"""CRUD API for roundtable-planning drafts + recommendation history.

A draft is one full roundtable session (Step 1 intent + Step 2 multi-agent
roundtable). Bound to the requesting user (not the browser), so it follows the
account across devices/sessions — replacing the old ``localStorage`` storage.

This store is **strictly per-user**. taskId 深链聊天记录 (无界嵌入抽屉) live in a
separate, unpartitioned store — see ``/api/roundtable-task-drafts``
(``roundtable_task_drafts`` table) — so the two never mix.

Recommendation history is bound to a draft: the recommend dialog shows "last
recommendation for this session" on open, while still letting the user
re-analyze (which appends a new history row).

Routes (prefix ``/api/roundtable-drafts``):
    GET    ""                         list current user's drafts (lightweight)
    POST   ""                         create a draft
    GET    "/{draft_id}"              full draft (incl. step1 / step2 blobs)
    PUT    "/{draft_id}"              partial update (title / step / snapshots)
    DELETE "/{draft_id}"              delete
    GET    "/{draft_id}/recommendations"   list recommendation history
    POST   "/{draft_id}/recommendations"   append one recommendation run
"""

from __future__ import annotations

import logging
from datetime import datetime
from typing import Any
from uuid import uuid4

from fastapi import APIRouter, HTTPException, Request
from pydantic import BaseModel, Field

from deerflow.persistence.roundtable_drafts.sql import DraftConcurrentWriteError
from deerflow.runtime.user_context import get_effective_user_id

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


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


class DraftMetaResponse(BaseModel):
    id: str
    # 外部任务 id（无界嵌入抽屉传入）；非空时草稿按 task_id 共享、不按 user 分权。
    task_id: str | None = None
    title: str = ""
    furthest_step: int = 1
    # 乐观锁版本号：PUT 时经 expected_version 回传，冲突 → 409 + current_version。
    version: int = 0
    # 本次会商所用业务链名（历史卡片展示）；无链条（自由/recommend 模式）时为 None。
    chain_title: str | None = None
    created_at: datetime | str | None = None
    updated_at: datetime | str | None = None
    # 最近一次后台作业的状态（Phase 6 历史下拉「进行中」loading 用）；无作业时为 None。
    status: str | None = None
    job_id: str | None = None


class DraftListResponse(BaseModel):
    drafts: list[DraftMetaResponse]


class DraftResponse(DraftMetaResponse):
    step1: dict[str, Any] | None = None
    step2: dict[str, Any] | None = None
    step3: dict[str, Any] | None = None


class DraftCreateRequest(BaseModel):
    # Optional client-provided id so the browser can keep one stable id across
    # the create + subsequent updates without an extra round-trip.
    id: str | None = Field(default=None, max_length=64)
    # 外部任务 id（无界嵌入抽屉）；设置后草稿按 task_id 共享、不按 user 分权。
    task_id: str | None = Field(default=None, max_length=128)
    title: str = Field(default="", max_length=512)
    furthest_step: int = Field(default=1, ge=1, le=3)
    step1: dict[str, Any] | None = None
    step2: dict[str, Any] | None = None
    step3: dict[str, Any] | None = None


class DraftUpdateRequest(BaseModel):
    # All optional → callers send only what changed. Auto-save omits ``title``
    # so it never clobbers a manual rename.
    title: str | None = Field(default=None, max_length=512)
    furthest_step: int | None = Field(default=None, ge=1, le=3)
    task_id: str | None = Field(default=None, max_length=128)
    step1: dict[str, Any] | None = None
    step2: dict[str, Any] | None = None
    step3: dict[str, Any] | None = None
    # 乐观锁：客户端基于的草稿版本号。缺省（旧客户端）= 盲写兼容；
    # 提供时版本不匹配 → 409，body 带 current_version 供重拉合并。
    expected_version: int | None = Field(default=None, ge=0)


class RecommendPickSchema(BaseModel):
    agent_id: str
    reason: str = ""


class RecommendCandidateSchema(BaseModel):
    agent_id: str
    name: str = ""
    description: str = ""


class RecommendHistoryResponse(BaseModel):
    id: str
    draft_id: str
    objective: str = ""
    status: str = "done"
    model: str | None = None
    rationale: str | None = None
    picks: list[RecommendPickSchema] = []
    candidates: list[RecommendCandidateSchema] = []
    created_at: datetime | str | None = None


class RecommendHistoryListResponse(BaseModel):
    history: list[RecommendHistoryResponse]


class RecommendHistoryCreateRequest(BaseModel):
    objective: str = Field(default="", max_length=512)
    status: str = Field(default="done", max_length=32)
    model: str | None = None
    rationale: str | None = None
    picks: list[RecommendPickSchema] = []
    candidates: list[RecommendCandidateSchema] = []


