DhcpLeaseParser

<?php

namespace App;

use Storage;
use Carbon\Carbon;
use GuzzleHttp\Client;

class DhcpLeaseParser
{

    /**
     * Create a new instance.
     *
     * @return void
     */
    public function __construct()
    {
        $this->leases_file = 'dhcp/dhcpd.leases';
    }

    /**
     * Get the entire contents of the leases file.  Remove lines beginning with "#" before returning
     * The "1" flag in preg_grep inverses the matching.
     */
    private function getLeasesFile()
    {
        if (Storage::exists($this->leases_file))
        {
            $myFile = Storage::get($this->leases_file);
            $lines = explode("\n", $myFile);
            $fileWithoutComments = implode("\n", preg_grep("/^#/", $lines, 1));
            return $fileWithoutComments;
        }
        return 'false';
    }

    /**
     * Get leases as a single dimensional array
     *
     * @return array
     */
    private function getLeasesAsSingleDimensionalArray()
    {
        $leasesArray = explode("lease", $this->getLeasesFile());
        $leasesArray = array_slice($leasesArray, 3);
        return $leasesArray;
    }

    /**
     * Get leases as a multidimensional array
     */
    private function getLeasesAsMultiDimensionalArray()
    {
        $leases = [];
        foreach ($this->getLeasesAsSingleDimensionalArray() as $lease)
        {
            $singleLease = explode("\n", $lease);
            array_push($leases, $singleLease);
        }
        return $leases;
    }

    /**
     * preg_grep returns an array so instead of starts and ends, etc having a string value, they
     * end up having an array as the value.  For that reason, we implode it to make a string
     * out of that array
     */

    /**
     * Find the IP address in the lease and then clean it up.  Remember, you can just return $ip_line
     * here if you want to see it raw
     */
    private function getCleanIp($lease)
    {
        $ip_line = implode('', preg_grep("/^\s*[0-9]/", $lease));
        $ipLineParts = explode(" ", $ip_line);
        return $ipLineParts[1];
    }

    /**
     * Get and clean the "starts" line
     */
    private function getCleanStarts($lease)
    {
        $starts_line = implode('', preg_grep("/^\s++starts/", $lease));
        $startsLineParts = preg_split("/\s+/", $starts_line);
        $date = $startsLineParts[3];
        $time = substr($startsLineParts[4], 0, -1);

        $timestamp = ($date . ' ' . $time);
        $myDate = Carbon::createFromFormat('Y/m/d H:i:s', $timestamp, 'UTC');
        $myDate->timezone(config('app.timezone'));
        return $myDate;
    }

    /**
     * Get and clean the "starts" line
     */
    private function getCleanEnds($lease)
    {
        $ends_line = implode('', preg_grep("/^\s++ends/", $lease));
        $endsLineParts = preg_split("/\s+/", $ends_line);
        $date = $endsLineParts[3];
        $time = substr($endsLineParts[4], 0, -1);

        $timestamp = ($date . ' ' . $time);
        $myDate = Carbon::createFromFormat('Y/m/d H:i:s', $timestamp, 'UTC');
        $myDate->timezone(config('app.timezone'));
        return $myDate;
    }

    /**
     * Get and clean the "binding state" line
     */
    private function getCleanBindingState($lease)
    {
        $binding_state_line = implode('', preg_grep("/^\s++binding\sstate/", $lease));
        $bindingStateLineParts = preg_split("/\s+/", $binding_state_line);
        $state = substr($bindingStateLineParts[3], 0, -1);
        return $state;
    }

    /**
     * Get and clean the "next binding state" line
     */
    private function getCleanNextBindingState($lease)
    {
        $next_binding_state_line = implode('', preg_grep("/^\s++next\sbinding\sstate/", $lease));
        if ( ! empty($next_binding_state_line))
        {
            $nextBindingStateLineParts = preg_split("/\s+/", $next_binding_state_line);
            $state = substr($nextBindingStateLineParts[4], 0, -1);
            return $state;
        }
    }

    /**
     * Get and clean the "rewind binding state" line
     */
    private function getCleanRewindBindingState($lease)
    {
        $rewind_binding_state_line = implode('', preg_grep("/^\s++rewind\sbinding\sstate/", $lease));
        if ( ! empty($rewind_binding_state_line))
        {
            $rewindBindingStateLineParts = preg_split("/\s+/", $rewind_binding_state_line);
            $state = substr($rewindBindingStateLineParts[4], 0, -1);
            return $state;
        }
    }

