<?php
/**
 * Maintenance mode handler
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

class MMBD_Maintenance {

    private $settings;

    public function __construct() {
        $this->settings = mmbd_get_settings();
        add_action( 'init', array( $this, 'check_secret_phrase' ), 1 );
        add_action( 'template_redirect', array( $this, 'maybe_display_maintenance' ), 1 );
        add_action( 'mmbd_maintenance_head', array( $this, 'print_module_styles' ), 1 );
        add_action( 'mmbd_maintenance_head', array( $this, 'output_analytics' ) );
        add_action( 'mmbd_maintenance_footer', array( $this, 'output_social_links' ) );
        add_action( 'mmbd_maintenance_footer', array( $this, 'print_module_scripts' ), 99 );
    }

    public function check_secret_phrase() {
        $secret_phrase = trim( $this->settings['secret_phrase'] );
        if ( empty( $secret_phrase ) ) {
            return;
        }

        // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Public bypass URL, no state change without valid phrase
        if ( isset( $_GET['mmbd_bypass'] ) ) {
            // phpcs:ignore WordPress.Security.NonceVerification.Recommended
            $provided = sanitize_text_field( wp_unslash( $_GET['mmbd_bypass'] ) );
            if ( hash_equals( $secret_phrase, $provided ) ) {
                $this->set_bypass_cookie();
                wp_safe_redirect( remove_query_arg( 'mmbd_bypass' ) );
                exit;
            }
        }
    }

    private function set_bypass_cookie() {
        $duration = absint( $this->settings['cookie_duration'] );
        $expiry = time() + ( $duration * DAY_IN_SECONDS );

        $cookie_value = $this->generate_cookie_value( $expiry );
        setcookie( 'mmbd_bypass', $cookie_value, array(
            'expires'  => $expiry,
            'path'     => COOKIEPATH,
            'domain'   => COOKIE_DOMAIN,
            'secure'   => is_ssl(),
            'httponly' => true,
            'samesite' => 'Lax',
        ) );
        $_COOKIE['mmbd_bypass'] = $cookie_value;
    }

    private function generate_cookie_value( $expiry ) {
        $data = $expiry . '|' . get_current_blog_id();
        $hash = hash_hmac( 'sha256', $data, wp_salt( 'auth' ) );
        return $data . '|' . $hash;
    }

    private function verify_bypass_cookie() {
        if ( ! isset( $_COOKIE['mmbd_bypass'] ) ) {
            return false;
        }

        $cookie = sanitize_text_field( wp_unslash( $_COOKIE['mmbd_bypass'] ) );
        $parts = explode( '|', $cookie );

        if ( count( $parts ) !== 3 ) {
            return false;
        }

        list( $expiry, $blog_id, $hash ) = $parts;

        if ( (int) $expiry < time() ) {
            return false;
        }
        if ( (int) $blog_id !== get_current_blog_id() ) {
            return false;
        }

        $expected = hash_hmac( 'sha256', $expiry . '|' . $blog_id, wp_salt( 'auth' ) );
        return hash_equals( $expected, $hash );
    }

    public function maybe_display_maintenance() {
        if ( $this->is_preview_mode() ) {
            $this->display_maintenance_page();
            return;
        }

        if ( empty( $this->settings['enabled'] ) ) {
            return;
        }

        if ( $this->can_bypass() ) {
            return;
        }

        $this->display_maintenance_page();
    }

    private function is_preview_mode() {
        // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Read-only preview check
        if ( ! isset( $_GET['mmbd_preview'] ) || sanitize_text_field( wp_unslash( $_GET['mmbd_preview'] ) ) !== '1' ) {
            return false;
        }
        return is_user_logged_in() && current_user_can( 'manage_options' );
    }

    public function can_bypass() {
        if ( $this->is_login_page() ) {
            return true;
        }
        if ( wp_doing_ajax() ) {
            return true;
        }
        if ( $this->is_rest_request() && is_user_logged_in() ) {
            return true;
        }
        if ( wp_doing_cron() ) {
            return true;
        }
        if ( $this->can_bypass_by_role() ) {
            return true;
        }
        if ( $this->can_bypass_by_ip() ) {
            return true;
        }
        if ( $this->verify_bypass_cookie() ) {
            return true;
        }

        return apply_filters( 'mmbd_can_bypass', false, $this->settings );
    }

    private function is_login_page() {
        $pagenow = isset( $GLOBALS['pagenow'] ) ? $GLOBALS['pagenow'] : '';
        return in_array( $pagenow, array( 'wp-login.php', 'wp-register.php' ), true );
    }

    private function is_rest_request() {
        if ( defined( 'REST_REQUEST' ) && REST_REQUEST ) {
            return true;
        }
        $prefix = rest_get_url_prefix();
        $uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
        return strpos( $uri, '/' . $prefix . '/' ) !== false;
    }

    private function can_bypass_by_role() {
        if ( ! is_user_logged_in() ) {
            return false;
        }

        $roles = $this->settings['bypass_roles'];
        if ( empty( $roles ) || ! is_array( $roles ) ) {
            return false;
        }

