"""Tests for sanguo_backtest.cta_engine module."""
import pytest
from unittest.mock import Mock, patch, MagicMock
from datetime import datetime
import pandas as pd
from sanguo_backtest.cta_engine import run_cta_backtest


class TestRunCtaBacktest:
    """Test suite for run_cta_backtest function."""

    def test_run_cta_backtest_returns_result(self, temp_db_path):
        """Test successful CTA backtest execution returns proper result."""
        # Mock strategy class
        mock_strategy_class = Mock()
        mock_strategy_class.__name__ = "TestStrategy"

        # Mock BacktestingEngine
        mock_engine = MagicMock()
        mock_engine.calculate_result.return_value = {
            "total_return": 0.15,
            "sharpe_ratio": 1.2,
            "max_drawdown": -0.08,
            "win_rate": 0.55
        }
        mock_engine.get_all_daily_results.return_value = [
            {"date": "2024-01-01", "balance": 100000},
            {"date": "2024-01-02", "balance": 101000},
        ]

        # Mock config
        mock_cfg = Mock()

        # Create mock module with BacktestingEngine
        mock_module = MagicMock()
        mock_module.BacktestingEngine = Mock(return_value=mock_engine)

        with patch.dict("sys.modules", {"vnpy_ctastrategy.backtesting": mock_module}):
            result = run_cta_backtest(
                strategy_class=mock_strategy_class,
                symbol="600000",
                params={"window": 20},
                start="2024-01-01",
                end="2024-03-31",
                cfg=mock_cfg,
                db_path=temp_db_path
            )

        # Verify result structure
        assert result.type == "cta"
        assert result.status == "done"
        assert result.strategy == "TestStrategy"
        assert result.symbol == "600000"
        assert result.params == {"window": 20}
        assert result.start == "2024-01-01"
        assert result.end == "2024-03-31"
        assert result.statistics == {
            "total_return": 0.15,
            "sharpe_ratio": 1.2,
            "max_drawdown": -0.08,
            "win_rate": 0.55
        }
        assert result.error_msg is None

        # Verify BacktestingEngine methods were called
        mock_engine.set_parameters.assert_called_once()
        mock_engine.add_strategy.assert_called_once_with(mock_strategy_class, {"window": 20})
        mock_engine.load_data.assert_called_once()
        mock_engine.run_backtesting.assert_called_once()
        mock_engine.calculate_result.assert_called_once()

    def test_run_cta_backtest_handles_exception(self, temp_db_path):
        """Test that exceptions during backtest are handled properly."""
        # Mock strategy class
        mock_strategy_class = Mock()
        mock_strategy_class.__name__ = "FailingStrategy"

        # Mock BacktestingEngine to raise exception
        mock_engine = MagicMock()
        mock_engine.load_data.side_effect = RuntimeError("Data loading failed")

        # Mock config
        mock_cfg = Mock()

        # Create mock module with BacktestingEngine
        mock_module = MagicMock()
        mock_module.BacktestingEngine = Mock(return_value=mock_engine)

        with patch.dict("sys.modules", {"vnpy_ctastrategy.backtesting": mock_module}):
            result = run_cta_backtest(
                strategy_class=mock_strategy_class,
                symbol="000001",
                params={"window": 20},
                start="2024-01-01",
                end="2024-03-31",
                cfg=mock_cfg,
                db_path=temp_db_path
            )

        # Verify failed result structure
        assert result.type == "cta"
        assert result.status == "failed"
        assert result.strategy == "FailingStrategy"
        assert result.symbol == "000001"
        assert result.error_msg is not None
        assert "RuntimeError" in result.error_msg
        assert "Data loading failed" in result.error_msg

    def test_run_cta_backtest_generates_task_id(self, temp_db_path):
        """Test that run_cta_backtest generates unique task IDs."""
        mock_strategy_class = Mock()
        mock_strategy_class.__name__ = "IdTestStrategy"

        mock_engine = MagicMock()
        mock_engine.calculate_result.return_value = {"sharpe_ratio": 1.0}
        mock_engine.get_all_daily_results.return_value = []

        mock_cfg = Mock()

        # Create mock module with BacktestingEngine
        mock_module = MagicMock()
        mock_module.BacktestingEngine = Mock(return_value=mock_engine)

        with patch.dict("sys.modules", {"vnpy_ctastrategy.backtesting": mock_module}):
            result1 = run_cta_backtest(
                strategy_class=mock_strategy_class,
                symbol="600000",
                params={},
                start="2024-01-01",
                end="2024-03-31",
                cfg=mock_cfg,
                db_path=temp_db_path
            )

            result2 = run_cta_backtest(
                strategy_class=mock_strategy_class,
                symbol="600001",
                params={},
                start="2024-01-01",
                end="2024-03-31",
                cfg=mock_cfg,
                db_path=temp_db_path
            )

        # Verify unique task IDs
        assert result1.task_id != result2.task_id
        assert result1.task_id.startswith("cta_")
        assert result2.task_id.startswith("cta_")