"""
岗位管理 API（真实数据库）
"""

from typing import Optional, List
from fastapi import APIRouter, Depends, Query, HTTPException
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, and_, func
from sqlalchemy.orm import selectinload
import sqlalchemy as sa

from app.core.deps import get_current_active_user as get_current_user, get_db, require_admin, require_admin_or_manager
from app.schemas.base import ResponseModel, PaginationParams, PaginatedResponse
from app.models.position import Position
from app.models.position_member import PositionMember
from app.models.position_course import PositionCourse
from app.models.user import User
from app.models.course import Course


router = APIRouter(prefix="/admin/positions")


@router.get("")
async def list_positions(
    pagination: PaginationParams = Depends(),
    keyword: Optional[str] = Query(None, description="关键词"),
    current_user=Depends(require_admin_or_manager),
    db: AsyncSession = Depends(get_db),
) -> ResponseModel:
    """分页获取岗位列表（管理员或经理）。"""
    stmt = select(Position).where(Position.is_deleted == False)
    if keyword:
        like = f"%{keyword}%"
        stmt = stmt.where((Position.name.ilike(like)) | (Position.description.ilike(like)))
    rows = (await db.execute(stmt)).scalars().all()
    total = len(rows)
    sliced = rows[pagination.offset : pagination.offset + pagination.limit]

    async def to_dict(p: Position) -> dict:
        """将Position对象转换为字典，并添加统计数据"""
        d = p.__dict__.copy()
        d.pop("_sa_instance_state", None)
        
        # 统计岗位成员数量
        member_count_result = await db.execute(
            select(func.count(PositionMember.id)).where(
                and_(
                    PositionMember.position_id == p.id,
                    PositionMember.is_deleted == False
                )
            )
        )
        d["memberCount"] = member_count_result.scalar() or 0
        
        # 统计必修课程数量
        required_count_result = await db.execute(
            select(func.count(PositionCourse.id)).where(
                and_(
                    PositionCourse.position_id == p.id,
                    PositionCourse.course_type == "required",
                    PositionCourse.is_deleted == False
                )
            )
        )
        d["requiredCourses"] = required_count_result.scalar() or 0
        
        # 统计选修课程数量
        optional_count_result = await db.execute(
            select(func.count(PositionCourse.id)).where(
                and_(
                    PositionCourse.position_id == p.id,
                    PositionCourse.course_type == "optional",
                    PositionCourse.is_deleted == False
                )
            )
        )
        d["optionalCourses"] = optional_count_result.scalar() or 0
        
        return d

    # 为每个岗位添加统计数据（使用异步）
    items = []
    for p in sliced:
        item = await to_dict(p)
        items.append(item)
    
    paged = {
        "items": items,
        "total": total,
        "page": pagination.page,
        "page_size": pagination.page_size,
        "pages": (total + pagination.page_size - 1) // pagination.page_size if pagination.page_size else 1,
    }
    return ResponseModel(message="获取岗位列表成功", data=paged)


@router.get("/tree")
async def get_position_tree(
    current_user=Depends(require_admin_or_manager), db: AsyncSession = Depends(get_db)
) -> ResponseModel:
    """获取岗位树（管理员或经理）。"""
    rows = (await db.execute(select(Position).where(Position.is_deleted == False))).scalars().all()
    id_to_node = {p.id: {**p.__dict__, "children": []} for p in rows}
    roots: List[dict] = []
    for p in rows:
        node = id_to_node[p.id]
        parent_id = p.parent_id
        if parent_id and parent_id in id_to_node:
            id_to_node[parent_id]["children"].append(node)
        else:
            roots.append(node)
    # 清理 _sa_instance_state
    def clean(d: dict):
        d.pop("_sa_instance_state", None)
        for c in d.get("children", []):
            clean(c)
    for r in roots:
        clean(r)
    return ResponseModel(message="获取岗位树成功", data=roots)


@router.post("")
async def create_position(
    payload: dict, current_user=Depends(require_admin), db: AsyncSession = Depends(get_db)
) -> ResponseModel:
    obj = Position(
        name=payload.get("name"),
        code=payload.get("code"),
        description=payload.get("description"),
        parent_id=payload.get("parentId"),
        status=payload.get("status", "active"),
        skills=payload.get("skills"),
        level=payload.get("level"),
        sort_order=payload.get("sort_order", 0),
        created_by=current_user.id,
    )
    db.add(obj)
    await db.commit()
    await db.refresh(obj)
    return ResponseModel(message="创建岗位成功", data={"id": obj.id})


