wpforms-paystack.php

<?php
/**
 * Plugin Name:       WPForms Paystack Gateway
 * Plugin URI:        https://theophilusadegbohungbe.com/plugins/wpforms-paystack
 * Description:       Paystack payment gateway integration for WPForms Pro. Supports one-time payments, multi-currency (NGN, GHS, ZAR, USD, KES, EGP, XOF, RWF), and webhook verification. Requires WPForms Pro.
 * Version:           1.0.1
 * Author:            Theophilus Adegbohungbe
 * Author URI:        https://theophilusadegbohungbe.com
 * License:           GPL-2.0-or-later
 * License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 * Text Domain:       wpforms-paystack
 * Domain Path:       /languages
 * Requires at least: 5.8
 * Requires PHP:      7.4
 * WPForms requires:  1.7.0 Pro
 *
 * @package    WPFormsPaystack
 * @author     Theophilus Adegbohungbe <hello@theophilusadegbohungbe.com>
 * @copyright  2024 Theophilus Adegbohungbe
 * @link       https://theophilusadegbohungbe.com
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit; // Exit if accessed directly.
}

// Plugin constants.
define( 'WPFORMS_PAYSTACK_VERSION', '1.0.1' );
define( 'WPFORMS_PAYSTACK_FILE', __FILE__ );
define( 'WPFORMS_PAYSTACK_PATH', plugin_dir_path( __FILE__ ) );
define( 'WPFORMS_PAYSTACK_URL', plugin_dir_url( __FILE__ ) );
define( 'WPFORMS_PAYSTACK_MIN_WPFORMS', '1.7.0' );

/**
 * Main plugin bootstrap class.
 *
 * @since 1.0.0
 */
final class WPForms_Paystack {

    /**
     * Singleton instance.
     *
     * @since 1.0.0
     * @var WPForms_Paystack
     */
    private static $instance = null;

    /**
     * Get singleton instance.
     *
     * @since 1.0.0
     * @return WPForms_Paystack
     */
    public static function instance() {
        if ( is_null( self::$instance ) ) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    /**
     * Constructor.
     *
     * @since 1.0.0
     */
    private function __construct() {
        add_action( 'plugins_loaded', array( $this, 'init' ) );
        register_activation_hook( WPFORMS_PAYSTACK_FILE, array( $this, 'activate' ) );
        register_deactivation_hook( WPFORMS_PAYSTACK_FILE, array( $this, 'deactivate' ) );
    }

    /**
     * Initialise plugin after plugins are loaded.
     *
     * @since 1.0.0
     */
    public function init() {
        // Check WPForms is active.
        if ( ! $this->check_wpforms() ) {
            return;
        }

        $this->load_textdomain();
        $this->includes();
        $this->hooks();

        /**
         * Fires after the plugin is fully initialised.
         *
         * @since 1.0.0
         */
        do_action( 'wpforms_paystack_loaded' );
    }

    /**
     * Check WPForms is active and meets the minimum version.
     *
     * @since 1.0.0
     * @return bool
     */
    private function check_wpforms() {
        if ( ! class_exists( 'WPForms' ) && ! class_exists( 'WPForms_Lite' ) ) {
            add_action( 'admin_notices', array( $this, 'notice_wpforms_missing' ) );
            return false;
        }

        $wpforms_version = defined( 'WPFORMS_VERSION' ) ? WPFORMS_VERSION : '0';
        if ( version_compare( $wpforms_version, WPFORMS_PAYSTACK_MIN_WPFORMS, '<' ) ) {
            add_action( 'admin_notices', array( $this, 'notice_wpforms_outdated' ) );
            return false;
        }

        return true;
    }

    /**
     * Load plugin text domain.
     *
     * @since 1.0.0
     */
    private function load_textdomain() {
        load_plugin_textdomain(
            'wpforms-paystack',
            false,
            dirname( plugin_basename( WPFORMS_PAYSTACK_FILE ) ) . '/languages'
        );
    }

