"""
Persistence and integrity verification tests for Flex-O entities.
Ensures fingerprints survive JSON export/import and detect tampering.
"""

import os
import sys
import json
import pytest

from datetime import datetime

sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))

from flexoentity import FlexOID, EntityType, EntityState, FlexoEntity


@pytest.fixture
def approved_entity():
    q = FlexoEntity(
        domain="AF",
        etype=EntityType.QUESTION,
        text_seed="What is Ohm’s law?",
        state=EntityState.DRAFT,
    )
    q.approve()
    q.sign()
    q.publish()
    return q

def test_json_roundtrip_preserves_integrity(approved_entity):
    """
    Export to JSON and reload — ensure state-aware and content-only integrity behave as expected.
    """

    json_str = approved_entity.to_json()
    loaded = FlexoEntity.from_json(json_str)

    # Because the signature encodes lifecycle state, any state change breaks strict integrity
    assert not FlexoEntity.verify_integrity(loaded)

    assert approved_entity.flexo_id.signature == loaded.flexo_id.signature
    assert approved_entity.flexo_id == loaded.flexo_id
    assert loaded.state == approved_entity.state


def test_json_tampering_detection(approved_entity):
    """Tampering with content should invalidate fingerprint verification."""
    json_str = approved_entity.to_json()
    tampered_data = json.loads(json_str)
    tampered_data["text_seed"] = "Tampered content injection"
    tampered_json = json.dumps(tampered_data)
    loaded = FlexoEntity.from_json(tampered_json)
    assert not FlexoEntity.verify_integrity(loaded)

def test_json_file_corruption(approved_entity, tmp_path):
    """Simulate file corruption — integrity check must fail."""
    file = tmp_path / "entity.json"
    json_str = approved_entity.to_json()
    file.write_text(json_str)

    # Corrupt the file
    corrupted = json_str.replace("Ohm’s", "Omm’s")
    file.write_text(corrupted)

    loaded = FlexoEntity.from_json(file.read_text())
    assert not FlexoEntity.verify_integrity(loaded)