@router.put("/{position_id}")
async def update_position(
    position_id: int, payload: dict, current_user=Depends(require_admin), db: AsyncSession = Depends(get_db)
) -> ResponseModel:
    obj = await db.get(Position, position_id)
    if not obj or obj.is_deleted:
        return ResponseModel(code=404, message="岗位不存在")
    obj.name = payload.get("name", obj.name)
    obj.code = payload.get("code", obj.code)
    obj.description = payload.get("description", obj.description)
    obj.parent_id = payload.get("parentId", obj.parent_id)
    obj.status = payload.get("status", obj.status)
    obj.skills = payload.get("skills", obj.skills)
    obj.level = payload.get("level", obj.level)
    obj.sort_order = payload.get("sort_order", obj.sort_order)
    obj.updated_by = current_user.id
    await db.commit()
    await db.refresh(obj)
    
    # 返回更新后的完整数据
    data = obj.__dict__.copy()
    data.pop("_sa_instance_state", None)
    return ResponseModel(message="更新岗位成功", data=data)


@router.get("/{position_id}")
async def get_position_detail(
    position_id: int, current_user=Depends(require_admin), db: AsyncSession = Depends(get_db)
) -> ResponseModel:
    obj = await db.get(Position, position_id)
    if not obj or obj.is_deleted:
        return ResponseModel(code=404, message="岗位不存在")
    data = obj.__dict__.copy()
    data.pop("_sa_instance_state", None)
    return ResponseModel(data=data)


@router.get("/{position_id}/check-delete")
async def check_position_delete(
    position_id: int, current_user=Depends(require_admin), db: AsyncSession = Depends(get_db)
) -> ResponseModel:
    obj = await db.get(Position, position_id)
    if not obj or obj.is_deleted:
        return ResponseModel(code=404, message="岗位不存在")
    
    # 检查是否有子岗位
    child_count_result = await db.execute(
        select(func.count(Position.id)).where(
            and_(
                Position.parent_id == position_id,
                Position.is_deleted == False
            )
        )
    )
    child_count = child_count_result.scalar() or 0
    
    if child_count > 0:
        return ResponseModel(data={
            "deletable": False, 
            "reason": f"该岗位下有 {child_count} 个子岗位，请先删除或移动子岗位"
        })
    
    # 检查是否有成员（仅作为提醒，不阻止删除）
    member_count_result = await db.execute(
        select(func.count(PositionMember.id)).where(
            and_(
                PositionMember.position_id == position_id,
                PositionMember.is_deleted == False
            )
        )
    )
    member_count = member_count_result.scalar() or 0
    
    warning = ""
    if member_count > 0:
        warning = f"注意：该岗位当前有 {member_count} 名成员，删除后这些成员将不再属于此岗位"
    
    return ResponseModel(data={"deletable": True, "reason": "", "warning": warning, "member_count": member_count})


@router.delete("/{position_id}")
async def delete_position(
    position_id: int, current_user=Depends(require_admin), db: AsyncSession = Depends(get_db)
) -> ResponseModel:
    obj = await db.get(Position, position_id)
    if not obj or obj.is_deleted:
        return ResponseModel(code=404, message="岗位不存在")
    
    # 检查是否有子岗位
    child_count_result = await db.execute(
        select(func.count(Position.id)).where(
            and_(
                Position.parent_id == position_id,
                Position.is_deleted == False
            )
        )
    )
    child_count = child_count_result.scalar() or 0
    
    if child_count > 0:
        return ResponseModel(
            code=400, 
            message=f"该岗位下有 {child_count} 个子岗位，请先删除或移动子岗位"
        )
    
    # 软删除岗位成员关联
    await db.execute(
        sa.update(PositionMember)
        .where(PositionMember.position_id == position_id)
        .values(is_deleted=True)
    )
    
    # 软删除岗位课程关联
    await db.execute(
        sa.update(PositionCourse)
        .where(PositionCourse.position_id == position_id)
        .values(is_deleted=True)
    )
    
    # 软删除岗位
    obj.is_deleted = True
    await db.commit()
    return ResponseModel(message="岗位已删除")


# ========== 岗位成员管理 API ==========

@router.get("/{position_id}/members")
async def get_position_members(
    position_id: int,
    pagination: PaginationParams = Depends(),
    keyword: Optional[str] = Query(None, description="搜索关键词"),
    current_user=Depends(require_admin),
    db: AsyncSession = Depends(get_db),
) -> ResponseModel:
    """获取岗位成员列表"""
    # 验证岗位存在
    position = await db.get(Position, position_id)
    if not position or position.is_deleted:
        return ResponseModel(code=404, message="岗位不存在")
    
    # 构建查询
    stmt = (
        select(PositionMember, User)
        .join(User, PositionMember.user_id == User.id)
        .where(
            and_(
                PositionMember.position_id == position_id,
                PositionMember.is_deleted == False,
                User.is_deleted == False
            )
        )
    )
    
    # 关键词搜索
    if keyword:
        like = f"%{keyword}%"
        stmt = stmt.where(
            (User.username.ilike(like)) |
            (User.full_name.ilike(like)) |
            (User.email.ilike(like))
        )
    
