package admin_system_menu_manage

import (
	"context"
	"sort"

	"github.com/gogf/gf/v2/errors/gerror"

	"service.xpcool.com/internal/consts"
	"service.xpcool.com/internal/dao"
	"service.xpcool.com/internal/library/response"
	"service.xpcool.com/internal/model/do"
	"service.xpcool.com/internal/model/dto"
	"service.xpcool.com/internal/model/entity"
)

// IMenuManage 管理菜单树（菜单 + 按钮权限）。
type IMenuManage interface {
	Tree(context.Context) ([]*dto.MenuNode, error)
	Create(context.Context, dto.MenuCreateInput) (uint64, error)
	Update(context.Context, dto.MenuUpdateInput) error
	Delete(context.Context, uint64) error
}

type menuManage struct{}

var localMenuManage IMenuManage

func NewMenuManage() IMenuManage { return &menuManage{} }

func MenuManage() IMenuManage {
	if localMenuManage == nil {
		panic("MenuManage implementation not registered")
	}
	return localMenuManage
}
func RegisterMenuManage(i IMenuManage) { localMenuManage = i }

// ---------------------- Menu manage ----------------------

func (s *menuManage) Tree(ctx context.Context) ([]*dto.MenuNode, error) {
	var list []entity.AdminMenu
	if err := dao.AdminMenu.Ctx(ctx).OrderAsc("sort").Scan(&list); err != nil {
		return nil, gerror.Wrap(err, "query menus")
	}
	byID := make(map[uint64]*dto.MenuNode, len(list))
	for i := range list {
		m := &list[i]
		byID[m.Id] = &dto.MenuNode{
			Id: m.Id, ParentId: m.ParentId, Name: m.Name, Icon: m.Icon, Type: m.Type,
			Path: m.Path, Component: m.Component, Permission: m.Permission,
			Sort: m.Sort, Status: m.Status, Hidden: m.Hidden,
		}
	}
	var roots []*dto.MenuNode
	for i := range list {
		m := &list[i]
		node := byID[m.Id]
		if m.ParentId == 0 {
			roots = append(roots, node)
		} else if p, ok := byID[m.ParentId]; ok {
			p.Children = append(p.Children, node)
		}
	}
	sort.Slice(roots, func(i, j int) bool { return roots[i].Sort < roots[j].Sort })
	for _, r := range roots {
		sortMenuChildren(r)
	}
	return roots, nil
}

func sortMenuChildren(n *dto.MenuNode) {
	sort.Slice(n.Children, func(i, j int) bool { return n.Children[i].Sort < n.Children[j].Sort })
	for _, c := range n.Children {
		sortMenuChildren(c)
	}
}

func (s *menuManage) Create(ctx context.Context, in dto.MenuCreateInput) (uint64, error) {
	count, err := dao.AdminMenu.Ctx(ctx).Where(do.AdminMenu{Permission: in.Permission}).Count()
	if err != nil {
		return 0, gerror.Wrap(err, "check menu permission")
	}
	if count > 0 {
		return 0, response.Error(consts.CodeInvalidParam, "permission already exists")
	}
	id, err := dao.AdminMenu.Ctx(ctx).Data(do.AdminMenu{
		ParentId: in.ParentId, Name: in.Name, Icon: in.Icon, Type: in.Type, Path: in.Path,
		Component: in.Component, Permission: in.Permission, Sort: in.Sort, Status: in.Status, Hidden: in.Hidden,
	}).InsertAndGetId()
	if err != nil {
		return 0, gerror.Wrap(err, "insert menu")
	}
	return uint64(id), nil
}

func (s *menuManage) Update(ctx context.Context, in dto.MenuUpdateInput) error {
	count, err := dao.AdminMenu.Ctx(ctx).Where("permission = ? AND id != ?", in.Permission, in.Id).Count()
	if err != nil {
		return gerror.Wrap(err, "check menu permission")
	}
	if count > 0 {
		return response.Error(consts.CodeInvalidParam, "permission already exists")
	}
	_, err = dao.AdminMenu.Ctx(ctx).Where(do.AdminMenu{Id: in.Id}).Data(do.AdminMenu{
		ParentId: in.ParentId, Name: in.Name, Icon: in.Icon, Type: in.Type, Path: in.Path,
		Component: in.Component, Permission: in.Permission, Sort: in.Sort, Status: in.Status, Hidden: in.Hidden,
	}).Update()
	if err != nil {
		return gerror.Wrap(err, "update menu")
	}
	return nil
}

func (s *menuManage) Delete(ctx context.Context, id uint64) error {
	// 删除前检查是否存在子节点。
	cnt, err := dao.AdminMenu.Ctx(ctx).Where(do.AdminMenu{ParentId: id}).Count()
	if err != nil {
		return gerror.Wrap(err, "check menu children")
	}
	if cnt > 0 {
		return response.Error(consts.CodeInvalidParam, "delete children first")
	}
	if _, err = dao.AdminMenu.Ctx(ctx).Where(do.AdminMenu{Id: id}).Delete(); err != nil {
		return gerror.Wrap(err, "delete menu")
	}
	if _, err = dao.AdminRoleMenu.Ctx(ctx).Unscoped().Where(do.AdminRoleMenu{MenuId: id}).Delete(); err != nil {
		return gerror.Wrap(err, "delete role menu bindings")
	}
	return nil
}