<?php

class AMP_HTML_Utils {
	public static function build_tag( $tag_name, $attributes = array(), $content = '' ) {
		$attr_string = self::build_attributes_string( $attributes );
		return sprintf( '<%1$s %2$s>%3$s</%1$s>', sanitize_key( $tag_name ), $attr_string, $content );
	}

	public static function build_attributes_string( $attributes ) {
		$string = array();
		foreach ( $attributes as $name => $value ) {
			if ( '' === $value ) {
				$string[] = sprintf( '%s', sanitize_key( $name ) );
			} else {
				$string[] = sprintf( '%s="%s"', sanitize_key( $name ), esc_attr( $value ) );
			}
		}
		return implode( ' ', $string );
	}

	public static function is_valid_json( $data ) {
		if ( ! empty( $data ) ) {
			$decoded = json_decode( $data );
			if ( function_exists( 'json_last_error' ) ) {
				return ( json_last_error() === JSON_ERROR_NONE );
			} else { // PHP 5.2 back-compatibility
				return null !== $decoded;
			}
		}
		return false;
	}
}