from sqlalchemy import select, func
from sqlalchemy.orm import Session, selectinload

from models.family import Records, Comments, Likes
from schemas.record import RecordCreate, RecordUpdate, RecordResponse, RecordPageResponse


def get_all_records_by_page(db: Session, user_id: int, page: int = 1, size: int = 20) -> RecordPageResponse:
    base_query = (
        select(Records)
        .options(
            selectinload(Records.user),
            selectinload(Records.comments).selectinload(Comments.user),
        )
        .order_by(Records.create_time.desc())
    )

    # 总数
    total = db.scalar(
        select(func.count()).select_from(base_query.subquery())
    )

    # 分页数据
    records = (
        db.execute(base_query.offset((page - 1) * size).limit(size))
        .scalars()
        .all()
    )

    # 批量判断当前用户点赞状态
    liked_record_ids: set[int] = set()

    if user_id and records:
        liked_record_ids = set(
            db.scalars(
                select(Likes.record_id).where(
                    Likes.record_id.in_([r.id for r in records]),
                    Likes.user_id == user_id,
                )
            ).all()
        )

    # 组装响应
    response_records = []
    for r in records:
        resp = RecordResponse.model_validate(r, from_attributes=True)
        resp.liked = r.id in liked_record_ids
        response_records.append(resp)

    return RecordPageResponse(
        records=response_records,
        total=total,
        page=page,
        size=size,
        pages=(total + size - 1) // size,
    )


def create_record(db: Session, record_dto: RecordCreate) -> bool:
    data = record_dto.model_dump()
    record = Records(**data)
    db.add(record)
    db.commit()
    db.refresh(record)

    return True


def get_record_by_id(db: Session, record_id: int) -> Records | None:
    result = db.execute(select(Records).where(Records.id == record_id))
    return result.scalar_one_or_none()


def update_record(db: Session, record_id: int, record_dto: RecordUpdate) -> bool:
    record = get_record_by_id(db, record_id)
    if not record:
        return False

    for field, value in record_dto.model_dump(exclude_unset=True).items():
        setattr(record, field, value)
    db.commit()
    db.refresh(record)

    return True


def delete_record(db: Session, record_id: int) -> bool:
    record = get_record_by_id(db, record_id)
    if not record:
        return False

    db.delete(record)
    db.commit()

    return True