<?php
// Serialiser.php
// Created: 2022-01-13
// Updated: 2022-02-27

namespace Index\Serialisation;

use Index\IO\Stream;

/**
 * Base class for Serialisers.
 */
abstract class Serialiser {
    /**
     * Returns a global Base32Serialiser instance with default settings.
     *
     * @return Base32Serialiser
     */
    public static function base32(): Base32Serialiser {
        static $instance = null;
        if($instance === null)
            $instance = new Base32Serialiser;
        return $instance;
    }

    /**
     * Returns a global Base62Serialiser instance with default settings.
     *
     * @return Base62Serialiser
     */
    public static function base62(): Base62Serialiser {
        static $instance = null;
        if($instance === null)
            $instance = new Base62Serialiser;
        return $instance;
    }

    /**
     * Returns a global Base64Serialiser instance with default settings.
     *
     * @return Base64Serialiser
     */
    public static function base64(): Base64Serialiser {
        static $instance = null;
        if($instance === null)
            $instance = new Base64Serialiser;
        return $instance;
    }

    /**
     * Returns a global UriBase64Serialiser instance with default settings.
     *
     * @return UriBase64Serialiser
     */
    public static function uriBase64(): UriBase64Serialiser {
        static $instance = null;
        if($instance === null)
            $instance = new UriBase64Serialiser;
        return $instance;
    }

    /**
     * Returns a global JsonSerialiser instance with default settings.
     *
     * @return JsonSerialiser
     */
    public static function json(): JsonSerialiser {
        static $instance = null;
        if($instance === null)
            $instance = new JsonSerialiser;
        return $instance;
    }

    /**
     * Returns a global BencodeSerialiser instance with default settings.
     *
     * @return BencodeSerialiser
     */
    public static function bencode(): BencodeSerialiser {
        static $instance = null;
        if($instance === null)
            $instance = new BencodeSerialiser;
        return $instance;
    }

    /**
     * Serialises data to a stringable format.
     *
     * @param mixed $input Data to be serialised.
     * @return string Serialised representation of the input data.
     */
    abstract public function serialise(mixed $input): string;

    /**
     * Deserialises a stringable format into data.
     *
     * @param Stream|string $input String or stream to be deserialised.
     * @return mixed Deserialised data of the input string.
     */
    abstract public function deserialise(Stream|string $input): mixed;

    /**
     * Serialises data to a stringable format into stream.
     *
     * @param mixed $input Data to be serialised.
     * @param Stream $output Target stream.
     */
    public function serialiseToStream(mixed $input, Stream $output): void {
        $output->write($this->serialise($input));
    }
}