from __future__ import annotations

import json
from copy import deepcopy
from pathlib import Path
from typing import Any

import jsonschema
import pytest

ROOT = Path(__file__).parents[2]
CONTRACT = ROOT / "contracts" / "repository" / "v1"
FIXTURES = CONTRACT / "fixtures"


def load(path: Path) -> Any:
    try:
        return json.loads(path.read_text(encoding="utf-8"))
    except (OSError, json.JSONDecodeError) as error:
        raise AssertionError(f"invalid contract JSON: {path}") from error


def validator(name: str) -> jsonschema.Draft202012Validator:
    schema = load(CONTRACT / f"{name}.schema.json")
    jsonschema.Draft202012Validator.check_schema(schema)
    return jsonschema.Draft202012Validator(
        schema,
        format_checker=jsonschema.FormatChecker(),
    )


def test_repository_and_manifest_golden_files_validate() -> None:
    for name in ("repository", "manifest"):
        validator(name).validate(load(FIXTURES / f"valid-{name}.json"))


def test_invalid_golden_files_are_rejected() -> None:
    for name in ("repository", "manifest"):
        with pytest.raises(jsonschema.ValidationError):
            validator(name).validate(load(FIXTURES / f"invalid-{name}.json"))


def test_valid_golden_files_are_canonical_json() -> None:
    for path in sorted(FIXTURES.glob("valid-*.json")):
        data = load(path)
        canonical = json.dumps(data, sort_keys=True, separators=(",", ":")) + "\n"
        assert path.read_text(encoding="utf-8") == canonical


def test_protocol_contracts_are_versioned_and_closed() -> None:
    repository_schema = load(CONTRACT / "repository.schema.json")
    manifest_schema = load(CONTRACT / "manifest.schema.json")

    assert repository_schema["properties"]["format_version"]["const"] == 1
    assert manifest_schema["properties"]["format_version"]["const"] == 1
    assert not repository_schema["additionalProperties"]
    assert not manifest_schema["additionalProperties"]


def test_uuidv7_and_rfc3339_formats_are_enforced() -> None:
    repository = load(FIXTURES / "valid-repository.json")
    manifest = load(FIXTURES / "valid-manifest.json")

    repository["repository_id"] = "123e4567-e89b-42d3-a456-426614174000"
    with pytest.raises(jsonschema.ValidationError):
        validator("repository").validate(repository)

    manifest["created_at"] = "2026-07-27 12:00:00"
    with pytest.raises(jsonschema.ValidationError):
        validator("manifest").validate(manifest)


def test_manifest_signature_and_source_consistency_are_required() -> None:
    manifest = load(FIXTURES / "valid-manifest.json")
    assert manifest["manifest_signature"]["algorithm"] == "ed25519"

    missing_signature = deepcopy(manifest)
    del missing_signature["manifest_signature"]
    with pytest.raises(jsonschema.ValidationError):
        validator("manifest").validate(missing_signature)

    incomplete_consistency = deepcopy(manifest)
    incomplete_consistency["source_consistency"] = {"adapter": "local"}
    with pytest.raises(jsonschema.ValidationError):
        validator("manifest").validate(incomplete_consistency)


def test_entry_types_bind_blobs_and_safe_link_targets() -> None:
    manifest = load(FIXTURES / "valid-manifest.json")
    entries = manifest["entries"]

    file_without_blob = deepcopy(manifest)
    file_without_blob["entries"][1]["blob_digest"] = None
    with pytest.raises(jsonschema.ValidationError):
        validator("manifest").validate(file_without_blob)

    directory_with_blob = deepcopy(manifest)
    directory_with_blob["entries"][0]["blob_digest"] = "c" * 64
    with pytest.raises(jsonschema.ValidationError):
        validator("manifest").validate(directory_with_blob)

    for unsafe_target in ("/etc/passwd", "../escape", "dir\\escape"):
        unsafe_symlink = deepcopy(manifest)
        unsafe_symlink["entries"] = [
            {
                "blob_digest": None,
                "link_target": unsafe_target,
                "metadata_support": [],
                "mode": None,
                "mtime_ns": None,
                "path": "link",
                "size": 0,
                "type": "symlink",
            }
        ]
        with pytest.raises(jsonschema.ValidationError):
            validator("manifest").validate(unsafe_symlink)

    assert entries[1]["type"] == "file"


def test_normalized_path_vectors_are_relative_posix_paths() -> None:
    vectors = load(CONTRACT / "normalized-paths.json")
    valid = [case for case in vectors if case["valid"]]
    invalid = [case for case in vectors if not case["valid"]]

    assert {case["raw"] for case in invalid} >= {"/absolute", "../escape", "a\\b"}
    for case in valid:
        normalized = case["normalized"]
        assert normalized and not normalized.startswith("/")
        assert "\\" not in normalized
        assert ".." not in normalized.split("/")


def test_state_errors_capabilities_and_fault_points_are_frozen() -> None:
    transitions = load(CONTRACT / "execution-transitions.json")
    assert transitions["queued"] == ["cancelled", "preparing"]
    assert transitions["verifying"] == ["committed", "failed"]
    assert transitions["committed"] == []

    errors = load(CONTRACT / "error-codes.json")
    assert len(errors) == len(set(errors))
    assert all(code == code.lower() and " " not in code for code in errors)

    capabilities = load(CONTRACT / "capabilities-v2.0.json")
    assert capabilities["sources"] == ["local", "ssh"]

    manifest_schema = load(CONTRACT / "manifest.schema.json")
    adapter_kinds = manifest_schema["properties"]["source_consistency"]["properties"]["adapter"][
        "enum"
    ]
    assert adapter_kinds == ["local", "postgresql", "mysql"]
    assert "ssh" not in adapter_kinds

    assert not capabilities["features"]["tar_download"]
    assert not capabilities["features"]["postgresql"]
    assert not capabilities["features"]["mysql"]

    fault_points = load(CONTRACT / "fault-points.json")
    assert {
        "blob.before_write",
        "blob.after_fsync",
        "manifest.before_publish",
        "metadata.before_commit",
        "restore.before_replace",
    }.issubset(fault_points)