Add A Coupon Dynamically based on Cart Subtotal with WooCommerce

add-coupon-dynamically-based-on-cart-subtotal-woocommerce.php

<?php

/**
 * @snippet       Add A Coupon Dynamically based on Cart Subtotal with WooCommerce
 * @sourcecode    http://hirejordansmith.com
 * @author        Jordan Smith
 * @compatible    WooCommerce 2.4.7
 */

add_action( 'woocommerce_before_cart', 'apply_matched_coupons' );
function apply_matched_coupons() {
  global $woocommerce;
  
  // Set your coupon codes
  $tri10 = 'tri10';
  $tri15 = 'tri15';
  $tri20 = 'tri20';
        
  // Get the cart subtotal in non-decimal number format
  $cart_subtotal = WC()->cart->subtotal;
  
  // If cart subtotal is less than 400 remove coupons
  if ($cart_subtotal < 400) {

	if ( $woocommerce->cart->has_discount( $tri10 ) || $woocommerce->cart->has_discount( $tri15 ) || $woocommerce->cart->has_discount( $tri20 ) ) {
		WC()->cart->remove_coupon( $tri10 );
		WC()->cart->remove_coupon( $tri15 );
		WC()->cart->remove_coupon( $tri20 );
	}

  } 
  
  // If cart subtotal is greater 399 AND is less than 600 add or remove coupons
  if ($cart_subtotal > 399 && $cart_subtotal < 600 ) {

	if ( $woocommerce->cart->has_discount( $tri10 ) ) return;

		if ( $woocommerce->cart->has_discount( $tri15 ) || $woocommerce->cart->has_discount( $tri20 ) ) {
			WC()->cart->remove_coupon( $tri15 );
			WC()->cart->remove_coupon( $tri20 );
		}

	  $woocommerce->cart->add_discount( $tri10 );
	  
  } 
  
  // If cart subtotal is greater than 599 AND is less than 800 add or remove coupons
  if ($cart_subtotal > 599 && $cart_subtotal < 800) {

  	if ( $woocommerce->cart->has_discount( $tri15 ) ) return;
  	
		if ( $woocommerce->cart->has_discount( $tri10 ) || $woocommerce->cart->has_discount( $tri20 ) ) {
			WC()->cart->remove_coupon( $tri10 );
			WC()->cart->remove_coupon( $tri20 );
		}

	  $woocommerce->cart->add_discount( $tri15 );	
  } 
	
  // If cart subtotal is greater than 799 add or remove coupons
  if ( $cart_subtotal > 799) {

  	if ( $woocommerce->cart->has_discount( $tri20 ) ) return;
  	
		if ( $woocommerce->cart->has_discount( $tri10 ) || $woocommerce->cart->has_discount( $tri15 ) ) {
			WC()->cart->remove_coupon( $tri10 );
			WC()->cart->remove_coupon( $tri15 );
		}

	  $woocommerce->cart->add_discount( $tri20 );
	  
  } 

}