unsupervised-scheduler/src/Auth/LoginPage.php

<?php
declare(strict_types=1);

namespace Unsupervised\Schedular\Auth;

class LoginPage {

	/**
	 * Renders the student login shortcode output.
	 *
	 * @param array<string, string> $atts Shortcode attributes (unused — reserved for future options).
	 */
	public function render( array $atts ): string { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
		if ( is_user_logged_in() ) {
			$redirect = esc_url( (string) get_permalink() );
			return sprintf(
				'<p>%s <a href="%s">%s</a>.</p>',
				esc_html__( 'You are already logged in.', 'unsupervised-schedular' ),
				$redirect,
				esc_html__( 'View available lessons', 'unsupervised-schedular' )
			);
		}

		$error    = '';
		$redirect = sanitize_url( (string) get_permalink() );

		if ( isset( $_POST['us_login'] ) && check_admin_referer( 'us_student_login' ) ) {
			$credentials = [
				'user_login'    => sanitize_user( wp_unslash( $_POST['log'] ?? '' ) ),
				// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- passwords must not be sanitized.
				'user_password' => wp_unslash( $_POST['pwd'] ?? '' ),
				'remember'      => isset( $_POST['rememberme'] ),
			];

			$user = wp_signon( $credentials, false );

			if ( is_wp_error( $user ) ) {
				$error = esc_html__( 'Invalid username or password.', 'unsupervised-schedular' );
			} else {
				wp_safe_redirect( $redirect );
				exit;
			}
		}

		ob_start();
		include USC_PLUGIN_DIR . 'templates/frontend/login-page.php';
		return (string) ob_get_clean();
	}
}