import subprocess
import tempfile
import unittest
from pathlib import Path


ROOT = Path(__file__).resolve().parents[2]
CHECKER = ROOT / "scripts" / "check-metrics-boundaries.py"


class MetricsBoundaryTests(unittest.TestCase):
    def run_checker(self, root: Path, *paths: str) -> subprocess.CompletedProcess[str]:
        return subprocess.run(
            ["python3", str(CHECKER), "--root", str(root), "--files", *paths],
            text=True,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            check=False,
        )

    def test_rejects_direct_alias_import_reexport_and_wrapper_bypasses(self) -> None:
        cases = {
            "direct.rs": 'metrics::counter!("bad").increment(1);',
            "alias.rs": 'use metrics as m; m::counter!("bad").increment(1);',
            "import.rs": 'use metrics::counter; counter!("bad").increment(1);',
            "reexport.rs": 'pub use metrics::histogram;',
            "absolute.rs": '::metrics::gauge!("bad").set(1.0);',
            "wrapper.rs": 'macro_rules! bad { () => { metrics::counter!("bad") } }',
        }
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            paths = []
            for name, content in cases.items():
                path = root / "apps" / "demo" / "src" / name
                path.parent.mkdir(parents=True, exist_ok=True)
                path.write_text(content, encoding="utf-8")
                paths.append(str(path.relative_to(root)))
            result = self.run_checker(root, *paths)
            self.assertNotEqual(result.returncode, 0)
            for name in cases:
                self.assertIn(name, result.stderr)
            self.assertNotIn(str(root), result.stderr)

    def test_allows_typed_facade_and_narrow_observability_adapter(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            product = root / "apps" / "demo" / "src" / "main.rs"
            adapter = root / "crates" / "crank-observability" / "src" / "instrumentation.rs"
            product.parent.mkdir(parents=True)
            adapter.parent.mkdir(parents=True)
            product.write_text("crank_metrics::record_cache_outcome(value);", encoding="utf-8")
            adapter.write_text("metrics::describe_counter!(definition.name, definition.description);", encoding="utf-8")
            result = self.run_checker(root, str(product.relative_to(root)), str(adapter.relative_to(root)))
            self.assertEqual(result.returncode, 0, result.stderr)

    def test_explicit_missing_traversal_and_symlink_fail_closed(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            outside = root.parent / "metrics-boundary-outside.rs"
            outside.write_text('metrics::counter!("bad");', encoding="utf-8")
            try:
                for path in ["missing.rs", "../metrics-boundary-outside.rs"]:
                    result = self.run_checker(root, path)
                    self.assertNotEqual(result.returncode, 0)
                target = root / "target.rs"
                target.write_text("", encoding="utf-8")
                link = root / "link.rs"
                link.symlink_to(target)
                result = self.run_checker(root, "link.rs")
                self.assertNotEqual(result.returncode, 0)
            finally:
                outside.unlink(missing_ok=True)


if __name__ == "__main__":
    unittest.main()