<?php

namespace Glovario\Frontend;

use Glovario\Domain\BuiltinVariables;
use Glovario\Domain\Renderer;
use Glovario\Domain\TokenParser;
use Glovario\Domain\VariableResolver;

defined( 'ABSPATH' ) || exit;

final class TitleShortcodes {
	const OPTION = 'glovario_title_shortcodes';

	private $resolver;

	public function __construct( VariableResolver $resolver ) {
		$this->resolver = $resolver;
	}

	public function register() {
		if ( '1' !== get_option( self::OPTION, '0' ) ) {
			return;
		}
		add_filter( 'the_title', array( $this, 'filter' ), 10, 2 );
		add_filter( 'single_post_title', array( $this, 'filter' ), 10, 2 );
		add_filter( 'nav_menu_item_title', array( $this, 'filter_menu_title' ), 10, 2 );
		add_filter( 'render_block_core/navigation', array( $this, 'filter_navigation_block' ), 10, 2 );
		add_filter( 'render_block_core/navigation-link', array( $this, 'filter_navigation_block' ), 10, 2 );
		add_filter( 'render_block_core/navigation-submenu', array( $this, 'filter_navigation_block' ), 10, 2 );
		add_filter( 'render_block_core/page-list', array( $this, 'filter_navigation_block' ), 10, 2 );
		// Automatic slugs come from the resolved title, only while a post is saved or previewed.
		add_filter( 'wp_insert_post_data', array( $this, 'filter_post_slug' ), 10, 3 );
		add_filter( 'get_sample_permalink', array( $this, 'filter_sample_permalink' ), 10, 5 );
	}

	public function filter( $title, $post = 0 ) {
		if ( false === strpos( $title, '[glvr' ) || ! $this->should_resolve( $title, $post ) ) {
			return $title;
		}

		$pattern = get_shortcode_regex( array( 'glvr' ) );
		return preg_replace_callback(
			'/' . $pattern . '/',
			function ( $matches ) use ( $post ) {
				if ( '[' === $matches[1] && ']' === $matches[6] ) {
					return substr( $matches[0], 1, -1 );
				}
				return esc_html( $this->render_match( $matches, $post ) );
			},
			$title
		);
	}

	/**
	 * Build an automatic slug from the resolved title, so a published post
	 * titled "Call [glvr key=…] now" gets "call-harbor-view-now". Runs only
	 * while a post is saved, and only when WordPress made the slug from the
	 * title (no slug was submitted).
	 *
	 * @param array $data                Slashed post data about to be saved.
	 * @param array $postarr             Sanitized post data.
	 * @param array $unsanitized_postarr Post data as submitted.
	 * @return array
	 */
	public function filter_post_slug( $data, $postarr = array(), $unsanitized_postarr = array() ) {
		$submitted = is_array( $unsanitized_postarr ) ? (string) ( $unsanitized_postarr['post_name'] ?? '' ) : '';
		$status    = (string) ( $data['post_status'] ?? '' );
		$title     = wp_unslash( (string) ( $data['post_title'] ?? '' ) );
		if ( '' !== $submitted || in_array( $status, array( 'draft', 'pending', 'auto-draft' ), true ) || false === strpos( $title, '[glvr' ) ) {
			return $data;
		}
		$slug = sanitize_title( $this->slug_source( $title ) );
		if ( '' !== $slug ) {
			$post_id           = absint( is_array( $postarr ) ? ( $postarr['ID'] ?? 0 ) : 0 );
			$data['post_name'] = wp_unique_post_slug( $slug, $post_id, $status, (string) ( $data['post_type'] ?? 'post' ), absint( $data['post_parent'] ?? 0 ) );
		}
		return $data;
	}

	/**
	 * Show the same automatic slug in the editors' permalink preview (the
	 * Classic Editor's permalink and the block editor's generated slug).
	 *
	 * @param array    $permalink Permalink template and slug.
	 * @param int      $post_id   Post ID.
	 * @param string   $title     Title given to the preview, if any.
	 * @param string   $name      Slug given to the preview, if any.
	 * @param \WP_Post $post      Post.
	 * @return array
	 */
	public function filter_sample_permalink( $permalink, $post_id, $title = null, $name = null, $post = null ) {
		$post = get_post( $post ? $post : $post_id );
		if ( ! $post || ! is_array( $permalink ) || '' !== (string) $name || '' !== (string) $post->post_name ) {
			return $permalink;
		}
		$title = null !== $name && null !== $title ? (string) $title : (string) $post->post_title;
		if ( false === strpos( $title, '[glvr' ) ) {
			return $permalink;
		}
		$slug = sanitize_title( $this->slug_source( $title ) );
		if ( '' !== $slug ) {
			$permalink[1] = wp_unique_post_slug( $slug, $post->ID, 'publish', $post->post_type, $post->post_parent );
		}
		return $permalink;
	}

