open-cmis-tck/src/guide_board/runners.py

"""Runner bridge for extension-provided checks."""

from __future__ import annotations

import importlib.util
from pathlib import Path
from types import ModuleType
from typing import Any, Callable

from guide_board.errors import ValidationError
from guide_board.io import load_json


RunnerCallable = Callable[[dict[str, Any]], dict[str, Any]]


def run_step(
    root: Path,
    run_dir: Path,
    run_id: str,
    plan: dict[str, Any],
    step: dict[str, Any],
) -> dict[str, Any]:
    runner_ref = step.get("runner_ref")
    if runner_ref is None:
        return _no_runner_result(step)

    extension = _extension_snapshot(plan, step["extension_id"])
    extension_path = root / extension["path"]
    manifest = load_json(extension_path / "extension.json")
    entrypoint = _runner_entrypoint(manifest, runner_ref)
    if entrypoint["kind"] == "python_module":
        return _run_python_module(root, run_dir, run_id, plan, step, extension_path, entrypoint)
    if entrypoint["kind"] == "external":
        return {
            "result": "blocked",
            "observations": [
                f"Runner {runner_ref!r} is declared as an external runner and is not implemented by the core."
            ],
            "facts": {
                "runner_ref": runner_ref,
                "runner_kind": "external",
            },
            "artifact_refs": [],
        }
    if entrypoint["kind"] == "command":
        return {
            "result": "blocked",
            "observations": [
                f"Runner {runner_ref!r} is declared as a command runner; command execution is not enabled yet."
            ],
            "facts": {
                "runner_ref": runner_ref,
                "runner_kind": "command",
            },
            "artifact_refs": [],
        }
    raise ValidationError(f"{runner_ref}: unsupported runner kind {entrypoint['kind']!r}")


def _no_runner_result(step: dict[str, Any]) -> dict[str, Any]:
    result = "manual" if step["kind"] == "check_group" else "skipped"
    return {
        "result": result,
        "observations": [
            "No runner is configured for this step in the baseline core."
        ],
        "facts": {
            "runner_ref": None,
            "runner_kind": None,
        },
        "artifact_refs": [],
    }


def _run_python_module(
    root: Path,
    run_dir: Path,
    run_id: str,
    plan: dict[str, Any],
    step: dict[str, Any],
    extension_path: Path,
    entrypoint: dict[str, Any],
) -> dict[str, Any]:
    module_path = entrypoint.get("module_path")
    callable_name = entrypoint.get("callable")
    if not module_path or not callable_name:
        raise ValidationError(f"{entrypoint['id']}: python_module runners need module_path and callable")

    module_file = (extension_path / module_path).resolve()
    try:
        module_file.relative_to(extension_path.resolve())
    except ValueError as exc:
        raise ValidationError(
            f"{entrypoint['id']}: module_path must stay inside the extension directory"
        ) from exc

    module = _load_module(module_file, entrypoint["id"])
    runner = getattr(module, callable_name, None)
    if not callable(runner):
        raise ValidationError(f"{entrypoint['id']}: callable {callable_name!r} was not found")

    context = {
        "root": str(root),
        "run_dir": str(run_dir),
        "run_id": run_id,
        "plan": plan,
        "step": step,
        "target_profile": plan["target_profile_snapshot"],
        "assessment_profile": plan["assessment_profile_snapshot"],
        "extension_path": str(extension_path),
        "runner": entrypoint,
    }
    try:
        result = runner(context)
    except Exception as exc:  # noqa: BLE001 - extension failures become evidence.
        return {
            "result": "infrastructure_error",
            "observations": [
                f"Runner {entrypoint['id']!r} failed before producing evidence: {exc}"
            ],
            "facts": {
                "runner_ref": entrypoint["id"],
                "runner_kind": "python_module",
                "error_type": type(exc).__name__,
            },
            "artifact_refs": [],
        }
    if not isinstance(result, dict):
        raise ValidationError(f"{entrypoint['id']}: runner must return an object")
    return {
        "result": result.get("result", "unknown"),
        "observations": result.get("observations", []),
        "facts": result.get("facts", {}),
        "artifact_refs": result.get("artifact_refs", []),
    }


def _load_module(path: Path, runner_id: str) -> ModuleType:
    if not path.exists():
        raise ValidationError(f"{runner_id}: module not found: {path}")
    module_name = f"_guide_board_runner_{runner_id.replace('-', '_')}"
    spec = importlib.util.spec_from_file_location(module_name, path)
    if spec is None or spec.loader is None:
        raise ValidationError(f"{runner_id}: unable to load module from {path}")
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    return module


def _extension_snapshot(plan: dict[str, Any], extension_id: str) -> dict[str, Any]:
    for extension in plan["extension_snapshots"]:
        if extension["id"] == extension_id:
            return extension
    raise ValidationError(f"step references unknown extension {extension_id!r}")


def _runner_entrypoint(manifest: dict[str, Any], runner_ref: str) -> dict[str, Any]:
    for entrypoint in manifest.get("runner_entrypoints", []):
        if entrypoint["id"] == runner_ref:
            return entrypoint
    raise ValidationError(f"{manifest['id']}: runner {runner_ref!r} is not declared")