    # 执行查询
    result = await db.execute(stmt)
    rows = result.all()
    total = len(rows)
    sliced = rows[pagination.offset : pagination.offset + pagination.limit]
    
    # 格式化数据
    items = []
    for pm, user in sliced:
        items.append({
            "id": pm.id,
            "user_id": user.id,
            "username": user.username,
            "full_name": user.full_name,
            "email": user.email,
            "phone": user.phone,
            "role": pm.role,
            "joined_at": pm.joined_at.isoformat() if pm.joined_at else None,
            "user_role": user.role,  # 系统角色
            "is_active": user.is_active,
        })
    
    return ResponseModel(
        message="获取成员列表成功",
        data={
            "items": items,
            "total": total,
            "page": pagination.page,
            "page_size": pagination.page_size,
            "pages": (total + pagination.page_size - 1) // pagination.page_size if pagination.page_size else 1,
        }
    )


@router.post("/{position_id}/members")
async def add_position_members(
    position_id: int,
    payload: dict,
    current_user=Depends(require_admin),
    db: AsyncSession = Depends(get_db),
) -> ResponseModel:
    """批量添加岗位成员"""
    # 验证岗位存在
    position = await db.get(Position, position_id)
    if not position or position.is_deleted:
        return ResponseModel(code=404, message="岗位不存在")
    
    user_ids = payload.get("user_ids", [])
    if not user_ids:
        return ResponseModel(code=400, message="请选择要添加的用户")
    
    # 验证用户存在
    users = await db.execute(
        select(User).where(
            and_(
                User.id.in_(user_ids),
                User.is_deleted == False
            )
        )
    )
    valid_users = {u.id: u for u in users.scalars().all()}
    
    if len(valid_users) != len(user_ids):
        invalid_ids = set(user_ids) - set(valid_users.keys())
        return ResponseModel(code=400, message=f"部分用户不存在: {invalid_ids}")
    
    # 检查是否已存在
    existing = await db.execute(
        select(PositionMember).where(
            and_(
                PositionMember.position_id == position_id,
                PositionMember.user_id.in_(user_ids),
                PositionMember.is_deleted == False
            )
        )
    )
    existing_user_ids = {pm.user_id for pm in existing.scalars().all()}
    
    # 添加新成员
    added_count = 0
    for user_id in user_ids:
        if user_id not in existing_user_ids:
            member = PositionMember(
                position_id=position_id,
                user_id=user_id,
                role=payload.get("role")
            )
            db.add(member)
            added_count += 1
    
    await db.commit()
    
    return ResponseModel(
        message=f"成功添加 {added_count} 个成员",
        data={"added_count": added_count}
    )


@router.delete("/{position_id}/members/{user_id}")
async def remove_position_member(
    position_id: int,
    user_id: int,
    current_user=Depends(require_admin),
    db: AsyncSession = Depends(get_db),
) -> ResponseModel:
    """移除岗位成员"""
    # 查找成员关系
    member = await db.execute(
        select(PositionMember).where(
            and_(
                PositionMember.position_id == position_id,
                PositionMember.user_id == user_id,
                PositionMember.is_deleted == False
            )
        )
    )
    member = member.scalar_one_or_none()
    
    if not member:
        return ResponseModel(code=404, message="成员关系不存在")
    
    # 软删除
    member.is_deleted = True
    await db.commit()
    
    return ResponseModel(message="成员已移除")


# ========== 岗位课程管理 API ==========

@router.get("/{position_id}/courses")
async def get_position_courses(
    position_id: int,
    course_type: Optional[str] = Query(None, description="课程类型：required/optional"),
    current_user=Depends(require_admin),
    db: AsyncSession = Depends(get_db),
) -> ResponseModel:
    """获取岗位课程列表"""
    # 验证岗位存在
    position = await db.get(Position, position_id)
    if not position or position.is_deleted:
        return ResponseModel(code=404, message="岗位不存在")
    
    # 构建查询
    stmt = (
        select(PositionCourse, Course)
        .join(Course, PositionCourse.course_id == Course.id)
        .where(
            and_(
                PositionCourse.position_id == position_id,
                PositionCourse.is_deleted == False,
                Course.is_deleted == False
            )
        )
    )
    
    # 课程类型筛选
    if course_type:
        stmt = stmt.where(PositionCourse.course_type == course_type)
    
    # 按优先级排序
    stmt = stmt.order_by(PositionCourse.priority, PositionCourse.id)
    
    # 执行查询
    result = await db.execute(stmt)
    rows = result.all()
    
    # 格式化数据
    items = []
    for pc, course in rows:
        items.append({
            "id": pc.id,
            "course_id": course.id,
            "course_name": course.name,
            "course_description": course.description,
            "course_category": course.category,
            "course_status": course.status,
            "course_duration_hours": course.duration_hours,
            "course_difficulty_level": course.difficulty_level,
            "course_type": pc.course_type,
            "priority": pc.priority,
            "created_at": pc.created_at.isoformat() if pc.created_at else None,
        })
    
