"""任务相关 API。"""

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy import and_, select
from sqlalchemy.ext.asyncio import AsyncSession

from ..core.database import get_db
from ..dependencies import get_current_user, require_manager_user
from ..models import Task, User, UserProject
from ..schemas import TaskBreakdownRequest, TaskBreakdownResponse
from ..services.llm_service import llm_service
from ..services.integrations.integration_core.plane_service import plane_service
from ..services.skill import recommend_personnel
from ..services.sstc.charter_data import (
    _build_task_breakdown_prompt,
    _load_available_skill_names,
    _load_task_breakdown_context,
)

router = APIRouter(prefix="/tasks", tags=["tasks"])


@router.post("/breakdown", response_model=TaskBreakdownResponse)
async def breakdown_tasks(
    request: TaskBreakdownRequest,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_manager_user),
):
    """AI 任务拆解"""
    tenant_id = int(current_user.tenant_id)
    context = await _load_task_breakdown_context(
        db,
        tenant_id=tenant_id,
        description=request.description,
        project_id=request.project_id,
        charter_id=request.charter_id,
    )
    if request.project_id is not None and not context.get("project"):
        raise HTTPException(status_code=404, detail="Project not found")
    if request.charter_id is not None and not context.get("charter"):
        raise HTTPException(status_code=404, detail="Charter not found")

    available_skills = await _load_available_skill_names(db, tenant_id=tenant_id)
    prompt = _build_task_breakdown_prompt(
        project_id=request.project_id,
        context=context,
        available_skills=available_skills,
    )
    try:
        raw_text = await llm_service.generate(
            prompt,
            db=db,
            tenant_id=tenant_id,
            function_name="generate_task_breakdown",
        )
        tasks = llm_service._parse_json_array(raw_text)
        if not tasks:
            raise ValueError("AI 拆解返回空结果或无法解析为 JSON 数组")
    except RuntimeError:
        raise HTTPException(status_code=403, detail="预算超限，AI 调用被阻止（hard limit）")
    except Exception as exc:
        raise HTTPException(status_code=500, detail=f"Failed to generate task breakdown: {exc}")

    sync_result = None
    if request.sync_to_plane:
        sync_result = await plane_service.sync_tasks(tasks)

    return {"tasks": tasks, "sync_result": sync_result}


@router.get("/recommend-assignees")
async def recommend_assignees(
    task_id: int = Query(..., description="任务 ID"),
    limit: int = Query(5, ge=1, le=20),
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """
    推荐任务负责人（按技能匹配 + 熟练度 + 负载）。
    仅在任务所属项目成员中选择，且排除禁用用户。
    """
    tenant_id = int(current_user.tenant_id)
    task = (
        await db.execute(
            select(Task).where(
                and_(
                    Task.id == task_id,
                    Task.tenant_id == tenant_id,
                )
            )
        )
    ).scalar_one_or_none()
    if not task:
        raise HTTPException(status_code=404, detail="Task not found")

    required_skills = [str(x) for x in (task.required_skill_tag_ids or [])]
    recommendations = await recommend_personnel(
        db=db,
        tenant_id=tenant_id,
        required_skills=required_skills,
        task_description=task.description or task.title,
        task_id=str(task.id),
        limit=limit * 2,
    )

    project_user_ids_result = await db.execute(
        select(UserProject.user_id).where(
            and_(
                UserProject.tenant_id == tenant_id,
                UserProject.project_id == int(task.project_id),
            )
        )
    )
    project_user_ids = {int(uid) for uid in project_user_ids_result.scalars().all()}

    active_users_result = await db.execute(
        select(User.id).where(
            and_(
                User.tenant_id == tenant_id,
                User.status == "active",
                User.is_active.is_(True),
            )
        )
    )
    active_user_ids = {int(uid) for uid in active_users_result.scalars().all()}

    filtered = []
    for item in recommendations.get("recommendations", []):
        try:
            uid = int(item.get("user_id"))
        except (TypeError, ValueError):
            continue
        if uid in project_user_ids and uid in active_user_ids:
            filtered.append(item)

    filtered.sort(
        key=lambda x: (
            float(x.get("workload_rate", 9999)) >= 70.0,
            float(x.get("workload_rate", 9999)),
            -float(x.get("match_score", 0)),
        )
    )

    final_items = filtered[:limit]
    return {
        "task_id": str(task.id),
        "required_skills": required_skills,
        "recommendations": final_items,
        "total_count": len(final_items),
    }