AffiliateWP - Add Desired Coupon Code Field with Auto-Association for WooCommerce

README.md

AffiliateWP - Desired Coupon Code Field with WooCommerce Integration

A single-file solution that adds a custom "Desired Coupon Code" field to AffiliateWP registration forms with automatic WooCommerce coupon creation and tracking.

Features

✅ Custom coupon code field on affiliate registration
✅ Automatic WooCommerce coupon creation when affiliate is approved
✅ Coupon-affiliate association for referral tracking
✅ Input validation (3-20 chars, alphanumeric + hyphens/underscores)
✅ Duplicate coupon prevention
✅ Full admin management interface

Requirements

• WordPress 5.0+
• AffiliateWP (required)
• WooCommerce (required for coupon features)

Installation

Option 1: Must-Use Plugin (Recommended)

# Download directly to mu-plugins folder
curl -L https://gist.github.com/vapvarun/02e9d5baefaaea36b3bad714b03f8ed5/raw/affiliatewp-coupon-field-complete.php \
  > wp-content/mu-plugins/affiliatewp-coupon-field-complete.php

Option 2: Regular Plugin

1. Download affiliatewp-coupon-field-complete.php
2. Place in wp-content/plugins/ folder
3. Activate via WP Admin

How It Works

1. Registration: Affiliate enters desired coupon code (optional field)
2. Validation: System checks for duplicates and validates format
3. Approval: Admin approves affiliate → WooCommerce coupon auto-created
4. Tracking: Customer uses coupon → Sale tracked as affiliate referral

Default Settings

• Discount: 10% (percentage)
• Character Limit: 3-20 characters
• Allowed Characters: A-Z, 0-9, hyphens, underscores
• Auto-uppercase: All codes converted to uppercase

Customization

Change Default Discount

add_filter( 'affwp_auto_coupon_settings', function( $settings ) {
    $settings['coupon_amount'] = '15'; // 15% instead of 10%
    $settings['discount_type'] = 'fixed_cart'; // or 'percent', 'fixed_product'
    return $settings;
}, 10 );

Add Free Shipping

add_filter( 'affwp_auto_coupon_settings', function( $settings ) {
    $settings['free_shipping'] = 'yes';
    return $settings;
}, 10 );

Admin Features

• Affiliates List: View coupon codes in table
• Edit Affiliate: Modify desired code, view associated coupon
• WooCommerce Integration: Direct edit links to coupons

Testing

1. Register test affiliate with code (e.g., "TEST20")
2. Approve affiliate in WP Admin → Affiliates
3. Check WooCommerce → Coupons for auto-created coupon
4. Make test purchase with coupon
5. Verify referral tracking in Affiliates → Referrals

Support

For issues, enable debug mode:

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );

License

Free to use with AffiliateWP and WooCommerce.

---

Version: 2.0.0
Author: Wbcom Designs
Single File: affiliatewp-coupon-field-complete.php

affiliatewp-coupon-association.php

<?php
/**
 * Must-Use Plugin: Auto-Associate WooCommerce Coupons with AffiliateWP
 * 
 * Description: Automatically creates and associates WooCommerce coupons with affiliates
 *              based on their desired coupon code when approved.
 * 
 * @author  Wbcom Designs
 * @version 1.0.0
 */

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

/**
 * Automatically create and associate WooCommerce coupon when affiliate is approved
 * 
 * This function:
 * 1. Checks if affiliate has a desired coupon code
 * 2. Creates a WooCommerce coupon with that code
 * 3. Associates the coupon with the affiliate for tracking
 */
add_action( 'affwp_set_affiliate_status', function( $affiliate_id, $status, $old_status ) {
    
    // Only proceed when affiliate is being activated/approved
    if ( 'active' !== $status ) {
        return;
    }
    
    // Don't create duplicate if already active
    if ( 'active' === $old_status ) {
        return;
    }
    
    // Check if WooCommerce and AffiliateWP are active
    if ( ! function_exists( 'WC' ) || ! function_exists( 'affwp_get_affiliate_meta' ) ) {
        return;
    }
    
    // Get the desired coupon code
    $desired_code = affwp_get_affiliate_meta( $affiliate_id, 'desired_coupon_code', true );
    
    // Skip if no desired code
    if ( empty( $desired_code ) ) {
        return;
    }
    
    // Check if coupon already exists
    $existing_coupon_id = wc_get_coupon_id_by_code( $desired_code );
    
    if ( $existing_coupon_id ) {
        // Coupon already exists, just associate it with affiliate
        update_post_meta( $existing_coupon_id, 'affwp_discount_affiliate', $affiliate_id );
        
        // Also store the coupon ID in affiliate meta for reference
        affwp_update_affiliate_meta( $affiliate_id, 'wc_coupon_id', $existing_coupon_id );
        
        // Log the association
        error_log( sprintf( 'Associated existing coupon %s (ID: %d) with affiliate %d', $desired_code, $existing_coupon_id, $affiliate_id ) );
        
        return;
    }
    
    // Get affiliate details
    $affiliate = affwp_get_affiliate( $affiliate_id );
    $user = get_userdata( $affiliate->user_id );
    
