"""Exercise timer expiry/cancellation ordering without a running AppDaemon."""
import ast
import unittest
from pathlib import Path
from types import SimpleNamespace
from unittest.mock import Mock


source = Path(__file__).resolve().parents[1] / 'virtualsensors.py'
node = next(node for node in ast.parse(source.read_text()).body
            if isinstance(node, ast.ClassDef) and node.name == 'ContinuousCondition')
namespace = {'VirtualSensorBase': object, 'SmartCondition': Mock()}
exec(compile(ast.Module(body=[node], type_ignores=[]), str(source), 'exec'), namespace)
ContinuousCondition = namespace['ContinuousCondition']


class FakeScheduler:
    def __init__(self):
        self.timers = {}
        self.next_id = 0
        self.warnings = []

    def run_in(self, callback, delay, **kwargs):
        self.next_id += 1
        handle = str(self.next_id)
        self.timers[handle] = (callback, kwargs)
        return handle

    def expire(self, handle):
        # AppDaemon removes the timer while its callback can still be queued.
        callback, kwargs = self.timers.pop(handle)
        return lambda: callback(kwargs)

    def cancel_timer(self, handle, silent=False):
        if handle in self.timers:
            del self.timers[handle]
            return True
        if not silent:
            self.warnings.append(handle)
        return False


class ContinuousConditionTests(unittest.TestCase):
    def setUp(self):
        self.scheduler = FakeScheduler()
        self.state = 'off'
        entity = Mock()
        entity.get_state.side_effect = lambda: self.state
        entity.set_state.side_effect = lambda *, state: setattr(self, 'state', state)
        self.sensor = ContinuousCondition()
        self.sensor.ad_api = SimpleNamespace(
            get_entity=lambda name: entity,
            run_in=self.scheduler.run_in,
            cancel_timer=self.scheduler.cancel_timer,
        )
        self.sensor.yaml_block = {'time': 5, 'conditions': 'paused'}
        self.sensor.sensor_name = 'binary_sensor.is_vertex2_content_idle'
        self.sensor.log_info = Mock()
        self.sensor.logger_interface = None
        self.sensor.constants = {}
        self.sensor.templates_library = None
        self.sensor.initialize()

    def test_valid_expiry_sets_state_and_clears_handle(self):
        self.sensor.on_condition_succeed()
        self.scheduler.expire(self.sensor.cb_handle)()
        self.assertEqual(self.state, 'on')
        self.assertIsNone(self.sensor.cb_handle)
        self.sensor.on_condition_fail()
        self.assertEqual(self.state, 'off')

    def test_failure_cancels_running_timer(self):
        self.sensor.on_condition_succeed()
        self.sensor.on_condition_fail()
        self.assertEqual(self.scheduler.timers, {})
        self.assertIsNone(self.sensor.cb_handle)
        self.assertEqual(self.state, 'off')

    def test_resume_at_expiry_ignores_queued_callback_without_warning(self):
        self.sensor.on_condition_succeed()
        queued = self.scheduler.expire(self.sensor.cb_handle)
        self.sensor.on_condition_fail()
        queued()
        self.assertEqual(self.state, 'off')
        self.assertEqual(self.scheduler.warnings, [])
        self.assertIsNone(self.sensor.cb_handle)

    def test_old_callback_preserves_new_timer_and_full_delay(self):
        self.sensor.on_condition_succeed()
        queued = self.scheduler.expire(self.sensor.cb_handle)
        self.sensor.on_condition_fail()
        self.sensor.on_condition_succeed()
        new_handle = self.sensor.cb_handle
        queued()
        self.assertEqual(self.state, 'off')
        self.assertEqual(self.sensor.cb_handle, new_handle)
        self.scheduler.expire(new_handle)()
        self.assertEqual(self.state, 'on')

    def test_repeated_success_keeps_existing_timer(self):
        self.sensor.on_condition_succeed()
        handle = self.sensor.cb_handle
        self.sensor.on_condition_succeed()
        self.assertEqual(self.sensor.cb_handle, handle)
        self.assertEqual(len(self.scheduler.timers), 1)

    def test_inverted_condition_also_ignores_stale_expiry(self):
        self.sensor.invert = True
        self.state = 'on'
        self.sensor.on_condition_succeed()
        queued = self.scheduler.expire(self.sensor.cb_handle)
        self.sensor.on_condition_fail()
        queued()
        self.assertEqual(self.state, 'on')
        self.sensor.on_condition_succeed()
        self.scheduler.expire(self.sensor.cb_handle)()
        self.assertEqual(self.state, 'off')


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