"""Session service — chat sessions (each = one idea discussion)."""

from uuid import uuid4

from sqlalchemy import select, update
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.session import Session


async def create_session(
    db: AsyncSession,
    user_id: str,
    title: str = "Новое обсуждение",
) -> Session:
    session = Session(
        id=uuid4(),
        user_id=user_id,
        title=title,
        status="active",
    )
    db.add(session)
    await db.commit()
    await db.refresh(session)
    return session


async def list_sessions(
    db: AsyncSession,
    user_id: str,
    status: str | None = None,
    limit: int = 50,
    offset: int = 0,
) -> list[Session]:
    stmt = (
        select(Session)
        .where(Session.user_id == user_id)
        .order_by(Session.updated_at.desc())
        .limit(limit)
        .offset(offset)
    )
    if status:
        stmt = stmt.where(Session.status == status)
    result = await db.execute(stmt)
    return list(result.scalars().all())


async def get_session(db: AsyncSession, session_id: str) -> Session | None:
    result = await db.execute(
        select(Session).where(Session.id == session_id)
    )
    return result.scalar_one_or_none()


async def update_session_title(
    db: AsyncSession,
    session_id: str,
    title: str,
) -> bool:
    result = await db.execute(
        update(Session)
        .where(Session.id == session_id)
        .values(title=title)
    )
    await db.commit()
    return result.rowcount > 0


async def update_session_idea(
    db: AsyncSession,
    session_id: str,
    idea_id: str,
) -> bool:
    result = await db.execute(
        update(Session)
        .where(Session.id == session_id)
        .values(idea_id=idea_id)
    )
    await db.commit()
    return result.rowcount > 0


async def archive_session(db: AsyncSession, session_id: str) -> bool:
    result = await db.execute(
        update(Session)
        .where(Session.id == session_id)
        .values(status="archived")
    )
    await db.commit()
    return result.rowcount > 0


async def delete_session(db: AsyncSession, session_id: str) -> bool:
    result = await db.execute(
        select(Session).where(Session.id == session_id)
    )
    session = result.scalar_one_or_none()
    if not session:
        return False
    await db.delete(session)
    await db.commit()
    return True