<?php

namespace App\Traits;

use Illuminate\Database\Eloquent\Casts\Attribute;
use Illuminate\Database\Eloquent\Model;

/**
 * Model Tree
 *
 * parent_id: 上级id, 默认: 0
 * path: 所有上级id, 例如: -1-2-3-
 * sort: 排序(正序)
 */
trait TreePath
{
    protected static function booted(): void
    {
        static::creating(function (Model $model) {
            if ($model->parent_id) {
                $parent = static::query()->findOrFail($model->parent_id);
                $model->path = $parent->path . $parent->id . '-';
            } else {
                $model->parent_id = 0;
                $model->path = '-';
            }
        });

        static::updating(function (Model $model) {
            if ($model->parent_id) {
                $parent = static::query()->findOrFail($model->parent_id);
                $model->path = $parent->path . $parent->id . '-';
            } else {
                $model->parent_id = 0;
                $model->path = '-';
            }
        });

        static::deleting(function (Model $model) {
            static::query()->allChildren($model->id)->delete();
        });
    }
    protected function parentIds(): Attribute
    {
        return Attribute::make(
            get: fn () => explode('-', substr($this->path, 1, -1)),
        );
    }

    public function children()
    {
        return $this->hasMany(static::class, 'parent_id');
    }

    public function parent()
    {
        return $this->belongsTo(static::class, 'parent_id');
    }

    public function scopeAllChildren($q, $pid)
    {
        return $q->where('path', 'like', '%-'.$pid.'-%');
    }

    public function scopeSort($q)
    {
        return $q->orderBy('parent_id')->orderBy('sort');
    }
}