SystemExit) as exc:
        example.main()
    assert exc.value.code == 0
    output = capsys.readouterr().out
    assert "--cal-path" in output and "--zero " in output
    assert ("--zero-fn-raw" in output) == advanced
    assert ("--export-dir" in output) == advanced
    assert ("--device-id" in output) == advanced


@pytest.mark.parametrize("failure", [None, "short", "nan", "legacy"])
def test_unloaded_reference_is_measured_atomically(example, failure):
    events = []
    frames = iter(range(30))
    count = 0

    def grab(**kwargs):
        nonlocal count
        count += 1
        return not (failure == "short" and count == 30), None

    def read(*keys):
        value = next(frames)
        return (float("nan") if failure == "nan" and value == 29 else value,)

    runtime = SimpleNamespace(
        tactile=SimpleNamespace(
            raw_sensor=SimpleNamespace(calibration=SimpleNamespace(
                schema_version=2 if failure == "legacy" else 3, channels={"fn": {}})),
            info=SimpleNamespace(FNORMAL_RAW=0, FSHEARX_RAW=1, FSHEARY_RAW=2),
            compute_deformation=lambda: None, read_info=read),
        grab_and_process=grab,
        set_calibration_reference=lambda raw, **kwargs: events.append((raw, kwargs)))
    if failure:
        with pytest.raises(ValueError):
            example.measure_unloaded_reference(runtime)
        assert events == []
    else:
        example.measure_unloaded_reference(runtime)
        assert events == [({"fn": 14.5}, {"reference_id": "startup-unloaded-reference"})]