UserModel.php

<?php

namespace App\Model;
use PDO;

class AddUserModel {
    // Function to add users to the database
    public  function addUser(){

        try {

            $username = filter_input(INPUT_POST, 'username', FILTER_SANITIZE_STRING);
            $password = filter_input(INPUT_POST, 'password', FILTER_SANITIZE_STRING);

            $password = hash('sha256', $password);


            require CONTROLLER_DIR . '/dbConnecterController.php';

            $result = $db->query('SELECT * FROM users WHERE username="'.$username.'"');

            if ($username && $password) {

                $row = $result->fetchColumn();
                if($row == 0){
                    $statement = $db->query("INSERT INTO users (username,password) VALUES ('$username', '$password')" );
                    $db = null;
                    return true;
                } else {
                    die("Username already taken, pick something else! <br><a href='/userlist'> Go back to user list");
                }
            }

        } catch (PDOException $e) {
            print "Error!: " . $e->getMessage() . "<br/>";
            die();
        }
    }


    // Function to display the users inside a table
    public function showUsers(){

        try{
            require CONTROLLER_DIR . '/dbConnecterController.php';

            $result = $db->query('SELECT id, username FROM users ORDER BY id');


            echo "<table border='1'>
                <tr>
                <th>ID</th>
                <th>Username</th>
                <th></th>
                <th></th>
                </tr>";
            // This will make it so admin is not displayed on the table
            $row = $result->fetchColumn();
            while($row = $result->fetch(PDO::FETCH_ASSOC)){
                echo "<tr>";
                echo "<td>" . $row['id'] . "</td>";
                echo "<td>" . $row['username'] . "</td>";
                echo '<td>
                        <form method="GET" action="/showEditUserPage">
                            <input type="hidden" name="id" value="' . $row['id'] . '"/>
                            <input type="hidden" name="username" value="' . $row['username'] . '"/>
                            <input type="submit" value="EDIT" name="showEditUserPage"/>
                        </form></td>';
                echo '<td>
                        <form method="POST" action="/deleteUser">
                            <input type="hidden" name="id" value="' . $row['id'] . '"/>
                            <input type="submit" value="DELETE" name="deleteUser"/>
                        </form></td>';
                echo "</tr>";
            }
            echo '</table>';

        } catch (PDOException $e) {
            print "Error!: " . $e->getMessage() . "<br/>";
            die();
        }
    }

    // Function to delete users from the database
    public function deleteUser(){
        $id = $_POST["id"];
        try {
            require CONTROLLER_DIR . '/dbConnecterController.php';
            $result = $db->query('SELECT * FROM users WHERE id="'.$id.'"');

            $row = $result->fetchColumn();
                if(!$row == 0){
                    $statement = $db->query('DELETE FROM users WHERE id="'.$id.'" ');
                    $db = null;
                    return true;
                } else {
                    die("No data present.");
                }

        } catch (PDOException $e) {
            print "Error!: " . $e->getMessage() . "<br/>";
            die();
        }
    }

    // Function to update users
    public function editUser(){


        $username = $_POST["username"];
        $id = $_POST["id"];
        try {
            require CONTROLLER_DIR . '/dbConnecterController.php';
            $result = $db->query('SELECT * FROM users WHERE username="'.$username.'"');

            $row = $result->fetchColumn();
                if(!$row == 0){
                    // To be continued
                    $statement = $db->query("UPDATE users SET username ='$username' WHERE id = '$id'");
                    $db = null;
                    return true;
                } else {
                    die("No data present.");
                }

        } catch (PDOException $e) {
            print "Error!: " . $e->getMessage() . "<br/>";
            die();
        }
    }
}