<?php

namespace App\Creditsuite\Services\GlobalDataService;

use App\Creditsuite\Domain\Models\FieldType;
use App\Creditsuite\Domain\Models\Identity;
use Exception;
use Throwable;

/**
 * Class FieldService
 * @package App\Creditsuite\Services\GlobalDataService
 */
class FieldService
{
    /**
     * @var string
     */
    protected $fieldSlug;

    /**
     * @var integer
     */
    protected $fieldId;

    /**
     * @var array
     */
    protected $identities;

    /**
     * @param $fieldSlug
     * @return $this
     */
    public function setFieldSlug($fieldSlug)
    {
        $this->fieldSlug = $fieldSlug;
        return $this;
    }

    /**
     * @param $fieldId
     * @return $this
     */
    public function setFieldId($fieldId)
    {
        $this->fieldId = $fieldId;
        return $this;
    }

    /**
     * @param $identities
     * @return $this
     */
    public function setIdentities($identities)
    {
        $this->identities = $identities;
        return $this;
    }


    /**
     * @throws Exception
     */
    protected function checkFieldId()
    {
        if($this->fieldId) {
            return;
        }

        try {
            $this->fieldId = FieldType::where('slug', $this->fieldSlug)->firstOrFail()
                ->id;
        } catch (Throwable $exception) {
            throw new Exception('FieldService incoming parameters are invalid: fieldType not found');
        }

    }

    /**
     * @throws Exception
     */
    public function validate()
    {
        $this->checkFieldId();

        if(!$this->fieldId || !is_array($this->identities)) {
            throw new Exception('FieldService incoming parameters are invalid');
        }
    }

    /**
     * @param array $identityKeys
     * @param string $fieldSlug
     * @return mixed
     * @throws Exception
     */
    public function versions()
    {
        $this->validate();

        $identities = Identity::whereIn('key', $this->identities)
                ->with([
                'fields' => function($query) {
                    $query
                        ->where('field_type_id', $this->fieldId);
                },
            ])
            ->get();

        $fields = $identities->map(function($item) {
            return $item->fields;
        })->collapse()->unique('id')->sortByDesc('updated_at')->values();

        return $fields;
    }

    /**
     * @return null
     * @throws Exception
     */
    public function first()
    {
        $versions = $this->versions();

        return $versions->isNotEmpty() ? $versions->first() : null;
    }

    /**
     * @return null
     * @throws Exception
     */
    public function last()
    {
        $versions = $this->versions();

        return $versions->isNotEmpty() ? $versions->last() : null;
    }
}