feat(backtest): cta_engine BacktestingEngine wrapper

sanguo_backtest/cta_engine.py

@@ -0,0 +1,148 @@
+"""CTA strategy backtesting engine wrapper using vnpy_ctastrategy.backtesting."""
+import sys
+import os
+import traceback
+import uuid
+from datetime import datetime
+from pathlib import Path
+
+# Add vnpy source to path for local development
+_VNPY_SRC = os.path.join(os.path.dirname(__file__), "..", "vnpy_v4.4.0")
+_VNPY_SRC = os.path.abspath(_VNPY_SRC)
+if _VNPY_SRC not in sys.path:
+    sys.path.insert(0, _VNPY_SRC)
+
+from sanguo_backtest.result_store import BacktestResult, save_result
+
+
+# Mock Exchange enum for local use (replaces vnpy.trader.constant.Exchange)
+class MockExchange:
+    SSE = "SSE"  # Shanghai Stock Exchange
+    SZSE = "SZSE"  # Shenzhen Stock Exchange
+
+    class Exchange:
+        SSE = "SSE"
+        SZSE = "SZSE"
+
+        def __init__(self, value):
+            self.value = value
+
+        def __repr__(self):
+            return f"Exchange.{self.value}"
+
+
+Exchange = MockExchange.Exchange
+
+
+def guess_exchange(symbol: str) -> Exchange:
+    """按代码前缀判断交易所：6/68/5x→SSE，0/3/15x→SZSE"""
+    if symbol.startswith(("60", "68", "51", "56", "58")):
+        return Exchange("SSE")
+    if symbol.startswith(("00", "30", "15")):
+        return Exchange("SZSE")
+    return Exchange("SSE")
+
+
+def run_cta_backtest(strategy_class, symbol: str, params: dict, start: str, end: str, cfg, db_path: str) -> BacktestResult:
+    """
+    Run CTA strategy backtest using vnpy_ctastrategy BacktestingEngine.
+
+    Args:
+        strategy_class: CTA strategy class to backtest
+        symbol: Stock symbol (e.g., "600000")
+        params: Strategy parameters dict
+        start: Backtest start date (YYYY-MM-DD format)
+        end: Backtest end date (YYYY-MM-DD format)
+        cfg: Configuration object (may contain data paths)
+        db_path: SQLite database path for saving results
+
+    Returns:
+        BacktestResult: Result object with backtest statistics and status
+    """
+    # Generate unique task ID
+    task_id = f"cta_{uuid.uuid4().hex[:8]}"
+
+    try:
+        # Lazy import of BacktestingEngine (local env may not have vnpy_ctastrategy)
+        from vnpy_ctastrategy.backtesting import BacktestingEngine
+
+        # Build vt_symbol for A-shares
+        vt_symbol = f"{symbol}.{guess_exchange(symbol).value}"
+
+        # Convert date strings to datetime objects
+        start_dt = datetime.strptime(start, "%Y-%m-%d")
+        end_dt = datetime.strptime(end, "%Y-%m-%d") if end else None
+
+        # Create and configure backtesting engine
+        engine = BacktestingEngine()
+
+        # Set parameters with A-share specific values
+        engine.set_parameters(
+            vt_symbol=vt_symbol,
+            interval="1d",  # Daily interval for A-shares
+            start=start_dt,
+            end=end_dt,
+            rate=0.001,  # Commission rate (0.1% for A-shares)
+            slippage=0,  # No slippage for simplicity
+            size=1,  # Contract size (1 for stocks)
+            pricetick=0.01,  # Minimum price tick (0.01 yuan for A-shares)
+            capital=0  # No initial capital limit
+        )
+
+        # Add strategy
+        engine.add_strategy(strategy_class, params)
+
+        # Load historical data
+        engine.load_data()
+
+        # Run backtesting
+        engine.run_backtesting()
+
+        # Calculate statistics
+        statistics = engine.calculate_result()
+
+        # Get daily results for equity curve
+        daily_results = engine.get_all_daily_results()
+
+        # Build result object
+        result = BacktestResult(
+            task_id=task_id,
+            type="cta",
+            status="done",
+            strategy=strategy_class.__name__,
+            symbol=symbol,
+            params=params,
+            start=start,
+            end=end,
+            statistics=statistics,
+            equity_curve=daily_results,  # Simplified: store raw daily results
+            trades=None  # Not implemented in this MVP
+        )
+
+    except Exception as e:
+        # Handle any exceptions and return failed result
+        error_msg = f"{type(e).__name__}: {e}\n{traceback.format_exc()}"
+
+        result = BacktestResult(
+            task_id=task_id,
+            type="cta",
+            status="failed",
+            strategy=strategy_class.__name__,
+            symbol=symbol,
+            params=params,
+            start=start,
+            end=end,
+            statistics={},
+            equity_curve=None,
+            trades=None,
+            error_msg=error_msg
+        )
+
+    # Save result to database
+    save_result(result, db_path=db_path)
+
+    return result
+
+
+# Module-level reference for mocking in tests
+BacktestingEngine = None  # Will be set when imported inside run_cta_backtest