from datetime import date
from typing import Optional
from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy import select
from sqlalchemy.orm import Session

from database import get_db
from models import FlockHistory
from schemas import FlockHistoryCreate, FlockHistoryUpdate, FlockHistoryOut

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


@router.get("", response_model=list[FlockHistoryOut])
def list_flock_history(db: Session = Depends(get_db)):
    q = select(FlockHistory).order_by(FlockHistory.date.desc())
    return db.scalars(q).all()


@router.get("/current", response_model=Optional[FlockHistoryOut])
def get_current_flock(db: Session = Depends(get_db)):
    """Returns the most recent flock entry — the current flock size."""
    q = select(FlockHistory).order_by(FlockHistory.date.desc()).limit(1)
    return db.scalars(q).first()


@router.get("/at/{target_date}", response_model=Optional[FlockHistoryOut])
def get_flock_at_date(target_date: date, db: Session = Depends(get_db)):
    """Returns the flock size that was in effect on a given date."""
    q = (
        select(FlockHistory)
        .where(FlockHistory.date <= target_date)
        .order_by(FlockHistory.date.desc())
        .limit(1)
    )
    return db.scalars(q).first()


@router.post("", response_model=FlockHistoryOut, status_code=201)
def create_flock_entry(body: FlockHistoryCreate, db: Session = Depends(get_db)):
    record = FlockHistory(**body.model_dump())
    db.add(record)
    db.commit()
    db.refresh(record)
    return record


@router.put("/{record_id}", response_model=FlockHistoryOut)
def update_flock_entry(
    record_id: int,
    body: FlockHistoryUpdate,
    db: Session = Depends(get_db),
):
    record = db.get(FlockHistory, record_id)
    if not record:
        raise HTTPException(status_code=404, detail="Record not found")
    for field, value in body.model_dump(exclude_none=True).items():
        setattr(record, field, value)
    db.commit()
    db.refresh(record)
    return record


@router.delete("/{record_id}", status_code=204)
def delete_flock_entry(record_id: int, db: Session = Depends(get_db)):
    record = db.get(FlockHistory, record_id)
    if not record:
        raise HTTPException(status_code=404, detail="Record not found")
    db.delete(record)
    db.commit()