"""
app/api/v1/fission.py — 第11环裂变路由

POST /fission           触发裂变(1源任务→N套子任务)
GET  /fission/{id}      查裂变进度(聚合N个子任务状态)
工作台内呈现,子任务走标准 SSE 流回进度。
"""
import logging
from typing import Annotated

from fastapi import APIRouter, Depends
from pydantic import BaseModel, Field
from sqlalchemy.orm import Session

from app.core.database import get_db
from app.core.response import ok, raise_not_found
from app.middleware.workspace_guard import CurrentUser, require_write_permission
from app.models.fission import FissionTask
from app.models.task import GenerationTask

logger = logging.getLogger(__name__)
router = APIRouter(tags=["fission"])


class FissionCreate(BaseModel):
    source_task_id: int
    reference_level: str = Field(default="mid")   # low/mid/high
    fanout_count: int = Field(default=3, ge=1, le=5)


@router.post("/fission")
def create_fission_endpoint(
    body: FissionCreate,
    current_user: Annotated[CurrentUser, Depends(require_write_permission)] = None,
    db: Session = Depends(get_db),
):
    """触发裂变：从源任务扇出 N 套完整笔记包。返回 fission_id + 子 task_ids。"""
    from app.services.fission_service import create_fission
    fission_id, task_ids = create_fission(
        db, current_user, body.source_task_id, body.reference_level, body.fanout_count,
    )
    return ok({"fission_id": fission_id, "task_ids": task_ids,
               "reference_level": body.reference_level, "fanout_count": len(task_ids)})


@router.get("/fission/{fission_id}")
def get_fission_progress(
    fission_id: int,
    current_user: Annotated[CurrentUser, Depends(require_write_permission)] = None,
    db: Session = Depends(get_db),
):
    """查裂变进度：聚合 N 个子任务状态（x/N 完成）。"""
    ft = db.query(FissionTask).filter(
        FissionTask.id == fission_id,
        FissionTask.workspace_id == current_user.workspace_id,
    ).first()
    if not ft:
        raise_not_found("裂变任务不存在")

    subs = db.query(GenerationTask).filter(
        GenerationTask.source_fission_id == fission_id,
        GenerationTask.workspace_id == current_user.workspace_id,
    ).all()
    done_states = {"pending_selection", "pending_review", "approved", "archived"}
    done = sum(1 for s in subs if s.status in done_states)
    failed = sum(1 for s in subs if s.status == "failed")
    total = len(subs)
    # 聚合状态：全失败=failed,全完成=done,否则generating
    agg = "done" if done == total and total > 0 else ("failed" if failed == total and total > 0 else "generating")
    if ft.status != agg:
        ft.status = agg; db.commit()

    return ok({
        "fission_id": ft.id, "reference_level": ft.reference_level,
        "fanout_count": ft.fanout_count, "status": agg,
        "progress": {"done": done, "failed": failed, "total": total},
        "task_ids": [s.id for s in subs],
    })