<?php
/**
 * Message templates with {variable} placeholders.
 *
 * @package Smsportal
 */

namespace Smsportal;

defined( 'ABSPATH' ) || exit;

/**
 * Fills {name} placeholders (letters, digits and _ : . - as in Contact Form 7 field names).
 * An empty or unknown variable disappears together with one adjacent space. Values go in whole. Built-in
 * variables answer to their Polish and English names alike (Smsportal\Variables).
 */
class Template {

	/**
	 * Render a template.
	 *
	 * @param string              $template Text with {name} placeholders.
	 * @param array<string,mixed> $vars     name => value (only scalar values are used).
	 * @return string
	 */
	public static function render( string $template, array $vars ): string {
		$vars = Variables::with_aliases( $vars );
		$text = preg_replace_callback(
			'/( ?)\{([A-Za-z0-9_:.\-]+)\}( ?)/',
			static function ( array $m ) use ( $vars ): string {
				$value = isset( $vars[ $m[2] ] ) && is_scalar( $vars[ $m[2] ] ) ? trim( (string) $vars[ $m[2] ] ) : '';
				if ( '' === $value ) {
					return $m[3];
				}
				return $m[1] . $value . $m[3];
			},
			$template
		);
		return trim( (string) preg_replace( '/ {2,}/', ' ', (string) $text ) );
	}
}