class-coupon-code-generator.php
<?php
/**
* This file is part of the WooCommerce Email Editor package.
*
* @package Automattic\WooCommerce\EmailEditor
*/
declare( strict_types = 1 );
namespace Automattic\WooCommerce\EmailEditor\Integrations\WooCommerce;
use Automattic\WooCommerce\EmailEditor\Engine\Renderer\ContentRenderer\Rendering_Context;
use Automattic\WooCommerce\EmailEditor\Integrations\WooCommerce\Renderer\Blocks\Coupon_Code;
/**
* Generates WooCommerce coupons at email send time for the coupon-code block.
*
* Hooks into the woocommerce_coupon_code_block_auto_generate filter to create
* a WC_Coupon from block attributes. This provides baseline auto-generation
* that works without any additional plugins (e.g. MailPoet).
*
* Integrators like MailPoet can hook the same filter at a higher priority
* to add features like per-subscriber restriction or coupon persistence.
*/
class Coupon_Code_Generator {
/**
* Maximum number of retries for generating a unique coupon code.
*/
const MAX_CODE_RETRIES = 5;
/**
* Initialize the generator by registering the filter hook.
*/
public function init(): void {
add_filter( 'woocommerce_coupon_code_block_auto_generate', array( $this, 'generate_coupon' ), 10, 3 );
}
/**
* Generate a WooCommerce coupon from block attributes.
*
* @param string $coupon_code The coupon code (empty if not yet generated).
* @param array $attrs Block attributes.
* @param Rendering_Context $rendering_context The rendering context.
* @return string The generated coupon code, or empty string on failure.
*/
public function generate_coupon( string $coupon_code, array $attrs, Rendering_Context $rendering_context ): string {
if ( ! empty( $coupon_code ) ) {
return $coupon_code;
}
if ( $rendering_context->get( 'is_user_preview' ) ) {
return Coupon_Code::COUPON_CODE_PLACEHOLDER;
}
if ( ! function_exists( 'wc_get_coupon_types' ) || ! class_exists( 'WC_Coupon' ) ) {
return '';
}
try {
$coupon = new \WC_Coupon();
$coupon->set_code( $this->generate_unique_code() );
$discount_type = $this->validate_discount_type( $attrs['discountType'] ?? 'percent' );
$coupon->set_discount_type( $discount_type );
if ( isset( $attrs['amount'] ) ) {
$coupon->set_amount( (float) $attrs['amount'] );
}
if ( ! empty( $attrs['expiryDay'] ) ) {
$expiration = time() + ( (int) $attrs['expiryDay'] * DAY_IN_SECONDS );
$coupon->set_date_expires( $expiration );
}
$coupon->set_free_shipping( ! empty( $attrs['freeShipping'] ) );
$coupon->set_minimum_amount( (float) ( $attrs['minimumAmount'] ?? 0 ) );
$coupon->set_maximum_amount( (float) ( $attrs['maximumAmount'] ?? 0 ) );
$coupon->set_individual_use( ! empty( $attrs['individualUse'] ) );
$coupon->set_exclude_sale_items( ! empty( $attrs['excludeSaleItems'] ) );
$coupon->set_product_ids( $this->extract_ids( $attrs['productIds'] ?? array() ) );
$coupon->set_excluded_product_ids( $this->extract_ids( $attrs['excludedProductIds'] ?? array() ) );
$coupon->set_product_categories( $this->extract_ids( $attrs['productCategoryIds'] ?? array() ) );
$coupon->set_excluded_product_categories( $this->extract_ids( $attrs['excludedProductCategoryIds'] ?? array() ) );
$email_restrictions = $this->parse_email_restrictions( $attrs['emailRestrictions'] ?? '' );
$recipient = $rendering_context->get_recipient_email();
if ( $recipient && is_email( $recipient ) ) {
$email_restrictions[] = $recipient;
}
$coupon->set_email_restrictions( array_unique( $email_restrictions ) );
$usage_limit = $attrs['usageLimit'] ?? 0;
$usage_limit_per_user = $attrs['usageLimitPerUser'] ?? 0;
$coupon->set_usage_limit( is_numeric( $usage_limit ) ? (int) $usage_limit : 0 );
$coupon->set_usage_limit_per_user( is_numeric( $usage_limit_per_user ) ? (int) $usage_limit_per_user : 0 );
$coupon->set_description(
__( 'Auto-generated coupon by WooCommerce Email Editor', 'woocommerce' )
);
$coupon->save();
return $coupon->get_code();
} catch ( \Exception $e ) {
wc_get_logger()->error(
'Coupon auto-generation failed: ' . $e->getMessage(),
array( 'source' => 'email-editor-coupon-generator' )
);
return '';
}
}
/**
* Parse and validate email restrictions string.
*
* @param mixed $raw Raw email restrictions value (comma-separated string).
* @return array Array of valid email addresses.
*/
private function parse_email_restrictions( $raw ): array {
if ( ! is_string( $raw ) || '' === $raw ) {
return array();
}
$emails = array_map( 'trim', explode( ',', $raw ) );
return array_values(
array_filter(
$emails,
function ( string $email ): bool {
return (bool) is_email( $email );
}
)
);
}
/**
* Validate discount type against WooCommerce's registered types.
*
* @param string $type The discount type to validate.
* @return string A valid discount type.
*/
private function validate_discount_type( string $type ): string {
$valid_types = array_keys( wc_get_coupon_types() );
return in_array( $type, $valid_types, true ) ? $type : 'percent';
}
/**
* Generate a unique random coupon code, retrying on collision.
*
* @return string A unique coupon code.
* @throws \RuntimeException When a unique code cannot be generated after max retries.
*/
private function generate_unique_code(): string {
for ( $i = 0; $i < self::MAX_CODE_RETRIES; $i++ ) {
$code = $this->generate_random_code();
$existing = wc_get_coupon_id_by_code( $code );
if ( ! $existing ) {
return $code;
}
}
// phpcs:ignore WordPress.Security.EscapeOutput.ExceptionNotEscaped -- exception message, not rendered output.
throw new \RuntimeException( 'Failed to generate a unique coupon code.' );
}
/**
* Generate a random coupon code in XXXX-XXXXXX-XXXX format.
*
* @return string
*/
private function generate_random_code(): string {
$characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
$length = strlen( $characters ) - 1;
$segment1 = '';
$segment2 = '';
$segment3 = '';
for ( $i = 0; $i < 4; $i++ ) {
$segment1 .= $characters[ random_int( 0, $length ) ];
}
for ( $i = 0; $i < 6; $i++ ) {
$segment2 .= $characters[ random_int( 0, $length ) ];
}
for ( $i = 0; $i < 4; $i++ ) {
$segment3 .= $characters[ random_int( 0, $length ) ];
}
return $segment1 . '-' . $segment2 . '-' . $segment3;
}
/**
* Extract integer IDs from an array of {id, title} objects.
*
* @param array $items Array of items with 'id' key.
* @return array Array of integer IDs.
*/
private function extract_ids( array $items ): array {
return array_map(
function ( $item ): int {
if ( ! is_array( $item ) ) {
return 0;
}
$id = $item['id'] ?? 0;
return is_numeric( $id ) ? (int) $id : 0;
},
$items
);
}
}