    // Prepare coupon settings (customize these as needed)
    $coupon_settings = apply_filters( 'affwp_auto_coupon_settings', [
        'discount_type'              => 'percent', // or 'fixed_cart', 'fixed_product'
        'coupon_amount'              => '10', // 10% discount - customize as needed
        'individual_use'             => 'no',
        'product_ids'                => '',
        'excluded_product_ids'       => '',
        'usage_limit'                => '',
        'usage_limit_per_user'       => '',
        'limit_usage_to_x_items'     => '',
        'free_shipping'              => 'no',
        'product_categories'         => [],
        'excluded_product_categories' => [],
        'exclude_sale_items'         => 'no',
        'minimum_amount'             => '',
        'maximum_amount'             => '',
        'email_restrictions'         => [],
        'description'                => sprintf( 'Affiliate coupon for %s (ID: %d)', $user->display_name, $affiliate_id ),
    ], $affiliate_id, $desired_code );
    
    // Create the coupon post
    $coupon_data = [
        'post_title'   => $desired_code,
        'post_content' => $coupon_settings['description'],
        'post_status'  => 'publish',
        'post_author'  => 1,
        'post_type'    => 'shop_coupon',
        'post_excerpt' => $coupon_settings['description'],
    ];
    
    $new_coupon_id = wp_insert_post( $coupon_data );
    
    if ( is_wp_error( $new_coupon_id ) ) {
        error_log( sprintf( 'Failed to create coupon for affiliate %d: %s', $affiliate_id, $new_coupon_id->get_error_message() ) );
        return;
    }
    
    // Set coupon meta data
    foreach ( $coupon_settings as $key => $value ) {
        if ( 'description' !== $key ) {
            update_post_meta( $new_coupon_id, $key, $value );
        }
    }
    
    // Associate coupon with affiliate for tracking
    update_post_meta( $new_coupon_id, 'affwp_discount_affiliate', $affiliate_id );
    
    // Store the coupon ID in affiliate meta for easy reference
    affwp_update_affiliate_meta( $affiliate_id, 'wc_coupon_id', $new_coupon_id );
    
    // Log successful creation
    error_log( sprintf( 'Created and associated coupon %s (ID: %d) with affiliate %d', $desired_code, $new_coupon_id, $affiliate_id ) );
    
    /**
     * Action hook after coupon is created and associated
     * 
     * @param int    $new_coupon_id The newly created coupon ID
     * @param int    $affiliate_id  The affiliate ID
     * @param string $desired_code  The coupon code
     */
    do_action( 'affwp_after_auto_coupon_created', $new_coupon_id, $affiliate_id, $desired_code );
    
}, 10, 3 );

/**
 * Display associated coupon in affiliate admin area
 */
add_action( 'affwp_edit_affiliate_end', function( $affiliate ) {
    
    if ( ! function_exists( 'WC' ) ) {
        return;
    }
    
    $coupon_id = affwp_get_affiliate_meta( $affiliate->affiliate_id, 'wc_coupon_id', true );
    
    if ( ! $coupon_id ) {
        return;
    }
    
    $coupon = get_post( $coupon_id );
    
    if ( ! $coupon || 'shop_coupon' !== $coupon->post_type ) {
        return;
    }
    
    $edit_link = get_edit_post_link( $coupon_id );
    $coupon_amount = get_post_meta( $coupon_id, 'coupon_amount', true );
    $discount_type = get_post_meta( $coupon_id, 'discount_type', true );
    
    ?>
    <tr class="form-row">
        <th scope="row">
            <label><?php esc_html_e( 'Associated WooCommerce Coupon', 'wbcom-affwp' ); ?></label>
        </th>
        <td>
            <strong><?php echo esc_html( $coupon->post_title ); ?></strong>
            <?php if ( $edit_link ) : ?>
                <a href="<?php echo esc_url( $edit_link ); ?>" target="_blank" style="margin-left: 10px;">
                    <?php esc_html_e( 'Edit Coupon', 'wbcom-affwp' ); ?>
                </a>
            <?php endif; ?>
            <p class="description">
                <?php
                printf(
                    esc_html__( 'Discount: %s%s', 'wbcom-affwp' ),
                    esc_html( $coupon_amount ),
                    'percent' === $discount_type ? '%' : ' ' . get_woocommerce_currency_symbol()
                );
                ?>
            </p>
        </td>
    </tr>
    <?php
}, 20 );

/**
 * Track referrals when the associated coupon is used
 * 
 * This ensures that when a customer uses an affiliate's coupon,
 * the sale is tracked as a referral for that affiliate
 */
add_action( 'woocommerce_checkout_order_processed', function( $order_id ) {
    
    if ( ! function_exists( 'affwp_get_affiliate' ) ) {
        return;
    }
    
    $order = wc_get_order( $order_id );
    
    if ( ! $order ) {
        return;
    }
    
    // Get applied coupons
    $coupons = $order->get_coupon_codes();
    
    if ( empty( $coupons ) ) {
        return;
    }
    
    foreach ( $coupons as $coupon_code ) {
        $coupon_id = wc_get_coupon_id_by_code( $coupon_code );
        
        if ( ! $coupon_id ) {
            continue;
        }
        
        // Check if this coupon is associated with an affiliate
        $affiliate_id = get_post_meta( $coupon_id, 'affwp_discount_affiliate', true );
        
        if ( ! $affiliate_id ) {
            continue;
        }
        
        // Verify affiliate exists and is active
        $affiliate = affwp_get_affiliate( $affiliate_id );
        
        if ( ! $affiliate || 'active' !== $affiliate->status ) {
            continue;
        }
        
