<?php

declare( strict_types=1 );

namespace AcezSeo\Schema;

use AcezSeo\Schema\Types\OrganizationSchemaType;
use AcezSeo\Schema\Types\WebSiteSchemaType;
use AcezSeo\Support\MultilingualPluginDetector;

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

/**
 * Assembles the JSON-LD graph for pages without a WP_Post of their own —
 * taxonomy archives (TermSchemaOutput) and the blog index
 * (BlogIndexSchemaOutput).
 *
 * The page's CollectionPage node points at the WebSite node through
 * `isPartOf`, so the WebSite node is always part of the same graph — an
 * `@id` reference to a node the page never prints cannot be resolved by a
 * consumer. Organization follows its scope setting, exactly like on singular
 * posts; when it is absent, the WebSite node's `publisher` reference goes too
 * (same reference-integrity rule as SchemaGraphBuilder).
 */
final class ArchiveGraph
{
	private OrganizationSchemaType $organization;

	public function __construct( OrganizationSchemaType $organization )
	{
		$this->organization = $organization;
	}

	/**
	 * @param array<string, mixed> $page_node The page's own node (CollectionPage).
	 *
	 * @return array<string, mixed>
	 */
	public function build( array $page_node ): array
	{
		// An empty description says nothing — leave the property out rather
		// than print `"description": ""`.
		if ( isset( $page_node['description'] ) && '' === $page_node['description'] )
		{
			unset( $page_node['description'] );
		}

		$website = WebSiteSchemaType::node();
		$nodes   = array( $page_node, $website );

		if ( $this->organization->applies_to_archive() )
		{
			$nodes[] = $this->organization->node();
		}
		else
		{
			unset( $nodes[1]['publisher'] );
		}

		$language = MultilingualPluginDetector::current_language();

		foreach ( $nodes as $index => $node )
		{
			if ( ! isset( $node['inLanguage'] ) )
			{
				$nodes[ $index ]['inLanguage'] = $language;
			}
		}

		return array(
			'@context' => 'https://schema.org',
			'@graph'   => $nodes,
		);
	}

	/**
	 * Serializes a graph for wp_print_inline_script_tag(). JSON_HEX_TAG turns
	 * every literal "<"/">" into </>, so no dynamic string (a term
	 * name, a page title) can close the script element early — same flags as
	 * SchemaOutput::cached_json(), kept in sync.
	 *
	 * @param array<string, mixed> $graph
	 */
	public static function encode( array $graph ): ?string
	{
		$json = wp_json_encode(
			$graph,
			JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT
		);

		return is_string( $json ) ? $json : null;
	}
}