from __future__ import annotations

from sqlalchemy import or_

from .shared import *

async def update_user_workload(
    db: AsyncSession,
    tenant_id: int,
    user_id: int,
    total_tasks_delta: int = 0,
    completed_tasks_delta: int = 0,
    in_progress_delta: int = 0,
    estimated_hours_delta: float = 0,
    completed_hours_delta: float = 0,
) -> Optional[UserWorkload]:
    """
    更新用户工作量。
    新 schema: current_assigned_hours, workload_ratio
    """
    result = await db.execute(
        select(UserWorkload).where(
            and_(
                UserWorkload.tenant_id == tenant_id,
                UserWorkload.user_id == user_id,
            )
        )
    )
    workload = result.scalar_one_or_none()

    if not workload:
        workload = UserWorkload(
            tenant_id=tenant_id,
            user_id=user_id,
            current_assigned_hours=0.0,
            max_available_hours_per_week=40.0,
            workload_ratio=0.0,
        )
        db.add(workload)
        await db.flush()

    delta = estimated_hours_delta + completed_hours_delta
    workload.current_assigned_hours = max(
        0, float(workload.current_assigned_hours or 0) + delta
    )
    max_hours = float(workload.max_available_hours_per_week or 40)
    workload.workload_ratio = min(
        100.0, (workload.current_assigned_hours / max_hours) * 100
    )

    await db.commit()
    await db.refresh(workload)

    user_result = await db.execute(select(User).where(User.id == user_id))
    user = user_result.scalar_one_or_none()
    if user:
        user.workload = int(workload.workload_ratio)
        await db.commit()

    return workload

async def recommend_personnel(
    db: AsyncSession,
    tenant_id: int,
    required_skills: List[str | int],
    task_description: Optional[str] = None,
    task_id: Optional[str] = None,
    limit: int = 5,
) -> dict:
    """
    根据所需技能推荐匹配人员。
    返回匹配度评分、推荐理由等。
    """
    if not required_skills:
        return {
            "task_id": task_id,
            "task_description": task_description,
            "required_skills": [],
            "recommendations": [],
            "total_count": 0,
        }

    skill_ids: list[int] = []
    skill_names: list[str] = []
    for raw in required_skills:
        if isinstance(raw, bool):
            continue
        try:
            skill_id = int(str(raw).strip())
        except (TypeError, ValueError):
            skill_id = 0
        if skill_id > 0 and str(raw).strip() == str(skill_id):
            skill_ids.append(skill_id)
            continue
        text = str(raw or "").strip()
        if text:
            skill_names.append(text)

    conditions = []
    if skill_ids:
        conditions.append(SkillTag.id.in_(skill_ids))
    if skill_names:
        conditions.append(or_(SkillTag.slug.in_(skill_names), SkillTag.name.in_(skill_names)))

    if not conditions:
        return {
            "task_id": task_id,
            "task_description": task_description,
            "required_skills": list(required_skills),
            "recommendations": [],
            "total_count": 0,
        }

    skill_tags_result = await db.execute(
        select(SkillTag).where(
            and_(
                SkillTag.tenant_id == tenant_id,
                or_(*conditions),
            )
        )
    )
    tags = skill_tags_result.scalars().all()
    tag_ids = [t.id for t in tags]

    if not tag_ids:
        return {
            "task_id": task_id,
            "task_description": task_description,
            "required_skills": required_skills,
            "recommendations": [],
            "total_count": 0,
        }

    # 查询拥有这些技能的用户及熟练度
    bindings_result = await db.execute(
        select(UserSkillBinding, SkillTag, User)
        .join(SkillTag, UserSkillBinding.skill_tag_id == SkillTag.id)
        .join(User, UserSkillBinding.user_id == User.id)
        .where(
            and_(
                UserSkillBinding.tenant_id == tenant_id,
                UserSkillBinding.skill_tag_id.in_(tag_ids),
                User.status == UserStatus.ACTIVE,
            )
        )
    )
    rows = bindings_result.all()

    # 按用户聚合
    user_scores: dict = {}
    for b, st, u in rows:
        uid = str(u.id)
        if uid not in user_scores:
            user_scores[uid] = {
                "user": u,
                "skills": [],
                "proficiencies": [],
                "match_count": 0,
            }
        user_scores[uid]["skills"].append(st.name)
        user_scores[uid]["proficiencies"].append(b.proficiency)
        user_scores[uid]["match_count"] = len(user_scores[uid]["skills"])

    # 计算匹配度并排序
    recommendations = []
    for uid, data in user_scores.items():
        u = data["user"]
        avg_prof = (
            sum(data["proficiencies"]) / len(data["proficiencies"])
            if data["proficiencies"]
            else 0
        )
        match_ratio = len(data["skills"]) / len(required_skills) if required_skills else 0
        match_score = min(100, (match_ratio * 60 + avg_prof * 0.4))
        reason = f"匹配技能: {', '.join(data['skills'])}"
        recommendations.append(
            {
                "user_id": uid,
                "user_name": u.name,
                "match_score": round(match_score, 1),
                "reason": reason,
                "skill_match_count": data["match_count"],
                "avg_proficiency": round(avg_prof, 1),
                "workload_rate": float(u.workload) if u.workload else 0,
                "recommended_role": u.role.value if hasattr(u.role, "value") else str(u.role),
            }
        )

    recommendations.sort(key=lambda x: (-x["match_score"], -x["skill_match_count"]))
    recommendations = recommendations[:limit]

    return {
        "task_id": task_id,
        "task_description": task_description,
        "required_skills": required_skills,
        "recommendations": recommendations,
        "total_count": len(recommendations),
    }