index.php

<?php
 $hellosalut = array(
  "code" => "none",
  "hello" => "Hello"
);

function getIP() {
/*
  Source: http://admincmd.blogspot.com/2007/08/php-get-client-ip-address.html
*/
  $ip;
  if (getenv("HTTP_CLIENT_IP")) 
    $ip = getenv("HTTP_CLIENT_IP"); 
  else if(getenv("HTTP_X_FORWARDED_FOR")) 
    $ip = getenv("HTTP_X_FORWARDED_FOR"); 
  else if(getenv("REMOTE_ADDR")) 
    $ip = getenv("REMOTE_ADDR"); 
  else 
    $ip = "UNKNOWN";
  return $ip; 
}
/*
Source: http://www.dyeager.org/blog/2008/10/getting-browser-default-language-php.html
*/

function getDefaultLanguage() {
   if (isset($_SERVER["HTTP_ACCEPT_LANGUAGE"]))
      return parseDefaultLanguage($_SERVER["HTTP_ACCEPT_LANGUAGE"]);
   else
      return parseDefaultLanguage(NULL);
   }

function parseDefaultLanguage($http_accept, $deflang = "en") {
   if(isset($http_accept) && strlen($http_accept) > 1)  {
      # Split possible languages into array
      $x = explode(",",$http_accept);
      foreach ($x as $val) {
         #check for q-value and create associative array. No q-value means 1 by rule
         if(preg_match("/(.*);q=([0-1]{0,1}\.\d{0,4})/i",$val,$matches))
            $lang[$matches[1]] = (float)$matches[2];
         else
            $lang[$val] = 1.0;
      }
      $qval = 0.0;
      foreach ($lang as $key => $value) {
         if ($value > $qval) {
            $qval = (float)$value;
            $deflang = $key;
         }
      }
   }
   return strtolower($deflang);
}

function getHelloFromLang($lang) {
    $connection = mysqli_connect( getenv( "DB_HOST" ), getenv( "DB_USERNAME" ), getenv( "DB_PASSWORD" ), getenv( "DB_NAME" ) );
    // $connection->set_charset("UTF-8");

    if (mysqli_connect_errno()){
      echo "Failed to connect to the database: " . mysqli_connect_error();
    }

    $query = "SELECT 
        cc.hello
      FROM 
        ip2nationCountries cc
      WHERE 
        cc.language = ?";
    $stmt = $connection->prepare($query);
    $stmt->bind_param("s", $lang);
    $stmt->execute();
    $stmt->bind_result($hello);
    $stmt->fetch();
    if (!is_null($hello)){
      global $hellosalut;

      $hellosalut["code"] = $lang;
      $hellosalut["hello"] = $hello;
      // $hellosalut["char_set"] = $connection->character_set_name();
    }
  }

function getHelloFromCountry($code) {
    $connection = mysqli_connect( getenv( "DB_HOST" ), getenv( "DB_USERNAME" ), getenv( "DB_PASSWORD" ), getenv( "DB_NAME" ) );
    // $connection->set_charset("UTF-8");

    if (mysqli_connect_errno()){
      echo "Failed to connect to the database: " . mysqli_connect_error();
    }

    $query = "SELECT 
        cc.hello
      FROM 
        ip2nationCountries cc
      WHERE 
        cc.code = ?";
    $stmt = $connection->prepare($query);
    $stmt->bind_param("s", $code);
    $stmt->execute();
    $stmt->bind_result($hello);
    $stmt->fetch();

    if (!is_null($hello)){
      global $hellosalut;

      $hellosalut["code"] = $code;
      $hellosalut["hello"] = $hello;
    }
  }

function getHelloFromIP($ipRaw) {
    $ip = sprintf("%u\n", ip2long($ipRaw));
    $connection = mysqli_connect( getenv( "DB_HOST" ), getenv( "DB_USERNAME" ), getenv( "DB_PASSWORD" ), getenv( "DB_NAME" ) );
    // $connection->set_charset("UTF-8");

    if (mysqli_connect_errno()){
      echo "Failed to connect to the database: " . mysqli_connect_error();
    }

    $query = "SELECT 
                cc.code, 
                cc.hello 
              FROM 
                ip2nationCountries cc, 
                ip2nation ip 
              WHERE 
                ip.ip < ?
              AND 
                cc.code = ip.country 
              ORDER BY 
                ip.ip DESC 
              LIMIT 0,1";

    $stmt = $connection->prepare($query);
    $stmt->bind_param("i", $ip);
    $stmt->execute();
    $stmt->bind_result($code, $hello);
    $stmt->fetch();


    if (!is_null($hello)){
      global $hellosalut;
      $hellosalut["code"] = $code;
      $hellosalut["hello"] = $hello;
    }
  }
 
if (!isset($_REQUEST['ip']) && !isset($_REQUEST['lang']) && !isset($_REQUEST['mode']) && !isset($_REQUEST['cc'])) {
  echo "Please see <a href='https://stefanbohacek.com/project/hellosalut-api/'>https://stefanbohacek.com/project/hellosalut-api/</a> for details on how to use this service.";
}
else{
  if (isset($_REQUEST['mode'])){
    switch ($_REQUEST['mode']){
      case "auto":
        getHelloFromIP(getIP());
        getHelloFromLang(getDefaultLanguage());
      break; 
    }
  }
  else{
    if (isset($_REQUEST['lang'])) {
      getHelloFromLang($_REQUEST['lang']);
    }
    else{
      if (isset($_REQUEST['ip'])) {
        getHelloFromIP($_REQUEST['ip']);
      }
      else{
        if (isset($_REQUEST['cc'])){
          getHelloFromCountry($_REQUEST['cc']);
        }
      }
    }
  }
  header('Content-type: application/json'); 
  header('Access-Control-Allow-Origin: *');
  echo json_encode($hellosalut);  
}