<?php
include("config/parametres.php");
include("includes/sessions.php");
include("includes/functions.php");


## -- 01. User Management Functions ////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////

  ## LOGIN ---------------------------------------------------------------------
  //////////////////////////////////////////////////////////////////////////////

  function try_login() {
	  // --- CASE ONE --- -- -- - - -
	  ## User is loged in already
	  if ( (isset($_SESSION['user_status'])) && ($_SESSION['user_status'] == 1) ) {
        return array(
                  'success' => true,
                  'data' => common_session_data__('array')
                );
	  }

	  // --- CASE TWO --- -- -- - - -
	  ## User POSTed credentials to authenticate
	  elseif ($_SERVER['REQUEST_METHOD'] == 'POST') {		// if data posted, then ...

        ## check if user made too many attempts; if so, add delay
        // -------------------------------------------------------------------

        if (!isset($_SESSION['login_attempts'])) {
            $_SESSION['login_attempts'] = array();
            $_SESSION['login_attempts'][] = time();
        }
        else {   // Check login attempts
            $TOTatts = sizeof($_SESSION['login_attempts']);

            // DENY if too many deny and force user to try later
            if (($TOTatts > 32) && (time()-$_SESSION['login_attempts'][$TOTatts - 1] < 600))
                  return  array('success' => false, 'data' => "Can not check; please try again after 10 minutes.");
            if (($TOTatts > 16) && (time()-$_SESSION['login_attempts'][$TOTatts - 1] < 300))
                  return  array('success' => false, 'data' => "Can not check; please try again after 5 minutes.");
            if (($TOTatts > 8) && (time()-$_SESSION['login_attempts'][$TOTatts - 1] < 55))
                  return  array('success' => false, 'data' => "Can not check; please try after 1 minute.");
            if (($TOTatts > 4) && (time()-$_SESSION['login_attempts'][$TOTatts - 1] < 25))
                  return  array('success' => false, 'data' => "Can not check; please try after 30 seconds. Forgot your password? Contact the administrator!");

            // if too many attempts but stil ok on timings
            // remove the first 10 attempts
            if ($TOTatts > 75) {
              for ($ti = 0 ; $ti < 16 ; $ti++)  array_shift($_SESSION['login_attempts']);
            }

            // if not gone already allow try to login; so log the attempt and continue
            $_SESSION['login_attempts'][] = time();
        }

        ## validate posted data (email, password)
        // -------------------------------------------------------------------

        // POST sent
        $post   = array('user' => $_POST['user'],        'pass' => $_POST['pass']);
        // validation rules
        $rules  = array('user' => FILTER_VALIDATE_EMAIL, 'pass' => true );
        // sanitize input array
        $input  = filter_var_array($post, $rules);

        // check if all valid and non empty; keep errors
        $valid = true;                        // valid (bool)
        $error = array();                     // errors (array)
        $nonEmpty = array('user', 'pass');    // required fields
        foreach($input as $k => $v) {
          if ($v === false) {                 // check not validated
            $valid = false; $error[] = $k ." not validated";
          }
          if ( (($v =="") || ($v === false)) && (in_array($k, $nonEmpty)) ) {   // check required non empty
            $valid = false; $error[] = $k . " is required";
          }
        }
        // echo "inp: "; print_r($input); echo "\nerr: "; print_r($error); die();

        if (!$valid) {  // if no valid data
            return array('success' => false,  'data' => join(", ", $error));   // return error(s)
        }


        ## CHECK DATABASE FOR USER
        // use prepare statements for security
        // -------------------------------------------------------------------

        // init database connection
        $_dbc = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_DBMS);
        if ($_dbc->connect_errno) {
          $_cError = "Database connection failed; Please try in a few minutes. ";
          if (TESTING) echo $_dbc->connect_error;
          $_dbc->close(); die();
        }
        $_dbc->set_charset("utf8");

        // prepare statemet
        $_stm = $_dbc->prepare("SELECT user_id, `user`, salt, pass, role, realname, birthstamp FROM `users` WHERE `user` = ?");
        $_stm->bind_param("s", $post['user']);    // bind values
        $_stm->execute();               // execute query
        $_stm->store_result();          // store result

        if ($_stm->num_rows == 1) {     // only one user should exist
            $_stm->bind_result($uid, $user, $salt, $pass, $role, $name, $birth);   // bind result variables
            $_stm->fetch();             // fetch FIRST record values
        }
        else {   // return error(s)
            return  array('success' => false,  'data' => "More than one users? Please contact system administrator");
        }

        $_stm->close();     // close statement
        $_dbc->close();     // close connection