        // Set affiliate tracking cookie to ensure proper attribution
        $affwp_ref = affwp_get_affiliate_username( $affiliate_id );
        
        if ( $affwp_ref ) {
            // Set tracking cookie (30 days default)
            setcookie( 
                'affwp_ref', 
                $affwp_ref, 
                time() + ( 30 * 24 * 60 * 60 ), 
                COOKIEPATH, 
                COOKIE_DOMAIN, 
                is_ssl(), 
                true 
            );
            
            // Also set visit tracking
            setcookie(
                'affwp_ref_visit_id',
                uniqid(),
                time() + ( 30 * 24 * 60 * 60 ),
                COOKIEPATH,
                COOKIE_DOMAIN,
                is_ssl(),
                true
            );
        }
        
        // Log the coupon-based referral
        error_log( sprintf( 
            'Coupon %s used on order %d - attributed to affiliate %d', 
            $coupon_code, 
            $order_id, 
            $affiliate_id 
        ) );
        
        // Only attribute to first affiliate coupon found
        break;
    }
    
}, 5 ); // Run early to set cookies before referral is tracked

/**
 * Add coupon column to affiliates list table
 */
add_filter( 'affwp_affiliate_table_columns', function( $columns ) {
    $columns['coupon'] = __( 'Coupon Code', 'wbcom-affwp' );
    return $columns;
} );

/**
 * Display coupon code in affiliates list table
 */
add_filter( 'affwp_affiliate_table_coupon', function( $value, $affiliate ) {
    
    $desired_code = affwp_get_affiliate_meta( $affiliate->affiliate_id, 'desired_coupon_code', true );
    $coupon_id = affwp_get_affiliate_meta( $affiliate->affiliate_id, 'wc_coupon_id', true );
    
    if ( $desired_code ) {
        if ( $coupon_id && get_post( $coupon_id ) ) {
            // Coupon exists and is active
            $edit_link = get_edit_post_link( $coupon_id );
            return sprintf( 
                '<strong style="color: green;">%s</strong> <a href="%s" target="_blank" style="text-decoration: none;">✏️</a>', 
                esc_html( $desired_code ),
                esc_url( $edit_link )
            );
        } else {
            // Coupon requested but not yet created
            return sprintf( 
                '<em style="color: orange;">%s (pending)</em>', 
                esc_html( $desired_code ) 
            );
        }
    }
    
    return '—';
    
}, 10, 2 );

/**
 * Add bulk action to create coupons for approved affiliates
 */
add_action( 'admin_footer-affiliates_page_affiliate-wp-affiliates', function() {
    ?>
    <script type="text/javascript">
        jQuery(document).ready(function($) {
            // Add custom bulk action
            $('<option>').val('create_coupons').text('<?php esc_html_e( 'Create Associated Coupons', 'wbcom-affwp' ); ?>')
                .appendTo("select[name='action'], select[name='action2']");
        });
    </script>
    <?php
} );

/**
 * Settings section for auto-coupon configuration
 */
add_filter( 'affwp_settings_integrations', function( $settings ) {
    
    $settings['wc_auto_coupons_header'] = [
        'name' => __( 'Automatic Coupon Creation', 'wbcom-affwp' ),
        'type' => 'header',
    ];
    
    $settings['auto_create_coupons'] = [
        'name' => __( 'Auto-Create Coupons', 'wbcom-affwp' ),
        'desc' => __( 'Automatically create WooCommerce coupons when affiliates are approved', 'wbcom-affwp' ),
        'type' => 'checkbox',
    ];
    
    $settings['auto_coupon_type'] = [
        'name' => __( 'Coupon Type', 'wbcom-affwp' ),
        'desc' => __( 'Default discount type for auto-created coupons', 'wbcom-affwp' ),
        'type' => 'select',
        'options' => [
            'percent' => __( 'Percentage Discount', 'wbcom-affwp' ),
            'fixed_cart' => __( 'Fixed Cart Discount', 'wbcom-affwp' ),
            'fixed_product' => __( 'Fixed Product Discount', 'wbcom-affwp' ),
        ],
        'std' => 'percent',
    ];
    
    $settings['auto_coupon_amount'] = [
        'name' => __( 'Coupon Amount', 'wbcom-affwp' ),
        'desc' => __( 'Default discount amount (number only, no % sign)', 'wbcom-affwp' ),
        'type' => 'number',
        'std' => '10',
        'min' => 0,
        'step' => 0.01,
    ];
    
    return $settings;
} );

