kernel.php

<?php
/**
*                 PHP APPLICATION BASE KERNEL
*
* DOES SOME GOOD THINGS SUCH AS MANAGE COMMUNICATION WITH DATABASE AND SECURE YOUR ASS
*
* WORKS ONLY IN >=PHP5.6
*
* @author MATHEUS HENRIQUE DE FREITAS (matheus.h.freitas@ufv.br)
*/


/*
  EXPECTED PATHS:
  CONFIG PATH: *ACTUAL KERNEL PATH*../config
  LOG PATH *ACTUAL KERNEL PATH*../logs
*/

class kernel {

  private $database;
  private $kernel_config;
  private $database_config;

  private $prepared_stmts = [];

  /* public calls */

  public function __construct()
  {
    date_default_timezone_set("America/Sao_Paulo");

    ob_start();

    /* files check */
    if(!file_exists(dirname(__FILE__) . "/../logs/kernel.log")) $this->panic("0x10", true);
    if(!file_exists(dirname(__FILE__) . "/../logs/security.log")) $this->panic("0x11");
    if(!file_exists(dirname(__FILE__) . "/../logs/database.log")) $this->panic("0x12");

    //config
    if(!file_exists(dirname(__FILE__) . "/../configs/kernel.json")) $this->panic("0x1");
    if(!file_exists(dirname(__FILE__) . "/../configs/database.json")) $this->panic("0x0");


    /* loading config */
    //kernel
    $kernel_jsoned_file = file_get_contents(dirname(__FILE__) . "/../configs/kernel.json");
    $this->kernel_config = json_decode($kernel_jsoned_file, true);

    if(json_last_error() != JSON_ERROR_NONE) $this->panic("1x1");

    //db
    $db_jsoned_file = file_get_contents(dirname(__FILE__) . "/../configs/database.json");
    $this->database_config = json_decode($db_jsoned_file, true);

    if(json_last_error() != JSON_ERROR_NONE) $this->panic("1x0");


    /* config added to be checked in kernel json */

    if(count($this->kernel_config["add_config_files"])>0){
      foreach($this->kernel_config["add_config_files"] as $file){
        if(!file_exists(dirname(__FILE__) . "/../configs/" . $file)) $this->panic("1x2");
      }
    }



    /* initing things that need it */
    $this->database_init();
    if($this->database===false) $this->panic("10x0");

    $this->security();

    session_start();
  }

  public function DBQuery($sql)
  {
    $temp_result = $this->database->query($sql);
    if($temp_result===false)
    {
      $additional_code = rand(100000, 9999999999);
      $this->log(2, "<helper code: #$additional_code> " . $this->database->error);
      $this->panic("10x1 / #$additional_code");
    }
    return $temp_result;
  }

  public function DBQuery_ps_automatic($query, $vs, $vars, $affected=false, $insertid=false)
  {
    $temp = $this->DBQuery_ps_prepare($query);
    $this->DBQuery_ps_bind($temp, $vs, $vars);
    $this->DBQuery_ps_execute($temp);
    if($affected && $insertid) $result = [$this->DBQuery_ps_affectedrows($temp),$this->DBQuery_ps_insertid($temp)];
    elseif($affected) $result = $this->DBQuery_ps_affectedrows($temp);
    elseif($insertid) $result = $this->DBQuery_ps_insertid($temp);
    else $result = $this->DBQuery_ps_result($temp);
    $this->DBQuery_ps_close($temp);
    return $result;
  }

  public function DBQuery_ps_prepare($query)
  {
    $temp_sm = $this->database->prepare($query);
    if($temp_sm===false)
    {
      $additional_code = rand(100000, 9999999999);
      $this->log(2, "PS_P <helper code: #$additional_code> " . $this->database->error);
      $this->panic("10x2 / #$additional_code");
    }

    $higher_index = $this->prepared_stmts===array()?0:(max(array_keys($this->prepared_stmts))+1);

    for($i=0;$i<=$higher_index;$i++){
      if(!isset($this->prepared_stmts[$i])){
        $this->prepared_stmts[$i] = $temp_sm;
        return $i;
      }
    }
    $this->panic("10x3");
  }

  public function DBQuery_ps_bind($id, $vs, $vars)
  {
    if(!is_numeric($id) || !isset($this->prepared_stmts[$id])) $this->panic("10x4");
    if(strlen($vs)!=count($vars)) $this->panic("10x5");