    # 统计
    stats = {
        "total": len(items),
        "required_count": sum(1 for item in items if item["course_type"] == "required"),
        "optional_count": sum(1 for item in items if item["course_type"] == "optional"),
    }
    
    return ResponseModel(
        message="获取课程列表成功",
        data={
            "items": items,
            "stats": stats
        }
    )


@router.post("/{position_id}/courses")
async def add_position_courses(
    position_id: int,
    payload: dict,
    current_user=Depends(require_admin),
    db: AsyncSession = Depends(get_db),
) -> ResponseModel:
    """批量添加岗位课程"""
    # 验证岗位存在
    position = await db.get(Position, position_id)
    if not position or position.is_deleted:
        return ResponseModel(code=404, message="岗位不存在")
    
    course_ids = payload.get("course_ids", [])
    if not course_ids:
        return ResponseModel(code=400, message="请选择要添加的课程")
    
    course_type = payload.get("course_type", "required")
    if course_type not in ["required", "optional"]:
        return ResponseModel(code=400, message="课程类型无效")
    
    # 验证课程存在
    courses = await db.execute(
        select(Course).where(
            and_(
                Course.id.in_(course_ids),
                Course.is_deleted == False
            )
        )
    )
    valid_courses = {c.id: c for c in courses.scalars().all()}
    
    if len(valid_courses) != len(course_ids):
        invalid_ids = set(course_ids) - set(valid_courses.keys())
        return ResponseModel(code=400, message=f"部分课程不存在: {invalid_ids}")
    
    # 检查是否已存在
    existing = await db.execute(
        select(PositionCourse).where(
            and_(
                PositionCourse.position_id == position_id,
                PositionCourse.course_id.in_(course_ids),
                PositionCourse.is_deleted == False
            )
        )
    )
    existing_course_ids = {pc.course_id for pc in existing.scalars().all()}
    
    # 获取当前最大优先级
    max_priority_result = await db.execute(
        select(sa.func.max(PositionCourse.priority)).where(
            and_(
                PositionCourse.position_id == position_id,
                PositionCourse.is_deleted == False
            )
        )
    )
    max_priority = max_priority_result.scalar() or 0
    
    # 添加新课程
    added_count = 0
    for idx, course_id in enumerate(course_ids):
        if course_id not in existing_course_ids:
            pc = PositionCourse(
                position_id=position_id,
                course_id=course_id,
                course_type=course_type,
                priority=max_priority + idx + 1,
            )
            db.add(pc)
            added_count += 1
    
    await db.commit()
    
    return ResponseModel(
        message=f"成功添加 {added_count} 门课程",
        data={"added_count": added_count}
    )


@router.put("/{position_id}/courses/{pc_id}")
async def update_position_course(
    position_id: int,
    pc_id: int,
    payload: dict,
    current_user=Depends(require_admin),
    db: AsyncSession = Depends(get_db),
) -> ResponseModel:
    """更新岗位课程设置"""
    # 查找课程关系
    pc = await db.execute(
        select(PositionCourse).where(
            and_(
                PositionCourse.id == pc_id,
                PositionCourse.position_id == position_id,
                PositionCourse.is_deleted == False
            )
        )
    )
    pc = pc.scalar_one_or_none()
    
    if not pc:
        return ResponseModel(code=404, message="课程关系不存在")
    
    # 更新课程类型
    if "course_type" in payload:
        course_type = payload["course_type"]
        if course_type not in ["required", "optional"]:
            return ResponseModel(code=400, message="课程类型无效")
        pc.course_type = course_type
    
    # 更新优先级
    if "priority" in payload:
        pc.priority = payload["priority"]
    
    # PositionCourse 未继承审计字段，避免写入不存在字段
    await db.commit()
    
    return ResponseModel(message="更新成功")


@router.delete("/{position_id}/courses/{course_id}")
async def remove_position_course(
    position_id: int,
    course_id: int,
    current_user=Depends(require_admin),
    db: AsyncSession = Depends(get_db),
) -> ResponseModel:
    """移除岗位课程"""
    # 查找课程关系
    pc = await db.execute(
        select(PositionCourse).where(
            and_(
                PositionCourse.position_id == position_id,
                PositionCourse.course_id == course_id,
                PositionCourse.is_deleted == False
            )
        )
    )
    pc = pc.scalar_one_or_none()
    
    if not pc:
        return ResponseModel(code=404, message="课程关系不存在")
    
    # 软删除
    pc.is_deleted = True
    # PositionCourse 未继承审计字段，避免写入不存在字段
    await db.commit()
    
    return ResponseModel(message="课程已移除")