<?php
/**
 * One-click migration from Yoast SEO, Rank Math and All in One SEO. Copies only into fields that are still blank,
 * so it is safe to run repeatedly and never overwrites anything written in Sentrixa SEO.
 */

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

class SXSEO_Importer {

	/** source => array of [their_meta_key => our_key] */
	private static function maps() {
		return array(
			'yoast'    => array(
				'_yoast_wpseo_title'                => 'title',
				'_yoast_wpseo_metadesc'             => 'desc',
				'_yoast_wpseo_focuskw'              => 'focus',
				'_yoast_wpseo_canonical'            => 'canonical',
				'_yoast_wpseo_opengraph-title'      => 'og_title',
				'_yoast_wpseo_opengraph-description'=> 'og_desc',
				'_yoast_wpseo_opengraph-image'      => 'og_image',
			),
			'rankmath' => array(
				'rank_math_title'         => 'title',
				'rank_math_description'   => 'desc',
				'rank_math_focus_keyword' => 'focus',
				'rank_math_canonical_url' => 'canonical',
			),
			'sentrixa-theme' => array(
				'_sxa_seo_title'    => 'title',
				'_sxa_seo_desc'     => 'desc',
				'_sxa_seo_keywords' => 'keywords',
			),
			'aioseo'   => array(
				'_aioseo_title'       => 'title',
				'_aioseo_description' => 'desc',
				'_aioseo_keywords'    => 'keywords',
			),
		);
	}

	/** Which other SEO plugins left data behind: [source => number of posts]. */
	public static function detect() {
		global $wpdb;
		$found = array();
		foreach ( self::maps() as $src => $map ) {
			$keys = array_keys( $map );
			$in   = implode( ',', array_fill( 0, count( $keys ), '%s' ) );
			$n    = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(DISTINCT post_id) FROM {$wpdb->postmeta} WHERE meta_key IN ($in) AND meta_value <> ''", $keys ) ); // phpcs:ignore WordPress.DB
			if ( $n ) {
				$found[ $src ] = $n;
			}
		}
		return $found;
	}

	/** @return array source => number of values copied */
	public static function run() {
		global $wpdb;
		$done = array();
		foreach ( self::maps() as $src => $map ) {
			$count = 0;
			foreach ( $map as $theirs => $ours ) {
				$count += (int) $wpdb->query(
					$wpdb->prepare(
						"INSERT INTO {$wpdb->postmeta} (post_id, meta_key, meta_value)
						 SELECT s.post_id, %s, REPLACE(s.meta_value, CONCAT(CHAR(37), CHAR(37)), CHAR(37))
						 FROM {$wpdb->postmeta} s
						 WHERE s.meta_key = %s AND s.meta_value <> ''
						 AND NOT EXISTS (SELECT 1 FROM {$wpdb->postmeta} t WHERE t.post_id = s.post_id AND t.meta_key = %s AND t.meta_value <> '')",
						SXSEO_Fields::PREFIX . $ours,
						$theirs,
						SXSEO_Fields::PREFIX . $ours
					)
				); // phpcs:ignore WordPress.DB
			}
			if ( 'yoast' === $src ) {
				$count += (int) $wpdb->query(
					"INSERT INTO {$wpdb->postmeta} (post_id, meta_key, meta_value)
					 SELECT s.post_id, '_sxseo_noindex', '1' FROM {$wpdb->postmeta} s
					 WHERE s.meta_key = '_yoast_wpseo_meta-robots-noindex' AND s.meta_value = '1'
					 AND NOT EXISTS (SELECT 1 FROM {$wpdb->postmeta} t WHERE t.post_id = s.post_id AND t.meta_key = '_sxseo_noindex')"
				); // phpcs:ignore WordPress.DB
			}
			if ( $count ) {
				$done[ $src ] = $count;
			}
		}
		// The Sentrixa theme stores its social image as an attachment ID; ours stores the URL.
		$rows = $wpdb->get_results( "SELECT post_id, meta_value FROM {$wpdb->postmeta} WHERE meta_key = '_sxa_seo_og_image' AND meta_value <> ''" ); // phpcs:ignore WordPress.DB
		foreach ( $rows as $r ) {
			$url = wp_get_attachment_image_url( (int) $r->meta_value, 'full' );
			if ( $url && '' === (string) get_post_meta( $r->post_id, '_sxseo_og_image', true ) ) {
				update_post_meta( $r->post_id, '_sxseo_og_image', esc_url_raw( $url ) );
				$done['sentrixa-theme'] = ( $done['sentrixa-theme'] ?? 0 ) + 1;
			}
		}
		// Rank Math keeps several focus keywords as "a, b, c": keep the first.
		$rows = $wpdb->get_results( "SELECT meta_id, meta_value FROM {$wpdb->postmeta} WHERE meta_key = '_sxseo_focus' AND meta_value LIKE '%,%'" ); // phpcs:ignore WordPress.DB
		foreach ( $rows as $r ) {
			$wpdb->update( $wpdb->postmeta, array( 'meta_value' => trim( explode( ',', $r->meta_value )[0] ) ), array( 'meta_id' => $r->meta_id ) );
		}
		SXSEO_Sitemap::purge();
		return $done;
	}
}