<?php

declare( strict_types=1 );

namespace AcezSeo\Schema;

use AcezSeo\Data\FeaturesRepositoryInterface;
use AcezSeo\Meta\BlogIndexResolver;
use AcezSeo\Support\SeoPluginDetector;

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

/**
 * Prints the JSON-LD graph for the blog index ("latest posts" front page or a
 * separate "Posts page" — see CurrentBlogIndex): a CollectionPage node plus
 * the site-level nodes it references (ArchiveGraph).
 *
 * Not cached, unlike SchemaOutput/TermSchemaOutput: the graph is built from a
 * handful of options already loaded on every request (no queries worth
 * saving), and site name / tagline changes do not bump CacheVersion, so a
 * cached copy could only go stale.
 */
final class BlogIndexSchemaOutput
{
	private BlogIndexResolver $resolver;
	private FeaturesRepositoryInterface $features;
	private ArchiveGraph $archive_graph;

	public function __construct( BlogIndexResolver $resolver, FeaturesRepositoryInterface $features, ArchiveGraph $archive_graph )
	{
		$this->resolver      = $resolver;
		$this->features      = $features;
		$this->archive_graph = $archive_graph;
	}

	public function register(): void
	{
		add_action( 'wp_head', array( $this, 'print_schema' ), 10 );
	}

	public function print_schema(): void
	{
		if ( ! $this->should_handle() || ! $this->features->enabled( 'schema' ) || ! $this->resolver->applies_to_schema() )
		{
			return;
		}

		$json = ArchiveGraph::encode( $this->archive_graph->build( $this->collection_page() ) );

		if ( ! is_string( $json ) )
		{
			return;
		}

		// Same printer and reasoning as SchemaOutput::print_schema():
		// wp_print_inline_script_tag() refuses text that could close the
		// element early and does not html-escape the JSON body.
		wp_print_inline_script_tag( $json, array( 'type' => 'application/ld+json' ) );
	}

	/**
	 * @return array<string, mixed>
	 */
	private function collection_page(): array
	{
		$url = $this->resolver->canonical();

		$node = array(
			'@type'       => 'CollectionPage',
			'@id'         => $url . '#collectionpage',
			'url'         => $url,
			'name'        => $this->resolver->name(),
			'description' => $this->resolver->description(),
			'isPartOf'    => array( '@id' => SchemaIds::website() ),
		);

		/**
		 * Filters the CollectionPage schema node of the blog index.
		 *
		 * @param array<string, mixed> $node
		 * @param \WP_Post|null         $posts_page The "Posts page", or null on a "latest posts" front page.
		 */
		return (array) apply_filters( 'acez_seo_blog_index_collection_page', $node, $this->resolver->posts_page() );
	}

	private function should_handle(): bool
	{
		return (bool) apply_filters( 'acez_seo_should_handle_schema', ! SeoPluginDetector::has_conflict() );
	}
}