<?php

declare(strict_types=1);

namespace App\FormBuilder\Publishing;

use App\Models\FormBuilder\FormField;
use App\Models\FormBuilder\FormFieldBinding;
use App\Models\FormBuilder\FormSchema;

/**
 * RFC-WS-6 §3 (Q8) — composite identity-key resolution is out of scope
 * for v1; this guard enforces single-key per target_entity at publish
 * time. Universal: wires into every PurposeGuardProvider.
 */
final class MaxOneIdentityKeyPerTargetEntity implements PublishGuard
{
    public function code(): string
    {
        return 'max_one_identity_key_per_target_entity';
    }

    public function evaluate(FormSchema $schema): PublishGuardResult
    {
        $countsByEntity = [];
        /** @var FormField $field */
        foreach ($schema->fields as $field) {
            /** @var FormFieldBinding $binding */
            foreach ($field->bindings as $binding) {
                if (! (bool) $binding->is_identity_key) {
                    continue;
                }
                $entity = (string) $binding->target_entity;
                $countsByEntity[$entity] = ($countsByEntity[$entity] ?? 0) + 1;
            }
        }

        foreach ($countsByEntity as $entity => $count) {
            if ($count > 1) {
                return PublishGuardResult::failed(
                    guardCode: $this->code(),
                    messageKey: 'form_builder_publish_guards.max_one_identity_key_per_target_entity',
                    context: ['entity' => $entity, 'count' => $count],
                );
            }
        }

        return PublishGuardResult::passed($this->code());
    }
}