# ── 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_draft_store", None)
    if store is None:
        raise HTTPException(status_code=503, detail="Roundtable draft store not available")
    return store


# ── draft routes ───────────────────────────────────────────────────────────


@router.get("", response_model=DraftListResponse)
async def list_drafts(request: Request) -> DraftListResponse:
    store = _get_store(request)
    user_id = _current_user_id(request)
    rows = await store.list_drafts(user_id)
    # 富化：给每个草稿带上「最近一次后台作业」的状态 + jobId（Phase 6 历史下拉 loading 用）。
    # job store 缺失（DB 未配置）或查询失败都不阻断列表，静默退化为无状态。
    job_store = getattr(request.app.state, "roundtable_job_store", None)
    if job_store is not None:
        try:
            status_map = await job_store.status_map_by_user(user_id)
        except Exception:  # noqa: BLE001 — 富化失败不能拖垮列表
            logger.warning("roundtable draft list: job status enrichment failed", exc_info=True)
            status_map = {}
        for r in rows:
            info = status_map.get(r.get("id"))
            if info:
                r["status"] = info.get("status")
                r["job_id"] = info.get("jobId")
    return DraftListResponse(drafts=[DraftMetaResponse(**r) for r in rows])


@router.post("", response_model=DraftResponse, status_code=201)
async def create_draft(request: Request, body: DraftCreateRequest) -> DraftResponse:
    store = _get_store(request)
    user_id = _current_user_id(request)
    row = await store.create_draft(
        user_id,
        {
            "id": (body.id or uuid4().hex),
            "task_id": (body.task_id or None),
            "title": body.title.strip(),
            "furthest_step": body.furthest_step,
            "step1": body.step1,
            "step2": body.step2,
            "step3": body.step3,
        },
    )
    return DraftResponse(**row)


@router.get("/{draft_id}", response_model=DraftResponse)
async def get_draft(request: Request, draft_id: str) -> DraftResponse:
    store = _get_store(request)
    user_id = _current_user_id(request)
    row = await store.get_draft(draft_id, user_id)
    if row is None:
        raise HTTPException(status_code=404, detail="Draft not found")
    return DraftResponse(**row)


@router.put("/{draft_id}", response_model=DraftResponse)
async def update_draft(request: Request, draft_id: str, body: DraftUpdateRequest) -> DraftResponse:
    store = _get_store(request)
    user_id = _current_user_id(request)
    # Build kwargs that distinguish "omitted" from "explicitly None". The store
    # uses a sentinel; here we pass only the fields the client actually sent.
    fields = body.model_dump(exclude_unset=True)
    try:
        row = await store.update_draft(draft_id, user_id, **fields)
    except DraftConcurrentWriteError as err:
        # 版本冲突：detail 里带 current_version，前端据此重拉最新草稿、本地合并后重试。
        raise HTTPException(
            status_code=409,
            detail={
                "error": "draft_version_conflict",
                "message": f"草稿已被并发修改（expected={err.expected}, actual={err.actual}）",
                "current_version": err.actual,
            },
        ) from err
    if row is None:
        raise HTTPException(status_code=404, detail="Draft not found")
    return DraftResponse(**row)


@router.delete("/{draft_id}", status_code=204)
async def delete_draft(request: Request, draft_id: str) -> None:
    store = _get_store(request)
    user_id = _current_user_id(request)
    deleted = await store.delete_draft(draft_id, user_id)
    if not deleted:
        raise HTTPException(status_code=404, detail="Draft not found")


# ── recommendation history routes ────────────────────────────────────────


@router.get("/{draft_id}/recommendations", response_model=RecommendHistoryListResponse)
async def list_recommendations(request: Request, draft_id: str) -> RecommendHistoryListResponse:
    store = _get_store(request)
    user_id = _current_user_id(request)
    rows = await store.list_recommendations(draft_id, user_id)
    return RecommendHistoryListResponse(history=[RecommendHistoryResponse(**r) for r in rows])


@router.post("/{draft_id}/recommendations", response_model=RecommendHistoryResponse, status_code=201)
async def add_recommendation(
    request: Request, draft_id: str, body: RecommendHistoryCreateRequest
) -> RecommendHistoryResponse:
    store = _get_store(request)
    user_id = _current_user_id(request)
    # Ownership: the draft must exist and belong to the caller.
    draft = await store.get_draft(draft_id, user_id)
    if draft is None:
        raise HTTPException(status_code=404, detail="Draft not found")
    row = await store.add_recommendation(
        user_id,
        draft_id,
        {
            "id": uuid4().hex,
            "objective": body.objective,
            "status": body.status,
            "model": body.model,
            "rationale": body.rationale,
            "picks": [p.model_dump() for p in body.picks],
            "candidates": [c.model_dump() for c in body.candidates],
        },
    )
    return RecommendHistoryResponse(**row)