<?php

namespace Reservair\Templating;

/** Holds the mapping from custom element tag names to their handlers. */
class RsvTemplateRegistry {
    /** @var array<string, RsvTemplateElement> */
    private array $elements = [];

    public function register(string $tag, RsvTemplateElement $element): void {
        $this->elements[$tag] = $element;
    }

    public function get(string $tag): ?RsvTemplateElement {
        return $this->elements[$tag] ?? null;
    }

    /** @return array<string, RsvTemplateElement> */
    public function all(): array {
        return $this->elements;
    }

    /**
     * Extends a wp_kses allowlist so the registered custom elements survive
     * sanitization of admin HTML. Each element contributes its tag and the
     * attributes it declares via symbols().
     *
     * @param array<string, mixed> $base A wp_kses allowed-html map to extend.
     * @return array<string, mixed>
     */
    public function kses_allowed(array $base = []): array {
        foreach ($this->elements as $tag => $element) {
            $attributes = [];
            foreach ($element->symbols() as $name) {
                $attributes[$name] = true;
            }
            $base[$tag] = $attributes;
        }
        return $base;
    }
}