<?php

declare(strict_types=1);

namespace App\FormBuilder\Purposes\Resolvers;

use App\Exceptions\FormBuilder\PurposeSubjectResolutionException;
use App\FormBuilder\Purposes\PurposeSubjectResolver;
use App\Models\FormBuilder\FormSubmission;
use App\Models\User;
use Illuminate\Database\Eloquent\Model;

/**
 * RFC §3 Q9 — signature_contract: subject is the authenticated User.
 */
final readonly class SignatureContractSubjectResolver implements PurposeSubjectResolver
{
    public function resolveOrProvision(FormSubmission $submission): User
    {
        if ($submission->subject_type === 'user' && $submission->subject_id !== null) {
            $subject = $submission->subject;
            if ($subject instanceof User) {
                return $subject;
            }
        }

        if ($submission->submitted_by_user_id === null) {
            throw new PurposeSubjectResolutionException(
                'signature_contract',
                'no_auth',
                (string) $submission->id,
                'signature_contract submission has no authenticated User',
            );
        }

        $user = User::query()->find($submission->submitted_by_user_id);
        if (! $user instanceof User) {
            throw new PurposeSubjectResolutionException(
                'signature_contract',
                'no_auth',
                (string) $submission->id,
                "submitted_by_user_id {$submission->submitted_by_user_id} not found",
            );
        }

        return $user;
    }
}