	/**
	 * A title with every Site Variable shortcode replaced by its plain value.
	 *
	 * @param string $title Unslashed title.
	 * @return string
	 */
	private function slug_source( $title ) {
		$resolved = preg_replace_callback(
			'/' . get_shortcode_regex( array( 'glvr' ) ) . '/',
			function ( $matches ) {
				if ( '[' === $matches[1] && ']' === $matches[6] ) {
					return substr( $matches[0], 1, -1 );
				}
				return $this->render_match( $matches, 0 );
			},
			$title
		);
		return null === $resolved ? $title : $resolved;
	}

	public function filter_menu_title( $title, $item ) {
		$post_id = is_object( $item ) && 'post_type' === ( $item->type ?? '' ) ? absint( $item->object_id ?? 0 ) : 0;
		return $this->filter( $title, $post_id );
	}

	public function filter_navigation_block( $content, $block ) {
		$post_id = isset( $block['attrs']['id'] ) ? absint( $block['attrs']['id'] ) : get_the_ID();
		return $this->filter( $content, $post_id );
	}

	private function should_resolve( $title, $post ) {
		$allowed = ! ( is_admin() && ! wp_doing_ajax() );
		if ( defined( 'REST_REQUEST' ) && REST_REQUEST ) {
			$allowed = false;
		}
		// The menu editor fills new items from titles over AJAX. A resolved title
		// would be saved as a fixed label and never follow the variable again.
		$action = isset( $_REQUEST['action'] ) ? sanitize_key( wp_unslash( $_REQUEST['action'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Read-only routing.
		if ( wp_doing_ajax() && in_array( $action, array( 'add-menu-item', 'menu-get-metabox', 'menu-quick-search', 'menu-locations-save' ), true ) ) {
			$allowed = false;
		}
		/**
		 * Filters whether Site Variable shortcodes should resolve in a title.
		 *
		 * @param bool                  $allowed Whether title resolution is enabled in this request.
		 * @param string                $title   Original title.
		 * @param int|\WP_Post|mixed     $post    Post identifier or object supplied by WordPress.
		 */
		return (bool) apply_filters( 'glovario_should_resolve_title_shortcodes', $allowed, $title, $post );
	}

	/**
	 * Every Site Variable shortcode and token in a text replaced with its value as
	 * plain text (tags removed, not HTML-escaped), for strings that their consumer
	 * escapes itself, such as the titles and descriptions of SEO plugins.
	 *
	 * @param string            $text Text.
	 * @param int|\WP_Post|null $post Post giving the resolution context.
	 * @return string
	 */
	public function plain( $text, $post = 0 ) {
		if ( ! is_string( $text ) || ( false === strpos( $text, '[glvr' ) && false === strpos( $text, '{{glvr:' ) ) ) {
			return $text;
		}
		if ( false !== strpos( $text, '[glvr' ) ) {
			$resolved = preg_replace_callback(
				'/' . get_shortcode_regex( array( 'glvr' ) ) . '/',
				function ( $matches ) use ( $post ) {
					if ( '[' === $matches[1] && ']' === $matches[6] ) {
						return substr( $matches[0], 1, -1 );
					}
					return $this->render_match( $matches, $post );
				},
				$text
			);
			$text     = null === $resolved ? $text : $resolved;
		}
		return ( new TokenParser() )->replace(
			$text,
			function ( $key, $original, $date_format ) use ( $post ) {
				return $this->render_key( $key, $post, $date_format, $original );
			}
		);
	}

	private function render_match( $matches, $post ) {
		$attributes = shortcode_atts(
			array(
				'key'      => '',
				'fallback' => '',
				'format'   => BuiltinVariables::DEFAULT_DATE_FORMAT,
			),
			shortcode_parse_atts( $matches[3] ),
			'glvr'
		);
		return $this->render_key( sanitize_key( $attributes['key'] ), $post, $attributes['format'], $attributes['fallback'] );
	}

	private function render_key( $key, $post, $format, $fallback ) {
		$post       = get_post( $post );
		$context    = array(
			'post_id'   => $post ? $post->ID : 0,
			'post_type' => $post ? $post->post_type : '',
			'source'    => 'title',
		);
		if ( BuiltinVariables::CURRENT_DATE_KEY === $key ) {
			$context['date_format'] = BuiltinVariables::sanitize_date_format( $format );
		}
		$resolved   = $key ? $this->resolver->resolve( $key, $context ) : null;
		$value      = $resolved ? $resolved['value'] : $fallback;
		$type       = $resolved ? $resolved['variable']['type'] : 'text';
		$value      = $resolved ? Renderer::text( $value, $type ) : $value;
		$value      = trim( preg_replace( '/\s+/', ' ', wp_strip_all_tags( (string) $value ) ) );

		/**
		 * Filters the plain-text value inserted into a title, menu label, or navigation block.
		 *
		 * Titles, menus, and navigation blocks HTML-escape the result, so it is safe in
		 * text and in attributes such as a navigation link's title.
		 *
		 * @param string $value   Plain-text value.
		 * @param string $key     Variable key.
		 * @param string $type    Variable type.
		 * @param array  $context Resolution context.
		 */
		return (string) apply_filters( 'glovario_title_variable_value', $value, $key, $type, $context );
	}
}