from __future__ import annotations

import importlib.util
from dataclasses import dataclass
from datetime import datetime, timedelta
from pathlib import Path
from types import ModuleType


def load_cleanup_module() -> ModuleType:
    script = Path(__file__).resolve().parents[2] / "scripts" / "cleanup_demo_artifacts.py"
    spec = importlib.util.spec_from_file_location("cleanup_demo_artifacts", script)
    assert spec is not None
    assert spec.loader is not None
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    return module


@dataclass
class ExportRow:
    id: str
    created_at: datetime | None
    storage_path: str


def test_cleanup_candidate_selection_keeps_newest_exports() -> None:
    cleanup = load_cleanup_module()
    base = datetime(2026, 1, 1, 12, 0, 0)
    exports = [
        ExportRow("old", base, "/tmp/old.json"),
        ExportRow("new", base + timedelta(days=2), "/tmp/new.json"),
        ExportRow("middle", base + timedelta(days=1), "/tmp/middle.json"),
        ExportRow("unknown", None, "/tmp/unknown.json"),
    ]

    kept, candidates = cleanup.select_cleanup_candidates(exports, keep_latest=2)

    assert [export.id for export in kept] == ["new", "middle"]
    assert [export.id for export in candidates] == ["old", "unknown"]


def test_cleanup_candidate_selection_rejects_negative_keep_latest() -> None:
    cleanup = load_cleanup_module()

    try:
        cleanup.select_cleanup_candidates([], keep_latest=-1)
    except ValueError as exc:
        assert "keep_latest" in str(exc)
    else:
        raise AssertionError("negative keep_latest should fail")


def test_cleanup_path_safety_requires_storage_root_containment(tmp_path: Path) -> None:
    cleanup = load_cleanup_module()
    storage_root = tmp_path / "storage"
    safe_export = storage_root / "exports" / "project" / "report.html"
    unsafe_export = tmp_path / "outside" / "report.html"

    safe_export.parent.mkdir(parents=True)
    unsafe_export.parent.mkdir(parents=True)

    assert cleanup.is_within_storage_root(safe_export, storage_root) is True
    assert cleanup.is_within_storage_root(unsafe_export, storage_root) is False


def test_cleanup_script_defaults_to_explicit_demo_project() -> None:
    cleanup = load_cleanup_module()
    parser = cleanup.build_parser()

    args = parser.parse_args([])

    assert args.project_name == cleanup.DEMO_PROJECT_NAME
    assert args.keep_latest == 3
    assert args.apply is False


def test_cleanup_script_reports_dry_run_candidates_separately() -> None:
    script = Path(__file__).resolve().parents[2] / "backend" / "scripts" / "cleanup_demo_artifacts.py"
    content = script.read_text(encoding="utf-8")

    assert '"candidate_files": []' in content
    assert 'summary["candidate_files"].append(str(path))' in content