        $user = wp_get_current_user();
        foreach ( $roles as $role ) {
            if ( in_array( $role, (array) $user->roles, true ) ) {
                return true;
            }
        }
        return false;
    }

    private function can_bypass_by_ip() {
        $whitelist = trim( $this->settings['ip_whitelist'] );
        if ( empty( $whitelist ) ) {
            return false;
        }

        $visitor_ip = $this->get_visitor_ip();
        $ips = array_filter( array_map( 'trim', explode( "\n", $whitelist ) ) );

        foreach ( $ips as $ip ) {
            if ( ! filter_var( $ip, FILTER_VALIDATE_IP ) ) {
                continue;
            }
            if ( $visitor_ip === $ip ) {
                return true;
            }
        }
        return false;
    }

    private function get_visitor_ip() {
        $headers = array( 'HTTP_CF_CONNECTING_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_REAL_IP', 'REMOTE_ADDR' );

        foreach ( $headers as $header ) {
            if ( ! empty( $_SERVER[ $header ] ) ) {
                $ip = sanitize_text_field( wp_unslash( $_SERVER[ $header ] ) );
                if ( strpos( $ip, ',' ) !== false ) {
                    $ip = trim( explode( ',', $ip )[0] );
                }
                if ( filter_var( $ip, FILTER_VALIDATE_IP ) ) {
                    return $ip;
                }
            }
        }
        return '';
    }

    private function enqueue_template_assets( $template_id ) {
        $css_file = MMBD_PLUGIN_DIR . 'assets/css/templates/' . $template_id . '.css';
        $css_url  = MMBD_PLUGIN_URL . 'assets/css/templates/' . $template_id . '.css';

        if ( file_exists( $css_file ) ) {
            wp_register_style(
                'mmbd-template-' . $template_id,
                $css_url,
                array(),
                MMBD_VERSION
            );
            wp_enqueue_style( 'mmbd-template-' . $template_id );
        }

        if ( 'countdown' === $template_id ) {
            $js_file = MMBD_PLUGIN_DIR . 'assets/js/countdown.js';
            $js_url  = MMBD_PLUGIN_URL . 'assets/js/countdown.js';

            if ( file_exists( $js_file ) ) {
                wp_register_script(
                    'mmbd-countdown',
                    $js_url,
                    array(),
                    MMBD_VERSION,
                    true
                );
                $countdown_date = ! empty( $this->settings['countdown_date'] ) ? $this->settings['countdown_date'] : '';
                wp_add_inline_script(
                    'mmbd-countdown',
                    'var mmbdCountdown = ' . wp_json_encode( array( 'targetDate' => $countdown_date ) ) . ';',
                    'before'
                );
                wp_enqueue_script( 'mmbd-countdown' );
            }
        }
    }

    public function print_module_styles() {
        wp_print_styles( 'mmbd-modules' );
        wp_print_styles( 'mmbd-gtag' );
    }

    public function print_module_scripts() {
        wp_print_scripts( 'mmbd-gtag' );
    }

    private function enqueue_module_assets() {
        wp_register_style(
            'mmbd-modules',
            MMBD_PLUGIN_URL . 'assets/css/modules.css',
            array(),
            MMBD_VERSION
        );
        wp_enqueue_style( 'mmbd-modules' );
    }

    public function output_analytics() {
        $analytics_id = isset( $this->settings['analytics_id'] ) ? trim( $this->settings['analytics_id'] ) : '';
        if ( empty( $analytics_id ) ) {
            return;
        }
        if ( ! preg_match( '/^G-[A-Z0-9]+$/i', $analytics_id ) ) {
            return;
        }
        $escaped_id = esc_attr( $analytics_id );
        wp_register_script( 'mmbd-gtag', 'https://www.googletagmanager.com/gtag/js?id=' . $escaped_id, array(), null, false );
        wp_enqueue_script( 'mmbd-gtag' );
        wp_add_inline_script( 'mmbd-gtag', "window.dataLayer=window.dataLayer||[];function gtag(){dataLayer.push(arguments);}gtag('js',new Date());gtag('config','" . esc_js( $analytics_id ) . "');" );
    }

