<?php

declare( strict_types=1 );

namespace AcezSeo\Import;

use AcezSeo\Data\PostMetaRepositoryInterface;
use AcezSeo\Data\TermMetaRepositoryInterface;

if ( ! defined( 'ABSPATH' ) )
{
	exit;
}

/**
 * Central lookup for SEO data importers. Extensible via the
 * `acez_seo_importers` filter without touching this class.
 */
final class ImporterRegistry
{
	/** @var array<string, SeoImporterInterface> */
	private array $importers = array();

	private PostMetaRepositoryInterface $post_meta;
	private TermMetaRepositoryInterface $term_meta;

	public function __construct( PostMetaRepositoryInterface $post_meta, TermMetaRepositoryInterface $term_meta )
	{
		$this->post_meta = $post_meta;
		$this->term_meta = $term_meta;
	}

	/**
	 * @return SeoImporterInterface[]
	 */
	public function all(): array
	{
		if ( array() === $this->importers )
		{
			$importers = array(
				new SlimSeoImporter( $this->post_meta, $this->term_meta ),
				new YoastImporter( $this->post_meta, $this->term_meta ),
				new AioseoImporter( $this->post_meta, $this->term_meta ),
			);

			/**
			 * Filters the list of available SEO data importers.
			 *
			 * @param SeoImporterInterface[] $importers
			 */
			$importers = (array) apply_filters( 'acez_seo_importers', $importers );

			foreach ( $importers as $importer )
			{
				if ( $importer instanceof SeoImporterInterface )
				{
					$this->importers[ $importer->get_id() ] = $importer;
				}
			}
		}

		return $this->importers;
	}

	/**
	 * @return SeoImporterInterface[] Only sources whose data is actually present.
	 */
	public function available(): array
	{
		return array_filter( $this->all(), static fn( SeoImporterInterface $importer ): bool => $importer->is_available() );
	}

	public function get( string $importer_id ): ?SeoImporterInterface
	{
		return $this->all()[ $importer_id ] ?? null;
	}
}