// Add admin notice for successful coupon creation
add_action( 'admin_notices', function() {
    if ( isset( $_GET['affwp_coupon_created'] ) && $_GET['affwp_coupon_created'] ) {
        ?>
        <div class="notice notice-success is-dismissible">
            <p><?php esc_html_e( 'WooCommerce coupon has been created and associated with the affiliate!', 'wbcom-affwp' ); ?></p>
        </div>
        <?php
    }
} );

affiliatewp-coupon-field-complete.php

<?php
/**
 * Must-Use Plugin: AffiliateWP Desired Coupon Code Field with Auto-Association
 * 
 * Description: Complete solution that adds a "Desired Coupon Code" field to AffiliateWP 
 *              registration forms and automatically creates/associates WooCommerce coupons.
 * 
 * Features:
 * - Custom field on registration form
 * - Input validation and sanitization
 * - Automatic WooCommerce coupon creation on approval
 * - Affiliate-coupon association for tracking
 * - Admin management interface
 * 
 * @author  Wbcom Designs
 * @version 2.0.0
 */

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

/**
 * =======================
 * PART 1: FIELD FUNCTIONALITY
 * =======================
 */

/**
 * Sanitize the desired coupon code
 * 
 * Rules:
 * - Allows only letters (A-Z), numbers (0-9), underscores (_), and hyphens (-)
 * - Converts to uppercase for consistency
 * 
 * @param string $raw Raw input string
 * @return string Sanitized coupon code
 */
function wb_affwp_sanitize_desired_coupon_code( $raw ) {
    $code = is_string( $raw ) ? $raw : '';
    $code = wp_unslash( $code );
    // Remove any characters that aren't alphanumeric, underscore, or hyphen
    $code = preg_replace( '/[^A-Z0-9_\-]/i', '', $code );
    // Convert to uppercase for consistency
    $code = strtoupper( $code );
    return $code;
}

/**
 * Add the Desired Coupon Code field to the frontend registration form
 * Using the hook that works with both shortcode and block-based forms
 */
add_action( 'affwp_register_fields_before_submit', function() {
    // Get the submitted value (if form was submitted with errors)
    $value = isset( $_POST['desired_coupon_code'] ) 
        ? esc_attr( wb_affwp_sanitize_desired_coupon_code( $_POST['desired_coupon_code'] ) ) 
        : '';
    ?>
    <p class="affwp-field affwp-field-text affwp-field-desired-coupon-code">
        <label for="desired_coupon_code" class="affwp-field-label">
            <?php esc_html_e( 'Desired Coupon Code', 'wbcom-affwp' ); ?>
            <span class="affwp-field-sublabel"><?php esc_html_e( '(optional)', 'wbcom-affwp' ); ?></span>
        </label>
        <input type="text"
               name="desired_coupon_code"
               id="desired_coupon_code"
               class="affwp-field-input"
               value="<?php echo $value; ?>"
               placeholder="<?php esc_attr_e( 'e.g., SAVE10', 'wbcom-affwp' ); ?>"
               />
        <span class="affwp-field-description">
            <?php esc_html_e( 'Request a custom coupon code for your referrals (3-20 characters, letters, numbers, hyphens and underscores only).', 'wbcom-affwp' ); ?>
        </span>
    </p>
    <?php
}, 10 );

/**
 * Validate the Desired Coupon Code on form submission
 */
add_action( 'affwp_process_register_form', function( $data ) {
    // Skip if field is empty (it's optional)
    if ( empty( $_POST['desired_coupon_code'] ) ) {
        return;
    }

    // Check if AffiliateWP is available
    if ( ! function_exists( 'affiliate_wp' ) ) {
        return;
    }

    // Sanitize the input
    $code = wb_affwp_sanitize_desired_coupon_code( $_POST['desired_coupon_code'] );

    // Validate length (3-20 characters)
    if ( strlen( $code ) < 3 || strlen( $code ) > 20 ) {
        affiliate_wp()->register->add_error(
            'desired_coupon_code_length',
            __( 'Desired Coupon Code must be between 3 and 20 characters.', 'wbcom-affwp' )
        );
        return;
    }

    // Check for duplicate WooCommerce coupons (if WooCommerce is active)
    if ( function_exists( 'wc_get_coupon_id_by_code' ) ) {
        $coupon_id = wc_get_coupon_id_by_code( $code );
        if ( $coupon_id ) {
            affiliate_wp()->register->add_error(
                'desired_coupon_code_taken',
                __( 'Sorry, that coupon code is already in use. Please choose another.', 'wbcom-affwp' )
            );
            return;
        }
    }
}, 10 );

/**
 * Save the Desired Coupon Code after successful registration
 */
add_action( 'affwp_post_insert_affiliate', function( $affiliate_id, $args ) {
    // Skip if no code was submitted
    if ( empty( $_POST['desired_coupon_code'] ) ) {
        return;
    }

    // Sanitize and save the code
    $code = wb_affwp_sanitize_desired_coupon_code( $_POST['desired_coupon_code'] );
    if ( $code && function_exists( 'affwp_update_affiliate_meta' ) ) {
        affwp_update_affiliate_meta( (int) $affiliate_id, 'desired_coupon_code', $code );
    }
}, 10, 2 );

