<?php

// from unpack('H*', file_get_contents("Char.d2s")) for 3v4l.org to read d2s file here
//$data = hex2bin('55aa55aa60000000f1060000b5bc59b300000000536f72630000000000000000000000002400000001103863000000003cc7ae62ffffffffffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff000000000000570300000000000000000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff8000005e3e9b11000000008888d5f80100000035b70300000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000576f6f21060000002a0101000190fd9ffe9ffd9ffe9ffd9f0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000057530100000050000201ffffffff7f00000000000000000000000000000000000201ffffffff7f00000000000000000000000000000000000201ffffffff7f0000000000000000000000000000000000017734002e000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000067660028083082000a06644000b10252067094c1018082800020292400480a0a0030c202008cc060dcc0f0ca3afa160a0000e03f696600000000000000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000004a4d32004a4d100082006500069226160382af144fb080e03f4a4d1000820065000a9226260302791c00c480e03f4a4d10008000654415c076c606821c7ffff58080010a06fe034a4d1000800065008013268303827e82896086dccb000066c5bcfeffff014a4d1000820065000022f6860782b067b7ec80e03f4a4d1000820065001a922636038249b154da80a025040000c07f4a4d1000a0006500a442665363034a4d1000a0006500fe13367703024a4d1000a0006500de13362703024a4d1000a0006500be13361703024a4d1000a00065009e13360703024a4d1000a00065007e1336a707024a4d1000a00065005e13369707024a4d1000a00065003e1336f706024a4d1000a0006500c013e65606024a4d1000a00065006012d68607024a4d1000a00065000e12d60603024a4d1000a00065006412564306024a4d1000800065001e83179303029920441686e03f4a4d1000a0006500fe12d69606024a4d1000a0006500de12d68606024a4d1000a0006500be12d67606024a4d1000a00065009e12e67606024a4d1000a00065007e12e69606024a4d1000a0006500fc13e6a606024a4d1000a0006500dc13c68603024a4d1000a0006500bc13e6b606024a4d1000800065009c83272303826f9aed3186e03f4a4d1000800065007c8317730302acd0c26e86e03f4a4d1000a00065005c13560603024a4d1000a00065003c13569607024a4d1000a00065001c13464603024a4d1000a00065001212d66607024a4d1000a00865001412d66607024a4d1000a0006500fc1226f606024a4d1000a0006500dc12265607024a4d1000a0086500bc12265607024a4d1000a00865009c12265607024a4d1000a00865007c12265607024a4d1000a0086500fa13265607024a4d1000a0006500da43665363034a4d1000a0086500ba43665363034a4d1000a00065009a53468333064a4d10008000650016421616038245fc36c6822cff014a4d100080006500a032166707028c6e88690101000408052c30c0c00054e03f4a4d10008000650411c026c60602385900c78080010a08fe034a4d1000800065004632166707822c1b5e930001000498042c30c0c00054e03f4a4d1000800065007a8337130382a07c2a5786e03f4a4d1008800065000ec326c60602915c92ea8280010a07e23f4a4d100880046500b23237470612e9b107ed80104b83c140fc3776ece0f80f4a4d1000a00065180010365603024a4d00006a664a4d00006b6600');

require_once './src/D2Functions.php';
require_once './src/D2BitReader.php';

class D2ByteReader {

    private string $data;
    private int $offset = 0;

    public function __construct(string $data) {
        if (!$data)
            return false;
        $this->data = $data;
    }

    public function skip(int $numBytes): bool {
        if ($numBytes < 0 || $numBytes > strlen($this->data))
            return false;
        $this->offset += $numBytes;
        return $true;
    }

    public function seek(int $pos): bool {
        if ($pos < 0 || $pos > strlen($this->data))
            return false;
        $this->offset = $pos;
        return true;
    }

    public function readh(int $numBytes, bool $str = true): string {
        $bytes = null;
        for ($i = $this->offset; $i < $this->offset + $numBytes; $i++) {
            $str ? $bytes .= $this->data[$i] : $bytes[] = $this->data[$i];
        }
        return unpack('H*', $bytes)[1];
    }