    //$temp_bind = call_user_func_array(array($this->prepared_stmts[$id], 'bind_param'), $vars);

    //Using new PHP5.6 spread operator(...)
    $temp_bind = $this->prepared_stmts[$id]->bind_param($vs, ...$vars);

    if($temp_bind===false) $this->panic("10x5");

    return true;
  }

  public function DBQuery_ps_execute($id)
  {
    if(!is_numeric($id) || !isset($this->prepared_stmts[$id])) $this->panic("10x4");

    $temp_exec = $this->prepared_stmts[$id]->execute();

    if($temp_exec===false) $this->panic("10x6");

    return true;
  }

  public function DBQuery_ps_result($id)
  {
    if(!is_numeric($id) || !isset($this->prepared_stmts[$id])) $this->panic("10x4");

    $temp_res = $this->prepared_stmts[$id]->get_result();

    if($temp_res===false) $this->panic("10x7");

    return $temp_res;
  }

  public function DBQuery_ps_close($id)
  {
    if(!is_numeric($id) || !isset($this->prepared_stmts[$id])) $this->panic("10x4");

    $this->prepared_stmts[$id]->close();
    unset($this->prepared_stmts[$id]);

    return true;
  }

  public function DBQuery_ps_affectedrows($id)
  {
    if(!is_numeric($id) || !isset($this->prepared_stmts[$id])) $this->panic("10x4");

    return $this->prepared_stmts[$id]->affected_rows;
  }

  public function DBQuery_ps_insertid($id)
  {
    if(!is_numeric($id) || !isset($this->prepared_stmts[$id])) $this->panic("10x4");

    return $this->prepared_stmts[$id]->insert_id;
  }




  /* private calls */


  /* application-kernel related funcs */

  private function database_init()
  {
    $this->database = mysqli_init( );
    $this->database->options( MYSQLI_OPT_CONNECT_TIMEOUT, 3 );
    $this->database->real_connect($this->database_config["hostname"], $this->database_config["user"], $this->database_config["pass"], $this->database_config["database"]);

    if($this->database->connect_errno > 0){
      $this->log(2, "<" . $this->database->connect_errno . "> " . $this->database->connect_error);
      $this->database = false;
    }
    else {
      $this->database->set_charset("utf8");
    }
  }


  private function security()
  {
    /*
    if(isset($_POST))
    {
        foreach($_POST as $key => $value)
        {
        if(!in_array($key, $this->kernel_config["html_parse_whitelist"]))
          $_POST[$key] = htmlspecialchars($_POST[$key]);

        if(!in_array($key, $this->kernel_config["html_slashe_whitelist"]))
          $_POST[$key] = addslashes($_POST[$key]);
        }
    }
    if(isset($_GET))
    {
        foreach($_GET as $key => $value)
        {
        if(!in_array($key, $this->kernel_config["html_parse_whitelist"]))
          $_GET[$key] = htmlspecialchars($_GET[$key]);

        if(!in_array($key, $this->kernel_config["html_slashe_whitelist"]))
          $_GET[$key] = addslashes($_GET[$key]);
        }
    } */
  }


  /* kernel related funcs */

  private function panic($code,$supress_log=false)
  {
    ob_clean();
    http_response_code(500);
    echo "<h1>APPLICATION KERNEL PANIC</h1>";
    echo "<p>Ocorreu um erro irrecuperável no núcleo da aplicação.</p>";
    echo "<p><b>Identificação do erro:</b> $code</p>";
    if(!$supress_log)
      $this->log(0, "Kernel panic - error code: $code");
    exit;
  }

  private function log($type, $to_log)
  {
    if($type==0)
      $file = "kernel";
    elseif($type==1)
      $file = "security";
    elseif($type==2)
      $file = "database";

    file_put_contents(dirname(__FILE__) . "/../logs/" . $file .".log", "[" . date("j/n/y G:i:s") . "] (" . $_SERVER['REMOTE_ADDR'] . ") $to_log" . PHP_EOL, FILE_APPEND);
  }

}