"""圆桌后台作业控制 API（Phase 3a）。

把 Step 2「后台挂起」的任务交给后端编排引擎跑，并暴露进度订阅 / 续跑 / 取消。

Routes（prefix ``/api/roundtable-jobs``）::
    POST   ""                 启动一个后台作业（创建 job 行 + 拉起执行器任务）
    GET    ""?draft_id=       查某草稿最近一个作业
    GET    "/{job_id}"        作业快照
    GET    "/{job_id}/stream" SSE 进度流（轮询 job 表，多 worker 安全）
    POST   "/{job_id}/resume" 回答澄清后续跑
    POST   "/{job_id}/cancel" 取消

进度数据源是 ``roundtable_jobs`` 表（Phase 1），SSE 走 DB 轮询而非内存 pub/sub —— 这样
刷新 / 换 worker / 重连都能继续收到进度，规避 ai_writing 踩过的「per-worker 内存 dict
丢会话」坑。响应统一 camelCase（对齐前端 §2.5）。
"""

from __future__ import annotations

import asyncio
import hashlib
import json
import logging
import time
from datetime import UTC, datetime, timedelta
from typing import Any
from uuid import uuid4

from fastapi import APIRouter, HTTPException, Request, Response
from fastapi.responses import StreamingResponse
from pydantic import BaseModel, Field

from app.gateway.roundtable_job_executor import build_start_snapshot
from deerflow.agents.roundtable_orchestrator import SeatRef
from deerflow.runtime.user_context import get_effective_user_id

logger = logging.getLogger(__name__)
router = APIRouter(prefix="/api/roundtable-jobs", tags=["roundtable-jobs"])

_TERMINAL = {"done", "error", "cancelled"}
# SSE 轮询间隔与最长存活（对齐 ai_writing：长连接最多挂 30 分钟）。
_POLL_INTERVAL_S = 0.7
_MAX_STREAM_TICKS = int(30 * 60 / _POLL_INTERVAL_S)

# 续跑澄清时拼给 leader 的 prompt 前缀。
_RESUME_PREFIX = "用户已回复你刚才的澄清问题，回答如下，请据此继续派活或给出结论：\n"


# ── schemas ──────────────────────────────────────────────────────────────────


class JobAgent(BaseModel):
    agentId: str
    name: str = ""


class StartJobRequest(BaseModel):
    # Phase 3 客户端幂等键：前端为每次「后台挂起」生成一个 requestId，网络重试**复用同一
    # requestId**。服务端据此审计 / 排查；「同草稿不双跑」本身由 active_dedupe_key 唯一索引
    # 保证（requestId 只是锦上添花的请求级指纹）。缺省（旧前端）→ 服务端生成一个。
    requestId: str | None = Field(default=None, max_length=64)
    draftId: str | None = Field(default=None, max_length=64)
    # 外部任务 id（taskId 深链会商）。非空 = task 作业：按 task_id 共享、不按 user 分权，
    # 其 draft_id 指向独立的 roundtable_task_drafts 表（最终报告写回那里）。
    taskId: str | None = Field(default=None, max_length=128)
    intent: str = ""
    agents: list[JobAgent] = Field(default_factory=list)
    model: str | None = None
    orchestrationMode: str = "recommend"
    chain: dict[str, Any] | None = None
    # dag 模式分层编排计划（前端 OrchestrationPlan：{mode,stages,finalSynthesis,coordinatorPrompt?}）。
    # 仅 orchestrationMode=="dag" 时携带；驱动后端 _run_dag。缺失 → 引擎回退 recommend。
    orchestrationPlan: dict[str, Any] | None = None
    # 第一轮 leader prompt；缺省用 intent。
    seedMessage: str | None = None
    # 预建好的 thread 映射（Phase 3b 真网关用；模拟网关忽略）。
    threadIds: dict[str, str] | None = None
    coordinatorName: str = "roundtable-coordinator"
    # 席位执行模式（快速/思考/专业问答/多智能体）派生参数，由前端 toStartBody 下发。
    # 仅 special 席位用：覆盖 roundtable_run_policy("seat") 的 thinking/reasoning；
    # None/缺省 → 后端按 policy 默认(≈pro)，向后兼容旧前端。subagent 仅 ultra 档为真。
    thinking_enabled: bool | None = None
    reasoning_effort: str | None = None
    subagent_enabled: bool = False
    # 每席位「技能识别强化」开关映射 {agent_id: bool}（前端读所选业务链条里**每个席位**的
    # 同名配置后下发）。后台席位 run 据此（与各席位 agent 自身 config.yaml 的开关取 OR）决定
    # 是否注入。缺省空 dict（全部按 False/关，仅各 agent 自身开关生效）。
    seat_skill_directives: dict[str, bool] = Field(default_factory=dict)
    # 每席位「推理深度覆盖」映射 {agent_id: SeatMode}（前端读所选业务链条里**每个席位**单独配的
    # 推理深度后下发；值为 flash/thinking/pro/ultra）。后台席位 run 按 agent_id 查表：命中则用该档
    # 派生的 thinking/reasoning/subagent 覆盖作业级 seatMode；未命中 → 跟随作业级。缺省空 dict。
    seat_modes: dict[str, str] = Field(default_factory=dict)
    # 是否研讨前先并行『取数』（业务链条逐条 opt-in；前端读所选链条的开关后下发）。默认 False。
    gather_first: bool = False
    # 深链接业务码（rwfx→6BF 等）。透传到后台总结报告的「业务链完整性核对」。普通会商为空。
    business_code: str | None = None