/**
 * Display the field in WordPress admin (Edit Affiliate screen)
 */
add_action( 'affwp_edit_affiliate_end', function( $affiliate ) {
    // Ensure we have a valid affiliate object
    if ( ! $affiliate || empty( $affiliate->affiliate_id ) ) {
        return;
    }

    // Retrieve the saved coupon code
    $code = function_exists( 'affwp_get_affiliate_meta' )
        ? affwp_get_affiliate_meta( (int) $affiliate->affiliate_id, 'desired_coupon_code', true )
        : '';
    ?>
    <tr class="form-row">
        <th scope="row">
            <label for="desired_coupon_code">
                <?php esc_html_e( 'Desired Coupon Code', 'wbcom-affwp' ); ?>
            </label>
        </th>
        <td>
            <input type="text" 
                   name="desired_coupon_code" 
                   id="desired_coupon_code" 
                   value="<?php echo esc_attr( $code ); ?>" 
                   class="regular-text" />
            <p class="description">
                <?php esc_html_e( 'Affiliate\'s requested coupon code. This can be used for reference or automated coupon creation.', 'wbcom-affwp' ); ?>
            </p>
        </td>
    </tr>
    <?php
}, 15 ); // Priority 15 to appear before the associated coupon field

/**
 * Save the field from WordPress admin
 */
add_action( 'affwp_update_affiliate', function( $data ) {
    // Ensure we have an affiliate ID
    if ( ! isset( $data['affiliate_id'] ) ) {
        return;
    }

    $affiliate_id = (int) $data['affiliate_id'];
    
    // Get and sanitize the submitted code
    $code = isset( $_POST['desired_coupon_code'] ) 
        ? wb_affwp_sanitize_desired_coupon_code( $_POST['desired_coupon_code'] ) 
        : '';
    
    // Update the affiliate meta
    if ( function_exists( 'affwp_update_affiliate_meta' ) ) {
        affwp_update_affiliate_meta( $affiliate_id, 'desired_coupon_code', $code );
    }
} );

/**
 * =======================
 * PART 2: AUTO-ASSOCIATION
 * =======================
 */

/**
 * Automatically create and associate WooCommerce coupon when affiliate is approved
 */
add_action( 'affwp_set_affiliate_status', function( $affiliate_id, $status, $old_status ) {
    
    // Only proceed when affiliate is being activated/approved
    if ( 'active' !== $status ) {
        return;
    }
    
    // Don't create duplicate if already active
    if ( 'active' === $old_status ) {
        return;
    }
    
    // Check if WooCommerce and AffiliateWP are active
    if ( ! function_exists( 'WC' ) || ! function_exists( 'affwp_get_affiliate_meta' ) ) {
        return;
    }
    
    // Get the desired coupon code
    $desired_code = affwp_get_affiliate_meta( $affiliate_id, 'desired_coupon_code', true );
    
    // Skip if no desired code
    if ( empty( $desired_code ) ) {
        return;
    }
    
    // Check if coupon already exists
    $existing_coupon_id = wc_get_coupon_id_by_code( $desired_code );
    
    if ( $existing_coupon_id ) {
        // Coupon already exists, just associate it with affiliate
        update_post_meta( $existing_coupon_id, 'affwp_discount_affiliate', $affiliate_id );
        
        // Also store the coupon ID in affiliate meta for reference
        affwp_update_affiliate_meta( $affiliate_id, 'wc_coupon_id', $existing_coupon_id );
        
        return;
    }
    
    // Get affiliate details
    $affiliate = affwp_get_affiliate( $affiliate_id );
    $user = get_userdata( $affiliate->user_id );
    
    // Prepare coupon settings (customize these as needed)
    $coupon_settings = apply_filters( 'affwp_auto_coupon_settings', [
        'discount_type'              => 'percent', // or 'fixed_cart', 'fixed_product'
        'coupon_amount'              => '10', // 10% discount - customize as needed
        'individual_use'             => 'no',
        'product_ids'                => '',
        'excluded_product_ids'       => '',
        'usage_limit'                => '',
        'usage_limit_per_user'       => '',
        'limit_usage_to_x_items'     => '',
        'free_shipping'              => 'no',
        'product_categories'         => [],
        'excluded_product_categories' => [],
        'exclude_sale_items'         => 'no',
        'minimum_amount'             => '',
        'maximum_amount'             => '',
        'email_restrictions'         => [],
        'description'                => sprintf( 'Affiliate coupon for %s (ID: %d)', $user->display_name, $affiliate_id ),
    ], $affiliate_id, $desired_code );
    
    // Create the coupon post
    $coupon_data = [
        'post_title'   => $desired_code,
        'post_content' => $coupon_settings['description'],
        'post_status'  => 'publish',
        'post_author'  => 1,
        'post_type'    => 'shop_coupon',
        'post_excerpt' => $coupon_settings['description'],
    ];
    
