<?php
/**
 * Helpers the sources share.
 *
 * @package ElevenRank
 * @since   1.0.0
 */

namespace ElevenRank\Modules\Import;

use ElevenRank\Modules\Meta\Keys;
use ElevenRank\Sanitize;

defined( 'ABSPATH' ) || exit;

/**
 * Small, side-effect free functions for reading other plugins' data.
 *
 * @since 1.0.0
 */
final class Source_Support {

	/**
	 * The id of a media library image, from an id and/or an address a plugin stored.
	 *
	 * @since 1.0.0
	 *
	 * @param mixed  $id  Stored attachment id.
	 * @param string $url Stored image address.
	 * @return int Zero when the image is not in the media library.
	 */
	public static function image_id( $id, string $url = '' ): int {
		$id = is_numeric( $id ) ? (int) $id : 0;

		if ( $id > 0 && wp_attachment_is_image( $id ) ) {
			return $id;
		}

		if ( '' !== $url && 1 === preg_match( '#^https?://#i', $url ) ) {
			return (int) attachment_url_to_postid( $url );
		}

		return 0;
	}

	/**
	 * Unserializes a value another plugin stored, without ever creating objects.
	 *
	 * @since 1.0.0
	 *
	 * @param mixed $value Stored value.
	 * @return mixed The value; arrays come back as arrays, anything that is not serialized as it was.
	 */
	public static function unserialize( $value ) {
		if ( ! is_string( $value ) || ! is_serialized( $value ) ) {
			return $value;
		}

		return unserialize( $value, array( 'allowed_classes' => false ) ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.serialize_unserialize -- Data another plugin stored; classes are not allowed.
	}

	/**
	 * Keywords from a comma-separated list: at most five, without empty ones.
	 *
	 * @since 1.0.0
	 *
	 * @param string $items Text such as `one, two`.
	 * @return string[]
	 */
	public static function keywords( string $items ): array {
		return Sanitize::keywords( array_map( 'trim', explode( ',', $items ) ) );
	}

	/**
	 * Drops fields that have nothing in them. Zero and false are values; empty strings and arrays are not.
	 *
	 * @since 1.0.0
	 *
	 * @param array<string, mixed> $fields Fields.
	 * @return array<string, mixed>
	 */
	public static function filled( array $fields ): array {
		return array_filter(
			$fields,
			static function ( $value ) {
				return ! ( '' === $value || array() === $value || null === $value || 0 === $value );
			}
		);
	}

	/**
	 * The ElevenRank meta keys that hold a template, which need their variables converted.
	 *
	 * @since 1.0.0
	 *
	 * @return string[]
	 */
	public static function template_keys(): array {
		return array( Keys::TITLE, Keys::DESCRIPTION, Keys::OG_TITLE, Keys::OG_DESCRIPTION, Keys::TWITTER_TITLE, Keys::TWITTER_DESCRIPTION );
	}

	/**
	 * Reads the meta of a set of objects in one query.
	 *
	 * @since 1.0.0
	 *
	 * @param string $table     Meta table (`postmeta`, `termmeta` or `usermeta`) without prefix.
	 * @param string $id_column `post_id`, `term_id` or `user_id`.
	 * @param int[]  $ids       Object ids.
	 * @param string $prefix    Only meta keys that start with this.
	 * @return array<int, array<string, string>> Values by object id and meta key.
	 */
	public static function meta_for( string $table, string $id_column, array $ids, string $prefix ): array {
		global $wpdb;

		if ( ! $ids ) {
			return array();
		}

		$ids   = array_map( 'absint', $ids );
		$rows  = array();
		$place = implode( ',', array_fill( 0, count( $ids ), '%d' ) );

		// phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching,WordPress.DB.PreparedSQL.InterpolatedNotPrepared,WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare,WordPress.DB.PreparedSQLPlaceholders.ReplacementsWrongNumber
		$found = $wpdb->get_results(
			$wpdb->prepare( "SELECT %i AS object_id, meta_key, meta_value FROM %i WHERE %i IN ({$place}) AND meta_key LIKE %s", array_merge( array( $id_column, $wpdb->prefix . $table, $id_column ), $ids, array( $wpdb->esc_like( $prefix ) . '%' ) ) ),
			ARRAY_A
		);
		// phpcs:enable

		foreach ( is_array( $found ) ? $found : array() as $row ) {
			$rows[ (int) $row['object_id'] ][ (string) $row['meta_key'] ] = (string) $row['meta_value'];
		}

		return $rows;
	}

	/**
	 * Ids of objects that have at least one meta key with a prefix, in id order, after a cursor.
	 *
	 * @since 1.0.0
	 *
	 * @param string $table     Meta table without prefix: `postmeta`, `termmeta` or `usermeta`.
	 * @param string $id_column `post_id`, `term_id` or `user_id`.
	 * @param string $prefix    Meta key prefix.
	 * @param int    $after     Only ids above this.
	 * @param int    $limit     Most ids.
	 * @return int[]
	 */
	public static function ids_with_meta( string $table, string $id_column, string $prefix, int $after, int $limit ): array {
		global $wpdb;

		// phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
		$ids = $wpdb->get_col(
			$wpdb->prepare( 'SELECT DISTINCT %i FROM %i WHERE meta_key LIKE %s AND %i > %d ORDER BY %i ASC LIMIT %d', $id_column, $wpdb->prefix . $table, $wpdb->esc_like( $prefix ) . '%', $id_column, $after, $id_column, $limit )
		);
		// phpcs:enable

		return array_map( 'intval', is_array( $ids ) ? $ids : array() );
	}

	/**
	 * Number of objects that have at least one meta key with a prefix.
	 *
	 * @since 1.0.0
	 *
	 * @param string $table     Meta table without prefix.
	 * @param string $id_column Id column.
	 * @param string $prefix    Meta key prefix.
	 * @return int
	 */
	public static function count_with_meta( string $table, string $id_column, string $prefix ): int {
		global $wpdb;

		// phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
		return (int) $wpdb->get_var(
			$wpdb->prepare( 'SELECT COUNT(DISTINCT %i) FROM %i WHERE meta_key LIKE %s', $id_column, $wpdb->prefix . $table, $wpdb->esc_like( $prefix ) . '%' )
		);
		// phpcs:enable
	}
}