Wordpress custom login and registration mechanism

functions.php

<?php
add_filter( 'logout_url', 'change_logout_url', 10, 2 );
function change_logout_url( $logout_url, $redirect ){
  $logout_url = site_url( '/logout/', 'login' );
  if ( ! empty( $redirect ) ) {
    $logout_url = add_query_arg( 'redirect_to', urlencode( $redirect ), $logout_url );
  }
  return $login_url;
}

add_filter( 'login_url', 'change_login_url', 10, 2 );
function change_login_url( $login_url, $redirect, $force_reauth ){
  $login_url = site_url( '/login/', 'login' );
  if ( ! empty( $redirect ) ) {
    $login_url = add_query_arg( 'redirect_to', urlencode( $redirect ), $login_url );
  }
  if ( $force_reauth ) {
    $login_url = add_query_arg( 'reauth', '1', $login_url );
  }
  return $login_url;
}

add_filter( 'lostpassword_url', 'my_lost_password_page', 10, 2 );
function my_lost_password_page( $lostpassword_url, $redirect ) {
  return home_url( '/login/?action=reset&redirect_to=' . $redirect );
}


add_filter( 'register_url', $register, 10, 2 );
function change_registration_url($register){
  $register_url = site_url('/register');
  return $register_url;
}

add_filter( 'retrieve_password_message', 'email_modifier', 10, 2 );
function email_mofifier($message, $key, $user_login, $user_data){
  return str_replace('wp-login.php?action=rp&', '/reset-password/?', $message);
}


add_filter( 'lostpassword_url', 'my_lost_password_page', 10, 2 );
function my_lost_password_page( $lostpassword_url, $redirect ) {
  return home_url( '/login/?action=reset&redirect_to=' . $redirect );
}
function redirect_login_page() {
  $login_page  = home_url( '/login/' );
  $page_viewed = basename($_SERVER['REQUEST_URI']);
  
  if( $page_viewed == "wp-login.php" && $_SERVER['REQUEST_METHOD'] == 'GET') {
    wp_redirect($login_page);
		exit;
	}
}
add_action( 'init', 'redirect_login_page' );

links.php

<?php $u = $_SERVER['REQUEST_URI']; ?>
<a href="<?=wp_lostpassword_url($r)?>">Lost Password</a>
<a href="<?=wp_login_url($r)?>">Login</a>
<a href="<?=wp_registration_url($r)?>">Register</a>
<a href="<?=wp_logout_url($r)?>Logout</a>

login.php

<?php
$current_user = wp_get_current_user();
//do_action('user_redirect_if_logged_in');
if(is_user_logged_in()){
  $url = site_url(get_query_var('redirect_to', (current_user_can('manage-options') ? '/wp-admin' : '/profile')));
  wp_redirect( $url );
  exit;
}
if( 'POST' == $_SERVER['REQUEST_METHOD'] ){
  if(empty($_POST['user'])) $error[] = 'Username is required.';
  if(empty($_POST['pass'])) $error[] = 'Password is required.';
  if(empty($error)){
    $creds = array(
      'user_login'    => $_POST['user'],
      'user_password' => $_POST['pass'],
      'remember'      => $_POST['rememberme']
    );
    $user = wp_signon( $creds, false );
    if ( is_wp_error( $user ) ) {
      $error = $user->get_error_message();
    }else{
      $url = site_url(get_query_var('redirect_to', '/dashboard'));  // user dashboard url
      wp_redirect( $url );
      exit;
    }
  }
}

logout.php

<?php
wp_logout(); //erase all authentication traces from browser
wp_redirect(home_url()); // redirect or do other actions.
?>

lost_password.php

<?php
if($_SERVER['REQUEST_METHOD'] == "POST" AND isset($_POST['email'])){
  $r = retrieve_password($_POST['email']);
  if(is_wp_error($r)){
    $error = $r->get_error_message();
  }
}

register.php

<?php
$user_name = $_POST['user'];
$password = $_POST['pass'];
$user_email = $_POST['email'];
$user_id = username_exists( $user_name );
if ( ! $user_id && false == email_exists( $user_email ) ) {
  $user_id = wp_create_user( $user_name, $password, $user_email );
  //Send email for verification here
  add_user_meta($user_id, 'evhash', 'random_hash');
  // wp_mail();
  echo 'Check your email for verification link';
} else {
  echo 'User already exists.';
}

reset_password.php

<?php
$user = check_password_reset_key( $_GET['key'], $_GET['login'] );
if ( ! $user || is_wp_error( $user ) ) {
  if ( $user && $user->get_error_code() === 'expired_key' ) {
    $error = 'Key expired.';
  } else {
    $error = 'Invalid Key.';
  }
}

// if the url checks out, proceed to password reset form


if(isset($_POST['pass1']) AND isset($_POST['pass2']) and $_POST['pass1'] == $_POST['pass2']){
  reset_password( $user, $_POST['pass1'] );
  wp_redirect( site_url('/login/?password=changed') );
  exit;
}
if(empty($_POST['pass1']) OR empty($_POST['pass2'])){
  $error = 'Please fill both fields for your own security.';
}elseif($_POST['pass1'] != $_POST['pass2']){
  $error = 'Ummmm.... They are two different passwords, which one should I save?';
}

verify_email.php

<?php
if(isset($_GET['email']) AND isset($_GET['hash'])){
  $user = get_user_by('email', $_GET['email']);
  if(is_wp_error($user)){
    $error = $user->get_error_message();
  }else{
    if($_GET['hash'] = get_user_meta($user->ID, 'evhash', true)){
      //verified;
      delete_user_meta($user->ID, 'evhash');
      wp_redirect(home_url('/dashboard'));
    }
  }
}