<?php

namespace AFEB\Modules\WPImport;

use WP_Error;

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

/**
 * "Vertex Addons for Elementor" XMLParser Class
 * 
 * @class XMLParser
 * @version 1.4.0
 */
class XMLParser
{
	private static $wp_tags = [
		'wp:post_id',
		'wp:post_date',
		'wp:post_date_gmt',
		'wp:comment_status',
		'wp:ping_status',
		'wp:attachment_url',
		'wp:status',
		'wp:post_name',
		'wp:post_parent',
		'wp:menu_order',
		'wp:post_type',
		'wp:post_password',
		'wp:is_sticky',
		'wp:term_id',
		'wp:category_nicename',
		'wp:category_parent',
		'wp:cat_name',
		'wp:category_description',
		'wp:tag_slug',
		'wp:tag_name',
		'wp:tag_description',
		'wp:term_taxonomy',
		'wp:term_parent',
		'wp:term_name',
		'wp:term_description',
		'wp:author_id',
		'wp:author_login',
		'wp:author_email',
		'wp:author_display_name',
		'wp:author_first_name',
		'wp:author_last_name',
	];

	private static $wp_sub_tags = [
		'wp:comment_id',
		'wp:comment_author',
		'wp:comment_author_email',
		'wp:comment_author_url',
		'wp:comment_author_IP',
		'wp:comment_date',
		'wp:comment_date_gmt',
		'wp:comment_content',
		'wp:comment_approved',
		'wp:comment_type',
		'wp:comment_parent',
		'wp:comment_user_id',
	];

	/**
	 * @var string
	 */
	private $wxr_version;

	/**
	 * @var string
	 */
	private $cdata;

	/**
	 * @var array
	 */
	private $data;

	/**
	 * @var array
	 */
	private $sub_data;

	/**
	 * @var boolean
	 */
	private $in_post;

	/**
	 * @var boolean
	 */
	private $in_tag;

	/**
	 * @var boolean
	 */
	private $in_sub_tag;

	/**
	 * @var array
	 */
	private $authors;

	/**
	 * @var array
	 */
	private $posts;

	/**
	 * @var array
	 */
	private $term;

	/**
	 * @var array
	 */
	private $category;

	/**
	 * @var array
	 */
	private $tag;

	/**
	 * @var string
	 */
	private $base_url;

	/**
	 * @var string
	 */
	private $base_blog_url;

	/**
	 * @param string $file
	 *
	 * @return array|WP_Error
	 */
	public function parse($file)
	{
		$this->clear();

		$xml = xml_parser_create('UTF-8');
		xml_parser_set_option($xml, XML_OPTION_SKIP_WHITE, 1);
		xml_parser_set_option($xml, XML_OPTION_CASE_FOLDING, 0);
		xml_set_object($xml, $this);

		xml_set_character_data_handler($xml, function ($parser, $cdata) {
			$this->cdata($cdata);
		});

		$tag_open_callback = function ($parse, $tag, $attr) {
			$this->tag_open($tag, $attr);
		};

		$tag_close_callback = function ($parser, $tag) {
			$this->tag_close($tag);
		};

		xml_set_element_handler($xml, $tag_open_callback, $tag_close_callback);

		if (!xml_parse($xml, file_get_contents($file), true)) {
			$current_line = xml_get_current_line_number($xml);
			$current_column = xml_get_current_column_number($xml);
			$error_code = xml_get_error_code($xml);
			$error_string = xml_error_string($error_code);

			return new WP_Error('XML_parse_error', 'There was an error when reading this WXR file', [
				$current_line,
				$current_column,
				$error_string,
			]);
		}
		xml_parser_free($xml);

		if (! preg_match('/^\d+\.\d+$/', $this->wxr_version))
			return new WP_Error('WXR_parse_error', esc_html__('This does not appear to be a WXR file, missing/invalid WXR version number', 'addons-for-elementor-builder'));

