package models

import (
	"gorm.io/gorm"
)

type Tree struct {
	BaseModel
	// ID       int64 `json:"id" gorm:"column:id;primary_key;type:bigint(20) auto_increment;"`
	Name     string `json:"name" gorm:"type:varchar(255);not null"`
	ParentID string `json:"parent_id" gorm:"column:parent_id; defualt:'-1' "`
	Level    int    `json:"level" gorm:"column:level; default:0 "`
}

// 获取子节点
func (t *Tree) Children(db *gorm.DB) ([]Tree, error) {
	var children []Tree
	err := db.Where("parent_id = ?", t.ID).Find(&children).Error
	return children, err
}

// 获取所有后代节点
//
//	func (t *Tree) Descendants(db *gorm.DB) ([]Tree, error) {
//		var descendants []Tree
//		err := db.Where("level > ? AND (parent_id = ? OR parent_id IN (SELECT id FROM trees WHERE level > ?))",
//			t.Level, t.ID, t.Level).Find(&descendants).Error
//		return descendants, err
//	}
func (t *Tree) Descendants(db *gorm.DB) ([]Tree, error) {
	var descendants []Tree

	// 使用GORM递归获取所有后代节点
	var getAllDescendants func(parentID string) error
	getAllDescendants = func(parentID string) error {
		var children []Tree
		if err := db.Where("parent_id = ?", parentID).Find(&children).Error; err != nil {
			return err
		}

		for _, child := range children {
			descendants = append(descendants, child)
			if err := getAllDescendants(child.ID); err != nil {
				return err
			}
		}
		return nil
	}

	// 从当前节点开始递归
	if err := getAllDescendants(t.ID); err != nil {
		return nil, err
	}

	return descendants, nil
}

func (t *Tree) ChildrenWithMinLevel(db *gorm.DB, minLevel int) ([]Tree, error) {
	var children []Tree
	if err := db.Where("parent_id = ? AND level >= ?", t.ID, minLevel).Find(&children).Error; err != nil {
		return nil, err
	}
	return children, nil
}