package dept

import (
	"context"
	"strings"

	"perms-system-server/internal/consts"
	"perms-system-server/internal/middleware"
	deptModel "perms-system-server/internal/model/dept"
	"perms-system-server/internal/response"
	"perms-system-server/internal/svc"
	"perms-system-server/internal/types"

	"github.com/zeromicro/go-zero/core/logx"
)

type DeptTreeLogic struct {
	logx.Logger
	ctx    context.Context
	svcCtx *svc.ServiceContext
}

func NewDeptTreeLogic(ctx context.Context, svcCtx *svc.ServiceContext) *DeptTreeLogic {
	return &DeptTreeLogic{
		Logger: logx.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx,
	}
}

// DeptTree 部门树。超管 / 产品 ADMIN 返回完整组织架构树；其他成员仅返回以其 DeptPath
// 为根的子树，避免 MEMBER 级账号枚举全公司组织结构、定位 DEV 部门用于针对性特权获取
// （见审计 M-2）。未归属部门或 DeptPath 为空的成员返回空树。
func (l *DeptTreeLogic) DeptTree() (resp []*types.DeptItem, err error) {
	caller := middleware.GetUserDetails(l.ctx)
	if caller == nil {
		return nil, response.ErrUnauthorized("未登录")
	}

	list, err := l.svcCtx.SysDeptModel.FindAll(l.ctx)
	if err != nil {
		return nil, err
	}

	fullAccess := caller.IsSuperAdmin || caller.MemberType == consts.MemberTypeAdmin

	if !fullAccess {
		if caller.DeptPath == "" {
			return make([]*types.DeptItem, 0), nil
		}
		filtered := make([]*deptModel.SysDept, 0, len(list))
		for _, d := range list {
			if strings.HasPrefix(d.Path, caller.DeptPath) {
				filtered = append(filtered, d)
			}
		}
		list = filtered
	}

	items := make([]*types.DeptItem, 0, len(list))
	for _, d := range list {
		items = append(items, &types.DeptItem{
			Id:         d.Id,
			ParentId:   d.ParentId,
			Name:       d.Name,
			Path:       d.Path,
			Sort:       d.Sort,
			DeptType:   d.DeptType,
			Remark:     d.Remark,
			Status:     d.Status,
			CreateTime: d.CreateTime,
			Children:   make([]*types.DeptItem, 0),
		})
	}

	itemMap := make(map[int64]*types.DeptItem)
	for _, item := range items {
		itemMap[item.Id] = item
	}

	roots := make([]*types.DeptItem, 0)
	for _, item := range items {
		// 非特权成员下只保留 caller 子树：原树的上级部门不出现在 items 中，item.ParentId
		// 找不到父节点时应当把当前节点当成局部根展示，而不是报错丢弃。
		if _, hasParent := itemMap[item.ParentId]; item.ParentId == 0 || !hasParent {
			if fullAccess && item.ParentId != 0 {
				l.Errorf("DeptTree: dept id=%d has parentId=%d which does not exist, treated as root", item.Id, item.ParentId)
			}
			roots = append(roots, item)
		} else {
			itemMap[item.ParentId].Children = append(itemMap[item.ParentId].Children, item)
		}
	}

	return roots, nil
}