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

	private function tag_open($tag, $attr)
	{
		if (in_array($tag, self::$wp_tags)) {
			$this->in_tag = substr($tag, 3);

			return;
		}

		if (in_array($tag, self::$wp_sub_tags)) {
			$this->in_sub_tag = substr($tag, 3);

			return;
		}

		switch ($tag) {
			case 'category':
				if (isset($attr['domain'], $attr['nicename'])) {
					$this->sub_data['domain'] = $attr['domain'];
					$this->sub_data['slug'] = $attr['nicename'];
				}
				break;
			case 'item':
				$this->in_post = true;
				// No break !!!.
			case 'title':
				if ($this->in_post)
					$this->in_tag = 'post_title';
				break;
			case 'guid':
				$this->in_tag = 'guid';
				break;
			case 'dc:creator':
				$this->in_tag = 'post_author';
				break;
			case 'content:encoded':
				$this->in_tag = 'post_content';
				break;
			case 'excerpt:encoded':
				$this->in_tag = 'post_excerpt';
				break;

			case 'wp:term_slug':
				$this->in_tag = 'slug';
				break;
			case 'wp:meta_key':
				$this->in_sub_tag = 'key';
				break;
			case 'wp:meta_value':
				$this->in_sub_tag = 'value';
				break;
		}
	}

	private function cdata($cdata)
	{
		if (!trim($cdata))
			return;

		if (false !== $this->in_tag || false !== $this->in_sub_tag) {
			$this->cdata .= $cdata;
		} else {
			$this->cdata .= trim($cdata);
		}
	}

	private function tag_close($tag)
	{
		switch ($tag) {
			case 'wp:comment':
				unset($this->sub_data['key'], $this->sub_data['value']); // Remove meta sub_data.
				if (! empty($this->sub_data))
					$this->data['comments'][] = $this->sub_data;

				$this->sub_data = [];
				break;
			case 'wp:commentmeta':
				$this->sub_data['commentmeta'][] = [
					'key' => $this->sub_data['key'],
					'value' => $this->sub_data['value'],
				];
				break;
			case 'category':
				if (!empty($this->sub_data)) {
					$this->sub_data['name'] = $this->cdata;
					$this->data['terms'][] = $this->sub_data;
				}
				$this->sub_data = [];
				break;
			case 'wp:postmeta':
				if (!empty($this->sub_data))
					$this->data['postmeta'][] = $this->sub_data;

				$this->sub_data = [];
				break;
			case 'item':
				$this->posts[] = $this->data;
				$this->data = [];
				break;
			case 'wp:category':
			case 'wp:tag':
			case 'wp:term':
				$n = substr($tag, 3);
				array_push($this->$n, $this->data);
				$this->data = [];
				break;
			case 'wp:termmeta':
				if (! empty($this->sub_data))
					$this->data['termmeta'][] = $this->sub_data;

				$this->sub_data = [];
				break;
			case 'wp:author':
				if (!empty($this->data['author_login']))
					$this->authors[$this->data['author_login']] = $this->data;

				$this->data = [];
				break;
			case 'wp:base_site_url':
				$this->base_url = $this->cdata;
				if (!isset($this->base_blog_url))
					$this->base_blog_url = $this->cdata;

				break;
			case 'wp:base_blog_url':
				$this->base_blog_url = $this->cdata;
				break;
			case 'wp:wxr_version':
				$this->wxr_version = $this->cdata;
				break;

			default:
				if ($this->in_sub_tag) {
					$this->sub_data[$this->in_sub_tag] = $this->cdata;
					$this->in_sub_tag = false;
				} elseif ($this->in_tag) {
					$this->data[$this->in_tag] = $this->cdata;
					$this->in_tag = false;
				}
		}

		$this->cdata = '';
	}

	private function clear()
	{
		$this->wxr_version = '';

		$this->cdata = '';
		$this->data = [];
		$this->sub_data = [];

		$this->in_post = false;
		$this->in_tag = false;
		$this->in_sub_tag = false;

		$this->authors = [];
		$this->posts = [];
		$this->term = [];
		$this->category = [];
		$this->tag = [];
	}
}