    public function readc(int $numBytes, bool $str = true): array {
        $bytes = null;
        for ($i = $this->offset; $i < $this->offset + $numBytes; $i++) {
            $str ? $bytes .= $this->data[$i] : $bytes[] = $this->data[$i];
        }
        return unpack('C*', $bytes);
    }

    public function rewind(): bool {
        $this->offset = 0;
        return true;
    }

    public function writeByte(int $offset, int $byte) {
        $this->data[$offset] = pack('C', $byte);
    }

    public function writeBytes(int $offset, string $bytes) {
        if ($offset < 0 || $offset > strlen($this->data) || $bytes == '')
            return false;
        $_bytes = str_split($bytes, 2);
        foreach ($_bytes as $k => $byte) {
            $pos = $offset + $k;
            $this->data[$pos] = pack('H*', $byte);
        }
    }

    public function getData() {
        return $this->data ? $this->data : false;
    }

    public function getOffset(): int {
        return $this->offset;
    }

    public function isHexString(string $str): bool {
        if (strlen($str) % 2 == 0 && (ctype_xdigit($str))) {
            return true;
        }
        return false;
    }

    public function toBits($input): string {
        $output = '';
        if ($this->isHexString($input)) {
            foreach (str_split($input, 2) as $byte) {
                $output .= (strrev(str_pad(decbin(hexdec($byte)), 8, 0, STR_PAD_LEFT)));
            }
            return $output;
        } else if (is_string($input)) {
            foreach (str_split($input) as $i) {
                $output .= strrev(str_pad(decbin(ord($i)), 8, 0, STR_PAD_LEFT));
            }
            return $output;
        } else if (is_int($input)) {
            return strrev(str_pad(decbin($input), 8, 0, STR_PAD_LEFT));
        } else if (is_array($input)) {
            foreach ($input as $i) {
                $output .= $this->tobits($i);
            }
            return $output;
        }
    }

    public function toBytes(string $bits) {
        foreach (str_split($bits, 8) as $byteString) {
            $bytes[] = (bindec(strrev($byteString)));
        }
        foreach ($bytes as $byte) {
            dump($byte);
        }
    }

    public function bitsToHexString(string $bits): string {
        $bytes = '';
        foreach (str_split($bits, 8) as $byte) {
            $bytes .= (str_pad(dechex((bindec(strrev($byte)))), 2, 0, STR_PAD_LEFT));
        }
        return $bytes;
    }

    public function bitsToHexArray(string $bits): array {
        $bytes = [];
        foreach (str_split($bits, 8) as $byte) {
            $bytes[] = (str_pad(dechex((bindec(strrev($byte)))), 2, 0, STR_PAD_LEFT));
        }
        return $bytes;
    }

    public function bitsToIntArray(string $bits): array {
        $bytes = [];
        foreach (str_split($bits, 8) as $byte) {
            $bytes[] = (int) (str_pad(dechex((bindec(strrev($byte)))), 2, 0, STR_PAD_LEFT));
        }
        return $bytes;
    }

    /*
      @return Byte with Nth bit set to X
     */

    public function setBit(int $byte, int $pos, bool $bit) {
        return ($bit ? ($byte | (1 << $pos)) : ($byte & ~(1 << $pos)) );
    }

    /*
      @return Bit at Nth position in Byte
     */

    public function getBit(int $byte, int $pos): int {
        return intval(($byte & (1 << $pos)) != 0);
    }

}

$file = "D:\Diablo II\MODS\ironman-dev\save\Barb.d2s";
$data = file_get_contents($file);

$c = new D2ByteReader($data);
$c->seek(643);
$bytes = $c->readh(5);
$bits = $c->toBits($bytes);

$bits[4] = 1;
$bits[5] = 1;
$bits[8] = 1;

$newBytes = $c->bitsToHexString($bits);
$c->writeBytes(643, $newBytes);

$c->writeBytes(12, "00000000"); // zero old checksum
$newChecksum = checksum(unpack('C*', $c->getData())); // get new checksum
dump($newChecksum);
$c->writeBytes(12, $newChecksum); // write new checksum
file_put_contents($file, $c->getData()); // write bytestream to file