"""Conversation repository — Conversation, Segment data access."""

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

from app.features.conversation.models import Conversation, Segment


async def get_conversation(conversation_id: str, db: AsyncSession) -> Conversation | None:
    return await db.get(Conversation, conversation_id)


async def get_user_conversations(user_id: str, db: AsyncSession) -> list[Conversation]:
    stmt = (
        select(Conversation)
        .where(Conversation.user_id == user_id)
        .order_by(func.coalesce(Conversation.last_message_at, Conversation.started_at).desc())
    )
    result = await db.execute(stmt)
    return list(result.scalars().all())


def add_conversation(conv: Conversation, db: AsyncSession) -> None:
    db.add(conv)


async def get_segments_for_conversation(conversation_id: str, db: AsyncSession) -> list[Segment]:
    stmt = (
        select(Segment)
        .where(Segment.conversation_id == conversation_id)
        .order_by(Segment.created_at)
    )
    result = await db.execute(stmt)
    return list(result.scalars().all())


async def get_segments_for_organize(conversation_id: str, db: AsyncSession) -> list[Segment]:
    """Unprocessed segments first; if none, all segments."""
    stmt = (
        select(Segment)
        .where(
            Segment.conversation_id == conversation_id,
            Segment.processed.is_(False),
        )
        .order_by(Segment.created_at)
    )
    result = await db.execute(stmt)
    segments = list(result.scalars().all())
    if not segments:
        return await get_segments_for_conversation(conversation_id, db)
    return segments


async def count_segments_for_user(user_id: str, db: AsyncSession) -> int:
    stmt = (
        select(func.count(Segment.id))
        .select_from(Segment)
        .join(Conversation, Segment.conversation_id == Conversation.id)
        .where(Conversation.user_id == user_id)
    )
    result = await db.execute(stmt)
    return result.scalar() or 0