"""岗位 (position) → resource subscription **sync engine**.

A user's position decides which agents / skills / scheduled tasks they are
subscribed to, and which recommended questions they can see. This service turns
a position's *tag bindings* into concrete, materialized rows in the existing
"我的" tables (idempotent, re-runnable).

Resolution rule (per resource type):

* The user's position is ``users.position_id``; if unset, the ``is_default``
  position is used; if there is none, every type falls back to its default set.
* For a resource type **with** bound tags → the union of resources carrying any
  of those tags.
* For a resource type **without** bound tags → the *default set*:
  - ``agent``               -> built-ins first, then filtered out of
    position-granted favorites
  - ``scheduled_task``      → empty (no built-in tasks)
  - ``skill``               → empty (the 广场 still shows every visible skill;
    a position only *adds* its tagged skills to the member's "我的技能")
  - ``recommended_question`` → *untagged-only* (handled at query time, never
    materialized — see :meth:`resolve_visible`). The default set is the
    questions carrying **no** 标签; tagged questions surface only for a position
    that binds their tag. (The recommended-questions router interprets a
    ``None`` from :meth:`resolve_visible` as "show only untagged".)

Materialization (``sync_user``) only ever touches rows it created itself
(``origin='position'``), so a user's own favorites / subscriptions are never
clobbered. ``agent`` keeps the original position-granted behavior for ordinary
tagged agents, but filters out built-ins and business-chain seats; those only
enter "mine" after an explicit user favorite. ``skill`` is still materialized
into ``skill_favorites`` so tagged skills are added to the user's "mine"
collection while the browse-all square stays complete (it is **not**
restricted).
Only recommended-question visibility is computed live by :meth:`resolve_visible`
and is *not* materialized. (The admin-configured prompts shown to users ARE the
recommended questions — there is no separate prompt-template store.)
"""

from __future__ import annotations

import json
import logging
import uuid
from datetime import UTC, datetime

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

from deerflow.persistence.agents.model import AgentFavoriteRow, AgentRow
from deerflow.persistence.positions.base import PositionStore
from deerflow.persistence.roundtable_chains.model import RoundtableChainRow
from deerflow.persistence.scheduled_tasks.model import ScheduledTaskSubscriptionRow
from deerflow.persistence.skills.model import SkillFavoriteRow
from deerflow.persistence.tags.base import TagStore

logger = logging.getLogger(__name__)

# Reconciled by sync_user. ``agent`` preserves ordinary position-granted rows,
# but filters built-ins and business-chain seats.
_MATERIALIZED_TYPES = ("agent", "skill", "scheduled_task")
# Resolved live at query time (visibility filters), never materialized.
_VISIBILITY_TYPES = ("recommended_question",)


class PositionSyncService:
    def __init__(self, session_factory: async_sessionmaker[AsyncSession], position_store: PositionStore, tag_store: TagStore) -> None:
        self._sf = session_factory
        self._positions = position_store
        self._tags = tag_store

    # ----------------------------------------------------------- resolution

    async def _effective_position_id(self, user_id: str) -> str | None:
        pid = await self._positions.get_user_position_id(user_id)
        if pid:
            return pid
        return await self._positions.get_default_position_id()

    async def resolve_visible(self, user_id: str, resource_type: str) -> set[str] | None:
        """Return the set of visible ``resource_type`` ids, or ``None`` = no tag binding.

        Used by the recommended-questions filter (the only remaining query-time
        visibility type; skills are now *materialized*, not filtered). A set
        means "restrict to exactly these ids". ``None`` means the effective
        position binds no tag for this type — the recommended-questions router
        treats that as "默认岗位 → show only untagged questions" (see
        ``app/gateway/routers/recommended_questions.py``).
        """
        pid = await self._effective_position_id(user_id)
        if not pid:
            return None
        bindings = await self._positions.get_tag_bindings(pid)
        tag_ids = bindings.get(resource_type) or []
        if not tag_ids:
            return None
        return set(await self._tags.list_targets_for_tags(resource_type, tag_ids))

    async def _resolve_materialized(self, user_id: str, resource_type: str, session: AsyncSession) -> set[str]:
        pid = await self._effective_position_id(user_id)
        bindings = await self._positions.get_tag_bindings(pid) if pid else {}
        tag_ids = bindings.get(resource_type) or []
        if tag_ids:
            target = set(await self._tags.list_targets_for_tags(resource_type, tag_ids))
        else:
            target = await self._default_set(resource_type, session)
        if resource_type == "agent":
            return await self._filter_materializable_agents(target, session)
        return target

    async def _default_set(self, resource_type: str, session: AsyncSession) -> set[str]:
        if resource_type == "agent":
            rows = (await session.execute(select(AgentRow.id).where(AgentRow.user_id.is_(None)))).all()
            return {r[0] for r in rows}
        # scheduled_task (and any other materialized type) defaults to empty.
        return set()