        ## decide if user is ok
        // -------------------------------------------------------------------
    		if ( $pass == md5($post['user'].$salt.$post['pass']) ) {	// User is validated and ok

            session_unset();     // unset $_SESSION,  and
            session_destroy();   // destroy current session's data before continue;
            session_start();     // then start a new session;
            session_regenerate_id();   // get a new session id to mitigate session fixation
                // setup his session data
            $_SESSION['user_status'] = 1;          // update session status
            $_SESSION['sess_expire'] = time() + SESSION_TTL;	  // session will expire after SESS_TTL seconds
            $_SESSION['sess_update'] = time() + SESSION_UPD;	  // session need to update agter SESS_UPD sec
                // keep critical user info into session
            $_SESSION['uid']  = $uid;
            $_SESSION['name'] = $name;
            $_SESSION['role'] = $role;
            $_SESSION['email'] = $post['user'];
            $_SESSION['birth'] = $birth;

            return  array('success' => true,  'data' => array('uid' => $uid, 'name' => $name, 'role' => $role) );
  		}
  		else {    // user is not ok unset critical session variables

            $_SESSION['user_status'] = 0;
            if (isset($_SESSION['uid']))    unset($_SESSION['uid']);
            if (isset($_SESSION['name']))   unset($_SESSION['name']);
            if (isset($_SESSION['role']))   unset($_SESSION['role']);
            if (isset($_SESSION['role']))   unset($_SESSION['role']);
            // then return failed
            return  array('success' => false, 'data' => "Not valid user credentials.");
  		}

	  }  // --- end CASE TWO

    // --- CASE THREE --- -- -- - - -
    ## credentials not send via POST
    else    return  array('success' => false, 'data' => "Data not sent correctly");
  }


  ## LOGOUT --------------------------------------------------------------------
  //////////////////////////////////////////////////////////////////////////////

	function try_logout()	{
      session_unset();     // unset,  and
      session_destroy();   // destroy session data;
      session_start();     // then start a new session
      session_regenerate_id();   // get a new session id to mitigate session fixation

      // remove cookies
      if (isset($_COOKIE[MAIN_COOKIE])) unset($_COOKIE[MAIN_COOKIE]);
      if (isset($_COOKIE[USER_COOKIE])) unset($_COOKIE[USER_COOKIE]);

      return array('success' => true, 'data' => "User disconected!");   // no chance for the function to fail
	}


## -- 02. Items Catalog Management  ////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////

  ## ADD ITEM ------------------------------------------------------------------
  //////////////////////////////////////////////////////////////////////////////

  function add_item() {
    if ((ROLE) && ($_SERVER['REQUEST_METHOD'] == 'POST')) {

      // POST sent
      $post = array(
        'ccode' =>  $_POST['ccode'],
        'summary' => $_POST['summary'],
        'condition' => $_POST['condition'],
        'decade' =>  $_POST['decade'],
        'operator' =>  $_SESSION['name'],
        'timestamp' =>  time(),
        'box' =>  $_POST['box'],
        'exhibition' =>  $_POST['exhibition'],
        'record' => serialize($_POST)
      );
      // VALIDATE RULES
      $rules = array(
        'ccode' => true,
        'summary' => FILTER_SANITIZE_STRING,
        'condition' => array('filter' => FILTER_VALIDATE_REGEXP, "options" => array("regexp" => "/^[A-Za-z0-9,]+$/")),
        'decade' => FILTER_VALIDATE_INT,
        'operator' => true,
        'timestamp' => true,
        'box' => FILTER_SANITIZE_STRING,
        'exhibition' => FILTER_SANITIZE_STRING,
        'record' => true
      );
      // SANITIZE input array
      $input = filter_var_array($post, $rules);

      // CHECK if all VALID and NON EMPTY
      // --- -- -- - - -
      $valid = true;        // valid flag
      $error = array();     // errors array
      $nonEmpty = array(    // required fields
        'ccode','operator','timestamp'
      );
      foreach($input as $k => $v) {
          // check not validated
          if ($v === false) {
              $valid = false;
              $error[] = $k ." not validated";
          }
          // check empty from required
          if ( (($v =="") || ($v === false)) && (in_array($k, $nonEmpty)) ) {
              $valid = false;
              $error[] = $k . " is required";
          }
      }

      // next line is check (uncomment for checking)
      // if (TESTING) { echo "\nses: "; print_r($_SESSION); echo "\npost:"; print_r($_POST); echo "\n, inp: "; print_r($input); echo "\nerr: "; print_r($error); die(); }

      // IF VALID add item
      // --- -- -- - - -
      if ($valid) {

        // init database connection
        $_dbc = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_DBMS);
        if ($_dbc->connect_errno) {
          echo "Database connection failed; Please try in a few minutes.";
          if (TESTING) echo $_dbc->connect_error;
          $_dbc->close(); die();
        }
        $_dbc->set_charset("utf8");

