from __future__ import annotations

import json
import hashlib
import sys
from pathlib import Path
import tempfile
import unittest


RUNTIME = Path(__file__).resolve().parents[1] / "runtime"
sys.path.insert(0, str(RUNTIME))

from layout_check import LayoutContractError, check_layout, enforce_write_paths, resolve_authority  # noqa: E402


class LayoutCheckTests(unittest.TestCase):
    def _fixture(self, root: Path) -> None:
        for path in (
            "raw/branch-notes",
            "wiki/concepts",
            "harness/source",
            "harness/adapters",
            "harness/runtime",
            "harness/tests",
            "vault/10-projects",
            "vault/30-knowledge",
        ):
            (root / path).mkdir(parents=True, exist_ok=True)
        (root / "harness/source/vault-layout.json").write_text(
            json.dumps(
                {
                    "schema_version": "vault-layout/v1",
                    "mode": "compatibility",
                    "vault_root": "vault",
                    "write_roots": {
                        "compatibility": ["raw", "wiki"],
                        "shadow": ["raw", "wiki"],
                        "canonical": ["vault"],
                    },
                    "migration_manifest": {"schema_version": "vault-migration/v1", "entries": []},
                    "rollback_mapping": {"schema_version": "vault-rollback/v1", "entries": []},
                    "areas": {
                        "10-projects": ["raw/branch-notes"],
                        "30-knowledge": ["wiki/concepts"],
                    },
                }
            ),
            encoding="utf-8",
        )

    def test_complete_unique_mapping_passes(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            self._fixture(root)
            self.assertEqual(check_layout(root)["status"], "PASS")

    def test_unassigned_root_fails(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            self._fixture(root)
            (root / "raw/orphan").mkdir()
            result = check_layout(root)
            self.assertEqual(result["status"], "FAIL")
            self.assertIn("UNASSIGNED_CONTENT_ROOT", {item["code"] for item in result["findings"]})

    def _configure_cutover(self, root: Path, mode: str, *, canonical_bytes: bytes, legacy_bytes: bytes) -> None:
        legacy = root / "raw/branch-notes/feature-example.md"
        canonical = root / "vault/10-projects/feature-example.md"
        legacy.write_bytes(legacy_bytes)
        canonical.write_bytes(canonical_bytes)
        manifest_path = root / "harness/source/vault-layout.json"
        manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
        manifest["mode"] = mode
        manifest["migration_manifest"]["entries"] = [{
            "legacy_path": "raw/branch-notes/feature-example.md",
            "canonical_path": "vault/10-projects/feature-example.md",
            "sha256": hashlib.sha256(canonical_bytes).hexdigest(),
        }]
        manifest["rollback_mapping"]["entries"] = [{
            "canonical_path": "vault/10-projects/feature-example.md",
            "legacy_path": "raw/branch-notes/feature-example.md",
        }]
        manifest_path.write_text(json.dumps(manifest), encoding="utf-8")

    def test_shadow_requires_byte_identical_mirror(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            self._fixture(root)
            content = b"---\ntitle: example\n---\n# Example\n"
            self._configure_cutover(root, "shadow", canonical_bytes=content, legacy_bytes=content)
            self.assertEqual(check_layout(root)["status"], "PASS")
            (root / "vault/10-projects/feature-example.md").write_text("drift\n", encoding="utf-8")
            result = check_layout(root)
            codes = {item["code"] for item in result["findings"]}
            self.assertIn("SHADOW_MIRROR_DRIFT", codes)
            self.assertIn("MIGRATION_HASH_MISMATCH", codes)

    def test_shadow_mirror_symlink_is_rejected(self) -> None:
        """shadow 미러가 심링크면 read_bytes 가 정본을 따라가 drift 를 못 잡는다(symlink-blind).

        예전엔 legacy 가 정본을 가리키는 심링크여도 바이트가 같아 PASS 했다 — shadow 불변식
        (독립 실파일 미러)을 위반하는데도 조용했다. 이제 심링크 자체를 loud 하게 잡는다.
        """
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            self._fixture(root)
            content = b"---\ntitle: example\n---\n# Example\n"
            self._configure_cutover(root, "shadow", canonical_bytes=content, legacy_bytes=content)
            self.assertEqual(check_layout(root)["status"], "PASS")
            # legacy 실파일을 정본을 가리키는 심링크로 바꾼다 → 바이트는 여전히 동일.
            legacy = root / "raw/branch-notes/feature-example.md"
            legacy.unlink()
            legacy.symlink_to(Path("../../vault/10-projects/feature-example.md"))
            result = check_layout(root)
            codes = {item["code"] for item in result["findings"]}
            self.assertEqual(result["status"], "FAIL")
            self.assertIn("SHADOW_MIRROR_SYMLINK", codes)
            self.assertNotIn("SHADOW_MIRROR_DRIFT", codes)  # 심링크가 바이트 비교를 가리기 전에 잡힘

    def test_canonical_requires_stub_owner_and_rollback_mapping(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            self._fixture(root)
            canonical = b"---\ntitle: example\n---\n# Example\n"
            stub = b"---\ntitle: moved\ncanonical_path: vault/10-projects/feature-example.md\n---\n# Moved\n"
            self._configure_cutover(root, "canonical", canonical_bytes=canonical, legacy_bytes=stub)
            result = check_layout(root)
            self.assertEqual(result["status"], "PASS", result["findings"])
            self.assertEqual(result["authority"], "vault")
            self.assertEqual(result["write_roots"], ["vault"])
            authority = resolve_authority(root)
            enforce_write_paths(root, [root / "vault/10-projects/new.md"], authority)
            with self.assertRaises(LayoutContractError) as raised:
                enforce_write_paths(root, [root / "raw/branch-notes/new.md"], authority)
            self.assertEqual(raised.exception.code, "WRITE_ROOT_VIOLATION")

            (root / "raw/branch-notes/feature-example.md").write_bytes(canonical)
            result = check_layout(root)
            self.assertIn("OLD_NEW_FULL_CONTENT_DUPLICATE", {item["code"] for item in result["findings"]})


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