import json
import os
import tempfile
from pathlib import Path
import pytest

import sys
sys.path.insert(0, str(Path(__file__).resolve().parents[1] / 'src'))

from data_logging import core


def test_log_data_creates_and_appends_valid_json(tmp_path, monkeypatch):
    log_file = tmp_path / 'log_data.json'

    # Patch the target output path in the function if it uses fixed path
    monkeypatch.setattr(core, 'Path', lambda p=None: tmp_path if p is None else Path(p))

    data_points = [
        {"timestamp": "2024-06-01T12:00:00Z", "temperature": 22.5, "signal_noise_ratio": 35.1},
        {"timestamp": "2024-06-01T12:05:00Z", "temperature": 22.7, "signal_noise_ratio": 34.8}
    ]

    for dp in data_points:
        core.log_data(dp['timestamp'], dp['temperature'], dp['signal_noise_ratio'])

    assert log_file.exists(), 'Log file should be created by log_data()'

    with open(log_file, 'r', encoding='utf-8') as f:
        content = f.read().strip()

    assert content, 'Log file must not be empty.'

    # Interpret as JSON lines
    lines = content.splitlines()
    parsed = [json.loads(l) for l in lines]

    assert all(isinstance(p, dict) for p in parsed)

    expected_keys = {'timestamp', 'temperature', 'signal_noise_ratio'}
    for p in parsed:
        assert expected_keys.issubset(p.keys())
        assert isinstance(p['timestamp'], str)
        assert isinstance(p['temperature'], (float, int))
        assert isinstance(p['signal_noise_ratio'], (float, int))

    # Check append behavior
    assert len(parsed) == len(data_points)


def test_log_data_handles_invalid_input(tmp_path):
    log_file = tmp_path / 'log_data.json'

    sys.path.insert(0, str(Path(__file__).resolve().parents[1] / 'src'))

    # Expect that invalid temperature type raises an error
    with pytest.raises((TypeError, ValueError)):
        core.log_data('2024-06-01T12:00:00Z', 'invalid', 34.2)

    assert not log_file.exists(), 'Invalid input should not create a file.'