<?php


> declare(strict_types=1);
namespace MaxMind\Db;
> 




> use ArgumentCountError;


use BadMethodCallException;
use Exception;
use InvalidArgumentException;
use MaxMind\Db\Reader\Decoder;
use MaxMind\Db\Reader\InvalidDatabaseException;
use MaxMind\Db\Reader\Metadata;
use MaxMind\Db\Reader\Util;
use UnexpectedValueException;

/**
 * Instances of this class provide a reader for the MaxMind DB format. IP
 * addresses can be looked up using the get method.
 */
class Reader
{

>     /**
    private static $DATA_SECTION_SEPARATOR_SIZE = 16;
>      * @var int
    private static $METADATA_START_MARKER = "\xAB\xCD\xEFMaxMind.com";
>      */


    private static $METADATA_START_MARKER_LENGTH = 14;

>     /**
    private static $METADATA_MAX_SIZE = 131072; // 128 * 1024 = 128KB
>      * @var string

>      */


    private $decoder;

>     /**
    private $fileHandle;
>      * @var int
    private $fileSize;
>      */



<     private static $METADATA_MAX_SIZE = 131072; // 128 * 1024 = 128KB



>     /**
>      * @var int
>      */
>     private static $METADATA_MAX_SIZE = 131072; // 128 * 1024 = 128KiB


    private $metadata;

>     /**

>      * @var Decoder
    /**
>      */


     * Constructs a Reader for the MaxMind DB format. The file passed to it must

>     /**
     * be a valid MaxMind DB file such as a GeoIp2 database file.
>      * @var resource
     *
>      */


     * @param string $database

>     /**
     *                         the MaxMind DB file to use
>      * @var int
     *
>      */


     * @throws InvalidArgumentException                    for invalid database path or unknown arguments

>     /**
     * @throws \MaxMind\Db\Reader\InvalidDatabaseException
>      * @var int
     *                                                     if the database is invalid or there is an error reading
>      */


     *                                                     from it

>     /**
     */
>      * @var Metadata
    public function __construct($database)
>      */



<      * @throws \MaxMind\Db\Reader\InvalidDatabaseException



>      * @throws InvalidDatabaseException



<     public function __construct($database)



>     public function __construct(string $database)



<             throw new InvalidArgumentException(
<                 'The constructor takes exactly one argument.'



>             throw new ArgumentCountError(
>                 sprintf('%s() expects exactly 1 parameter, %d given', __METHOD__, \func_num_args())


            );
        }


<         if (!is_readable($database)) {



>         $fileHandle = @fopen($database, 'rb');
>         if ($fileHandle === false) {


            throw new InvalidArgumentException(
                "The file \"$database\" does not exist or is not readable."
            );
        }

<         $this->fileHandle = @fopen($database, 'rb');
<         if ($this->fileHandle === false) {
<             throw new InvalidArgumentException(
<                 "Error opening \"$database\"."
<             );
<         }
<         $this->fileSize = @filesize($database);
<         if ($this->fileSize === false) {



>         $this->fileHandle = $fileHandle;
> 
>         $fileSize = @filesize($database);
>         if ($fileSize === false) {


            throw new UnexpectedValueException(
                "Error determining the size of \"$database\"."
            );
        }

>         $this->fileSize = $fileSize;



        $start = $this->findMetadataStart($database);
        $metadataDecoder = new Decoder($this->fileHandle, $start);

<         list($metadataArray) = $metadataDecoder->decode($start);



>         [$metadataArray] = $metadataDecoder->decode($start);


        $this->metadata = new Metadata($metadataArray);
        $this->decoder = new Decoder(
            $this->fileHandle,
            $this->metadata->searchTreeSize + self::$DATA_SECTION_SEPARATOR_SIZE
        );
        $this->ipV4Start = $this->ipV4StartNode();
    }

    /**
     * Retrieves the record for the IP address.
     *
     * @param string $ipAddress
     *                          the IP address to look up
     *
     * @throws BadMethodCallException   if this method is called on a closed database
     * @throws InvalidArgumentException if something other than a single IP address is passed to the method
     * @throws InvalidDatabaseException
     *                                  if the database is invalid or there is an error reading
     *                                  from it
     *
     * @return mixed the record for the IP address
     */

<     public function get($ipAddress)



>     public function get(string $ipAddress)


    {
        if (\func_num_args() !== 1) {

<             throw new InvalidArgumentException(
<                 'Method takes exactly one argument.'