class ResumeJobRequest(BaseModel):
    answer: str = ""


class CleanupRequest(BaseModel):
    retention_days: int = Field(default=7, ge=0, description="保留多少天内的作业；0 = 不保留")
    only_finished: bool = Field(default=True, description="仅清终态（done/error/cancelled），保护在跑作业")
    batch_size: int = Field(default=500, ge=1, le=5000)


class CleanupResponse(BaseModel):
    deleted: int
    elapsed_seconds: float
    params: dict[str, Any]


class RoundtableJobResponse(BaseModel):
    id: str
    draftId: str | None = None
    status: str = "queued"
    phase: str = "initializing"
    cycle: int = 0
    dispatchChain: list[dict[str, Any]] = Field(default_factory=list)
    activeAgentId: str | None = None
    consensusPercentage: int = 0
    pendingClarification: str | None = None
    orchestrationMode: str = "recommend"
    chain: dict[str, Any] | None = None
    orchestrationPlan: dict[str, Any] | None = None
    error: str | None = None
    dialogues: list[dict[str, Any]] = Field(default_factory=list)
    step3: dict[str, Any] | None = None
    createdAt: datetime | str | None = None
    updatedAt: datetime | str | None = None


# ── helpers ──────────────────────────────────────────────────────────────────


def _current_user_id(request: Request) -> str:
    user = getattr(request.state, "user", None)
    if user is not None:
        return str(user.id)
    return get_effective_user_id()


def _get_store(request: Request):
    store = getattr(request.app.state, "roundtable_job_store", None)
    if store is None:
        raise HTTPException(status_code=503, detail="Roundtable job store not available")
    return store


def _get_executor(request: Request):
    executor = getattr(request.app.state, "roundtable_job_executor", None)
    if executor is None:
        raise HTTPException(status_code=503, detail="Roundtable job executor not available")
    return executor


def _get_dispatcher(request: Request):
    """Phase 3 dispatcher（可能为 None：store 未配置时）。nudge 前先判空。"""
    return getattr(request.app.state, "roundtable_job_dispatcher", None)


def _request_hash(body: StartJobRequest) -> str:
    """启动入参指纹（sha256）——审计/排查「同 requestId 但入参变了」的异常重试。"""
    canonical = json.dumps(
        body.model_dump(mode="json", exclude={"requestId"}),
        ensure_ascii=False, sort_keys=True, default=str,
    )
    return hashlib.sha256(canonical.encode("utf-8")).hexdigest()


def _pending_nodes(agents: list[JobAgent]) -> list[dict[str, Any]]:
    """启动即落一份「全 pending」的派活链路，使 GET / 首帧 SSE 立刻能渲染流程图。"""
    return [
        {"agentId": a.agentId, "name": a.name or a.agentId, "order": i + 1, "state": "pending"}
        for i, a in enumerate(agents)
    ]


def _to_response(row: dict[str, Any]) -> RoundtableJobResponse:
    return RoundtableJobResponse(
        id=row["id"],
        draftId=row.get("draft_id"),
        status=row.get("status") or "queued",
        phase=row.get("phase") or "initializing",
        cycle=int(row.get("cycle") or 0),
        dispatchChain=row.get("dispatch_chain") or [],
        activeAgentId=row.get("active_agent_id"),
        consensusPercentage=int(row.get("consensus_percentage") or 0),
        pendingClarification=row.get("pending_clarification"),
        orchestrationMode=row.get("orchestration_mode") or "recommend",
        chain=row.get("chain"),
        orchestrationPlan=row.get("orchestration_plan"),
        error=row.get("error"),
        dialogues=row.get("dialogues") or [],
        step3=row.get("step3"),
        createdAt=row.get("created_at"),
        updatedAt=row.get("updated_at"),
    )


def _seat_refs_from_nodes(nodes: list[dict[str, Any]] | None) -> list[SeatRef]:
    out: list[SeatRef] = []
    for n in nodes or []:
        aid = str(n.get("agentId") or "")
        if aid:
            out.append(SeatRef(aid, str(n.get("name") or aid)))
    return out


