<?php
/**
 * Yoast SEO data reader.
 *
 * @package OrbitstemSEO
 */

namespace Orbitstem\SEO\Import;

defined( 'ABSPATH' ) || exit;

/**
 * Posts: _yoast_wpseo_* post meta (WPSEO_Meta). Terms: the wpseo_taxonomy_meta
 * option, an array of [taxonomy][term_id] => fields (WPSEO_Taxonomy_Meta).
 * Formats checked against Yoast SEO 28.7.
 */
class Yoast extends Source {

	/**
	 * Machine id.
	 *
	 * @return string
	 */
	public function id() {
		return 'yoast';
	}

	/**
	 * Display name.
	 *
	 * @return string
	 */
	public function name() {
		return 'Yoast SEO';
	}

	/**
	 * Post meta keys by Orbitstem field.
	 *
	 * @return array<string,string>
	 */
	protected function post_keys() {
		return array(
			'title'         => '_yoast_wpseo_title',
			'description'   => '_yoast_wpseo_metadesc',
			'canonical'     => '_yoast_wpseo_canonical',
			'noindex'       => '_yoast_wpseo_meta-robots-noindex',
			'nofollow'      => '_yoast_wpseo_meta-robots-nofollow',
			'focus_keyword' => '_yoast_wpseo_focuskw',
		);
	}

	/**
	 * Yoast variable names => Orbitstem variables.
	 *
	 * @return array<string,string>
	 */
	protected function variables() {
		return array(
			'title'                => '%title%',
			'sitename'             => '%sitename%',
			'sitedesc'             => '%tagline%',
			'sep'                  => '%sep%',
			'excerpt'              => '%excerpt%',
			'excerpt_only'         => '%excerpt%',
			'page'                 => '%page%',
			'term_title'           => '%term%',
			'term_description'     => '%term_description%',
			'category_description' => '%term_description%',
			'tag_description'      => '%term_description%',
			'name'                 => '%author%',
			'searchphrase'         => '%search%',
			'pt_plural'            => '%type%',
		);
	}

	/**
	 * Yoast variables: %%name%%, where the name may hold any character but %.
	 *
	 * @return string
	 */
	protected function token_pattern() {
		return '/%%([^%\s]+)%%/';
	}

	/**
	 * Post meta "1" = noindex/nofollow ("2" = forced index, "0" = default).
	 * Term option "noindex" = noindex.
	 *
	 * @param string $field Field.
	 * @param mixed  $raw   Stored value.
	 * @return bool
	 */
	protected function robots_flag( $field, $raw ) {
		if ( 'noindex' === $field && 'noindex' === $raw ) {
			return true;
		}
		return '1' === (string) $raw;
	}

	/**
	 * Templates from the wpseo_titles option (Search Appearance settings).
	 *
	 * @return array<string,string>
	 */
	public function templates() {
		$titles = get_option( 'wpseo_titles', array() );
		if ( ! is_array( $titles ) ) {
			return array();
		}
		$out        = array();
		$separators = array(
			'sc-dash'   => 'dash',
			'sc-ndash'  => 'ndash',
			'sc-mdash'  => 'mdash',
			'sc-pipe'   => 'pipe',
			'sc-middot' => 'middot',
			'sc-bull'   => 'bullet',
			'sc-raquo'  => 'raquo',
		);
		if ( isset( $titles['separator'], $separators[ $titles['separator'] ] ) ) {
			$out['separator'] = $separators[ $titles['separator'] ];
		}
		$keys = array(
			'title-home-wpseo'    => 'home_title',
			'metadesc-home-wpseo' => 'home_description',
			'title-author-wpseo'  => 'author_archive.title',
			'title-archive-wpseo' => 'date_archive.title',
			'title-search-wpseo'  => 'search_title',
			'title-404-wpseo'     => 'not_found_title',
		);
		foreach ( get_post_types( array( 'public' => true ) ) as $type ) {
			$keys[ 'title-' . $type ]    = 'post_types.' . $type . '.title';
			$keys[ 'metadesc-' . $type ] = 'post_types.' . $type . '.description';
		}
		foreach ( get_taxonomies( array( 'public' => true ) ) as $taxonomy ) {
			$keys[ 'title-tax-' . $taxonomy ]    = 'taxonomies.' . $taxonomy . '.title';
			$keys[ 'metadesc-tax-' . $taxonomy ] = 'taxonomies.' . $taxonomy . '.description';
		}
		foreach ( $keys as $yoast => $path ) {
			if ( isset( $titles[ $yoast ] ) && is_string( $titles[ $yoast ] ) && '' !== trim( $titles[ $yoast ] ) ) {
				$value = $this->convert_variables( $titles[ $yoast ] );
				if ( '' !== $value ) {
					$out[ $path ] = $value;
				}
			}
		}
		return $out;
	}

	/**
	 * Term data from the option, flattened to term_id => fields. Entries that
	 * hold only non-importable keys (focus keyword, scores) are skipped by the
	 * base class because they convert to empty values.
	 *
	 * @return array<int,array>
	 */
	private function term_map() {
		$option = get_option( 'wpseo_taxonomy_meta', array() );
		$map    = array();
		if ( ! is_array( $option ) ) {
			return $map;
		}
		foreach ( $option as $terms ) {
			if ( ! is_array( $terms ) ) {
				continue; // E.g. the top-level "wpseo_already_validated" flag.
			}
			foreach ( $terms as $term_id => $fields ) {
				if ( is_array( $fields ) ) {
					$map[ (int) $term_id ] = $fields;
				}
			}
		}
		ksort( $map );
		return $map;
	}

	/**
	 * Term IDs present in the option, after a cursor.
	 *
	 * @param int $after Last processed ID.
	 * @param int $limit Batch size.
	 * @return int[]
	 */
	protected function candidate_term_ids( $after, $limit ) {
		$ids = array_filter(
			array_keys( $this->term_map() ),
			function ( $id ) use ( $after ) {
				return $id > $after;
			}
		);
		return array_slice( array_values( $ids ), 0, $limit );
	}

	/**
	 * Raw values for one term.
	 *
	 * @param int $term_id Term ID.
	 * @return array
	 */
	protected function read_term_raw( $term_id ) {
		$map    = $this->term_map();
		$fields = isset( $map[ $term_id ] ) ? $map[ $term_id ] : array();
		return array(
			'title'       => isset( $fields['wpseo_title'] ) ? $fields['wpseo_title'] : '',
			'description' => isset( $fields['wpseo_desc'] ) ? $fields['wpseo_desc'] : '',
			'canonical'   => isset( $fields['wpseo_canonical'] ) ? $fields['wpseo_canonical'] : '',
			'noindex'     => isset( $fields['wpseo_noindex'] ) ? $fields['wpseo_noindex'] : '',
			'nofollow'    => '',
		);
	}
}