<?php

namespace TIOB\Importers\WP;
use WP_Error;

/**
 * WXR Parser that makes use of the SimpleXML PHP extension.
 */
class WXR_Parser_SimpleXML {
	/**
	 * @param string $file file path.
	 *
	 * @return array | WP_Error
	 */
	public function parse( $file ) {
		global $wp_filesystem;
		WP_Filesystem();

		if ( ! $wp_filesystem->exists( $file ) ) {
			return new WP_Error( 'SimpleXML_parse_error', 'The specified WXR file does not exist' );
		}

		$contents = $wp_filesystem->get_contents( $file );
		if ( empty( $contents ) ) {
			return new WP_Error( 'SimpleXML_parse_error', 'There was an error when reading this WXR file' );
		}

		$authors         = $posts = $categories = $tags = $terms = array();
		$internal_errors = libxml_use_internal_errors( true );
		$dom             = new \DOMDocument;
		$old_value       = null;
		if ( \PHP_VERSION_ID < 80000 && function_exists( 'libxml_disable_entity_loader' ) ) {
			$old_value = libxml_disable_entity_loader( true );
		}

		$success = $dom->loadXML( $contents );
		if ( ! is_null( $old_value ) ) {
			libxml_disable_entity_loader( $old_value );
		}
		if ( ! $success || isset( $dom->doctype ) ) {
			return new WP_Error( 'SimpleXML_parse_error', 'There was an error when reading this WXR file', libxml_get_errors() );
		}
		$xml = simplexml_import_dom( $dom );
		unset( $dom );
		// halt if loading produces an error
		if ( ! $xml ) {
			return new WP_Error( 'SimpleXML_parse_error', 'There was an error when reading this WXR file', libxml_get_errors() );
		}
		$wxr_version = $xml->xpath( '/rss/channel/wp:wxr_version' );
		if ( ! $wxr_version ) {
			return new WP_Error( 'WXR_parse_error', 'This does not appear to be a WXR file, missing/invalid WXR version number' );
		}
		$wxr_version = (string) trim( $wxr_version[0] );
		// confirm that we are dealing with the correct file format
		if ( ! preg_match( '/^\d+\.\d+$/', $wxr_version ) ) {
			return new WP_Error( 'WXR_parse_error', 'This does not appear to be a WXR file, missing/invalid WXR version number' );
		}
		$base_url      = $xml->xpath( '/rss/channel/wp:base_site_url' );
		$base_url      = (string) trim( $base_url[0] );
		$base_blog_url = $xml->xpath( '/rss/channel/wp:base_blog_url' );
		$base_blog_url = (string) trim( $base_blog_url[0] );
		$namespaces    = $xml->getDocNamespaces();
		if ( ! isset( $namespaces['wp'] ) ) {
			$namespaces['wp'] = 'http://wordpress.org/export/1.1/';
		}
		if ( ! isset( $namespaces['excerpt'] ) ) {
			$namespaces['excerpt'] = 'http://wordpress.org/export/1.1/excerpt/';
		}
		// grab authors
		foreach ( $xml->xpath( '/rss/channel/wp:author' ) as $author_arr ) {
			$a                 = $author_arr->children( $namespaces['wp'] );
			$login             = (string) $a->author_login;
			$authors[ $login ] = array(
				'author_id'           => (int) $a->author_id,
				'author_login'        => $login,
				'author_email'        => (string) $a->author_email,
				'author_display_name' => (string) $a->author_display_name,
				'author_first_name'   => (string) $a->author_first_name,
				'author_last_name'    => (string) $a->author_last_name,
			);
		}
		// grab cats, tags and terms
		foreach ( $xml->xpath( '/rss/channel/wp:category' ) as $term_arr ) {
			$t        = $term_arr->children( $namespaces['wp'] );
			$category = array(
				'term_id'              => (int) $t->term_id,
				'category_nicename'    => (string) $t->category_nicename,
				'category_parent'      => (string) $t->category_parent,
				'cat_name'             => (string) $t->cat_name,
				'category_description' => (string) $t->category_description,
			);
			foreach ( $t->termmeta as $meta ) {
				$category['termmeta'][] = array(
					'key'   => (string) $meta->meta_key,
					'value' => (string) $meta->meta_value,
				);
			}
			$categories[] = $category;
		}
		foreach ( $xml->xpath( '/rss/channel/wp:tag' ) as $term_arr ) {
			$t   = $term_arr->children( $namespaces['wp'] );
			$tag = array(
				'term_id'         => (int) $t->term_id,
				'tag_slug'        => (string) $t->tag_slug,
				'tag_name'        => (string) $t->tag_name,
				'tag_description' => (string) $t->tag_description,
			);
			foreach ( $t->termmeta as $meta ) {