# ── routes ───────────────────────────────────────────────────────────────────


@router.post("", response_model=RoundtableJobResponse, status_code=201)
async def start_job(
    request: Request, body: StartJobRequest, response: Response
) -> RoundtableJobResponse:
    """启动一个后台作业（Phase 3：唯一活跃键去重 + dispatcher 领取执行）。

    流程：
      1. 把整份启动入参序列化成 ``input_snapshot`` 落库（跨 worker 重建 StartParams 的前提）；
      2. ``try_create_or_get_active`` 直接 INSERT 并占用 ``active_dedupe_key`` 唯一索引 ——
         冲突（同草稿已有活跃作业）即幂等返回它（``created=False`` → HTTP 200），不再新建；
      3. 新建成功（HTTP 201，status=queued）后 ``nudge`` dispatcher，由它 ``claim_job``
         原子领取并在本（或其它）worker 执行 —— **不再由路由直接拉起进程内任务**。

    「同一草稿至多一个活跃作业」由 DB 唯一索引强制，跨 worker / 并发 / 重试天然互斥，
    不依赖 GET_LOCK 命名锁或进程内 asyncio。
    """
    store = _get_store(request)
    user_id = _current_user_id(request)

    if not body.agents:
        raise HTTPException(status_code=400, detail="agents is required")

    task_id = (body.taskId or "").strip() or None
    draft_id = (body.draftId or "").strip() or None
    agents = [SeatRef(a.agentId, a.name or a.agentId) for a in body.agents]
    seed_message = (body.seedMessage or body.intent or "").strip()

    # 整份启动入参快照 —— dispatcher 在任意 worker 领取后据此无损重建 StartParams。
    snapshot = build_start_snapshot(
        user_id=user_id,
        agents=agents,
        seed_message=seed_message,
        model=body.model,
        mode=body.orchestrationMode,
        intent_text=body.intent,
        thread_ids=body.threadIds,
        coordinator_name=body.coordinatorName,
        draft_id=draft_id,
        task_id=task_id,
        is_resume=False,
        chain=body.chain,
        orchestration_plan=body.orchestrationPlan,
        seat_thinking_enabled=body.thinking_enabled,
        seat_reasoning_effort=body.reasoning_effort,
        seat_subagent_enabled=body.subagent_enabled,
        seat_skill_directives=dict(body.seat_skill_directives or {}),
        seat_modes=dict(body.seat_modes or {}),
        gather_first=bool(body.gather_first),
        business_code=(body.business_code or None),
    )
    request_id = (body.requestId or "").strip() or uuid4().hex

    job_id = uuid4().hex
    row, created = await store.try_create_or_get_active(
        draft_id=draft_id,
        user_id=user_id,
        task_id=task_id,
        id=job_id,
        orchestration_mode=body.orchestrationMode,
        coordinator_name=body.coordinatorName,
        thread_ids=body.threadIds,
        chain=body.chain,
        orchestration_plan=body.orchestrationPlan,
        dispatch_chain=_pending_nodes(body.agents),
        status="queued",
        request_id=request_id,
        request_hash=_request_hash(body),
        input_snapshot=snapshot,
    )
    if created:
        # 新建（queued）：交给 dispatcher 领取执行。
        response.status_code = 201
    else:
        # 命中已有活跃作业：幂等返回（不重复建 / 不重复跑）。
        response.status_code = 200
    # 任一分支都唤醒 dispatcher：新建需被领取；幂等命中时若既有作业还在 queued、未被任何
    # worker 领走（如 dispatcher 正在轮询间隙），nudge 确保它被立刻 claim，无感延迟。
    dispatcher = _get_dispatcher(request)
    if dispatcher is not None:
        dispatcher.nudge()
    return _to_response(row)


@router.get("", response_model=RoundtableJobResponse | None)
async def get_job_by_draft(request: Request, draft_id: str, task_id: str | None = None) -> RoundtableJobResponse | None:
    # task_id 非空 = task 作业查询（按 task 共享、不分权）；否则按 user 分权。
    store = _get_store(request)
    tid = (task_id or "").strip() or None
    user_id = _current_user_id(request)
    row = await store.get_by_draft(draft_id, user_id=user_id, task_id=tid)
    return _to_response(row) if row is not None else None


