"""
Unit tests for Schedule signals.

Tests signal definitions and handler function signatures.
Signal handlers that use local imports are tested via their existence and signature.
"""
from unittest.mock import Mock, patch, MagicMock
from datetime import datetime, timedelta
import inspect
import pytest


class TestCustomSignals:
    """Test that custom signals are defined correctly."""

    def test_event_status_changed_signal_exists(self):
        """Test that event_status_changed signal is defined."""
        from smoothschedule.scheduling.schedule.signals import event_status_changed
        from django.dispatch import Signal

        assert isinstance(event_status_changed, Signal)

    def test_customer_notification_requested_signal_exists(self):
        """Test that customer_notification_requested signal is defined."""
        from smoothschedule.scheduling.schedule.signals import customer_notification_requested
        from django.dispatch import Signal

        assert isinstance(customer_notification_requested, Signal)


class TestBroadcastEventChangeSync:
    """Test broadcast_event_change_sync function."""

    def test_function_exists(self):
        """Test that broadcast function is defined."""
        from smoothschedule.scheduling.schedule.signals import broadcast_event_change_sync

        assert callable(broadcast_event_change_sync)

    def test_function_signature(self):
        """Test function accepts expected parameters."""
        from smoothschedule.scheduling.schedule.signals import broadcast_event_change_sync

        sig = inspect.signature(broadcast_event_change_sync)
        params = list(sig.parameters.keys())

        assert 'event' in params
        assert 'update_type' in params
        assert 'changed_fields' in params
        assert 'old_status' in params


class TestAutoAttachGlobalPlugins:
    """Test auto_attach_global_plugins handler."""

    def test_handler_exists(self):
        """Test that handler function exists."""
        from smoothschedule.scheduling.schedule.signals import auto_attach_global_plugins

        assert callable(auto_attach_global_plugins)

    def test_handler_signature(self):
        """Test handler accepts Django signal parameters."""
        from smoothschedule.scheduling.schedule.signals import auto_attach_global_plugins

        sig = inspect.signature(auto_attach_global_plugins)
        params = list(sig.parameters.keys())

        assert 'sender' in params
        assert 'instance' in params
        assert 'created' in params

    def test_skips_when_not_created(self):
        """Test that handler returns early when event is not new."""
        from smoothschedule.scheduling.schedule.signals import auto_attach_global_plugins

        mock_event = Mock()

        # The function checks `if not created: return`
        # We verify this by checking the function doesn't raise
        # when called with created=False (it should return immediately)
        result = auto_attach_global_plugins(sender=None, instance=mock_event, created=False)
        assert result is None


class TestTrackEventChanges:
    """Test track_event_changes pre_save handler."""

    def test_handler_exists(self):
        """Test that handler function exists."""
        from smoothschedule.scheduling.schedule.signals import track_event_changes

        assert callable(track_event_changes)

    def test_handler_signature(self):
        """Test handler accepts Django signal parameters."""
        from smoothschedule.scheduling.schedule.signals import track_event_changes

        sig = inspect.signature(track_event_changes)
        params = list(sig.parameters.keys())

        assert 'sender' in params
        assert 'instance' in params

    def test_skips_for_new_events(self):
        """Test that handler skips new events (no pk)."""
        from smoothschedule.scheduling.schedule.signals import track_event_changes

        mock_event = Mock()
        mock_event.pk = None

        # Should return early without error
        result = track_event_changes(sender=None, instance=mock_event)
        assert result is None


class TestSignalHandlerRegistration:
    """Test that signal handlers are properly registered."""

    def test_post_save_has_receivers(self):
        """Test that post_save signal has receivers."""
        from django.db.models.signals import post_save

        # Import signals module to ensure handlers are registered
        from smoothschedule.scheduling.schedule import signals  # noqa

        assert len(post_save.receivers) > 0

    def test_pre_save_has_receivers(self):
        """Test that pre_save signal has receivers."""
        from django.db.models.signals import pre_save

        # Import signals module to ensure handlers are registered
        from smoothschedule.scheduling.schedule import signals  # noqa

        assert len(pre_save.receivers) > 0


class TestEventPluginSignalHandlers:
    """Test EventPlugin-related signal handlers."""

    def test_signals_module_has_plugin_handlers(self):
        """Test that plugin-related handlers exist."""
        from smoothschedule.scheduling.schedule import signals

        # Check for any plugin-related functions
        module_functions = [name for name in dir(signals) if callable(getattr(signals, name, None))]

        # Should have functions that handle plugins
        assert len(module_functions) > 5  # Basic sanity check


class TestEventDeletionSignals:
    """Test event deletion signal handlers."""

    def test_pre_delete_has_receivers(self):
        """Test that pre_delete signal has receivers."""
        from django.db.models.signals import pre_delete

        # Import signals module to ensure handlers are registered
        from smoothschedule.scheduling.schedule import signals  # noqa

        # May or may not have receivers depending on setup
        # Just verify the signal exists
        assert pre_delete is not None
