"""SQLAlchemy-backed per-conversation share-link repository."""

from __future__ import annotations

from datetime import datetime
from typing import Any

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

from deerflow.persistence.thread_shares.base import ThreadShareStore, generate_share_code
from deerflow.persistence.thread_shares.model import ThreadShareRow


def _row_to_dict(row: ThreadShareRow) -> dict[str, Any]:
    data = row.to_dict()
    created = data.get("created_at")
    if isinstance(created, datetime):
        data["created_at"] = created.isoformat()
    return data


class ThreadShareRepository(ThreadShareStore):
    def __init__(self, session_factory: async_sessionmaker[AsyncSession]) -> None:
        self._sf = session_factory

    async def create(self, owner_user_id: str, thread_id: str, *, mode: str = "import") -> dict[str, Any]:
        # Retry on the (astronomically unlikely) code collision.
        async with self._sf() as session:
            for _ in range(8):
                code = generate_share_code()
                if await session.get(ThreadShareRow, code) is not None:
                    continue
                row = ThreadShareRow(
                    share_code=code,
                    owner_user_id=owner_user_id,
                    thread_id=thread_id,
                    revoked=False,
                    mode=mode,
                )
                session.add(row)
                await session.commit()
                await session.refresh(row)
                return _row_to_dict(row)
        raise RuntimeError("Failed to allocate a unique share code")

    async def get(self, share_code: str) -> dict[str, Any] | None:
        async with self._sf() as session:
            row = await session.get(ThreadShareRow, share_code)
            return _row_to_dict(row) if row is not None else None

    async def get_active_for_thread(self, owner_user_id: str, thread_id: str, *, mode: str = "import") -> dict[str, Any] | None:
        stmt = (
            select(ThreadShareRow)
            .where(
                ThreadShareRow.owner_user_id == owner_user_id,
                ThreadShareRow.thread_id == thread_id,
                ThreadShareRow.mode == mode,
                ThreadShareRow.revoked.is_(False),
            )
            .order_by(ThreadShareRow.created_at.desc())
        )
        async with self._sf() as session:
            row = (await session.execute(stmt)).scalars().first()
            return _row_to_dict(row) if row is not None else None

    async def list_for_owner(self, owner_user_id: str) -> list[dict[str, Any]]:
        stmt = select(ThreadShareRow).where(ThreadShareRow.owner_user_id == owner_user_id).order_by(ThreadShareRow.created_at.desc())
        async with self._sf() as session:
            result = await session.execute(stmt)
            return [_row_to_dict(row) for row in result.scalars()]

    async def revoke(self, share_code: str, owner_user_id: str) -> bool:
        async with self._sf() as session:
            row = await session.get(ThreadShareRow, share_code)
            if row is None or row.owner_user_id != owner_user_id:
                return False
            row.revoked = True
            await session.commit()
            return True