				$tag['termmeta'][] = array(
					'key'   => (string) $meta->meta_key,
					'value' => (string) $meta->meta_value,
				);
			}
			$tags[] = $tag;
		}
		foreach ( $xml->xpath( '/rss/channel/wp:term' ) as $term_arr ) {
			$t    = $term_arr->children( $namespaces['wp'] );
			$term = array(
				'term_id'          => (int) $t->term_id,
				'term_taxonomy'    => (string) $t->term_taxonomy,
				'slug'             => (string) $t->term_slug,
				'term_parent'      => (string) $t->term_parent,
				'term_name'        => (string) $t->term_name,
				'term_description' => (string) $t->term_description,
			);
			foreach ( $t->termmeta as $meta ) {
				$term['termmeta'][] = array(
					'key'   => (string) $meta->meta_key,
					'value' => (string) $meta->meta_value,
				);
			}
			$terms[] = $term;
		}
		// grab posts
		foreach ( $xml->channel->item as $item ) {
			$post                   = array(
				'post_title' => (string) $item->title,
				'guid'       => (string) $item->guid,
			);
			$dc                     = $item->children( 'http://purl.org/dc/elements/1.1/' );
			$post['post_author']    = (string) $dc->creator;
			$content                = $item->children( 'http://purl.org/rss/1.0/modules/content/' );
			$excerpt                = $item->children( $namespaces['excerpt'] );
			$post['post_content']   = (string) $content->encoded;
			$post['post_excerpt']   = (string) $excerpt->encoded;
			$wp                     = $item->children( $namespaces['wp'] );
			$post['post_id']        = (int) $wp->post_id;
			$post['post_date']      = (string) $wp->post_date;
			$post['post_date_gmt']  = (string) $wp->post_date_gmt;
			$post['comment_status'] = (string) $wp->comment_status;
			$post['ping_status']    = (string) $wp->ping_status;
			$post['post_name']      = (string) $wp->post_name;
			$post['status']         = (string) $wp->status;
			$post['post_parent']    = (int) $wp->post_parent;
			$post['menu_order']     = (int) $wp->menu_order;
			$post['post_type']      = (string) $wp->post_type;
			$post['post_password']  = (string) $wp->post_password;
			$post['is_sticky']      = (int) $wp->is_sticky;
			if ( isset( $wp->attachment_url ) ) {
				$post['attachment_url'] = (string) $wp->attachment_url;
			}
			foreach ( $item->category as $c ) {
				$att = $c->attributes();
				if ( isset( $att['nicename'] ) ) {
					$post['terms'][] = array(
						'name'   => (string) $c,
						'slug'   => (string) $att['nicename'],
						'domain' => (string) $att['domain'],
					);
				}
			}
			foreach ( $wp->postmeta as $meta ) {
				$post['postmeta'][] = array(
					'key'   => (string) $meta->meta_key,
					'value' => (string) $meta->meta_value,
				);
			}
			foreach ( $wp->comment as $comment ) {
				$meta = array();
				if ( isset( $comment->commentmeta ) ) {
					foreach ( $comment->commentmeta as $m ) {
						$meta[] = array(
							'key'   => (string) $m->meta_key,
							'value' => (string) $m->meta_value,
						);
					}
				}
				$post['comments'][] = array(
					'comment_id'           => (int) $comment->comment_id,
					'comment_author'       => (string) $comment->comment_author,
					'comment_author_email' => (string) $comment->comment_author_email,
					'comment_author_IP'    => (string) $comment->comment_author_IP,
					'comment_author_url'   => (string) $comment->comment_author_url,
					'comment_date'         => (string) $comment->comment_date,
					'comment_date_gmt'     => (string) $comment->comment_date_gmt,
					'comment_content'      => (string) $comment->comment_content,
					'comment_approved'     => (string) $comment->comment_approved,
					'comment_type'         => (string) $comment->comment_type,
					'comment_parent'       => (string) $comment->comment_parent,
					'comment_user_id'      => (int) $comment->comment_user_id,
					'commentmeta'          => $meta,
				);
			}
			$posts[] = $post;
		}

		return array(
			'authors'       => $authors,
			'posts'         => $posts,
			'categories'    => $categories,
			'tags'          => $tags,
			'terms'         => $terms,
			'base_url'      => $base_url,
			'base_blog_url' => $base_blog_url,
			'version'       => $wxr_version,
		);
	}
}