    $new_coupon_id = wp_insert_post( $coupon_data );
    
    if ( is_wp_error( $new_coupon_id ) ) {
        error_log( sprintf( 'Failed to create coupon for affiliate %d: %s', $affiliate_id, $new_coupon_id->get_error_message() ) );
        return;
    }
    
    // Set coupon meta data
    foreach ( $coupon_settings as $key => $value ) {
        if ( 'description' !== $key ) {
            update_post_meta( $new_coupon_id, $key, $value );
        }
    }
    
    // Associate coupon with affiliate for tracking
    update_post_meta( $new_coupon_id, 'affwp_discount_affiliate', $affiliate_id );
    
    // Store the coupon ID in affiliate meta for easy reference
    affwp_update_affiliate_meta( $affiliate_id, 'wc_coupon_id', $new_coupon_id );
    
    /**
     * Action hook after coupon is created and associated
     */
    do_action( 'affwp_after_auto_coupon_created', $new_coupon_id, $affiliate_id, $desired_code );
    
}, 10, 3 );

/**
 * Display associated coupon in affiliate admin area
 */
add_action( 'affwp_edit_affiliate_end', function( $affiliate ) {
    
    if ( ! function_exists( 'WC' ) ) {
        return;
    }
    
    $coupon_id = affwp_get_affiliate_meta( $affiliate->affiliate_id, 'wc_coupon_id', true );
    
    if ( ! $coupon_id ) {
        return;
    }
    
    $coupon = get_post( $coupon_id );
    
    if ( ! $coupon || 'shop_coupon' !== $coupon->post_type ) {
        return;
    }
    
    $edit_link = get_edit_post_link( $coupon_id );
    $coupon_amount = get_post_meta( $coupon_id, 'coupon_amount', true );
    $discount_type = get_post_meta( $coupon_id, 'discount_type', true );
    
    ?>
    <tr class="form-row">
        <th scope="row">
            <label><?php esc_html_e( 'Associated WooCommerce Coupon', 'wbcom-affwp' ); ?></label>
        </th>
        <td>
            <strong><?php echo esc_html( $coupon->post_title ); ?></strong>
            <?php if ( $edit_link ) : ?>
                <a href="<?php echo esc_url( $edit_link ); ?>" target="_blank" style="margin-left: 10px;">
                    <?php esc_html_e( 'Edit Coupon', 'wbcom-affwp' ); ?>
                </a>
            <?php endif; ?>
            <p class="description">
                <?php
                printf(
                    esc_html__( 'Discount: %s%s', 'wbcom-affwp' ),
                    esc_html( $coupon_amount ),
                    'percent' === $discount_type ? '%' : ' ' . get_woocommerce_currency_symbol()
                );
                ?>
            </p>
        </td>
    </tr>
    <?php
}, 20 );

/**
 * Track referrals when the associated coupon is used
 * This ensures that when a customer uses an affiliate's coupon,
 * the sale is tracked as a referral for that affiliate
 */
add_action( 'woocommerce_checkout_order_processed', function( $order_id ) {
    
    if ( ! function_exists( 'affwp_get_affiliate' ) ) {
        return;
    }
    
    $order = wc_get_order( $order_id );
    
    if ( ! $order ) {
        return;
    }
    
    // Get applied coupons
    $coupons = $order->get_coupon_codes();
    
    if ( empty( $coupons ) ) {
        return;
    }
    
    foreach ( $coupons as $coupon_code ) {
        $coupon_id = wc_get_coupon_id_by_code( $coupon_code );
        
        if ( ! $coupon_id ) {
            continue;
        }
        
        // Check if this coupon is associated with an affiliate
        $affiliate_id = get_post_meta( $coupon_id, 'affwp_discount_affiliate', true );
        
        if ( ! $affiliate_id ) {
            continue;
        }
        
        // Verify affiliate exists and is active
        $affiliate = affwp_get_affiliate( $affiliate_id );
        
        if ( ! $affiliate || 'active' !== $affiliate->status ) {
            continue;
        }
        
        // Set affiliate tracking cookie to ensure proper attribution
        $affwp_ref = affwp_get_affiliate_username( $affiliate_id );
        
        if ( $affwp_ref ) {
            // Set tracking cookie (30 days default)
            setcookie( 
                'affwp_ref', 
                $affwp_ref, 
                time() + ( 30 * 24 * 60 * 60 ), 
                COOKIEPATH, 
                COOKIE_DOMAIN, 
                is_ssl(), 
                true 
            );
            
            // Also set visit tracking
            setcookie(
                'affwp_ref_visit_id',
                uniqid(),
                time() + ( 30 * 24 * 60 * 60 ),
                COOKIEPATH,
                COOKIE_DOMAIN,
                is_ssl(),
                true
            );
        }
        
        // Only attribute to first affiliate coupon found
        break;
    }
    
}, 5 ); // Run early to set cookies before referral is tracked

/**
 * =======================
 * PART 3: ADMIN ENHANCEMENTS
 * =======================
 */

/**
 * Add coupon column to affiliates list table
 */
add_filter( 'affwp_affiliate_table_columns', function( $columns ) {
    $columns['coupon'] = __( 'Coupon Code', 'wbcom-affwp' );
    return $columns;
} );

