feat: add backtest Pydantic schemas

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/app/schemas/__init__.py

@@ -15,6 +15,11 @@ from app.schemas.strategy import (
     StockFactor, StrategyResult,
     StockInfo, StockSearchResult, PriceData,
 )
+from app.schemas.backtest import (
+    RebalancePeriod, BacktestStatus,
+    BacktestCreate, BacktestMetrics, BacktestResponse, BacktestListItem,
+    EquityCurvePoint, HoldingItem, RebalanceHoldings, TransactionItem,
+)
 
 __all__ = [
     "UserBase",
@@ -34,4 +39,7 @@ __all__ = [
     "StrategyRequest", "MultiFactorRequest", "QualityRequest", "ValueMomentumRequest",
     "StockFactor", "StrategyResult",
     "StockInfo", "StockSearchResult", "PriceData",
+    "RebalancePeriod", "BacktestStatus",
+    "BacktestCreate", "BacktestMetrics", "BacktestResponse", "BacktestListItem",
+    "EquityCurvePoint", "HoldingItem", "RebalanceHoldings", "TransactionItem",
 ]

backend/app/schemas/backtest.py

@@ -0,0 +1,128 @@
+"""
+Backtest related Pydantic schemas.
+"""
+from datetime import date, datetime
+from decimal import Decimal
+from typing import Optional, List, Dict, Any
+from enum import Enum
+
+from pydantic import BaseModel, Field
+
+
+class RebalancePeriod(str, Enum):
+    MONTHLY = "monthly"
+    QUARTERLY = "quarterly"
+    SEMI_ANNUAL = "semi_annual"
+    ANNUAL = "annual"
+
+
+class BacktestStatus(str, Enum):
+    PENDING = "pending"
+    RUNNING = "running"
+    COMPLETED = "completed"
+    FAILED = "failed"
+
+
+class BacktestCreate(BaseModel):
+    """Request to create a new backtest."""
+    strategy_type: str = Field(..., description="multi_factor, quality, or value_momentum")
+    strategy_params: Dict[str, Any] = Field(default_factory=dict)
+    start_date: date
+    end_date: date
+    rebalance_period: RebalancePeriod = RebalancePeriod.QUARTERLY
+    initial_capital: Decimal = Field(default=Decimal("100000000"), gt=0)
+    commission_rate: Decimal = Field(default=Decimal("0.00015"), ge=0, le=1)
+    slippage_rate: Decimal = Field(default=Decimal("0.001"), ge=0, le=1)
+    benchmark: str = Field(default="KOSPI")
+    top_n: int = Field(default=30, ge=1, le=100)
+
+
+class BacktestMetrics(BaseModel):
+    """Backtest result metrics."""
+    total_return: Decimal
+    cagr: Decimal
+    mdd: Decimal
+    sharpe_ratio: Decimal
+    volatility: Decimal
+    benchmark_return: Decimal
+    excess_return: Decimal
+
+
+class BacktestResponse(BaseModel):
+    """Backtest response with status and optional results."""
+    id: int
+    user_id: int
+    strategy_type: str
+    strategy_params: Dict[str, Any]
+    start_date: date
+    end_date: date
+    rebalance_period: str
+    initial_capital: Decimal
+    commission_rate: Decimal
+    slippage_rate: Decimal
+    benchmark: str
+    status: str
+    created_at: datetime
+    completed_at: Optional[datetime] = None
+    error_message: Optional[str] = None
+    result: Optional[BacktestMetrics] = None
+
+    class Config:
+        from_attributes = True
+
+
+class BacktestListItem(BaseModel):
+    """Backtest item for list view."""
+    id: int
+    strategy_type: str
+    start_date: date
+    end_date: date
+    rebalance_period: str
+    status: str
+    created_at: datetime
+    total_return: Optional[Decimal] = None
+    cagr: Optional[Decimal] = None
+    mdd: Optional[Decimal] = None
+
+    class Config:
+        from_attributes = True
+
+
+class EquityCurvePoint(BaseModel):
+    """Single point in equity curve."""
+    date: date
+    portfolio_value: Decimal
+    benchmark_value: Decimal
+    drawdown: Decimal
+
+    class Config:
+        from_attributes = True
+
+
+class HoldingItem(BaseModel):
+    """Single holding at a rebalance date."""
+    ticker: str
+    name: str
+    weight: Decimal
+    shares: int
+    price: Decimal
+
+
+class RebalanceHoldings(BaseModel):
+    """Holdings at a specific rebalance date."""
+    rebalance_date: date
+    holdings: List[HoldingItem]
+
+
+class TransactionItem(BaseModel):
+    """Single transaction."""
+    id: int
+    date: date
+    ticker: str
+    action: str
+    shares: int
+    price: Decimal
+    commission: Decimal
+
+    class Config:
+        from_attributes = True