        $_stm = $_dbc->prepare("INSERT INTO items
            (ccode, summary, `condition`, decade, operator, `timestamp`, `box`, exhibition, record)
            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)"
          );
        $_stm->bind_param("sssisdsss",
          $post['ccode'], $post['summary'], $post['condition'], $post['decade'], $post['operator'], $post['timestamp'], $post['box'], $post['exhibition'], $post['record']
        );
        $_stm->execute();
        $_newid = $_dbc->insert_id;
        $_stm->close();

        if ($_newid > 0) {

          // update individual category table
          // -------------------------------------------------------------------
          $cc = parse_ccode($post['ccode']);
          $_Table = 'tt_'. $cc->idx;    // find table
              // do the insert
          $_stm2 = $_dbc->prepare("INSERT INTO {$_Table} ( id ) VALUES ( ? )");
          $_stm2->bind_param("d", $_newid);
          $_stm2->execute();
          $_iid = $_dbc->insert_id;   // get new index
          $_stm2->close();


          // update record with individual index
          // -------------------------------------------------------------------
          $identity = $post['ccode'] .'.'. $_iid;
              // do the insert
          $_upd = $_dbc->prepare("UPDATE items SET identity = ? WHERE id = ?");
          $_upd->bind_param("sd", $identity, $_newid);
          $_upd->execute();
          $_upd->close();

          return  array('success' => true, 'data' => "Item added", id => $_newid );
        }
        else
          return  array('success' => false, 'data' => "Unknown database error. Please contact the administrator");
      }
      else
          return  array('success' => false, 'data' => implode(", ", $error));

    }
    else  return  array('success' => false, 'data' => "Operation Denied.");
  }


  ## UPDATE ITEM ---------------------------------------------------------------
  //////////////////////////////////////////////////////////////////////////////

  function update_item($id) {
    if ((ROLE) && ($_SERVER['REQUEST_METHOD'] == 'POST')) {

      // POST sent
      // * CCODE : sent correctly but WILL NOT CHANGE; exclude it from UPDATE statement
      // * OPERATOR, TIMESTAMP : not need to change
      $post = array(
        'summary' => $_POST['summary'],
        'condition' => $_POST['condition'],
        'decade' =>  $_POST['decade'],
        'box' =>  $_POST['box'],
        'exhibition' =>  $_POST['exhibition'],
        'record' => serialize($_POST)
      );
      // VALIDATE RULES
      $rules = array(
        'summary' => FILTER_SANITIZE_STRING,
        'condition' => array('filter' => FILTER_VALIDATE_REGEXP, "options" => array("regexp" => "/^[A-Za-z0-9,]+$/")),
        'decade' => FILTER_VALIDATE_INT,
        'box' => FILTER_SANITIZE_STRING,
        'exhibition' => FILTER_SANITIZE_STRING,
        'record' => true
      );
      // SANITIZE input array
      $input = filter_var_array($post, $rules);

      // CHECK if all VALID and NON EMPTY
      // * ALL required fields ARE ALREADY SET; no need to check if empty
      // --- -- -- - - -
      $valid = true;        // valid flag
      $error = array();     // errors array
      foreach($input as $k => $v) {
          // check not validated
          if ($v === false) {
              $valid = false;
              $error[] = $k ." not validated";
          }
      }

      // next line is check (uncomment for checking)
      // if (TESTING) { echo "\nses: "; print_r($_SESSION); echo "\npost:"; print_r($_POST); echo "\n, inp: "; print_r($input); echo "\nerr: "; print_r($error); die(); }

      // IF VALID add item
      // --- -- -- - - -
      if ($valid) {

        // init database connection
        $_dbc = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_DBMS);
        if ($_dbc->connect_errno) {
          echo "Database connection failed; Please try in a few minutes.";
          if (TESTING) echo $_dbc->connect_error;
          $_dbc->close(); die();
        }
        $_dbc->set_charset("utf8");

        $_stm = $_dbc->prepare("UPDATE items
            SET summary = ?, `condition` = ?, decade = ?, `box` = ?, exhibition = ?, record = ?
            WHERE id = ?"
          );
        $_stm->bind_param("ssisssd",
          $post['summary'], $post['condition'], $post['decade'], $post['box'], $post['exhibition'], $post['record'], $id
        );
        $_stm->execute();
        $_stm->close();

        return  array('success' => true, 'data' => "Item Updated", id => $_newid );

      }
      else
          return  array('success' => false, 'data' => implode(", ", $error));

    }
    else  return  array('success' => false, 'data' => "Operation Denied.");
  }

## -- 10. SWITCH THE requested CASES ///////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////

// parse GET argument(s)
$do = (isset($_GET['do'])) ? $_GET['do'] : "none";

// switch the 'do' cases
switch ($do) {

    case 'login':
          $reply = try_login();
          echo json_encode($reply, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
          break;

    case 'logout':
          $reply = try_logout();
          echo json_encode($reply, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
          break;

    case 'additem':
          $reply = add_item();
          echo json_encode($reply, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
          break;

    case 'upditem':
          if (isset($_GET['id']) && is_numeric($_GET['id']) && (($_GET['id'] != '0'))) {
              $item_id  = $_GET['id'];                 // id of photo to upload
              $reply = update_item($item_id);
          }
          else {
              $reply = array('success' => false, 'data' => "ID error");
          }
          echo json_encode($reply, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
          break;


    default:
      // code...
      break;
}