from missionledger.dsl import PlanDelta
from missionledger.csfd import generate_csfd


def test_csfd_generation_small_plandelta():
    pd = PlanDelta(delta={"move": True, "safe_buffer": 0.5}, version=2, metadata={
        "invariants": {"collision": True, "energy": True},
        "proof_stub_hash": "stub-abc",
        "expected_resource_bounds": {"energy": [0, 100]},
    })

    csfd = generate_csfd(pd, signer="planner-v1", n_frames=3)

    assert csfd is not None
    assert csfd.signer == "planner-v1"
    # frames count should be at least 1 and at most requested
    assert 1 <= len(csfd.frames) <= 3
    # digest hex should be a 64-char hex string
    assert isinstance(csfd.digest_hex, str)
    assert len(csfd.digest_hex) == 64


def test_csfd_size_bound():
    # Create a PlanDelta with large metadata to force truncation path
    large_meta = {f"k{i}": "v" * 200 for i in range(5)}
    pd = PlanDelta(delta={"x": 1}, version=1, metadata={"invariants": {"a": True}, **large_meta})

    csfd = generate_csfd(pd, signer="s", n_frames=5)
    # Ensure serialized representation is <= 512 bytes as enforced
    import json

    serialized = json.dumps({"frames": [f.__dict__ for f in csfd.frames], "signer": csfd.signer, "digest_hex": csfd.digest_hex}, sort_keys=True, separators=(",", ":"))
    assert len(serialized.encode()) <= 512


def test_csfd_signing_and_verification():
    import pytest
    pytest.importorskip("nacl")

    # now import local helpers
    from missionledger.dsl import PlanDelta
    from missionledger.csfd import generate_csfd, sign_csfd, verify_csfd_signature

    # create a small plandelta
    pd = PlanDelta(delta={"x": 1}, version=1, metadata={"invariants": {"a": True}})
    csfd = generate_csfd(pd, signer="s", n_frames=1)

    # Generate an ephemeral Ed25519 keypair for signing
    from nacl.signing import SigningKey

    sk = SigningKey.generate()
    sig_hex = sign_csfd(csfd, sk.encode())
    assert isinstance(sig_hex, str)
    assert len(sig_hex) > 0

    vk = sk.verify_key
    ok = verify_csfd_signature(csfd, sig_hex, vk.encode())
    assert ok is True