<?php

require_once 'config.php';

/**
 * Manage DHCP configuration
 */
function DisplayDHCPConfig()
{
    $status = new \RaspAP\Messages\StatusMessage;
    if (!RASPI_MONITOR_ENABLED) {
        if (isset($_POST['savedhcpdsettings'])) {
            saveDHCPConfig($status);
        }
    }
    exec('pidof dnsmasq | wc -l', $dnsmasq);
    $dnsmasq_state = ($dnsmasq[0] > 0);

    if (!RASPI_MONITOR_ENABLED) {
        if (isset($_POST['startdhcpd'])) {
            if ($dnsmasq_state) {
                $status->addMessage('dnsmasq already running', 'info');
            } else {
                exec('sudo /bin/systemctl start dnsmasq.service', $dnsmasq, $return);
                if ($return == 0) {
                    $status->addMessage('Successfully started dnsmasq', 'success');
                    $dnsmasq_state = true;
                } else {
                    $status->addMessage('Failed to start dnsmasq', 'danger');
                }
            }
        } elseif (isset($_POST['stopdhcpd'])) {
            if ($dnsmasq_state) {
                exec('sudo /bin/systemctl stop dnsmasq.service', $dnsmasq, $return);
                if ($return == 0) {
                    $status->addMessage('Successfully stopped dnsmasq', 'success');
                    $dnsmasq_state = false;
                } else {
                    $status->addMessage('Failed to stop dnsmasq', 'danger');
                }
            } else {
                $status->addMessage('dnsmasq already stopped', 'info');
            }
        }
    }
    getWifiInterface();
    $ap_iface = $_SESSION['ap_interface'];
    $serviceStatus = $dnsmasq_state ? "up" : "down";
    exec('cat '. RASPI_DNSMASQ_PREFIX.'raspap.conf', $return);
    $log_dhcp = (preg_grep('/log-dhcp/', $return));
    $log_queries = (preg_grep('/log-queries/', $return));
    $conf = ParseConfig($return);
    exec('cat '. RASPI_DNSMASQ_PREFIX.$ap_iface.'.conf', $return);
    $conf = array_merge(ParseConfig($return));
    $hosts = (array)$conf['dhcp-host'];
    $upstreamServers = (array)$conf['server'];
    exec("ip -o link show | awk -F': ' '{print $2}'", $interfaces);
    exec('cat ' . RASPI_DNSMASQ_LEASES, $leases);

    count($log_dhcp) > 0 ? $conf['log-dhcp'] = true : false ;
    count($log_queries) > 0 ? $conf['log-queries'] = true : false ;

    exec('sudo /bin/chmod o+r '.RASPI_DHCPCD_LOG);
    $logdata = getLogLimited(RASPI_DHCPCD_LOG);

    echo renderTemplate(
        "dhcp", compact(
            "status",
            "serviceStatus",
            "dnsmasq_state",
            "ap_iface",
            "conf",
            "hosts",
            "upstreamServers",
            "interfaces",
            "leases",
            "logdata"
        )
    );
}

/**
 * Saves a DHCP configuration
 *
 * @return object $status
 */
function saveDHCPConfig($status)
{
    $iface = $_POST['interface'];
    $return = 1;

    // handle disable dhcp option
    if (!isset($_POST['dhcp-iface']) && file_exists(RASPI_DNSMASQ_PREFIX.$iface.'.conf')) {
        // remove dhcp + dnsmasq configs for selected interface
        $return = removeDHCPConfig($iface,$status);
        $return = removeDnsmasqConfig($iface,$status);
    } else {
        $errors = validateDHCPInput();
        if (empty($errors)) {
            $return = updateDHCPConfig($iface,$status);
        } else {
            foreach ($errors as $error) {
                $status->addMessage($error, 'danger');
            }
        }
        if ($return == 1) {
            $status->addMessage('Dnsmasq configuration failed to be updated.', 'danger');
            return false;
        }

        if (($_POST['dhcp-iface'] == "1") || (isset($_POST['mac']))) {
            $errors = validateDnsmasqInput();
            if (empty($errors)) {
                $return = updateDnsmasqConfig($iface,$status);
            } else {
                foreach ($errors as $error) {
                    $status->addMessage($error, 'danger');
                }
                $return = 1;
            }
        }

        if ($return == 0) {
            $status->addMessage('Dnsmasq configuration updated successfully.', 'success');
        } else {
            $status->addMessage('Dnsmasq configuration failed to be updated.', 'danger');
            return false;
        }
        return true;
    }
}

