"""Thin CLI smoke coverage for `giant rollout` (issues.md Issue 5) — confirms
the CheckpointCompatibilityError raised by giant.checkpoint_io.load_for_inference
surfaces as a clean typer.Exit(1) with the expected message, end-to-end
through the CLI, not just at the giant.checkpoint_io unit level."""

from __future__ import annotations

import torch
from typer.testing import CliRunner

from giant.cli import _build_rollout_timing, app

runner = CliRunner()


def test_build_rollout_timing_excludes_synthetic_rows_from_per_step_cost():
    # 100 rows total, 30 of them synthetic termination markers (escape) ->
    # us_per_step should be normalized over the 70 physical rows only, the
    # same unit giant.analysis.geant4_reference measures Geant4 in.
    timing = _build_rollout_timing(
        setup_s=1.0,
        rollout_s=10.0,
        write_s=2.0,
        n_rows=100,
        termination_reason_counts={"escaped": 30, "natural_end": 70},
        n_seed_events=5,
        device="cpu",
        torch_threads=4,
    )
    assert timing["n_rows"] == 100
    assert timing["n_physical_rows"] == 70
    assert timing["n_physical_rows"] < timing["n_rows"]
    assert timing["sample_s"] == 8.0  # rollout_s - write_s
    assert timing["us_per_step"] == 8.0 / 70 * 1e6
    assert timing["write_us_per_step"] == 2.0 / 70 * 1e6
    assert timing["ms_per_event"] == 10.0 / 5 * 1e3
    assert timing["device"] == "cpu" and timing["torch_threads"] == 4


def test_build_rollout_timing_handles_zero_physical_rows_and_events():
    timing = _build_rollout_timing(
        setup_s=1.0,
        rollout_s=1.0,
        write_s=0.0,
        n_rows=5,
        termination_reason_counts={"escaped": 5},
        n_seed_events=0,
        device="cpu",
        torch_threads=1,
    )
    assert timing["n_physical_rows"] == 0
    assert timing["us_per_step"] is None
    assert timing["write_us_per_step"] is None
    assert timing["ms_per_event"] is None


def test_rollout_exits_1_on_checkpoint_missing_model_config(tmp_path):
    checkpoint = tmp_path / "bad.pt"
    torch.save({"sec_decoder": {}, "normalizer": {"sec_phys": {}}}, checkpoint)

    result = runner.invoke(
        app,
        [
            "rollout",
            "dummy.parquet",
            "--checkpoint",
            str(checkpoint),
            "--geometry",
            "dummy_geometry.pkl",
        ],
    )

    assert result.exit_code == 1
    assert "checkpoint has no model_config" in result.output


def test_rollout_set_flag_disallowed_path_surfaces_compat_error(tmp_path):
    checkpoint = tmp_path / "ckpt.pt"
    torch.save(
        {"model_config": {"stage1_model": {}, "stage2_model": {}}, "sec_decoder": {}, "normalizer": {"sec_phys": {}}},
        checkpoint,
    )

    result = runner.invoke(
        app,
        [
            "rollout",
            "dummy.parquet",
            "--checkpoint",
            str(checkpoint),
            "--geometry",
            "dummy_geometry.pkl",
            "--set",
            "stage2_model.n_sec.typo=sample",
        ],
    )

    assert result.exit_code == 1
    assert "not an inference-safe override" in result.output