import pytest

from mltrail_verifiable_provenance_ledger_for.ledger import Ledger, delta_sync
from mltrail_verifiable_provenance_ledger_for.contracts import Experiment, Run, Dataset, Model, Environment, EvaluationMetric, Policy


def test_ledger_append_and_chain():
    ledger = Ledger()
    e = Experiment(id="exp1", name="Demo", version=1, description="test", metadata={"owner": "alice"})
    ledger.add_record("Experiment", e.to_dict())
    head1 = ledger.head
    assert head1.index == 1
    assert head1.previous_hash == "0" * 64
    assert len(head1.data) == 1
    # Add a Run in a new block
    r = Run(id="run1", experiment_id="exp1", parameters={"lr": 0.01}, metrics={"acc": 0.9}, environment_hash="abc123")
    ledger.add_record("Run", r.to_dict())
    head2 = ledger.head
    assert head2.index == 2
    assert head2.previous_hash == head1.hash
    assert len(head2.data) == 1


def test_delta_sync_basic():
    a = Ledger()
    b = Ledger()
    # A has two blocks now
    a.add_record("Experiment", Experiment(id="exp1", name="Demo", version=1, description="test", metadata={}).to_dict())
    a.add_record("Run", Run(id="run1", experiment_id="exp1", parameters={}, metrics={}, environment_hash="e1").to_dict())

    # B only has genesis and first block (simulate partition)
    b.add_record("Experiment", Experiment(id="exp1", name="Demo", version=1, description="test", metadata={}).to_dict())

    delta = delta_sync(a, b.head_hash())
    assert isinstance(delta, list)
    assert len(delta) == 1 or len(delta) == 2  # depending on whether b's head matches a's first block


def test_environment_hash_reproducibility():
    from mltrail_verifiable_provenance_ledger_for.util import environment_hash
    deps1 = {"numpy": "1.26.0", "pandas": "2.0.0"}
    deps2 = {"pandas": "2.0.0", "numpy": "1.26.0"}
    assert environment_hash(deps1) == environment_hash(deps2)