/**
 * Validates DHCP user input from the $_POST object
 *
 * @return array $errors
 */
function validateDHCPInput()
{
    $errors = [];
    define('IFNAMSIZ', 16);
    $iface = $_POST['interface'];
    if (!preg_match('/^[^\s\/\\0]+$/', $iface)
        || strlen($iface) >= IFNAMSIZ
    ) {
        $errors[] = _('Invalid interface name.');
    }
    if (!filter_var($_POST['StaticIP'], FILTER_VALIDATE_IP) && !empty($_POST['StaticIP'])) {
        $errors[] = _('Invalid static IP address.');
    }
    if (!filter_var($_POST['SubnetMask'], FILTER_VALIDATE_IP) && !empty($_POST['SubnetMask'])) {
        $errors[] = _('Invalid subnet mask.');
    }
    if (!filter_var($_POST['DefaultGateway'], FILTER_VALIDATE_IP) && !empty($_POST['DefaultGateway'])) {
        $errors[] = _('Invalid default gateway.');
    }
    if (($_POST['dhcp-iface'] == "1")) {
        if (!filter_var($_POST['RangeStart'], FILTER_VALIDATE_IP) && !empty($_POST['RangeStart'])) {
            $errors[] = _('Invalid DHCP range start.');
        }
        if (!filter_var($_POST['RangeEnd'], FILTER_VALIDATE_IP) && !empty($_POST['RangeEnd'])) {
            $errors[] = _('Invalid DHCP range end.');
        }
        if (!ctype_digit($_POST['RangeLeaseTime']) && $_POST['RangeLeaseTimeUnits'] !== 'i') {
            $errors[] = _('Invalid DHCP lease time, not a number.');
        }
        if (!in_array($_POST['RangeLeaseTimeUnits'], array('m', 'h', 'd', 'i'))) {
            $errors[] = _('Unknown DHCP lease time unit.');
        }
        if ($_POST['Metric'] !== '' && !ctype_digit($_POST['Metric'])) {
            $errors[] = _('Invalid metric value, not a number.');
        }
    }
    return $errors;
}

/**
 * Compares to string IPs
 *
 * @param string $ip1
 * @param string $ip2
 * @return boolean $result
 */
function compareIPs($ip1, $ip2)
{
    $ipu1 = sprintf('%u', ip2long($ip1["ip"])) + 0;
    $ipu2 = sprintf('%u', ip2long($ip2["ip"])) + 0;
    return $ipu1 > $ipu2;
}

/**
 * Validates Dnsmasq user input from the $_POST object
 *
 * @return array $errors
 */
function validateDnsmasqInput()
{
    $errors = [];
    $encounteredIPs = [];

    if (isset($_POST["static_leases"]["mac"])) {
        for ($i=0; $i < count($_POST["static_leases"]["mac"]); $i++) {
            $mac = trim($_POST["static_leases"]["mac"][$i]);
            $ip  = trim($_POST["static_leases"]["ip"][$i]);
            if (!validateMac($mac)) {
                $errors[] = _('Invalid MAC address: '.$mac);
            }
            if (in_array($ip, $encounteredIPs)) {
                $errors[] = _('Duplicate IP address entered: ' . $ip);
            } else {
                $encounteredIPs[] = $ip;
            }
        }
    }
    return $errors;
}


/**
 * Updates a dnsmasq configuration
 *
 * @param string $iface
 * @param object $status
 * @return boolean $result
 */
function updateDnsmasqConfig($iface,$status)
{

    $config = '# RaspAP '.$iface.' configuration'.PHP_EOL;
    $config .= 'interface='.$iface.PHP_EOL.'dhcp-range='.$_POST['RangeStart'].','.$_POST['RangeEnd'].','.$_POST['SubnetMask'].',';
    if ($_POST['RangeLeaseTimeUnits'] !== 'i') {
        $config .= $_POST['RangeLeaseTime'];
        $config .= $_POST['RangeLeaseTimeUnits'].PHP_EOL;
    } else {
        $config .= 'infinite'.PHP_EOL;
    }
    //  Static leases
    $staticLeases = array();
    if (isset($_POST["static_leases"]["mac"])) {
        for ($i=0; $i < count($_POST["static_leases"]["mac"]); $i++) {
            $mac = trim($_POST["static_leases"]["mac"][$i]);
            $ip  = trim($_POST["static_leases"]["ip"][$i]);
            $comment  = trim($_POST["static_leases"]["comment"][$i]);
            if ($mac != "" && $ip != "") {
                $staticLeases[] = array('mac' => $mac, 'ip' => $ip, 'comment' => $comment);
            }
        }
    }
    //  Sort ascending by IPs
    usort($staticLeases, "compareIPs");
    //  Update config
    for ($i = 0; $i < count($staticLeases); $i++) {
        $mac = $staticLeases[$i]['mac'];
        $ip = $staticLeases[$i]['ip'];
        $comment = $staticLeases[$i]['comment'];
        $config .= "dhcp-host=$mac,$ip # $comment".PHP_EOL;
    } 
    if ($_POST['no-resolv'] == "1") {
        $config .= "no-resolv".PHP_EOL;
    }
    foreach ($_POST['server'] as $server) {
        $config .= "server=$server".PHP_EOL;
    }
    if ($_POST['DNS1']) {
        $config .= "dhcp-option=6," . $_POST['DNS1'];
        if ($_POST['DNS2']) {
            $config .= ','.$_POST['DNS2'];
        }
        $config .= PHP_EOL;
    }
    file_put_contents("/tmp/dnsmasqdata", $config);
    $msg = file_exists(RASPI_DNSMASQ_PREFIX.$iface.'.conf') ? 'updated' : 'added';
    system('sudo cp /tmp/dnsmasqdata '.RASPI_DNSMASQ_PREFIX.$iface.'.conf', $result);
    if ($result == 0) {
        $status->addMessage('Dnsmasq configuration for '.$iface.' '.$msg.'.', 'success');
    }

