<?php

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;
use Illuminate\Database\Eloquent\Model as Model;
use Jenssegers\Mongodb\Eloquent\Model as Document;

class ExistsRule implements Rule
{
    CONST FIELD = '_id';

    private Model|Document $model;

    private array $invalidItems;

    /**
     * Create a new rule instance.
     *
     * @param Model|Document $model
     * @param string $field
     */
    public function __construct(Model|Document $model)
    {
        $this->model = $model;
    }

    /**
     * Determine if the validation rule passes.
     *
     * @param string $attribute
     * @param mixed $value
     * @return bool
     */
    public function passes($attribute, $value)
    {
        $valid = true;
        $value = collect($value);
        // if value is empty do not validate
        if ($value->isEmpty()) {
            return $valid;
        }
        // query to fetch records base on field and value.
        $validCollection = $this->model->select(self::FIELD)
            ->whereIn(self::FIELD, $value->toArray())
            ->withoutTrash()
            ->get()->map(fn($m) => $m->{self::FIELD});

        // check if all values are existed.
        $valid = $value->count() === $validCollection->count();
        // extract invalid values.
        $this->invalidItems = $value->diff($validCollection)->toArray();

        return $valid;
    }

    /**
     * Get the validation error message.
     *
     * @return string
     */
    public function message()
    {
        return implode(',', $this->invalidItems) .
            (count($this->invalidItems) > 1 ? ' are ' : ' is ') .
            'invalid!';
    }
}