"""固定成本 Schema"""

from typing import Optional
from datetime import datetime
from enum import Enum

from pydantic import BaseModel, Field, field_validator
import re


class CostType(str, Enum):
    """成本类型枚举"""
    
    RENT = "rent"  # 房租
    UTILITIES = "utilities"  # 水电
    PROPERTY = "property"  # 物业
    OTHER = "other"  # 其他


class AllocationMethod(str, Enum):
    """分摊方式枚举"""
    
    COUNT = "count"  # 按项目数量
    REVENUE = "revenue"  # 按营收占比
    DURATION = "duration"  # 按时长占比


class FixedCostBase(BaseModel):
    """固定成本基础字段"""
    
    cost_name: str = Field(..., min_length=1, max_length=100, description="成本名称")
    cost_type: CostType = Field(..., description="类型")
    monthly_amount: float = Field(..., gt=0, description="月度金额")
    year_month: str = Field(..., description="年月：2026-01")
    allocation_method: AllocationMethod = Field(AllocationMethod.COUNT, description="分摊方式")
    is_active: bool = Field(True, description="是否启用")
    
    @field_validator("year_month")
    @classmethod
    def validate_year_month(cls, v: str) -> str:
        """验证年月格式"""
        if not re.match(r"^\d{4}-\d{2}$", v):
            raise ValueError("年月格式必须为 YYYY-MM")
        return v


class FixedCostCreate(FixedCostBase):
    """创建固定成本请求"""
    pass


class FixedCostUpdate(BaseModel):
    """更新固定成本请求"""
    
    cost_name: Optional[str] = Field(None, min_length=1, max_length=100, description="成本名称")
    cost_type: Optional[CostType] = Field(None, description="类型")
    monthly_amount: Optional[float] = Field(None, gt=0, description="月度金额")
    year_month: Optional[str] = Field(None, description="年月：2026-01")
    allocation_method: Optional[AllocationMethod] = Field(None, description="分摊方式")
    is_active: Optional[bool] = Field(None, description="是否启用")
    
    @field_validator("year_month")
    @classmethod
    def validate_year_month(cls, v: Optional[str]) -> Optional[str]:
        """验证年月格式"""
        if v is not None and not re.match(r"^\d{4}-\d{2}$", v):
            raise ValueError("年月格式必须为 YYYY-MM")
        return v


class FixedCostResponse(FixedCostBase):
    """固定成本响应"""
    
    id: int
    created_at: datetime
    updated_at: datetime
    
    class Config:
        from_attributes = True