    async def _filter_materializable_agents(self, agent_ids: set[str], session: AsyncSession) -> set[str]:
        if not agent_ids:
            return set()
        rows = (
            await session.execute(
                select(AgentRow.id).where(
                    AgentRow.id.in_(agent_ids),
                    AgentRow.user_id.is_not(None),
                )
            )
        ).all()
        candidate_ids = {r[0] for r in rows}
        return candidate_ids - await self._business_chain_agent_ids(session)

    async def _business_chain_agent_ids(self, session: AsyncSession) -> set[str]:
        rows = (await session.execute(select(RoundtableChainRow.seats))).scalars()
        agent_ids: set[str] = set()
        for raw in rows:
            if not raw:
                continue
            try:
                seats = json.loads(raw) if isinstance(raw, str) else raw
            except Exception:
                continue
            if not isinstance(seats, list):
                continue
            for seat in seats:
                if isinstance(seat, dict) and isinstance(seat.get("agent_id"), str):
                    agent_ids.add(seat["agent_id"])
        return agent_ids

    # --------------------------------------------------------- materialize

    async def sync_user(self, user_id: str) -> None:
        """Reconcile all materialized subscriptions for one user (idempotent)."""
        if self._sf is None:
            return
        pid = await self._effective_position_id(user_id)
        async with self._sf() as session:
            await self._sync_agents(session, user_id, pid)
            await self._sync_skills(session, user_id, pid)
            await self._sync_tasks(session, user_id, pid)
            await session.commit()

    async def _sync_agents(self, session: AsyncSession, user_id: str, position_id: str | None) -> None:
        target = await self._resolve_materialized(user_id, "agent", session)
        rows = list((await session.execute(select(AgentFavoriteRow).where(AgentFavoriteRow.user_id == user_id))).scalars())
        owned_any = {r.agent_id for r in rows}
        position_rows = {r.agent_id: r for r in rows if r.origin == "position"}
        now = datetime.now(UTC)
        for agent_id in target - owned_any:
            session.add(AgentFavoriteRow(id=uuid.uuid4().hex, user_id=user_id, agent_id=agent_id, origin="position", position_id=position_id, created_at=now))
        for agent_id, row in position_rows.items():
            if agent_id not in target:
                await session.delete(row)

    async def _sync_skills(self, session: AsyncSession, user_id: str, position_id: str | None) -> None:
        target = await self._resolve_materialized(user_id, "skill", session)
        rows = list((await session.execute(select(SkillFavoriteRow).where(SkillFavoriteRow.user_id == user_id))).scalars())
        owned_any = {r.skill_name for r in rows}
        position_rows = {r.skill_name: r for r in rows if r.origin == "position"}
        now = datetime.now(UTC)
        for skill_name in target - owned_any:
            session.add(SkillFavoriteRow(id=uuid.uuid4().hex, user_id=user_id, skill_name=skill_name, origin="position", position_id=position_id, created_at=now))
        for skill_name, row in position_rows.items():
            if skill_name not in target:
                await session.delete(row)

    async def _sync_tasks(self, session: AsyncSession, user_id: str, position_id: str | None) -> None:
        target = await self._resolve_materialized(user_id, "scheduled_task", session)
        rows = list((await session.execute(select(ScheduledTaskSubscriptionRow).where(ScheduledTaskSubscriptionRow.user_id == user_id))).scalars())
        owned_any = {r.task_id for r in rows}
        position_rows = {r.task_id: r for r in rows if r.origin == "position"}
        now = datetime.now(UTC)
        for task_id in target - owned_any:
            session.add(ScheduledTaskSubscriptionRow(id=uuid.uuid4().hex, task_id=task_id, user_id=user_id, notify_element=False, origin="position", position_id=position_id, created_at=now, updated_at=now))
        for task_id, row in position_rows.items():
            if task_id not in target:
                await session.delete(row)

    # ------------------------------------------------------------- fan-out

    async def sync_position(self, position_id: str) -> int:
        """Re-sync every member of a position. Returns the member count."""
        member_ids = await self._positions.list_member_ids(position_id)
        for uid in member_ids:
            try:
                await self.sync_user(uid)
            except Exception:
                logger.exception("position sync failed for user %s (position %s)", uid, position_id)
        return len(member_ids)

    async def sync_default_members(self) -> int:
        """Re-sync users with NO explicit position (they inherit the default)."""
        default_id = await self._positions.get_default_position_id()
        if not default_id:
            return 0
        assigned = set(await self._positions.list_assigned_user_ids())
        count = 0
        if self._sf is None:
            return 0
        from deerflow.persistence.user.model import UserRow

        async with self._sf() as session:
            all_ids = [uid for (uid,) in (await session.execute(select(UserRow.id))).all()]
        for uid in all_ids:
            if uid in assigned:
                continue
            try:
                await self.sync_user(uid)
                count += 1
            except Exception:
                logger.exception("default position sync failed for user %s", uid)
        return count