    public function output_social_links() {
        $platforms = array(
            'facebook'  => array(
                'url'   => isset( $this->settings['social_facebook'] ) ? $this->settings['social_facebook'] : '',
                'label' => 'Facebook',
                'icon'  => '<svg viewBox="0 0 24 24" width="20" height="20" fill="currentColor"><path d="M24 12.073c0-6.627-5.373-12-12-12s-12 5.373-12 12c0 5.99 4.388 10.954 10.125 11.854v-8.385H7.078v-3.47h3.047V9.43c0-3.007 1.792-4.669 4.533-4.669 1.312 0 2.686.235 2.686.235v2.953H15.83c-1.491 0-1.956.925-1.956 1.874v2.25h3.328l-.532 3.47h-2.796v8.385C19.612 23.027 24 18.062 24 12.073z"/></svg>',
            ),
            'twitter'   => array(
                'url'   => isset( $this->settings['social_twitter'] ) ? $this->settings['social_twitter'] : '',
                'label' => 'Twitter / X',
                'icon'  => '<svg viewBox="0 0 24 24" width="20" height="20" fill="currentColor"><path d="M18.244 2.25h3.308l-7.227 8.26 8.502 11.24H16.17l-5.214-6.817L4.99 21.75H1.68l7.73-8.835L1.254 2.25H8.08l4.713 6.231zm-1.161 17.52h1.833L7.084 4.126H5.117z"/></svg>',
            ),
            'instagram' => array(
                'url'   => isset( $this->settings['social_instagram'] ) ? $this->settings['social_instagram'] : '',
                'label' => 'Instagram',
                'icon'  => '<svg viewBox="0 0 24 24" width="20" height="20" fill="currentColor"><path d="M12 2.163c3.204 0 3.584.012 4.85.07 3.252.148 4.771 1.691 4.919 4.919.058 1.265.069 1.645.069 4.849 0 3.205-.012 3.584-.069 4.849-.149 3.225-1.664 4.771-4.919 4.919-1.266.058-1.644.07-4.85.07-3.204 0-3.584-.012-4.849-.07-3.26-.149-4.771-1.699-4.919-4.92-.058-1.265-.07-1.644-.07-4.849 0-3.204.013-3.583.07-4.849.149-3.227 1.664-4.771 4.919-4.919 1.266-.057 1.645-.069 4.849-.069zM12 0C8.741 0 8.333.014 7.053.072 2.695.272.273 2.69.073 7.052.014 8.333 0 8.741 0 12c0 3.259.014 3.668.072 4.948.2 4.358 2.618 6.78 6.98 6.98C8.333 23.986 8.741 24 12 24c3.259 0 3.668-.014 4.948-.072 4.354-.2 6.782-2.618 6.979-6.98.059-1.28.073-1.689.073-4.948 0-3.259-.014-3.667-.072-4.947-.196-4.354-2.617-6.78-6.979-6.98C15.668.014 15.259 0 12 0zm0 5.838a6.162 6.162 0 100 12.324 6.162 6.162 0 000-12.324zM12 16a4 4 0 110-8 4 4 0 010 8zm6.406-11.845a1.44 1.44 0 100 2.881 1.44 1.44 0 000-2.881z"/></svg>',
            ),
            'linkedin'  => array(
                'url'   => isset( $this->settings['social_linkedin'] ) ? $this->settings['social_linkedin'] : '',
                'label' => 'LinkedIn',
                'icon'  => '<svg viewBox="0 0 24 24" width="20" height="20" fill="currentColor"><path d="M20.447 20.452h-3.554v-5.569c0-1.328-.027-3.037-1.852-3.037-1.853 0-2.136 1.445-2.136 2.939v5.667H9.351V9h3.414v1.561h.046c.477-.9 1.637-1.85 3.37-1.85 3.601 0 4.267 2.37 4.267 5.455v6.286zM5.337 7.433a2.062 2.062 0 01-2.063-2.065 2.064 2.064 0 112.063 2.065zm1.782 13.019H3.555V9h3.564v11.452zM22.225 0H1.771C.792 0 0 .774 0 1.729v20.542C0 23.227.792 24 1.771 24h20.451C23.2 24 24 23.227 24 22.271V1.729C24 .774 23.2 0 22.222 0h.003z"/></svg>',
            ),
        );

        $has_links = false;
        foreach ( $platforms as $platform ) {
            if ( ! empty( $platform['url'] ) ) {
                $has_links = true;
                break;
            }
        }

        if ( ! $has_links ) {
            return;
        }

        echo '<div class="mmbd-social-links">';
        foreach ( $platforms as $key => $platform ) {
            if ( empty( $platform['url'] ) ) {
                continue;
            }
            printf(
                '<a href="%s" class="mmbd-social-link mmbd-social-%s" target="_blank" rel="noopener noreferrer" aria-label="%s">%s</a>',
                esc_url( $platform['url'] ),
                esc_attr( $key ),
                esc_attr( $platform['label'] ),
                $platform['icon']
            );
        }
        echo '</div>';
    }

    public function display_maintenance_page() {
        status_header( 503 );
        header( 'Retry-After: 3600' );
        header( 'Content-Type: text/html; charset=utf-8' );
        nocache_headers();

        $message = wp_kses_post( $this->settings['message'] );
        $message = apply_filters( 'mmbd_maintenance_message', $message );

        // Get template ID and enqueue assets
        $template_id = isset( $this->settings['template'] ) ? $this->settings['template'] : 'classic';
        $this->enqueue_template_assets( $template_id );
        $this->enqueue_module_assets();

        $template = $this->locate_template();
        if ( $template ) {
            include $template;
        } else {
            wp_die( wp_kses_post( $message ), esc_html__( 'Maintenance Mode', 'devlab-maintenance-mode' ), array( 'response' => 503, 'back_link' => false ) );
        }
        exit;
    }

    private function locate_template() {
        $id = isset( $this->settings['template'] ) ? $this->settings['template'] : 'classic';
        return MMBD_Templates::get_template_path( $id );
    }
}

new MMBD_Maintenance();