>             throw new ArgumentCountError(
>                 sprintf('%s() expects exactly 1 parameter, %d given', __METHOD__, \func_num_args())


            );
        }

<         list($record) = $this->getWithPrefixLen($ipAddress);



>         [$record] = $this->getWithPrefixLen($ipAddress);



        return $record;
    }

    /**
     * Retrieves the record for the IP address and its associated network prefix length.
     *
     * @param string $ipAddress
     *                          the IP address to look up
     *
     * @throws BadMethodCallException   if this method is called on a closed database
     * @throws InvalidArgumentException if something other than a single IP address is passed to the method
     * @throws InvalidDatabaseException
     *                                  if the database is invalid or there is an error reading
     *                                  from it
     *
     * @return array an array where the first element is the record and the
     *               second the network prefix length for the record
     */

<     public function getWithPrefixLen($ipAddress)



>     public function getWithPrefixLen(string $ipAddress): array


    {
        if (\func_num_args() !== 1) {

<             throw new InvalidArgumentException(
<                 'Method takes exactly one argument.'



>             throw new ArgumentCountError(
>                 sprintf('%s() expects exactly 1 parameter, %d given', __METHOD__, \func_num_args())


            );
        }

        if (!\is_resource($this->fileHandle)) {
            throw new BadMethodCallException(
                'Attempt to read from a closed MaxMind DB.'
            );
        }


<         if (!filter_var($ipAddress, FILTER_VALIDATE_IP)) {
<             throw new InvalidArgumentException(
<                 "The value \"$ipAddress\" is not a valid IP address."
<             );
<         }
< 
<         list($pointer, $prefixLen) = $this->findAddressInTree($ipAddress);



>         [$pointer, $prefixLen] = $this->findAddressInTree($ipAddress);


        if ($pointer === 0) {
            return [null, $prefixLen];
        }

        return [$this->resolveDataPointer($pointer), $prefixLen];
    }


<     private function findAddressInTree($ipAddress)



>     private function findAddressInTree(string $ipAddress): array


    {

<         $rawAddress = unpack('C*', inet_pton($ipAddress));



>         $packedAddr = @inet_pton($ipAddress);
>         if ($packedAddr === false) {
>             throw new InvalidArgumentException(
>                 "The value \"$ipAddress\" is not a valid IP address."
>             );
>         }
> 
>         $rawAddress = unpack('C*', $packedAddr);



        $bitCount = \count($rawAddress) * 8;

        // The first node of the tree is always node 0, at the beginning of the
        // value
        $node = 0;

        $metadata = $this->metadata;

        // Check if we are looking up an IPv4 address in an IPv6 tree. If this
        // is the case, we can skip over the first 96 nodes.
        if ($metadata->ipVersion === 6) {
            if ($bitCount === 32) {
                $node = $this->ipV4Start;
            }
        } elseif ($metadata->ipVersion === 4 && $bitCount === 128) {
            throw new InvalidArgumentException(
                "Error looking up $ipAddress. You attempted to look up an"
                . ' IPv6 address in an IPv4-only database.'
            );
        }

        $nodeCount = $metadata->nodeCount;

        for ($i = 0; $i < $bitCount && $node < $nodeCount; ++$i) {
            $tempBit = 0xFF & $rawAddress[($i >> 3) + 1];
            $bit = 1 & ($tempBit >> 7 - ($i % 8));

            $node = $this->readNode($node, $bit);
        }
        if ($node === $nodeCount) {
            // Record is empty
            return [0, $i];
        } elseif ($node > $nodeCount) {
            // Record is a data pointer
            return [$node, $i];
        }

<         throw new InvalidDatabaseException('Something bad happened');



>         throw new InvalidDatabaseException(
>             'Invalid or corrupt database. Maximum search depth reached without finding a leaf node'
>         );


    }


<     private function ipV4StartNode()



>     private function ipV4StartNode(): int


    {
        // If we have an IPv4 database, the start node is the first node
        if ($this->metadata->ipVersion === 4) {
            return 0;
        }

        $node = 0;

        for ($i = 0; $i < 96 && $node < $this->metadata->nodeCount; ++$i) {
            $node = $this->readNode($node, 0);
        }

        return $node;
    }


<     private function readNode($nodeNumber, $index)