@router.get("/{job_id}", response_model=RoundtableJobResponse)
async def get_job(request: Request, job_id: str, task_id: str | None = None) -> RoundtableJobResponse:
    store = _get_store(request)
    tid = (task_id or "").strip() or None
    user_id = _current_user_id(request)
    row = await store.get(job_id, user_id=user_id, task_id=tid)
    if row is None:
        raise HTTPException(status_code=404, detail="Job not found")
    return _to_response(row)


@router.get("/{job_id}/stream")
async def stream_job(request: Request, job_id: str, task_id: str | None = None) -> StreamingResponse:
    store = _get_store(request)
    tid = (task_id or "").strip() or None
    user_id = _current_user_id(request)

    def _frame(payload: dict[str, Any]) -> str:
        return f"data: {json.dumps(payload, ensure_ascii=False)}\n\n"

    async def gen():
        for _ in range(_MAX_STREAM_TICKS):
            if await request.is_disconnected():
                return
            row = await store.get(job_id, user_id=user_id, task_id=tid)
            if row is None:
                yield _frame({"event": "error", "detail": "Job not found"})
                return
            yield _frame({"event": "progress", **_to_response(row).model_dump(mode="json")})
            if (row.get("status") or "") in _TERMINAL:
                return
            await asyncio.sleep(_POLL_INTERVAL_S)

    return StreamingResponse(
        gen(),
        media_type="text/event-stream",
        headers={"Cache-Control": "no-cache", "X-Accel-Buffering": "no", "Connection": "keep-alive"},
    )


@router.post("/{job_id}/resume", response_model=RoundtableJobResponse)
async def resume_job(
    request: Request, job_id: str, body: ResumeJobRequest, task_id: str | None = None
) -> RoundtableJobResponse:
    """回答澄清后续跑（Phase 3：条件 UPDATE 串行 + dispatcher 领取）。

    ``queue_for_resume`` 用**原子条件 UPDATE**（WHERE status='awaiting_input'）把作业翻成
    queued —— 并发 / 重复的 resume 只有一个能成功（其余返回 None → 409），杜绝「同一澄清
    被续跑两次」的双跑。成功后清租约 + 写含续跑语义的新 snapshot，``nudge`` dispatcher 由
    它在任意 worker 领取执行；**路由不再直接拉起进程内任务**。
    """
    store = _get_store(request)
    tid = (task_id or "").strip() or None
    user_id = _current_user_id(request)

    row = await store.get(job_id, user_id=user_id, task_id=tid)
    if row is None:
        raise HTTPException(status_code=404, detail="Job not found")

    answer = body.answer.strip()
    if not answer:
        raise HTTPException(status_code=400, detail="answer is required")

    # task 作业不分权：放开写入归属校验（user_id=None）。
    write_user_id = None if tid else user_id
    run_user_id = row.get("user_id") or user_id

    # 续跑 snapshot：优先复用原 input_snapshot（含席位/模式/链条等完整入参），覆盖续跑三件套
    # （is_resume / seed_message / intent_text），并用作业行里**最新**的 thread_ids /
    # coordinator_name（首跑建线程后由执行器写回，比原 snapshot 里的更新）。旧作业无 snapshot
    # 时从作业行字段兜底重建。
    base_snapshot = row.get("input_snapshot") or {}
    if not isinstance(base_snapshot, dict):
        base_snapshot = {}
    resume_snapshot: dict[str, Any] = {
        "v": base_snapshot.get("v", 1),
        "user_id": run_user_id,
        "agents": base_snapshot.get("agents")
        or [{"agent_id": n.get("agentId"), "name": n.get("name")} for n in (row.get("dispatch_chain") or [])],
        "seed_message": _RESUME_PREFIX + answer,
        "model": base_snapshot.get("model"),
        "mode": row.get("orchestration_mode") or base_snapshot.get("mode") or "recommend",
        "intent_text": answer,
        "thread_ids": row.get("thread_ids"),
        "coordinator_name": row.get("coordinator_name") or "roundtable-coordinator",
        "draft_id": row.get("draft_id"),
        "task_id": tid or row.get("task_id"),
        "is_resume": True,
        "chain": row.get("chain"),
        "orchestration_plan": row.get("orchestration_plan"),
        "enable_report": base_snapshot.get("enable_report", True),
        "seat_thinking_enabled": base_snapshot.get("seat_thinking_enabled"),
        "seat_reasoning_effort": base_snapshot.get("seat_reasoning_effort"),
        "seat_subagent_enabled": base_snapshot.get("seat_subagent_enabled", False),
        "seat_skill_directives": base_snapshot.get("seat_skill_directives") or {},
        "seat_modes": base_snapshot.get("seat_modes") or {},
        "gather_first": base_snapshot.get("gather_first", False),
        "business_code": base_snapshot.get("business_code"),
    }

