<?php 
use kornrunner\Keccak;
use BitWasp\Bitcoin\Key\Factory\PrivateKeyFactory;
use BitWasp\Bitcoin\Crypto\Random\Random;

include_once "../libraries/vendor/autoload.php";
include_once("html_iframe_header.php");

function toChecksumAddress($address) 
{
	
	$address = strtolower(str_replace('0x', '', $address));
	$hash = Keccak::hash(strtolower($address), 256);
	$checksumAddress = '0x';
	
	for($i=0;$i<strlen($address);$i++) {
		
		if (intval($hash{$i}, 16) > 7) {
			$checksumAddress .= strtoupper($address{$i});
		} else {
			$checksumAddress .= $address{$i};
		}
	}
	
	return $checksumAddress;
	
}

if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    try {
       
        $privKeyFactory = new PrivateKeyFactory();

        if (!$_POST['input'] OR ctype_xdigit($_POST['input'])) 
        {
            if (!$_POST['input']) 
            { 
                $rbg = new Random();
                $privateKey = $privKeyFactory->generateUncompressed($rbg);
                
            } else {
                
                $privateKey = $privKeyFactory->fromHexUncompressed($_POST['input']);
            }
        } 
       
		$publicKey = $privateKey->getPublicKey();
		$publicKey = substr($publicKey->getHex(), 2);
		$madeUpEthAddress = $publicKey;
		
		$hash = Keccak::hash(hex2bin($madeUpEthAddress), 256);
		// Ethereum address has 20 bytes length. (40 hex characters long)
		// We only need the last 20 bytes as Ethereum address
		$ethAddress = toChecksumAddress('0x' . substr($hash, -40));
		
    ?>
        <div class="table-responsive">
            <table border=0 class='table'>
                <tr style='background-color:#f0f0f0'><td>Address</td><td><?php echo $ethAddress?></td></tr>
                <tr><td>Private Key Hex</td><td><?php echo $privateKey->getHex()?></td></tr>               
                <tr style='background-color:#f0f0f0'><td>Public Key Hex</td><td><?php echo $publicKey?></td></tr>
            </table>
        </div>
<?php 
    } catch (Exception $e) {
        $errmsg .= "Problem found. " . $e->getMessage();

    }
} 

if ($errmsg) {
?>
    <div class="alert alert-danger">
        <strong>Error!</strong> <?php echo $errmsg?>
    </div>
<?php
}
?>
<form action='' method='post'>
    <div class="form-group">
        <label for="input">Private Key (Hex):</label>
        <input class="form-control" type='text' name='input' id='input' value='<?php echo $_POST['input']?>'>
        <small>Put empty if you want system assign you a random private key.</small>
    </div>
   
    <input type='submit' class="btn btn-success btn-block"/>
</form>
<?php
include_once("html_iframe_footer.php");

<?php 
use kornrunner\Keccak;

include_once "../libraries/vendor/autoload.php";
include_once("html_iframe_header.php");

class EthAddressValidator
{
	private $addressValid = false;
	private $address = "";
	
	function __construct(string $address) 
	{
		$this->address = $address;
		if ($this->isPatternMatched()) {
			if (!$this->isAllSameCaps()) {
				$this->addressValid = $this->isValidChecksum();	
			} else {
				$this->addressValid = true;
			}
        }
	}
	
    public function isValidAddress(): bool
    {	
        return $this->addressValid;
    }
	
    protected function isPatternMatched(): int
    {
        return preg_match('/^(0x)?[0-9a-f]{40}$/i', $this->address);
    }

    public function isAllSameCaps(): bool
    {
        return preg_match('/^(0x)?[0-9a-f]{40}$/', $this->address) || preg_match('/^(0x)?[0-9A-F]{40}$/', $this->address);
    }

    protected function isValidChecksum(): bool
    {
        $address = str_replace('0x', '', $this->address);
        $hash = Keccak::hash(strtolower($address), 256);

        for ($i = 0; $i < 40; $i++ ) {
            if (ctype_alpha($address{$i})) {
                // Each uppercase letter should correlate with a first bit of 1 in the hash char with the same index,
                // and each lowercase letter with a 0 bit.
                $charInt = intval($hash{$i}, 16);

                if ((ctype_upper($address{$i}) && $charInt <= 7) || (ctype_lower($address{$i}) && $charInt > 7)) {
					
                    return false;
                }
            }
        }

        return true;
    }
}

if ($_SERVER['REQUEST_METHOD'] == 'POST') {
   
    $validator = new EthAddressValidator($_POST['address']);
	
	if ($validator->isAllSameCaps() === true) {
	?>
		<div class="alert alert-info">
			<strong>Notice!</strong> Address pattern valid but checksum cannot be verified.
		</div>
	<?php 
	} else if ($validator->isValidAddress() === true) {
?>
		<div class="alert alert-success">
			<strong>Success!</strong> Checksum validation was passed.
		</div>
<?php
	} else {
?>
		<div class="alert alert-danger">
			<strong>Error!</strong> Invalid address.
		</div>	
<?php	
	}
}
?>
<form action='' method='post'>
    <div class="form-group">
        <label for="address">Address:</label>
        <input class="form-control" type='text' name='address' id='address' value='<?php echo $_POST['address']?>'>
    </div>
   
    <input type='submit' class="btn btn-success btn-block"/>
</form>
<?php
include_once("html_iframe_footer.php");