<?php

declare(strict_types=1);

namespace App\FormBuilder\Publishing;

use App\Enums\FormBuilder\BindingTargetType;
use App\Enums\FormBuilder\FormFieldBindingMergeStrategy;
use App\Exceptions\FormBuilder\UnknownBindingTargetException;
use App\FormBuilder\Bindings\BindingTypeRegistry;
use App\Models\FormBuilder\FormField;
use App\Models\FormBuilder\FormFieldBinding;
use App\Models\FormBuilder\FormSchema;

/**
 * RFC-WS-6 §4 (V1) — Append is collection-only. Targets unknown to
 * BindingTypeRegistry fail with a distinct context payload so admins
 * see the actionable distinction.
 */
final readonly class AppendStrategyRequiresCollectionTarget implements PublishGuard
{
    public function __construct(private BindingTypeRegistry $registry) {}

    public function code(): string
    {
        return 'append_strategy_requires_collection_target';
    }

    public function evaluate(FormSchema $schema): PublishGuardResult
    {
        /** @var FormField $field */
        foreach ($schema->fields as $field) {
            /** @var FormFieldBinding $binding */
            foreach ($field->bindings as $binding) {
                if ($binding->merge_strategy !== FormFieldBindingMergeStrategy::Append) {
                    continue;
                }

                $entity = (string) $binding->target_entity;
                $attribute = (string) $binding->target_attribute;

                try {
                    $meta = $this->registry->resolve($entity, $attribute);
                } catch (UnknownBindingTargetException) {
                    return PublishGuardResult::failed(
                        guardCode: $this->code(),
                        messageKey: 'form_builder_publish_guards.append_strategy_requires_collection_target',
                        offendingFormFieldId: (string) $field->id,
                        context: [
                            'reason' => 'unknown_target',
                            'entity' => $entity,
                            'attribute' => $attribute,
                        ],
                    );
                }

                if ($meta->type !== BindingTargetType::COLLECTION) {
                    return PublishGuardResult::failed(
                        guardCode: $this->code(),
                        messageKey: 'form_builder_publish_guards.append_strategy_requires_collection_target',
                        offendingFormFieldId: (string) $field->id,
                        context: [
                            'reason' => 'scalar_target',
                            'entity' => $entity,
                            'attribute' => $attribute,
                            'target_type' => $meta->type->value,
                        ],
                    );
                }
            }
        }

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