feat: Add scheduler for daily user credits recharge

tests/services/test_scheduler.py

@@ -0,0 +1,80 @@
+"""Tests for scheduler service."""
+
+from unittest.mock import AsyncMock, patch
+
+import pytest
+from sqlmodel.ext.asyncio.session import AsyncSession
+
+from app.services.scheduler import SchedulerService
+
+
+class TestSchedulerService:
+    """Test scheduler service functionality."""
+
+    @pytest.fixture
+    def mock_db_session_factory(self):
+        """Create a mock database session factory."""
+        session = AsyncMock(spec=AsyncSession)
+        return lambda: session
+
+    @pytest.fixture
+    def scheduler_service(self, mock_db_session_factory):
+        """Create a scheduler service instance for testing."""
+        return SchedulerService(mock_db_session_factory)
+
+    @pytest.mark.asyncio
+    async def test_start_scheduler(self, scheduler_service) -> None:
+        """Test starting the scheduler service."""
+        with patch.object(scheduler_service.scheduler, 'add_job') as mock_add_job, \
+             patch.object(scheduler_service.scheduler, 'start') as mock_start:
+            
+            await scheduler_service.start()
+
+            # Verify job was added
+            mock_add_job.assert_called_once_with(
+                scheduler_service._daily_credit_recharge,
+                "cron",
+                hour=0,
+                minute=0,
+                id="daily_credit_recharge",
+                name="Daily Credit Recharge",
+                replace_existing=True,
+            )
+
+            # Verify scheduler was started
+            mock_start.assert_called_once()
+
+    @pytest.mark.asyncio
+    async def test_stop_scheduler(self, scheduler_service) -> None:
+        """Test stopping the scheduler service."""
+        with patch.object(scheduler_service.scheduler, 'shutdown') as mock_shutdown:
+            await scheduler_service.stop()
+            mock_shutdown.assert_called_once()
+
+    @pytest.mark.asyncio
+    async def test_daily_credit_recharge_success(self, scheduler_service) -> None:
+        """Test successful daily credit recharge task."""
+        mock_stats = {
+            "total_users": 10,
+            "recharged_users": 8,
+            "skipped_users": 2,
+            "total_credits_added": 500,
+        }
+
+        with patch.object(scheduler_service.credit_service, 'recharge_all_users_credits') as mock_recharge:
+            mock_recharge.return_value = mock_stats
+
+            await scheduler_service._daily_credit_recharge()
+
+            mock_recharge.assert_called_once()
+
+    @pytest.mark.asyncio
+    async def test_daily_credit_recharge_failure(self, scheduler_service) -> None:
+        """Test daily credit recharge task with failure."""
+        with patch.object(scheduler_service.credit_service, 'recharge_all_users_credits') as mock_recharge:
+            mock_recharge.side_effect = Exception("Database error")
+
+            # Should not raise exception, just log it
+            await scheduler_service._daily_credit_recharge()
+
+            mock_recharge.assert_called_once()