feat: add portfolio Pydantic schemas

backend/app/schemas/__init__.py

@@ -1,5 +1,14 @@
 from app.schemas.user import UserBase, UserCreate, UserResponse
 from app.schemas.auth import Token, TokenPayload, LoginRequest
+from app.schemas.portfolio import (
+    TargetCreate, TargetResponse,
+    HoldingCreate, HoldingResponse, HoldingWithValue,
+    TransactionCreate, TransactionResponse,
+    PortfolioCreate, PortfolioUpdate, PortfolioResponse, PortfolioDetail,
+    SnapshotResponse, SnapshotHoldingResponse,
+    RebalanceItem, RebalanceResponse,
+    RebalanceSimulationRequest, RebalanceSimulationResponse,
+)
 
 __all__ = [
     "UserBase",
@@ -8,4 +17,11 @@ __all__ = [
     "Token",
     "TokenPayload",
     "LoginRequest",
+    "TargetCreate", "TargetResponse",
+    "HoldingCreate", "HoldingResponse", "HoldingWithValue",
+    "TransactionCreate", "TransactionResponse",
+    "PortfolioCreate", "PortfolioUpdate", "PortfolioResponse", "PortfolioDetail",
+    "SnapshotResponse", "SnapshotHoldingResponse",
+    "RebalanceItem", "RebalanceResponse",
+    "RebalanceSimulationRequest", "RebalanceSimulationResponse",
 ]

backend/app/schemas/portfolio.py

@@ -0,0 +1,158 @@
+"""
+Portfolio related Pydantic schemas.
+"""
+from datetime import datetime, date
+from decimal import Decimal
+from typing import Optional, List
+
+from pydantic import BaseModel, Field
+
+
+# Target schemas
+class TargetBase(BaseModel):
+    ticker: str
+    target_ratio: Decimal = Field(..., ge=0, le=100)
+
+
+class TargetCreate(TargetBase):
+    pass
+
+
+class TargetResponse(TargetBase):
+    class Config:
+        from_attributes = True
+
+
+# Holding schemas
+class HoldingBase(BaseModel):
+    ticker: str
+    quantity: int = Field(..., ge=0)
+    avg_price: Decimal = Field(..., ge=0)
+
+
+class HoldingCreate(HoldingBase):
+    pass
+
+
+class HoldingResponse(HoldingBase):
+    class Config:
+        from_attributes = True
+
+
+class HoldingWithValue(HoldingResponse):
+    """Holding with calculated values."""
+    current_price: Decimal | None = None
+    value: Decimal | None = None
+    current_ratio: Decimal | None = None
+    profit_loss: Decimal | None = None
+    profit_loss_ratio: Decimal | None = None
+
+
+# Transaction schemas
+class TransactionBase(BaseModel):
+    ticker: str
+    tx_type: str  # "buy" or "sell"
+    quantity: int = Field(..., gt=0)
+    price: Decimal = Field(..., gt=0)
+    executed_at: datetime
+    memo: Optional[str] = None
+
+
+class TransactionCreate(TransactionBase):
+    pass
+
+
+class TransactionResponse(TransactionBase):
+    id: int
+
+    class Config:
+        from_attributes = True
+
+
+# Portfolio schemas
+class PortfolioBase(BaseModel):
+    name: str = Field(..., min_length=1, max_length=100)
+    portfolio_type: str = "general"  # "pension" or "general"
+
+
+class PortfolioCreate(PortfolioBase):
+    pass
+
+
+class PortfolioUpdate(BaseModel):
+    name: Optional[str] = Field(None, min_length=1, max_length=100)
+    portfolio_type: Optional[str] = None
+
+
+class PortfolioResponse(PortfolioBase):
+    id: int
+    user_id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class PortfolioDetail(PortfolioResponse):
+    """Portfolio with targets and holdings."""
+    targets: List[TargetResponse] = []
+    holdings: List[HoldingWithValue] = []
+    total_value: Decimal | None = None
+    total_invested: Decimal | None = None
+    total_profit_loss: Decimal | None = None
+
+
+# Snapshot schemas
+class SnapshotHoldingResponse(BaseModel):
+    ticker: str
+    quantity: int
+    price: Decimal
+    value: Decimal
+    current_ratio: Decimal
+
+    class Config:
+        from_attributes = True
+
+
+class SnapshotResponse(BaseModel):
+    id: int
+    portfolio_id: int
+    total_value: Decimal
+    snapshot_date: date
+    holdings: List[SnapshotHoldingResponse] = []
+
+    class Config:
+        from_attributes = True
+
+
+# Rebalancing schemas
+class RebalanceItem(BaseModel):
+    ticker: str
+    name: str | None = None
+    target_ratio: Decimal
+    current_ratio: Decimal
+    current_quantity: int
+    current_value: Decimal
+    target_value: Decimal
+    diff_value: Decimal
+    diff_quantity: int
+    action: str  # "buy", "sell", or "hold"
+
+
+class RebalanceResponse(BaseModel):
+    portfolio_id: int
+    total_value: Decimal
+    items: List[RebalanceItem]
+
+
+class RebalanceSimulationRequest(BaseModel):
+    additional_amount: Decimal = Field(..., gt=0)
+
+
+class RebalanceSimulationResponse(BaseModel):
+    portfolio_id: int
+    current_total: Decimal
+    additional_amount: Decimal
+    new_total: Decimal
+    items: List[RebalanceItem]