"""因子组合 API（M7.2b）：/api/composites CRUD。

组合 = 可复用因子权重集；计算时方向取因子注册表，落库冗余快照。
"""

from __future__ import annotations

from fastapi import APIRouter, HTTPException

from app.api.deps import CompositeRepoDep, DbSession
from app.application.services.job_executor import new_id
from app.domain.entities.composite import CompositeComponent, CompositeDefinition
from app.quant.factors import FactorError, get_factor

router = APIRouter(prefix="/composites", tags=["composites"])


def _fill_direction(definition: CompositeDefinition) -> CompositeDefinition:
    """以因子注册表元数据补齐/校正组件 direction（登记但不可计算的因子报错）。"""
    out = []
    for c in definition.components:
        try:
            defn, _fn = get_factor(c.name)
        except FactorError as exc:
            raise HTTPException(status_code=400, detail=str(exc)) from exc
        out.append(CompositeComponent(name=c.name, weight=c.weight, direction=defn.direction))
    return definition.model_copy(update={"components": out})


@router.post("", summary="保存因子组合", response_model=CompositeDefinition)
def create_composite(
    definition: CompositeDefinition,
    composite_repo: CompositeRepoDep,
    session: DbSession,
) -> CompositeDefinition:
    prepared = _fill_direction(definition.model_copy(update={"id": ""}))
    try:
        saved = composite_repo.save(
            prepared.model_copy(update={"id": new_id("CF")})
        )
        session.commit()
        return saved
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc


@router.get("", summary="因子组合列表", response_model=list[CompositeDefinition])
def list_composites(composite_repo: CompositeRepoDep) -> list[CompositeDefinition]:
    return composite_repo.list()


@router.get("/{composite_id}", summary="读取因子组合", response_model=CompositeDefinition)
def get_composite(composite_id: str, composite_repo: CompositeRepoDep) -> CompositeDefinition:
    row = composite_repo.get(composite_id)
    if row is None:
        raise HTTPException(status_code=404, detail=f"组合 {composite_id} 不存在")
    return row


@router.delete("/{composite_id}", summary="删除因子组合")
def delete_composite(
    composite_id: str,
    composite_repo: CompositeRepoDep,
    session: DbSession,
) -> dict:
    if not composite_repo.delete(composite_id):
        raise HTTPException(status_code=404, detail=f"组合 {composite_id} 不存在")
    session.commit()
    return {"deleted": composite_id}