<?php

declare(strict_types=1);

namespace App\Constants\Common;


final class ClientIpRequestConstant
{
    /**
     * RFC 7239 标准的 Forwarded 头
     */
    public const int HEADER_FORWARDED = 0b000001;

    /**
     * 客户端原始 IP
     */
    public const int HEADER_X_FORWARDED_FOR = 0b000010;

    /**
     * 原始主机名
     */
    public const int HEADER_X_FORWARDED_HOST = 0b000100;

    /**
     * 原始协议 (http/https)
     */
    public const int HEADER_X_FORWARDED_PROTO = 0b001000;

    /**
     * 原始端口
     */
    public const int HEADER_X_FORWARDED_PORT = 0b010000;

    /**
     * 原始路径前缀
     */
    public const int HEADER_X_FORWARDED_PREFIX = 0b100000;

    /**
     * 将部分标志映射到 RFC 7239 Forwarded 头中的参数名
     */
    public const array FORWARDED_PARAMS = [
        self::HEADER_X_FORWARDED_FOR => 'for',
        self::HEADER_X_FORWARDED_HOST => 'host',
        self::HEADER_X_FORWARDED_PROTO => 'proto',
        self::HEADER_X_FORWARDED_PORT => 'host',
    ];

    /**
     * 将标志映射到实际的 HTTP 头名称
     */
    public const array TRUSTED_HEADERS = [
        self::HEADER_FORWARDED => 'forwarded',
        self::HEADER_X_FORWARDED_FOR => 'x-forwarded-for',
        self::HEADER_X_FORWARDED_HOST => 'x-forwarded-host',
        self::HEADER_X_FORWARDED_PROTO => 'x-forwarded-proto',
        self::HEADER_X_FORWARDED_PORT => 'x-forwarded-port',
        self::HEADER_X_FORWARDED_PREFIX => 'x-forwarded-prefix',
    ];
}