"""
Quant strategy API endpoints.
"""
from typing import Set

from fastapi import APIRouter, Depends
from sqlalchemy.orm import Session

from app.core.database import get_db
from app.api.deps import CurrentUser
from app.models.stock import ETF
from app.schemas.strategy import (
    MultiFactorRequest, QualityRequest, ValueMomentumRequest, KJBRequest, StrategyResult,
)
from app.services.strategy import MultiFactorStrategy, QualityStrategy, ValueMomentumStrategy, KJBStrategy

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


def _filter_dc_only(result: StrategyResult, db: Session) -> StrategyResult:
    """Filter strategy result to include only ETFs (DC pension investable)."""
    tickers = [s.ticker for s in result.stocks]
    etf_tickers: Set[str] = set(
        row[0] for row in db.query(ETF.ticker).filter(ETF.ticker.in_(tickers)).all()
    ) if tickers else set()

    filtered = [s for s in result.stocks if s.ticker in etf_tickers]
    # Re-rank
    for i, stock in enumerate(filtered, 1):
        stock.rank = i

    return StrategyResult(
        strategy_name=result.strategy_name,
        base_date=result.base_date,
        universe_count=result.universe_count,
        result_count=len(filtered),
        stocks=filtered,
    )


@router.post("/multi-factor", response_model=StrategyResult)
async def run_multi_factor(
    request: MultiFactorRequest,
    current_user: CurrentUser,
    db: Session = Depends(get_db),
):
    """Run multi-factor strategy."""
    strategy = MultiFactorStrategy(db)
    result = strategy.run(
        universe_filter=request.universe,
        top_n=request.top_n,
        base_date=request.base_date,
        weights=request.weights,
    )
    return _filter_dc_only(result, db) if request.dc_only else result


@router.post("/quality", response_model=StrategyResult)
async def run_quality(
    request: QualityRequest,
    current_user: CurrentUser,
    db: Session = Depends(get_db),
):
    """Run super quality strategy."""
    strategy = QualityStrategy(db)
    result = strategy.run(
        universe_filter=request.universe,
        top_n=request.top_n,
        base_date=request.base_date,
        min_fscore=request.min_fscore,
    )
    return _filter_dc_only(result, db) if request.dc_only else result


@router.post("/value-momentum", response_model=StrategyResult)
async def run_value_momentum(
    request: ValueMomentumRequest,
    current_user: CurrentUser,
    db: Session = Depends(get_db),
):
    """Run value-momentum strategy."""
    strategy = ValueMomentumStrategy(db)
    result = strategy.run(
        universe_filter=request.universe,
        top_n=request.top_n,
        base_date=request.base_date,
        value_weight=request.value_weight,
        momentum_weight=request.momentum_weight,
    )
    return _filter_dc_only(result, db) if request.dc_only else result


@router.post("/kjb", response_model=StrategyResult)
async def run_kjb(
    request: KJBRequest,
    current_user: CurrentUser,
    db: Session = Depends(get_db),
):
    """Run KJB strategy."""
    strategy = KJBStrategy(db)
    result = strategy.run(
        universe_filter=request.universe,
        top_n=request.top_n,
        base_date=request.base_date,
    )
    return _filter_dc_only(result, db) if request.dc_only else result