import json
import hashlib
import pytest

from marketmesh_privacy_preserving_federated_.core import DeltaSync


def test_delta_sync_merge_basic():
    ds1 = DeltaSync(
        contract_id="c1",
        version_vector={"p1": 1},
        payload={"revenue": 10.0, "customers": 5.0},
        hash_="h1",
    )
    ds2 = DeltaSync(
        contract_id="c1",
        version_vector={"p1": 2, "p2": 1},
        payload={"revenue": 20.0, "customers": 3.0, "activation": 0.5},
        hash_="h2",
    )

    merged = ds1.merge(ds2)

    # version vector should be per-peer max
    assert merged.contract_id == "c1"
    assert merged.version_vector["p1"] == 2
    assert merged.version_vector["p2"] == 1

    # KPI merging: revenue and customers present in both -> average; new KPI from ds2 is included
    assert pytest.approx(merged.payload["revenue"]) == (10.0 + 20.0) / 2.0
    assert pytest.approx(merged.payload["customers"]) == (5.0 + 3.0) / 2.0
    assert pytest.approx(merged.payload["activation"]) == 0.5

    # Merging again with the same pair should produce the same result (deterministic)
    merged_again = ds1.merge(ds2)
    assert merged.payload == merged_again.payload
    assert merged.version_vector == merged_again.version_vector
    assert merged.hash == merged_again.hash