import unittest
from unittest.mock import MagicMock, patch

import obd

from modules import app_obd


class CarConnectedFlagTest(unittest.TestCase):
    def setUp(self):
        app_obd._car_ever_connected = False

    def tearDown(self):
        app_obd._car_ever_connected = False

    def test_was_ever_connected_reads_persisted_flag(self):
        with patch("modules.app_sql.get_setting", return_value="1"):
            self.assertTrue(app_obd.was_car_ever_connected())
            self.assertTrue(app_obd._car_ever_connected)

    def test_was_ever_connected_defaults_false(self):
        with patch("modules.app_sql.get_setting", return_value="0"):
            self.assertFalse(app_obd.was_car_ever_connected())

    def test_persist_car_connected_writes_setting(self):
        with patch("modules.app_sql.set_setting") as mock_set:
            app_obd._persist_car_connected()
            mock_set.assert_called_once_with("car_ever_connected", "1")


class ClearDtcCodesTest(unittest.TestCase):
    def setUp(self):
        self.original_connection = app_obd.connection
        self.original_dtc_codes = app_obd.dtc_codes
        self.original_mil_on = app_obd.mil_on

    def tearDown(self):
        app_obd.connection = self.original_connection
        app_obd.dtc_codes = self.original_dtc_codes
        app_obd.mil_on = self.original_mil_on

    def test_not_connected_returns_not_connected(self):
        app_obd.connection = None
        result = app_obd.clear_dtc_codes()
        self.assertEqual(result["status"], "not_connected")

    def test_connected_clears_ecu_and_resets_state(self):
        fake_conn = MagicMock()
        app_obd.connection = fake_conn
        app_obd.dtc_codes = [{"code": "P0300", "description": "Misfire"}]
        app_obd.mil_on = True
        with patch.object(app_obd, "_is_car_connected", return_value=True), \
             patch("modules.app_sql.clear_dtc_state") as mock_clear, \
             patch("modules.app_events.socketio.emit") as mock_emit:
            result = app_obd.clear_dtc_codes()
        self.assertEqual(result["status"], "cleared")
        fake_conn.query.assert_called_once_with(obd.commands.CLEAR_DTC)
        self.assertEqual(app_obd.dtc_codes, [])
        self.assertFalse(app_obd.mil_on)
        mock_clear.assert_called_once_with()
        self.assertTrue(mock_emit.called)

    def test_query_error_returns_error(self):
        fake_conn = MagicMock()
        fake_conn.query.side_effect = RuntimeError("boom")
        app_obd.connection = fake_conn
        with patch.object(app_obd, "_is_car_connected", return_value=True), \
             patch.object(app_obd, "_mark_connection_lost") as mock_mark:
            result = app_obd.clear_dtc_codes()
        self.assertEqual(result["status"], "error")
        self.assertIn("boom", result["error"])
        mock_mark.assert_called_once()


if __name__ == "__main__":
    unittest.main()