<?php
namespace PressForeImporter\Parser;

/**
 * WXR Parser that makes use of the XML Parser PHP extension.
 */
class WXR_Parser_XML {
    var $wp_tags = array(
        '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: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',
    );
    var $wp_sub_tags = array(
        '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',
    );

    function parse( $file ) {
        $this->wxr_version = $this->in_post = $this->cdata = $this->data = $this->sub_data = $this->in_tag = $this->in_sub_tag = false;
        $this->authors = $this->posts = $this->term = array();

        $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, 'cdata' );
        xml_set_element_handler( $xml, 'tag_open', 'tag_close' );

        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', array( $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', __( 'This does not appear to be a WXR file, missing/invalid WXR version number', 'wordpress-importer' ) );

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

    function tag_open( $parse, $tag, $attr ) {
        if ( in_array( $tag, $this->wp_tags ) ) {
            $this->in_tag = substr( $tag, 3 );
            return;
        }

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

        switch ( $tag ) {
            case 'item': $this->in_post = true;
            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;
        }
    }

    function cdata( $parser, $cdata ) {
        if ( ! trim( $cdata ) )
            return;

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

    function tag_close( $parser, $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 = false;
                break;
            case 'wp:commentmeta':
                $this->sub_data['commentmeta'][] = array(
                    '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 = false;
                break;
            case 'wp:postmeta':
                if ( ! empty( $this->sub_data ) )
                    $this->data['postmeta'][] = $this->sub_data;
                $this->sub_data = false;
                break;
            case 'item':
                $this->posts[] = $this->data;
                $this->data = false;
                break;
            case 'wp:term':
                $n = substr( $tag, 3 );
                array_push( $this->$n, $this->data );
                $this->data = false;
                break;
            case 'wp:author':
                if ( ! empty($this->data['author_login']) )
                    $this->authors[$this->data['author_login']] = $this->data;
                $this->data = false;
                break;
            case 'wp:base_site_url':
                $this->base_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] = ! empty( $this->cdata ) ? $this->cdata : '';
                    $this->in_sub_tag = false;
                } else if ( $this->in_tag ) {
                    $this->data[$this->in_tag] = ! empty( $this->cdata ) ? $this->cdata : '';
                    $this->in_tag = false;
                }
        }

        $this->cdata = false;
    }
}