import uuid
from typing import Sequence

from sqlalchemy import delete as sa_delete, func, select, update as sa_update
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.faq_reply import FaqReply
from app.schemas.faq import FaqReplyCreate


async def create_reply(
    db: AsyncSession,
    *,
    faq_id: uuid.UUID,
    study_id: uuid.UUID | None,
    created_by: uuid.UUID,
    reply_in: FaqReplyCreate,
) -> FaqReply:
    reply = FaqReply(
        faq_id=faq_id,
        study_id=study_id,
        content=reply_in.content,
        created_by=created_by,
        quote_reply_id=reply_in.quote_reply_id,
    )
    db.add(reply)
    await db.commit()
    await db.refresh(reply)
    return reply


async def list_replies(db: AsyncSession, faq_id: uuid.UUID) -> Sequence[FaqReply]:
    result = await db.execute(
        select(FaqReply).where(FaqReply.faq_id == faq_id).order_by(FaqReply.created_at)
    )
    return result.scalars().all()


async def get_reply(db: AsyncSession, reply_id: uuid.UUID) -> FaqReply | None:
    result = await db.execute(select(FaqReply).where(FaqReply.id == reply_id))
    return result.scalar_one_or_none()


async def delete_reply(db: AsyncSession, reply: FaqReply) -> None:
    await db.delete(reply)
    await db.commit()


async def soft_delete_reply(db: AsyncSession, reply: FaqReply) -> None:
    reply.is_deleted = True
    reply.content = ""
    await db.commit()


async def count_quote_references(db: AsyncSession, reply_id: uuid.UUID) -> int:
    result = await db.execute(
        select(func.count()).select_from(FaqReply).where(FaqReply.quote_reply_id == reply_id)
    )
    return int(result.scalar_one())


async def count_active_replies(db: AsyncSession, faq_id: uuid.UUID) -> int:
    result = await db.execute(
        select(func.count())
        .select_from(FaqReply)
        .where(FaqReply.faq_id == faq_id, FaqReply.is_deleted.is_(False))
    )
    return int(result.scalar_one())


async def delete_replies_by_faq_id(db: AsyncSession, faq_id: uuid.UUID) -> None:
    await db.execute(
        sa_update(FaqReply)
        .where(FaqReply.faq_id == faq_id)
        .values(quote_reply_id=None)
    )
    await db.execute(sa_delete(FaqReply).where(FaqReply.faq_id == faq_id))
    await db.commit()