"""SQLAlchemy-backed roundtable business-chain store.

The ``seats`` JSON column is stored as a serialized string in
``PortableLongText`` and round-tripped here with ``json.dumps`` / ``json.loads``
— same approach as ``roundtable_drafts`` / ``ai_writing_sessions``.

All write/read paths are scoped by ``user_id`` for ownership isolation; a row
that belongs to another user is treated as not found.
"""

from __future__ import annotations

import json
from datetime import UTC, datetime
from typing import Any

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

from deerflow.persistence.roundtable_chains.model import RoundtableChainRow

_UNSET = object()


def _loads(value: Any) -> Any:
    if not isinstance(value, str):
        return value
    if not value:
        return None
    try:
        return json.loads(value)
    except Exception:
        return None


def _dumps(value: Any) -> str | None:
    if value is None:
        return None
    return json.dumps(value, ensure_ascii=False)


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

    @staticmethod
    def _to_dict(row: RoundtableChainRow, current_user_id: str | None = None) -> dict[str, Any]:
        return {
            "id": row.id,
            "title": row.title,
            "description": row.description,
            "seats": _loads(row.seats) or [],
            # None when absent → frontend reads it as "linear chain" (no layering).
            "stages": _loads(row.stages),
            # Per-stage goals aligned to ``stages``; None when absent.
            "stage_goals": _loads(getattr(row, "stage_goals", None)),
            # 总控编排提示（写给总控的派活指引，dag-only）；None/空 = 不注入。纯文本,不 json。
            "coordinator_prompt": getattr(row, "coordinator_prompt", None),
            # 默认席位执行模式（flash/thinking/pro/ultra）；None = 未设。
            "seat_mode": getattr(row, "seat_mode", None),
            # 研讨前并行取数开关（逐条 opt-in）；缺省 False。
            "gather_first": bool(getattr(row, "gather_first", False)),
            # 发布状态 + 是否本人所有（前端据此显示「公共」徽标、决定能否编辑 / 发布）。
            "is_public": bool(getattr(row, "is_public", False)),
            # 启停状态：缺省 True（存量行 / 补列前视为启用）。
            "enabled": bool(getattr(row, "enabled", True)),
            # 「待审核」标记：True = owner 已提交审核、等待管理员发布；发布时清回 False。
            "pending_review": bool(getattr(row, "pending_review", False)),
            "is_mine": (current_user_id is None) or (row.user_id == current_user_id),
            # 配置者（owner）的 user_id；路由层据此解析成可读用户名（owner_name）。
            "owner_id": row.user_id,
            "created_at": row.created_at.isoformat() if isinstance(row.created_at, datetime) else row.created_at,
            "updated_at": row.updated_at.isoformat() if isinstance(row.updated_at, datetime) else row.updated_at,
        }

    async def list_chains(
        self, user_id: str, *, scope: str = "mine", limit: int = 200, is_admin: bool = False
    ) -> list[dict[str, Any]]:
        """列出链条。

        ``scope``:
          - ``"mine"``（默认）：仅当前用户自己的链条；
          - ``"public"``：所有**已发布**（``is_public=True``）链条，含本人发布的；
          - ``"pending"``：所有**待审核**（``pending_review=True``）链条，**仅管理员**（由路由层
            校验后传 ``is_admin=True``；非管理员误传则按 ``"mine"`` 退化，绝不越权）；
          - ``"all"``：所有账号的全部链条（**仅管理员**，由路由层校验后传 ``is_admin=True``；
            非管理员误传则按 ``"mine"`` 退化，绝不越权）。
        其余值按 ``"mine"`` 处理。``is_mine`` 标记每条是否本人所有，供前端判断可否编辑。
        """
        if scope == "public":
            cond = RoundtableChainRow.is_public.is_(True)
        elif scope == "pending" and is_admin:
            cond = RoundtableChainRow.pending_review.is_(True)
        elif scope == "all" and is_admin:
            cond = None
        else:
            cond = RoundtableChainRow.user_id == user_id
        stmt = select(RoundtableChainRow)
        if cond is not None:
            stmt = stmt.where(cond)
        stmt = stmt.order_by(RoundtableChainRow.updated_at.desc()).limit(limit)
        async with self._sf() as session:
            result = await session.execute(stmt)
            return [self._to_dict(row, user_id) for row in result.scalars()]

