<?php

namespace app\extra\ip2region\xdb;

const IPv4VersionNo    = 4;

class IPv4
{
    public $id;
    public $name;
    public $bytes;
    public $segmentIndexSize;

    private static $C = null;
    public static function default() {
        if (self::$C == null) {
            // 14 = 4 + 4 + 2 + 4
            self::$C = new self(IPv4VersionNo, 'IPv4', 4, 14);
        }
        return self::$C;
    }

    public function __construct($id, $name, $bytes, $segmentIndexSize) {
        $this->id = $id;
        $this->name = $name;
        $this->bytes = $bytes;
        $this->segmentIndexSize = $segmentIndexSize;
    }

    // compare the two ip bytes with the current version
    public function ipSubCompare($ip1, $buff, $offset) {
        // ip1: Little endian byte order encoded long from searcher.
        // ip2: Little endian byte order read from xdb index.
        $len  = strlen($ip1);
        $eIdx = $offset + $len;
        for ($i = 0, $j = $eIdx - 1; $i < $len; $i++, $j--) {
            $i1 = ord($ip1[$i]) & 0xFF;
            $i2 = ord($buff[$j]) & 0xFF;
            // printf("i:%d, j:%d, i1:%d, i2:%d\n", $i, $j, $i1, $i2);
            if ($i1 > $i2) {
                return 1;
            } else if ($i1 < $i2) {
                return -1;
            }
        }

        return 0;
    }

    public function __toString() {
        return sprintf(
            "{id:%d, name:%s, bytes:%d, segmentIndexSize:%d}",
            $this->id, $this->name, $this->bytes, $this->segmentIndexSize
        );
    }

}