>     private function readNode(int $nodeNumber, int $index): int


    {
        $baseOffset = $nodeNumber * $this->metadata->nodeByteSize;

        switch ($this->metadata->recordSize) {
            case 24:
                $bytes = Util::read($this->fileHandle, $baseOffset + $index * 3, 3);

<                 list(, $node) = unpack('N', "\x00" . $bytes);



>                 [, $node] = unpack('N', "\x00" . $bytes);



                return $node;
            case 28:
                $bytes = Util::read($this->fileHandle, $baseOffset + 3 * $index, 4);
                if ($index === 0) {
                    $middle = (0xF0 & \ord($bytes[3])) >> 4;
                } else {
                    $middle = 0x0F & \ord($bytes[0]);
                }

<                 list(, $node) = unpack('N', \chr($middle) . substr($bytes, $index, 3));



>                 [, $node] = unpack('N', \chr($middle) . substr($bytes, $index, 3));



                return $node;
            case 32:
                $bytes = Util::read($this->fileHandle, $baseOffset + $index * 4, 4);

<                 list(, $node) = unpack('N', $bytes);



>                 [, $node] = unpack('N', $bytes);



                return $node;
            default:
                throw new InvalidDatabaseException(
                    'Unknown record size: '
                    . $this->metadata->recordSize
                );
        }
    }


<     private function resolveDataPointer($pointer)



>     /**
>      * @return mixed
>      */
>     private function resolveDataPointer(int $pointer)


    {
        $resolved = $pointer - $this->metadata->nodeCount
            + $this->metadata->searchTreeSize;
        if ($resolved >= $this->fileSize) {
            throw new InvalidDatabaseException(
                "The MaxMind DB file's search tree is corrupt"
            );
        }


<         list($data) = $this->decoder->decode($resolved);



>         [$data] = $this->decoder->decode($resolved);



        return $data;
    }

    /*
     * This is an extremely naive but reasonably readable implementation. There
     * are much faster algorithms (e.g., Boyer-Moore) for this if speed is ever
     * an issue, but I suspect it won't be.
     */

<     private function findMetadataStart($filename)



>     private function findMetadataStart(string $filename): int


    {
        $handle = $this->fileHandle;
        $fstat = fstat($handle);
        $fileSize = $fstat['size'];
        $marker = self::$METADATA_START_MARKER;
        $markerLength = self::$METADATA_START_MARKER_LENGTH;

        $minStart = $fileSize - min(self::$METADATA_MAX_SIZE, $fileSize);

        for ($offset = $fileSize - $markerLength; $offset >= $minStart; --$offset) {
            if (fseek($handle, $offset) !== 0) {
                break;
            }

            $value = fread($handle, $markerLength);
            if ($value === $marker) {
                return $offset + $markerLength;
            }
        }
        throw new InvalidDatabaseException(
            "Error opening database file ($filename). " .
            'Is this a valid MaxMind DB file?'
        );
    }

    /**
     * @throws InvalidArgumentException if arguments are passed to the method
     * @throws BadMethodCallException   if the database has been closed
     *
     * @return Metadata object for the database
     */

<     public function metadata()



>     public function metadata(): Metadata


    {
        if (\func_num_args()) {

<             throw new InvalidArgumentException(
<                 'Method takes no arguments.'



>             throw new ArgumentCountError(
>                 sprintf('%s() expects exactly 0 parameters, %d given', __METHOD__, \func_num_args())


            );
        }

        // Not technically required, but this makes it consistent with
        // C extension and it allows us to change our implementation later.
        if (!\is_resource($this->fileHandle)) {
            throw new BadMethodCallException(
                'Attempt to read from a closed MaxMind DB.'
            );
        }


<         return $this->metadata;



>         return clone $this->metadata;


    }

    /**
     * Closes the MaxMind DB and returns resources to the system.
     *
     * @throws Exception
     *                   if an I/O error occurs
     */

<     public function close()



>     public function close(): void


    {

>         if (\func_num_args()) {
        if (!\is_resource($this->fileHandle)) {
>             throw new ArgumentCountError(
            throw new BadMethodCallException(
>                 sprintf('%s() expects exactly 0 parameters, %d given', __METHOD__, \func_num_args())
                'Attempt to close a closed MaxMind DB.'
>             );
            );
>         }
        }
> 


        fclose($this->fileHandle);
    }
}