    async def get_chain(
        self, chain_id: str, user_id: str, *, is_admin: bool = False
    ) -> dict[str, Any] | None:
        """取一条链条：owner 可见,**已发布的公共链条任何人可见**(供选入研讨)；
        **管理员可见任意链条**(``is_admin=True``，供后台管理配置)。"""
        async with self._sf() as session:
            row = await session.get(RoundtableChainRow, chain_id)
            if row is None:
                return None
            if not is_admin and row.user_id != user_id and not bool(getattr(row, "is_public", False)):
                return None
            return self._to_dict(row, user_id)

    async def create_chain(self, user_id: str, data: dict[str, Any]) -> dict[str, Any]:
        now = datetime.now(UTC)
        row = RoundtableChainRow(
            id=data["id"],
            user_id=user_id,
            title=(data.get("title") or "").strip(),
            description=(data.get("description") or None),
            seats=_dumps(data.get("seats") or []),
            stages=_dumps(data.get("stages")),
            stage_goals=_dumps(data.get("stage_goals")),
            coordinator_prompt=(data.get("coordinator_prompt") or None),
            seat_mode=(data.get("seat_mode") or None),
            gather_first=bool(data.get("gather_first") or False),
            is_public=bool(data.get("is_public") or False),
            enabled=True if data.get("enabled") is None else bool(data.get("enabled")),
            pending_review=bool(data.get("pending_review") or False),
            created_at=now,
            updated_at=now,
        )
        async with self._sf() as session:
            session.add(row)
            await session.commit()
            await session.refresh(row)
            return self._to_dict(row, user_id)

    async def update_chain(
        self,
        chain_id: str,
        user_id: str,
        *,
        title=_UNSET,
        description=_UNSET,
        seats=_UNSET,
        stages=_UNSET,
        stage_goals=_UNSET,
        coordinator_prompt=_UNSET,
        seat_mode=_UNSET,
        gather_first=_UNSET,
        is_public=_UNSET,
        enabled=_UNSET,
        pending_review=_UNSET,
        is_admin: bool = False,
    ) -> dict[str, Any] | None:
        async with self._sf() as session:
            row = await session.get(RoundtableChainRow, chain_id)
            # 管理员可改任意链条；否则仅 owner 本人。不变更 user_id（不转移归属）。
            if row is None or (not is_admin and row.user_id != user_id):
                return None
            if title is not _UNSET and title is not None:
                row.title = str(title).strip()
            if description is not _UNSET:
                row.description = description or None
            if seats is not _UNSET:
                row.seats = _dumps(seats)
            if stages is not _UNSET:
                row.stages = _dumps(stages)
            if stage_goals is not _UNSET:
                row.stage_goals = _dumps(stage_goals)
            if coordinator_prompt is not _UNSET:
                row.coordinator_prompt = coordinator_prompt or None
            if seat_mode is not _UNSET:
                row.seat_mode = seat_mode or None
            if gather_first is not _UNSET and gather_first is not None:
                row.gather_first = bool(gather_first)
            if is_public is not _UNSET and is_public is not None:
                row.is_public = bool(is_public)
            if enabled is not _UNSET and enabled is not None:
                row.enabled = bool(enabled)
            if pending_review is not _UNSET and pending_review is not None:
                row.pending_review = bool(pending_review)
            row.updated_at = datetime.now(UTC)
            await session.commit()
            await session.refresh(row)
            return self._to_dict(row, user_id)

    async def delete_chain(self, chain_id: str, user_id: str, *, is_admin: bool = False) -> bool:
        async with self._sf() as session:
            row = await session.get(RoundtableChainRow, chain_id)
            # 管理员可删任意链条；否则仅 owner 本人。
            if row is None or (not is_admin and row.user_id != user_id):
                return False
            await session.delete(row)
            await session.commit()
            return True