"""Evidence bundler pytest plugin.

For each test, collects supporting artifacts (`.tlog`, FDR archive snapshots,
screenshots, profiler traces, tegrastats / jtop CSVs) into a per-run bundle
at ``--evidence-out`` (default ``/e2e-results/<run-id>/evidence/``) and
records the resulting paths in the CSV reporter's ``evidence_paths`` column.

The bundler is INERT by default: tests opt in by calling the
``attach_evidence`` fixture with a file path. The runner conftest registers
this plugin via `pytest_plugins`.
"""

from __future__ import annotations

import shutil
from collections.abc import Callable
from pathlib import Path

import pytest

from .csv_reporter import reporter_for


def _safe_relpath(target: Path, base: Path) -> str:
    try:
        return str(target.relative_to(base))
    except ValueError:
        # If the target isn't under base, we still record its absolute path
        # — the bundle copy below makes the absolute fallback robust to
        # arbitrary source locations (e.g. /tlogs/<run>.tlog).
        return str(target)


@pytest.fixture
def attach_evidence(
    request: pytest.FixtureRequest,
    evidence_dir: Path,
) -> Callable[[str | Path], str]:
    """Copy a file into the run evidence bundle and record its CSV path.

    Returns a callable ``attach(path) -> str`` — the test invokes it after
    capturing an artifact (e.g., the .tlog file or an FDR snapshot). The
    returned string is the path that will appear in the CSV
    ``evidence_paths`` column.

    The implementation copies the file (rather than moving it) so the same
    artifact can be referenced by multiple tests if needed.
    """
    nodeid = request.node.nodeid
    config = request.config
    reporter = reporter_for(config)
    bundle_root = evidence_dir / _slug(nodeid)
    bundle_root.mkdir(parents=True, exist_ok=True)

    def _attach(path: str | Path) -> str:
        src = Path(path)
        if not src.exists():
            raise FileNotFoundError(f"attach_evidence: {src} not found")
        dst = bundle_root / src.name
        # If a test attaches the same name twice in one run, disambiguate.
        if dst.exists():
            stem, suffix = src.stem, src.suffix
            counter = 1
            while dst.exists():
                dst = bundle_root / f"{stem}__{counter}{suffix}"
                counter += 1
        shutil.copy2(src, dst)
        rel = _safe_relpath(dst, evidence_dir.parent)
        if reporter is not None:
            reporter.attach_evidence(nodeid, rel)
        return rel

    return _attach


def _slug(nodeid: str) -> str:
    """Filesystem-safe slug for the nodeid (preserves uniqueness, no path chars)."""
    return (
        nodeid.replace("/", "_")
        .replace("::", "__")
        .replace("[", "_")
        .replace("]", "")
        .replace(" ", "")
    )