    /**
     * Include required files.
     *
     * @since 1.0.0
     */
    private function includes() {
        require_once WPFORMS_PAYSTACK_PATH . 'includes/functions.php';
        require_once WPFORMS_PAYSTACK_PATH . 'includes/class-paystack-gateway.php';
        require_once WPFORMS_PAYSTACK_PATH . 'includes/class-paystack-webhook.php';
        require_once WPFORMS_PAYSTACK_PATH . 'includes/class-paystack-admin.php';
        // Register the Paystack draggable field in the Payment Fields builder panel.
        require_once WPFORMS_PAYSTACK_PATH . 'includes/class-paystack-field.php';

        // Instantiate the gateway once so its constructor hooks (process_payment,
        // AJAX handlers, builder sections) are all registered.
        new WPForms_Paystack_Gateway();
    }

    /**
     * Register hooks.
     *
     * @since 1.0.0
     */
    private function hooks() {
        // Register the gateway with WPForms.
        add_filter( 'wpforms_payments_available', array( $this, 'register_gateway' ) );

        // Inject Paystack-supported currencies into the WPForms global currency list.
        add_filter( 'wpforms_currencies', array( $this, 'register_currencies' ) );

        // Register the Paystack field (Payment Fields panel button).
        add_action( 'wpforms_loaded', array( $this, 'register_field' ) );

        // Enqueue frontend assets.
        add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_frontend_assets' ) );

        // Enqueue admin assets.
        add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_admin_assets' ) );

        // Initialise webhook listener.
        add_action( 'init', array( 'WPForms_Paystack_Webhook', 'listen' ) );
    }

    /**
     * Register Paystack gateway with WPForms.
     *
     * @since  1.0.0
     * @param  array $gateways Existing gateways.
     * @return array
     */
    /**
     * Inject Paystack-supported currencies into the WPForms global currency
     * selector (WPForms → Settings → Payments → Currency dropdown).
     *
     * WPForms uses the wpforms_currencies filter to build that dropdown.
     * Each entry must follow the format WPForms expects:
     *   'CODE' => array( 'name', 'symbol', 'symbol_pos', 'thousands_sep',
     *                    'decimal_sep', 'decimals' )
     *
     * @since 1.0.0
     *
     * @param array $currencies Existing WPForms currencies.
     * @return array
     */
    public function register_currencies( $currencies ) {
        $paystack_currencies = array(
            'NGN' => array(
                'name'          => esc_html__( 'Nigerian Naira', 'wpforms-paystack' ),
                'symbol'        => '&#8358;',
                'symbol_pos'    => 'left',
                'thousands_sep' => ',',
                'decimal_sep'   => '.',
                'decimals'      => 2,
            ),
            'GHS' => array(
                'name'          => esc_html__( 'Ghanaian Cedi', 'wpforms-paystack' ),
                'symbol'        => '&#x20B5;',
                'symbol_pos'    => 'left',
                'thousands_sep' => ',',
                'decimal_sep'   => '.',
                'decimals'      => 2,
            ),
            'ZAR' => array(
                'name'          => esc_html__( 'South African Rand', 'wpforms-paystack' ),
                'symbol'        => 'R',
                'symbol_pos'    => 'left',
                'thousands_sep' => ',',
                'decimal_sep'   => '.',
                'decimals'      => 2,
            ),
            'KES' => array(
                'name'          => esc_html__( 'Kenyan Shilling', 'wpforms-paystack' ),
                'symbol'        => 'KSh',
                'symbol_pos'    => 'left',
                'thousands_sep' => ',',
                'decimal_sep'   => '.',
                'decimals'      => 2,
            ),
            'EGP' => array(
                'name'          => esc_html__( 'Egyptian Pound', 'wpforms-paystack' ),
                'symbol'        => 'E&#163;',
                'symbol_pos'    => 'left',
                'thousands_sep' => ',',
                'decimal_sep'   => '.',
                'decimals'      => 2,
            ),
            'XOF' => array(
                'name'          => esc_html__( 'West African CFA Franc', 'wpforms-paystack' ),
                'symbol'        => 'CFA',
                'symbol_pos'    => 'left',
                'thousands_sep' => ',',
                'decimal_sep'   => '.',
                'decimals'      => 0,
            ),
            'RWF' => array(
                'name'          => esc_html__( 'Rwandan Franc', 'wpforms-paystack' ),
                'symbol'        => 'Fr',
                'symbol_pos'    => 'left',
                'thousands_sep' => ',',
                'decimal_sep'   => '.',
                'decimals'      => 0,
            ),
        );

