tasks.php

<?php
session_start();
include_once 'config.php';
$action=$_POST['action']??'';
$status=0;
$connection=mysqli_connect(DB_HOST,DB_USER,DB_PASSWORD,DB_NAME);
mysqli_set_charset($connection,"utf8");
if(!$connection){
    throw new Exception("Database did not connect");

}
else{
    if('register'==$action){
        $username=$_POST['email'];
        $password=$_POST['password'];
        if($username && $password){

            $hash=password_hash($password,PASSWORD_BCRYPT);
            $query="INSERT INTO users (email,password) VALUES('{$username}','{$hash}')";
            mysqli_query($connection,$query);
            if(mysqli_error($connection)){
                $status=1;//duplicate
            }else{
                $status=3;//ok
            }
        }else{
            $status=2;//empty
        }

  

    }else if('login'==$action){
        $username=$_POST['email'];
        $password=$_POST['password'];
        if($username && $password){
            $query="SELECT id,password FROM users WHERE email='{$username}'";
            $result=mysqli_query($connection,$query);
            if(mysqli_num_rows($result)>0){
                $data=mysqli_fetch_assoc($result);
                $_password=$data['password'];
                $_id=$data['id'];
                
                if(password_verify($password, $_password)){
                    $_SESSION['id']=$_id;
                    header("Location:words.php");
                    die();
                }else{
                    $status=4;
                }

            }else{
                $status=5;
            }
        }
        else{
            $status=2;
        }
    }
    else if("addword"==$action){
      $word=$_POST['word']??"";
      $meaning=$_POST['meaning']??""; 
      $user_id=$_SESSION['id'];

      if($word&&$meaning&&$user_id){
         
        $query="INSERT INTO words (user_id,word,meaning) VALUES ('{$user_id}','{$word}','{$meaning}')";
        mysqli_query($connection,$query);
        header("Location:words.php");
        die();
      }

    }
    header("Location:index.php?status=$status");
}