    updated = await store.queue_for_resume(
        job_id, input_snapshot=resume_snapshot, user_id=write_user_id, task_id=tid
    )
    if updated is None:
        # 条件 UPDATE 未命中：作业已不在 awaiting_input（被并发 resume 抢先 / 已续跑 / 已终态）。
        raise HTTPException(status_code=409, detail="Job is not awaiting input")

    dispatcher = _get_dispatcher(request)
    if dispatcher is not None:
        dispatcher.nudge()
    return _to_response(updated)


async def _require_admin(request: Request) -> None:
    """放行 admin / auth-disabled，其余 403（与 ai_writing / scheduled_tasks 同套语义）。"""
    from app.gateway.deps import get_optional_user_from_request

    user = await get_optional_user_from_request(request)
    if user is None:
        return
    if getattr(user, "system_role", None) != "admin":
        raise HTTPException(status_code=403, detail="圆桌作业清理管理接口仅限管理员")


@router.post("/admin/cleanup", response_model=CleanupResponse)
async def admin_cleanup(request: Request, body: CleanupRequest) -> CleanupResponse:
    """清理过期作业行（活跃作业受 only_finished 保护，永不误删）。

    分批 ``list_older_than`` → ``delete_by_ids``，避免大事务。``retention_days=0``
    一刷清空所有终态作业（调试用）。
    """
    await _require_admin(request)
    store = _get_store(request)
    cutoff = datetime.now(UTC) - timedelta(days=body.retention_days)

    t0 = time.perf_counter()
    deleted = 0
    while True:
        ids = await store.list_older_than(cutoff, only_finished=body.only_finished, limit=body.batch_size)
        if not ids:
            break
        deleted += await store.delete_by_ids(ids)
        if len(ids) < body.batch_size:
            break

    return CleanupResponse(
        deleted=deleted,
        elapsed_seconds=round(time.perf_counter() - t0, 3),
        params={"retention_days": body.retention_days, "only_finished": body.only_finished, "batch_size": body.batch_size},
    )


@router.post("/{job_id}/cancel", response_model=RoundtableJobResponse)
async def cancel_job(request: Request, job_id: str, task_id: str | None = None) -> RoundtableJobResponse:
    """取消作业（Phase 3：两段式 cancel）。

    1. ``request_cancel``：原子条件 UPDATE（可取消态 → ``cancel_requested``）—— 权威意图落库，
       重复 cancel 幂等（已 cancel_requested/cancelled/终态时返回 None，直接回现状）。
    2. **无持租者**（queued / awaiting_input，执行器未在跑）→ 路由立刻 ``finalize_cancel``
       收口为终态 ``cancelled``（清唯一活跃键 + 租约）。
    3. **有持租者**（running）→ 保留 ``cancel_requested``，由持租者的 DB 看门狗收口
       ``cancelled``；本接口先回 ``cancel_requested``（SSE 随后见翻转）。租约过期前未能
       收口（例如 worker 崩溃）时，dispatcher 会回收该取消请求。

    「已取消」终态永远由持租者或 finalize 收口，避免与执行器的进度写竞态。
    """
    store = _get_store(request)
    tid = (task_id or "").strip() or None
    user_id = _current_user_id(request)

    row = await store.get(job_id, user_id=user_id, task_id=tid)
    if row is None:
        raise HTTPException(status_code=404, detail="Job not found")

    # task 作业不分权：放开写入归属校验。
    write_user_id = None if tid else user_id
    requested = await store.request_cancel(job_id, user_id=write_user_id, task_id=tid)
    if requested is None:
        # 已不可取消（终态 / 已 cancel_requested）：幂等返回现状，不当作错误。
        fresh = await store.get(job_id, user_id=user_id, task_id=tid)
        return _to_response(fresh or row)

    if not requested.get("lease_owner"):
        # 无持租者：路由直接收口（queued / awaiting_input）。
        finalized = await store.finalize_cancel(job_id)
        return _to_response(finalized or requested)

    # 有持租者（running）：不要直接 task.cancel()。直接取消会中断当前 worker 的看门狗，
    # 使 DB 永久遗留在 cancel_requested；让 DB 看门狗以持租者身份收口，崩溃时由 dispatcher
    # 在租约到期后回收，才能保证跨进程取消最终完成。
    return _to_response(requested)