        // Merge — Paystack currencies come first so they are easy to find.
        return array_merge( $paystack_currencies, $currencies );
    }

    public function register_gateway( $gateways ) {
        // WPForms Pro iterates $gateways and calls new $class_name() on each string.
        // WPForms Lite does not use this filter but our gateway self-registers via
        // its constructor hooks when included, so both paths are covered.
        $gateways['paystack'] = 'WPForms_Paystack_Gateway';
        return $gateways;
    }

    /**
     * Instantiate the WPForms_Field_Paystack class so WPForms registers the
     * "Paystack" button in the Payment Fields panel of the form builder.
     *
     * WPForms auto-discovers field classes when they are instantiated after the
     * wpforms_loaded action fires. The parent WPForms_Field constructor calls
     * wpforms()->fields->register( $this ) internally.
     *
     * @since 1.0.0
     */
    public function register_field() {
        if ( class_exists( 'WPForms_Field' ) ) {
            new WPForms_Field_Paystack();
        }
    }

    /**
     * Enqueue frontend scripts and styles.
     *
     * @since 1.0.0
     */
    /**
     * Check whether the current page has at least one WPForms form that has
     * Paystack enabled, so we only load scripts when truly needed.
     *
     * Falls back to TRUE when we cannot determine at enqueue time (e.g. forms
     * loaded via shortcode in a widget or block), letting the JS self-abort.
     *
     * @since 1.0.0
     * @return bool
     */
    private function page_has_paystack_form() {
        global $post;

        if ( ! $post instanceof WP_Post ) {
            return true; // Cannot determine — load anyway to be safe.
        }

        // Quick scan: does the post content reference [wpforms id="..."]?
        if ( ! has_shortcode( $post->post_content, 'wpforms' ) && ! has_block( 'wpforms/form-selector', $post ) ) {
            return false;
        }

        // Check all forms on this post for Paystack being enabled.
        preg_match_all( '/\[wpforms[^\]]+id=["\']?(\d+)["\']?/i', $post->post_content, $matches );
        $form_ids = $matches[1] ?? array();

        foreach ( $form_ids as $form_id ) {
            $form_data = wpforms()->form->get( absint( $form_id ), array( 'content_only' => true ) );
            if ( ! empty( $form_data['payments']['paystack']['enable'] ) ) {
                return true;
            }
        }

        // Block editor: trust that wpforms block might use Paystack.
        if ( has_block( 'wpforms/form-selector', $post ) ) {
            return true;
        }

        return false;
    }

    public function enqueue_frontend_assets() {
        if ( ! wpforms_is_amp() ) {
            wp_enqueue_style(
                'wpforms-paystack',
                WPFORMS_PAYSTACK_URL . 'assets/css/wpforms-paystack.css',
                array(),
                WPFORMS_PAYSTACK_VERSION
            );
            wp_enqueue_script(
                'paystack-inline',
                'https://js.paystack.co/v2/inline.js',
                array(),
                null,
                true
            );
            wp_enqueue_script(
                'wpforms-paystack',
                WPFORMS_PAYSTACK_URL . 'assets/js/wpforms-paystack.js',
                array( 'jquery', 'paystack-inline' ),
                WPFORMS_PAYSTACK_VERSION,
                true
            );
            wp_localize_script(
                'wpforms-paystack',
                'wpformsPaystack',
                array(
                    'ajaxUrl'   => admin_url( 'admin-ajax.php' ),
                    'nonce'     => wp_create_nonce( 'wpforms_paystack_nonce' ),
                    'i18n'      => array(
                        'processing'     => esc_html__( 'Opening payment window…', 'wpforms-paystack' ),
                        'verifying'      => esc_html__( 'Verifying payment, please wait…', 'wpforms-paystack' ),
                        'error'          => esc_html__( 'Payment failed. Please try again.', 'wpforms-paystack' ),
                        'cancelled'      => esc_html__( 'Payment was cancelled. Please try again.', 'wpforms-paystack' ),
                        'emailRequired'  => esc_html__( 'Please enter your email address before paying.', 'wpforms-paystack' ),
                        'amountRequired' => esc_html__( 'A payment amount greater than zero is required.', 'wpforms-paystack' ),
                    ),
                )
            );
        }
    }

