"""Tests for APScheduler task scheduler.

T55: Unit tests for the task scheduler implementation.
"""
import pytest
from unittest.mock import Mock, patch, MagicMock
from apscheduler.schedulers.asyncio import AsyncIOScheduler
from apscheduler.triggers.interval import IntervalTrigger
from apscheduler.triggers.cron import CronTrigger


@pytest.mark.unit
class TestScheduler:
    """Test suite for scheduler singleton and decorator."""
    
    def test_get_scheduler_returns_singleton(self):
        """Test that get_scheduler returns the same instance."""
        # Arrange & Act
        from openrouter_monitor.tasks.scheduler import get_scheduler, _scheduler
        
        # First call should create scheduler
        scheduler1 = get_scheduler()
        scheduler2 = get_scheduler()
        
        # Assert
        assert scheduler1 is scheduler2
        assert isinstance(scheduler1, AsyncIOScheduler)
        assert scheduler1.timezone.zone == 'UTC'
    
    def test_get_scheduler_creates_new_if_none(self):
        """Test that get_scheduler creates scheduler if None."""
        # Arrange
        from openrouter_monitor.tasks import scheduler as scheduler_module
        
        # Reset singleton
        original_scheduler = scheduler_module._scheduler
        scheduler_module._scheduler = None
        
        try:
            # Act
            scheduler = scheduler_module.get_scheduler()
            
            # Assert
            assert scheduler is not None
            assert isinstance(scheduler, AsyncIOScheduler)
        finally:
            # Restore
            scheduler_module._scheduler = original_scheduler
    
    def test_scheduled_job_decorator_registers_job(self):
        """Test that @scheduled_job decorator registers a job."""
        # Arrange
        from openrouter_monitor.tasks.scheduler import get_scheduler, scheduled_job
        
        scheduler = get_scheduler()
        initial_job_count = len(scheduler.get_jobs())
        
        # Act
        @scheduled_job(IntervalTrigger(hours=1), id='test_job')
        async def test_task():
            """Test task."""
            pass
        
        # Assert
        jobs = scheduler.get_jobs()
        assert len(jobs) == initial_job_count + 1
        
        # Find our job
        job = scheduler.get_job('test_job')
        assert job is not None
        assert job.func == test_task
    
    def test_scheduled_job_with_cron_trigger(self):
        """Test @scheduled_job with CronTrigger."""
        # Arrange
        from openrouter_monitor.tasks.scheduler import get_scheduler, scheduled_job
        
        scheduler = get_scheduler()
        
        # Act
        @scheduled_job(CronTrigger(hour=2, minute=0), id='daily_job')
        async def daily_task():
            """Daily task."""
            pass
        
        # Assert
        job = scheduler.get_job('daily_job')
        assert job is not None
        assert isinstance(job.trigger, CronTrigger)
    
    def test_init_scheduler_starts_scheduler(self):
        """Test that init_scheduler starts the scheduler."""
        # Arrange
        from openrouter_monitor.tasks.scheduler import init_scheduler, get_scheduler
        
        scheduler = get_scheduler()
        
        with patch.object(scheduler, 'start') as mock_start:
            # Act
            init_scheduler()
            
            # Assert
            mock_start.assert_called_once()
    
    def test_shutdown_scheduler_stops_scheduler(self):
        """Test that shutdown_scheduler stops the scheduler."""
        # Arrange
        from openrouter_monitor.tasks.scheduler import shutdown_scheduler, get_scheduler
        
        scheduler = get_scheduler()
        
        with patch.object(scheduler, 'shutdown') as mock_shutdown:
            # Act
            shutdown_scheduler()
            
            # Assert
            mock_shutdown.assert_called_once_with(wait=True)
    
    def test_scheduler_timezone_is_utc(self):
        """Test that scheduler uses UTC timezone."""
        # Arrange & Act
        from openrouter_monitor.tasks.scheduler import get_scheduler
        
        scheduler = get_scheduler()
        
        # Assert
        assert scheduler.timezone.zone == 'UTC'
    
    def test_scheduled_job_preserves_function(self):
        """Test that decorator preserves original function."""
        # Arrange
        from openrouter_monitor.tasks.scheduler import scheduled_job
        
        # Act
        @scheduled_job(IntervalTrigger(minutes=5), id='preserve_test')
        async def my_task():
            """My task docstring."""
            return "result"
        
        # Assert - function should be returned unchanged
        assert my_task.__name__ == 'my_task'
        assert my_task.__doc__ == 'My task docstring.'


@pytest.mark.unit
class TestSchedulerIntegration:
    """Integration tests for scheduler lifecycle."""
    
    @pytest.mark.asyncio
    async def test_scheduler_start_stop_cycle(self):
        """Test complete scheduler start/stop cycle."""
        # Arrange
        from openrouter_monitor.tasks.scheduler import get_scheduler
        import asyncio
        
        scheduler = get_scheduler()
        
        # Act & Assert - should not raise
        scheduler.start()
        assert scheduler.running
        
        scheduler.shutdown(wait=True)
        # Give async loop time to process shutdown
        await asyncio.sleep(0.1)
        # Note: scheduler.running might still be True in async tests
        # due to event loop differences, but shutdown should not raise
    
    def test_multiple_jobs_can_be_registered(self):
        """Test that multiple jobs can be registered."""
        # Arrange
        from openrouter_monitor.tasks.scheduler import get_scheduler, scheduled_job
        from apscheduler.triggers.interval import IntervalTrigger
        
        scheduler = get_scheduler()
        
        # Act
        @scheduled_job(IntervalTrigger(hours=1), id='job1')
        async def job1():
            pass
        
        @scheduled_job(IntervalTrigger(hours=2), id='job2')
        async def job2():
            pass
        
        @scheduled_job(CronTrigger(day_of_week='sun', hour=3), id='job3')
        async def job3():
            pass
        
        # Assert
        jobs = scheduler.get_jobs()
        job_ids = [job.id for job in jobs]
        assert 'job1' in job_ids
        assert 'job2' in job_ids
        assert 'job3' in job_ids