    // write default 090_raspap.conf
    $config = '# RaspAP default config'.PHP_EOL;
    $config .='log-facility='.RASPI_DHCPCD_LOG.PHP_EOL;
    $config .='conf-dir=/etc/dnsmasq.d'.PHP_EOL;
    // handle log option
    if ($_POST['log-dhcp'] == "1") {
        $config .= "log-dhcp".PHP_EOL;
    }
    if ($_POST['log-queries'] == "1") {
      $config .= "log-queries".PHP_EOL;
    }
    $config .= PHP_EOL;
    file_put_contents("/tmp/dnsmasqdata", $config);
    system('sudo cp /tmp/dnsmasqdata '.RASPI_DNSMASQ_PREFIX.'raspap.conf', $result);

    return $result;
}

/**
 * Updates a dhcp configuration
 *
 * @param string $iface
 * @param object $status
 * @return boolean $result
 */
function updateDHCPConfig($iface,$status)
{
    $cfg[] = '# RaspAP '.$iface.' configuration';
    $cfg[] = 'interface '.$iface;
    if (isset($_POST['StaticIP']) && $_POST['StaticIP'] !== '') {
        $mask = ($_POST['SubnetMask'] !== '' && $_POST['SubnetMask'] !== '0.0.0.0') ? '/'.mask2cidr($_POST['SubnetMask']) : null;
        $cfg[] = 'static ip_address='.$_POST['StaticIP'].$mask;
    }
    if (isset($_POST['DefaultGateway']) && $_POST['DefaultGateway'] !== '') {
        $cfg[] = 'static routers='.$_POST['DefaultGateway'];
    }
    if ($_POST['DNS1'] !== '' || $_POST['DNS2'] !== '') {
        $cfg[] = 'static domain_name_server='.$_POST['DNS1'].' '.$_POST['DNS2'];
    }
    if ($_POST['Metric'] !== '') {
        $cfg[] = 'metric '.$_POST['Metric'];
    }
    if ($_POST['Fallback'] == 1) {
        $cfg[] = 'profile static_'.$iface;
        $cfg[] = 'fallback static_'.$iface;
    }
    $cfg[] = $_POST['DefaultRoute'] == '1' ? 'gateway' : 'nogateway';
    if (( substr($iface, 0, 2) === "wl") && $_POST['NoHookWPASupplicant'] == '1') {
        $cfg[] = 'nohook wpa_supplicant';
    }
    $dhcp_cfg = file_get_contents(RASPI_DHCPCD_CONFIG);
    if (!preg_match('/^interface\s'.$iface.'$/m', $dhcp_cfg)) {
        $cfg[] = PHP_EOL;
        $cfg = join(PHP_EOL, $cfg);
        $dhcp_cfg .= $cfg;
        $status->addMessage('DHCP configuration for '.$iface.' added.', 'success');
    } else {
        $cfg = join(PHP_EOL, $cfg);
        $dhcp_cfg = preg_replace('/^#\sRaspAP\s'.$iface.'\s.*?(?=\s*^\s*$)/ms', $cfg, $dhcp_cfg, 1);
        $status->addMessage('DHCP configuration for '.$iface.' updated.', 'success');
    }
    file_put_contents("/tmp/dhcpddata", $dhcp_cfg);
    system('sudo cp /tmp/dhcpddata '.RASPI_DHCPCD_CONFIG, $result);

    return $result;
}