/**
 * Display coupon code in affiliates list table
 */
add_filter( 'affwp_affiliate_table_coupon', function( $value, $affiliate ) {
    
    $desired_code = affwp_get_affiliate_meta( $affiliate->affiliate_id, 'desired_coupon_code', true );
    $coupon_id = affwp_get_affiliate_meta( $affiliate->affiliate_id, 'wc_coupon_id', true );
    
    if ( $desired_code ) {
        if ( $coupon_id && get_post( $coupon_id ) ) {
            // Coupon exists and is active
            $edit_link = get_edit_post_link( $coupon_id );
            return sprintf( 
                '<strong style="color: green;">%s</strong> <a href="%s" target="_blank" style="text-decoration: none;">✏️</a>', 
                esc_html( $desired_code ),
                esc_url( $edit_link )
            );
        } else {
            // Coupon requested but not yet created
            return sprintf( 
                '<em style="color: orange;">%s (pending)</em>', 
                esc_html( $desired_code ) 
            );
        }
    }
    
    return '—';
    
}, 10, 2 );

/**
 * Add admin notice for successful coupon creation
 */
add_action( 'admin_notices', function() {
    if ( isset( $_GET['affwp_coupon_created'] ) && $_GET['affwp_coupon_created'] ) {
        ?>
        <div class="notice notice-success is-dismissible">
            <p><?php esc_html_e( 'WooCommerce coupon has been created and associated with the affiliate!', 'wbcom-affwp' ); ?></p>
        </div>
        <?php
    }
} );

/**
 * USAGE NOTES:
 * 
 * 1. Installation:
 *    - Save this file to wp-content/mu-plugins/ folder
 *    - It will load automatically (no activation needed)
 * 
 * 2. Configuration:
 *    - Default discount: 10% (modify via affwp_auto_coupon_settings filter)
 *    - Field is optional on registration
 *    - Coupons created when affiliate is approved
 * 
 * 3. To retrieve data:
 *    $coupon_code = affwp_get_affiliate_meta( $affiliate_id, 'desired_coupon_code', true );
 *    $coupon_id = affwp_get_affiliate_meta( $affiliate_id, 'wc_coupon_id', true );
 * 
 * 4. Hooks available:
 *    - affwp_auto_coupon_settings - Modify coupon settings
 *    - affwp_after_auto_coupon_created - After coupon is created
 */

affiliatewp-desired-coupon-field.php

<?php
/**
 * Must-Use Plugin: Add Desired Coupon Code Field to AffiliateWP Registration
 * 
 * Description: Adds a custom "Desired Coupon Code" field to AffiliateWP registration forms,
 *              validates the input, and stores it as affiliate meta data.
 * 
 * @author  Wbcom Designs
 * @version 1.0.1
 */

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

/**
 * Sanitize the desired coupon code
 * 
 * Rules:
 * - Allows only letters (A-Z), numbers (0-9), underscores (_), and hyphens (-)
 * - Converts to uppercase for consistency
 * 
 * @param string $raw Raw input string
 * @return string Sanitized coupon code
 */
function wb_affwp_sanitize_desired_coupon_code( $raw ) {
    $code = is_string( $raw ) ? $raw : '';
    $code = wp_unslash( $code );
    // Remove any characters that aren't alphanumeric, underscore, or hyphen
    $code = preg_replace( '/[^A-Z0-9_\-]/i', '', $code );
    // Convert to uppercase for consistency
    $code = strtoupper( $code );
    return $code;
}

/**
 * STEP 1: Add the Desired Coupon Code field to the frontend registration form
 * Using the hook that works with both shortcode and block-based forms
 * 
 * Hook: affwp_register_fields_before_submit
 * Priority: 10
 */
add_action( 'affwp_register_fields_before_submit', function() {
    // Get the submitted value (if form was submitted with errors)
    $value = isset( $_POST['desired_coupon_code'] ) 
        ? esc_attr( wb_affwp_sanitize_desired_coupon_code( $_POST['desired_coupon_code'] ) ) 
        : '';
    ?>
    <p class="affwp-field affwp-field-text affwp-field-desired-coupon-code">
        <label for="desired_coupon_code" class="affwp-field-label">
            <?php esc_html_e( 'Desired Coupon Code', 'wbcom-affwp' ); ?>
            <span class="affwp-field-sublabel"><?php esc_html_e( '(optional)', 'wbcom-affwp' ); ?></span>
        </label>
        <input type="text"
               name="desired_coupon_code"
               id="desired_coupon_code"
               class="affwp-field-input"
               value="<?php echo $value; ?>"
               placeholder="<?php esc_attr_e( 'e.g., SAVE10', 'wbcom-affwp' ); ?>"
               />
        <span class="affwp-field-description">
            <?php esc_html_e( 'Request a custom coupon code for your referrals (3-20 characters, letters, numbers, hyphens and underscores only).', 'wbcom-affwp' ); ?>
        </span>
    </p>
    <?php
}, 10 );

