"""因子组合（Composite Factor）领域实体（M7.2b，v2 §13）。

组合 = 一组 {因子, 权重} + method（MVP fixed：截面 zscore×方向×权重求和；
方向在计算时取因子注册表元数据，落库时冗余快照以便列表展示）。
"""

from __future__ import annotations

from datetime import datetime

from pydantic import BaseModel, Field, model_validator


class CompositeComponent(BaseModel):
    name: str
    weight: float = Field(default=1.0, gt=0)
    direction: str = Field(default="higher_is_better")


class CompositeDefinition(BaseModel):
    id: str = ""
    name: str = Field(min_length=1, max_length=64)
    method: str = Field(default="fixed", pattern="^(fixed)$")
    description: str = ""
    components: list[CompositeComponent] = Field(min_length=1)
    created_at: datetime | None = None

    @model_validator(mode="after")
    def _no_duplicate(self) -> CompositeDefinition:
        names = [c.name for c in self.components]
        if len(set(names)) != len(names):
            raise ValueError("components 存在重复因子名")
        return self