    /**
     * Get and clean the "hardware ethernet" line
     */
    private function getCleanHardwareEthernet($lease)
    {
        $hardware_ethernet_line = implode('', preg_grep("/^\s++hardware\sethernet/", $lease));
        if ( ! empty($hardware_ethernet_line))
        {
            $hardwareEthernetLineParts = preg_split("/\s+/", $hardware_ethernet_line);
            $hardware_ethernet = substr($hardwareEthernetLineParts[3], 0, -1);
            return $hardware_ethernet;
        }
    }

    /**
     * Get and clean the "option agent.circuit-id" line
     */
    private function getCleanUid($lease)
    {
        $uid_line = implode('', preg_grep("/^\s++uid/", $lease));
        if ( ! empty($uid_line))
        {
            $uidLineParts = preg_split("/\s+/", $uid_line);
            $uid = substr($uidLineParts[2], 0, -1);
            return $uid;
        }
    }

    /**
     * Get and clean the "option agent.circuit-id" line
     */
    private function getCleanCircuitId($lease)
    {
        $circuit_id_line = implode('', preg_grep("/^\s++option\sagent\.circuit-id/", $lease));
        if ( ! empty($circuit_id_line))
        {
            $circuitIdLineParts = preg_split("/\s+/", $circuit_id_line);
            $circuit_id = substr($circuitIdLineParts[3], 0, -1);
            return $circuit_id;
        }
    }

    /**
     * Get and clean the "option agent.remote-id" line
     */
    private function getCleanRemoteId($lease)
    {
        $remote_id_line = implode('', preg_grep("/^\s++option\sagent\.remote-id/", $lease));
        if ( ! empty($remote_id_line))
        {
            $remoteIdLineParts = preg_split("/\s+/", $remote_id_line);
            $remote_id = substr($remoteIdLineParts[3], 0, -1);
            return $remote_id;
        }
    }

    /**
     * Get and clean the "option agent.subscriber-id" line
     */
    private function getCleanSubscriberId($lease)
    {
        $subscriber_id_line = implode('', preg_grep("/^\s++option\sagent\.subscriber-id/", $lease));
        if ( ! empty($subscriber_id_line))
        {
            $subscriberIdLineParts = preg_split("/\s+/", $subscriber_id_line);
            $subscriber_id = substr($subscriberIdLineParts[3], 0, -1);
            return $subscriber_id;
        }
    }

    /**
     * Get all the stats provided by dhcpd-pools
     */
    public function getDhcpStats()
    {
        $client = new Client();
        $dhcpServer = env('DHCP_SERVER', 'localhost');
        $response = $client->get('http://' . $dhcpServer . '/dhcp.php');
        $liveDhcpInfo = $response->json();
        return collect($liveDhcpInfo);
    }

    /**
     * Get the hash of all leases in the file
     */
    public function getAllLeases()
    {
        $leases = [];
        foreach ($this->getLeasesAsMultiDimensionalArray() as $lease)
        {
            $hash['ip'] = $this->getCleanIp($lease);
            $hash['starts'] = $this->getCleanStarts($lease);
            $hash['ends'] = $this->getCleanEnds($lease);
            // $hash['tstp'] = implode('', preg_grep("/^\s++tstp/", $lease));
            // $hash['cltt'] = implode('', preg_grep("/^\s++cltt/", $lease));
            $hash['binding_state'] = $this->getCleanBindingState($lease);
            $hash['next_binding_state'] = $this->getCleanNextBindingState($lease);
            $hash['rewind_binding_state'] = $this->getCleanRewindBindingState($lease);
            $hash['hardware_ethernet'] = $this->getCleanHardwareEthernet($lease);
            $hash['uid'] = $this->getCleanUid($lease);
            $hash['option_agent_circuit-id'] = $this->getCleanCircuitId($lease);
            $hash['option_agent_remote-id'] = $this->getCleanRemoteId($lease);
            $hash['option_agent_subscriber-id'] = $this->getCleanSubscriberId($lease);
            array_push($leases, $hash);
        }
        return collect($leases);
    }

    /**
     * Get the latest entry in the file for a particular IP
     */
    public function getActiveLeases()
    {
        $leases = $this->getAllLeases()->reverse()->unique('ip');
        return $leases;
    }

    /**
     * Get the stats for each defined shared-network
     */
    public function getDhcpSharedNetworkStats()
    {
        $stats = $this->getDhcpStats();
        return $stats['shared-networks'];
    }

    /**
     * Get the stats for each defined subnet
     */
    public function getDhcpSubnetStats()
    {
        $stats = $this->getDhcpStats();
        return $stats['subnets'];
    }

    /**
     * Get the summary stats for the entire dhcp server
     */
    public function getDhcpSummaryStats()
    {
        $stats = $this->getDhcpStats();
        return $stats['summary'];
    }
}