import pytest

from viano_bug_analysis.package import PackageReader, PackageReadError


def test_open_reader_uses_immutable_snapshot(make_package):
    path=make_package(entries={"data":b"original"})
    with PackageReader(path) as reader:
        path.write_bytes(b"damaged after opening")
        assert reader.read_bytes("data")==b"original"
    with pytest.raises(PackageReadError):
        with PackageReader(path):pass


def test_cached_validation_is_detached_and_limits_are_part_of_key(make_package):
    from viano_bug_analysis.package import PackageLimits
    path=make_package(entries={"data":b"original"})
    with PackageReader(path) as reader:
        reader._result.manifest["case_id"]="mutated-private-result"
    with PackageReader(path) as reader:assert reader.manifest["case_id"]=="case-A"
    with pytest.raises(PackageReadError):
        with PackageReader(path,PackageLimits(max_file_bytes=1)):pass


def test_cached_reader_rejects_changed_bytes_even_when_mtime_and_size_match(make_package):
    import os
    path=make_package(entries={"data":b"original"})
    with PackageReader(path):pass
    stat=path.stat();path.write_bytes(b"x"*stat.st_size)
    os.utime(path,ns=(stat.st_atime_ns,stat.st_mtime_ns))
    with pytest.raises(PackageReadError):
        with PackageReader(path):pass


def test_read_only_and_filename_independent(make_package):
    path = make_package(entries={"unknown/data.bin": b"\x00\xff"})
    before = path.read_bytes()
    renamed = path.with_name("different.name")
    path.rename(renamed)
    with PackageReader(renamed) as reader:
        assert reader.manifest["package_id"] == "stable-package"
        assert reader.read_bytes("unknown/data.bin") == b"\x00\xff"
        modified = reader.manifest
        modified["case_id"] = "changed"
        assert reader.manifest["case_id"] == "case-A"
        with pytest.raises(PackageReadError):
            reader.read_bytes("../outside")
    assert renamed.read_bytes() == before
    with pytest.raises(RuntimeError):
        reader.read_bytes("manifest.json")


def test_reader_rejection_and_cleanup(make_package):
    reader = PackageReader(make_package(raw=b"{}"))
    with pytest.raises(PackageReadError) as error:
        with reader:
            pytest.fail("Invalid package opened")
    assert not error.value.result.valid
    assert reader._source is None


def test_reader_missing_file(tmp_path):
    with pytest.raises(PackageReadError):
        with PackageReader(tmp_path / "absent"):
            pass