import pytest
import pandas as pd
import json
from types import SimpleNamespace
from pathlib import Path

import src.log_analysis.core as core


def make_sample_csv(tmp_path: Path, name: str, warn_rate: float, unknown_rate: float, policy_hash: str) -> str:
    data = [
        {
            'timestamp': '2024-04-01T12:00:00',
            'run_id': 'runA',
            'policy_hash': policy_hash,
            'warn_rate': warn_rate,
            'unknown_rate': unknown_rate,
            't_index_visible': 1.0,
            't_gate_read': 2.0,
            'pinned_status': 'unpinned'
        }
    ]
    file_path = tmp_path / f"{name}.csv"
    pd.DataFrame(data).to_csv(file_path, index=False)
    return str(file_path)


@pytest.fixture
def sample_logs(tmp_path):
    run_new = make_sample_csv(tmp_path, 'runA', 0.12, 0.02, 'abc123')
    run_base = make_sample_csv(tmp_path, 'runB', 0.10, 0.01, 'abc123')
    return SimpleNamespace(new=run_new, base=run_base)


def test_analyze_logs_basic(sample_logs):
    result = core.analyze_logs(sample_logs.new, sample_logs.base)
    assert isinstance(result, dict)
    assert set(result.keys()) == {'policy_hash', 'warn_rate', 'unknown_rate', 'timing_analysis'}
    assert result['policy_hash'] == 'MATCH: abc123'
    assert abs(result['warn_rate'] - 0.02) < 1e-6
    assert abs(result['unknown_rate'] - 0.01) < 1e-6
    assert isinstance(result['timing_analysis'], str)


def test_analyze_logs_different_policy(sample_logs, tmp_path):
    run_other = make_sample_csv(tmp_path, 'runC', 0.12, 0.02, 'def999')
    result = core.analyze_logs(run_other, sample_logs.base)
    assert 'MISMATCH' in result['policy_hash']


def test_analyze_logs_missing_file():
    with pytest.raises(FileNotFoundError):
        core.analyze_logs('no_such_file.csv', 'no_such_base.csv')


def test_analyze_logs_edge_cases(tmp_path):
    f1 = make_sample_csv(tmp_path, 'f1', 0.0, 0.0, 'x1')
    f2 = make_sample_csv(tmp_path, 'f2', 0.0, 0.0, 'x1')
    result = core.analyze_logs(f1, f2)
    assert result['warn_rate'] == 0.0
    assert result['unknown_rate'] == 0.0
    assert isinstance(result['timing_analysis'], str)


def test_result_serializable(sample_logs):
    result = core.analyze_logs(sample_logs.new, sample_logs.base)
    dumped = json.dumps(result)
    reloaded = json.loads(dumped)
    assert isinstance(reloaded, dict)
    assert 'policy_hash' in reloaded