    /**
     * Enqueue admin scripts and styles.
     *
     * @since 1.0.0
     * @param string $hook Current admin page hook.
     */
    public function enqueue_admin_assets( $hook ) {
        // Load on: settings, overview, and the form builder (where Payment Fields panel lives).
        $allowed_hooks = array(
            'wpforms_page_wpforms-settings',
            'toplevel_page_wpforms-overview',
            'wpforms_page_wpforms-builder',
        );
        if ( ! in_array( $hook, $allowed_hooks, true ) ) {
            return;
        }
        wp_enqueue_style(
            'wpforms-paystack-admin',
            WPFORMS_PAYSTACK_URL . 'assets/css/wpforms-paystack-admin.css',
            array(),
            WPFORMS_PAYSTACK_VERSION
        );
    }

    /**
     * Plugin activation routine.
     *
     * @since 1.0.0
     */
    public function activate() {
        // Create a custom DB table for payment logs.
        global $wpdb;

        $table_name      = $wpdb->prefix . 'wpforms_paystack_log';
        $charset_collate = $wpdb->get_charset_collate();

        $sql = "CREATE TABLE IF NOT EXISTS {$table_name} (
            id            BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT,
            form_id       BIGINT(20) UNSIGNED NOT NULL DEFAULT 0,
            entry_id      BIGINT(20) UNSIGNED NOT NULL DEFAULT 0,
            reference     VARCHAR(100)        NOT NULL DEFAULT '',
            amount        BIGINT(20) UNSIGNED NOT NULL DEFAULT 0,
            currency      VARCHAR(10)         NOT NULL DEFAULT 'NGN',
            status        VARCHAR(30)         NOT NULL DEFAULT 'pending',
            customer_email VARCHAR(200)       NOT NULL DEFAULT '',
            meta          LONGTEXT,
            created_at    DATETIME            NOT NULL DEFAULT CURRENT_TIMESTAMP,
            updated_at    DATETIME            NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
            PRIMARY KEY (id),
            KEY form_id (form_id),
            KEY entry_id (entry_id),
            KEY reference (reference),
            KEY status (status)
        ) {$charset_collate};";

        require_once ABSPATH . 'wp-admin/includes/upgrade.php';
        dbDelta( $sql );

        update_option( 'wpforms_paystack_db_version', WPFORMS_PAYSTACK_VERSION );
    }

    /**
     * Plugin deactivation routine.
     *
     * @since 1.0.0
     */
    public function deactivate() {
        // Clean up scheduled events if any.
        wp_clear_scheduled_hook( 'wpforms_paystack_verify_pending' );
    }

    /**
     * Admin notice: WPForms missing.
     *
     * @since 1.0.0
     */
    public function notice_wpforms_missing() {
        echo '<div class="notice notice-error"><p>' .
            sprintf(
                /* translators: %s: WPForms plugin link */
                esc_html__( 'WPForms Paystack requires %s to be installed and activated.', 'wpforms-paystack' ),
                '<strong><a href="https://wordpress.org/plugins/wpforms-lite/" target="_blank">WPForms</a></strong>'
            ) .
        '</p></div>';
    }

    /**
     * Admin notice: WPForms outdated.
     *
     * @since 1.0.0
     */
    public function notice_wpforms_outdated() {
        echo '<div class="notice notice-warning"><p>' .
            sprintf(
                /* translators: %s: minimum version */
                esc_html__( 'WPForms Paystack requires WPForms version %s or higher. Please update WPForms.', 'wpforms-paystack' ),
                '<strong>' . esc_html( WPFORMS_PAYSTACK_MIN_WPFORMS ) . '</strong>'
            ) .
        '</p></div>';
    }
}

// Boot the plugin.
WPForms_Paystack::instance();