/**
 * STEP 2: Validate the Desired Coupon Code on form submission
 * 
 * Validation rules:
 * - Must be 3-20 characters long
 * - If WooCommerce is active, check for duplicate coupon codes
 * 
 * Hook: affwp_process_register_form
 */
add_action( 'affwp_process_register_form', function( $data ) {
    // Skip if field is empty (it's optional)
    if ( empty( $_POST['desired_coupon_code'] ) ) {
        return;
    }

    // Check if AffiliateWP is available
    if ( ! function_exists( 'affiliate_wp' ) ) {
        return;
    }

    // Sanitize the input
    $code = wb_affwp_sanitize_desired_coupon_code( $_POST['desired_coupon_code'] );

    // Validate length (3-20 characters)
    if ( strlen( $code ) < 3 || strlen( $code ) > 20 ) {
        affiliate_wp()->register->add_error(
            'desired_coupon_code_length',
            __( 'Desired Coupon Code must be between 3 and 20 characters.', 'wbcom-affwp' )
        );
        return;
    }

    // Check for duplicate WooCommerce coupons (if WooCommerce is active)
    if ( function_exists( 'wc_get_coupon_id_by_code' ) ) {
        $coupon_id = wc_get_coupon_id_by_code( $code );
        if ( $coupon_id ) {
            affiliate_wp()->register->add_error(
                'desired_coupon_code_taken',
                __( 'Sorry, that coupon code is already in use. Please choose another.', 'wbcom-affwp' )
            );
            return;
        }
    }
}, 10 );

/**
 * STEP 3: Save the Desired Coupon Code after successful registration
 * 
 * Stores the code as affiliate meta data
 * 
 * Hook: affwp_post_insert_affiliate
 */
add_action( 'affwp_post_insert_affiliate', function( $affiliate_id, $args ) {
    // Skip if no code was submitted
    if ( empty( $_POST['desired_coupon_code'] ) ) {
        return;
    }

    // Sanitize and save the code
    $code = wb_affwp_sanitize_desired_coupon_code( $_POST['desired_coupon_code'] );
    if ( $code && function_exists( 'affwp_update_affiliate_meta' ) ) {
        affwp_update_affiliate_meta( (int) $affiliate_id, 'desired_coupon_code', $code );
    }
}, 10, 2 );

/**
 * STEP 4: Display the field in WordPress admin (Edit Affiliate screen)
 * 
 * Location: wp-admin → Affiliates → Edit Affiliate
 * 
 * Hook: affwp_edit_affiliate_end
 */
add_action( 'affwp_edit_affiliate_end', function( $affiliate ) {
    // Ensure we have a valid affiliate object
    if ( ! $affiliate || empty( $affiliate->affiliate_id ) ) {
        return;
    }

    // Retrieve the saved coupon code
    $code = function_exists( 'affwp_get_affiliate_meta' )
        ? affwp_get_affiliate_meta( (int) $affiliate->affiliate_id, 'desired_coupon_code', true )
        : '';
    ?>
    <tr class="form-row">
        <th scope="row">
            <label for="desired_coupon_code">
                <?php esc_html_e( 'Desired Coupon Code', 'wbcom-affwp' ); ?>
            </label>
        </th>
        <td>
            <input type="text" 
                   name="desired_coupon_code" 
                   id="desired_coupon_code" 
                   value="<?php echo esc_attr( $code ); ?>" 
                   class="regular-text" />
            <p class="description">
                <?php esc_html_e( 'Affiliate\'s requested coupon code. This can be used for reference or automated coupon creation.', 'wbcom-affwp' ); ?>
            </p>
        </td>
    </tr>
    <?php
} );

/**
 * STEP 5: Save the field from WordPress admin
 * 
 * Processes and saves the coupon code when edited from the admin panel
 * 
 * Hook: affwp_update_affiliate
 */
add_action( 'affwp_update_affiliate', function( $data ) {
    // Ensure we have an affiliate ID
    if ( ! isset( $data['affiliate_id'] ) ) {
        return;
    }

    $affiliate_id = (int) $data['affiliate_id'];
    
    // Get and sanitize the submitted code
    $code = isset( $_POST['desired_coupon_code'] ) 
        ? wb_affwp_sanitize_desired_coupon_code( $_POST['desired_coupon_code'] ) 
        : '';
    
    // Update the affiliate meta
    if ( function_exists( 'affwp_update_affiliate_meta' ) ) {
        affwp_update_affiliate_meta( $affiliate_id, 'desired_coupon_code', $code );
    }
} );

/**
 * USAGE NOTES:
 * 
 * 1. To retrieve the desired coupon code for an affiliate:
 *    $coupon_code = affwp_get_affiliate_meta( $affiliate_id, 'desired_coupon_code', true );
 * 
 * 2. To automatically create WooCommerce coupons based on desired codes, hook into:
 *    - 'affwp_set_affiliate_status' when affiliate is approved
 *    - Check if desired code exists and create the coupon
 * 
 * 3. The code is stored in uppercase format for consistency
 * 
 * 4. Allowed characters: A-Z, 0-9, underscore (_), hyphen (-)
 */