Calculate GST for Australian billing addresses/residents

pmpro-australian-gst.php

<?php
/**
 * Plugin Name: Paid Memberships Pro - Australian GST
 * Plugin URI: https://eighty20results.com/paid-memberships-pro/do-it-for-me/
 * Description: Calculate and display GST for Australian customers at checkout
 * Version: 1.0
 * Author: Paid Memberships Pro / Thomas Sjolshagen <thomas@eighty20results.com>
 * Author URI: https://eighty20results.com/thomas-sjolshagen/
 * License URI: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * License: GPLv2 or later
 *
 * Copyright (c) 2017 - Eighty / 20 Results by Wicked Strong Chicks.
 * ALL RIGHTS RESERVED
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/** Credit: Jason @ Stranger Studios (Original Developer) */
/*
  Tax solution for Australia
  
  This solution assume the GST tax rate of 10% from March 15th, 2017. Ask your accountant how much tax you must charge.
  More info: https://www.business.gov.au/info/run/tax/register-for-goods-and-services-tax-gst
  
  Edit as needed, then save this file in your plugins folder and activate it through the plugins page in the WP dashboard.
*/

if ( ! defined( "PMPRO_AGST_TAX_RATE" ) ) {
    define( "AGST_PCT_TAX_RATE", 10 ); // As of March 15th, 2017
}

/**
 * Calculate the tax multiplier (from the constant)
 *
 * @return float
 */
function agst_get_tax_rate() {
    
    return (float) ( intval( AGST_PCT_TAX_RATE ) / 100 );
}

/**
 * Calculate the tax amount as part of the pmpro_tax filter
 *
 * @filter: pmpro_tax
 *
 * @param float $tax
 * @param array $values
 * @param MemberOrder $order
 *
 * @return float
 */
function agst_pmpro_tax( $tax, $values, $order ) {
 
	$tax = round( (float) $values[ 'price' ] * agst_get_tax_rate(), 2 );
	
	return $tax;
}

add_filter( 'pmpro_tax', 'agst_pmpro_tax', 10, 3 );

/**
 * Generate the Text to show as the Level Cost w/ GST included
 *
 * @param string $level_cost_text
 * @param stdClass $level
 *
 * @return string
 */
function agst_pmpro_level_cost_text( $level_cost_text, $level ) {
	
    global $pmpro_currencies;
    global $pmpro_currency_symbol;
    
    $initial_price_tax = 0.00;
	$billing_amount_tax = 0.00;
	$new_cost_text = '';
	
	
    if ( ! empty( $level->initial_payment )) {
	    $initial_price_tax = round( (float) $level->initial_payment * agst_get_tax_rate(), 2 );
	    $initial_amount = number_format_i18n( ((float)($level->initial_payment) + $initial_price_tax),2 );
	    
	    $new_cost_text = sprintf( __( 'You will be billed %s %.2f immediately. ', 'pmpro-australia-gst' ), $pmpro_currency_symbol, $initial_amount );
    }
    
    if ( ! empty( $level->billing_amount) ) {
	 
	    $billing_amount_tax = round( (float) $level->billing_amount * agst_get_tax_rate(), 2 );
	    $billing_amount = number_format_i18n( ((float)($level->billing_amount) + $billing_amount_tax),2 );
	    
	    
        $new_cost_text .= sprintf( __( 'Then %s %.2f every %d %s(s). ', 'pmpro-australia-gst' ), $pmpro_currency_symbol, $billing_amount, $level->cycle_number, $level->cycle_period );
     
    }
    
    if ( !empty( $new_cost_text ) ) {
        
        $new_cost_text .= sprintf( __( "(amount(s) include %d%% GST)", 'pmpro-australia-gst' ), AGST_PCT_TAX_RATE );
        return $new_cost_text;
        
    } else {
	    return $level_cost_text;
    }
}

add_filter( "pmpro_level_cost_text", "agst_pmpro_level_cost_text", 10, 2 );

/**
 * Set the default billing country to be Australia
 *
 * @param string $country - Country code (2 letters)
 *
 * @return string
 */
function agst_pmpro_default_country( $country ) {
	return 'AU';
}

add_filter( 'pmpro_default_country', 'agst_pmpro_default_country' );

/**
 * Add a checkbox for residency to the checkout page
 */
function agst_pmpro_checkout_boxes() {
	
    // Should we include taxes?
    $add_tax = ( isset( $_REQUEST['taxregion'] ) || isset( $_SESSION['taxregion'] ) );
    ?>
    <table id="pmpro_pricing_fields" class="pmpro_checkout" width="100%" cellpadding="0" cellspacing="0" border="0">
        <thead>
        <tr>
            <th>
				<?php _e( 'Australian Resident', 'pmpro-australia-gst' ); ?>
            </th>
        </tr>
        </thead>
        <tbody>
        <tr>
            <td>
                <div>
                    <input id="taxregion" name="taxregion" type="checkbox" value="1" <?php checked( $add_tax, true ); ?> />
                    <label for="taxregion"
                           class="pmpro_normal pmpro_clickable"><?php _e( 'Check this box if your billing address is in Australia.', 'pmpro-australian-gst' ); ?></label>
                </div>
            </td>
        </tr>
        </tbody>
    </table>
	<?php
}

add_action( "pmpro_checkout_boxes", "agst_pmpro_checkout_boxes" );

/**
 * Add the pmpro_tax filter if the new member is in a tax region
 */
function agst_region_tax_check() {
 
	// Grab info from request & assign it to a session variable
	if ( isset( $_REQUEST['taxregion'] ) ) {

		//Add the tax calculation filter
		if ( ! empty( $_REQUEST['taxregion'] ) ) {
			add_filter( "pmpro_tax", "agst_pmpro_tax", 10, 3 );
		}
		
	} else if ( ! empty( $_SESSION['taxregion'] ) ) {
		//add the filter
		add_filter( "pmpro_tax", "agst_pmpro_tax", 10, 3 );
	} else {
		//check state and country
		if ( ! empty( $_REQUEST['bcountry'] ) ) {
			$bcountry = trim( strtolower( $_REQUEST['bcountry'] ) );
			if ( $bcountry == "au" ) {
				//billing address is in AU
				add_filter( "pmpro_tax", "agst_pmpro_tax", 10, 3 );
			}
		}
	}
}

add_action( "pmpro_checkout_preheader", "agst_region_tax_check", 5 );

/**
 * Save to the session variable once the session is known to exist
 * The session is (minimally) initialized in the `pmpro_checkout_preheader` action.
 * Unless there's no session support...
 */
function agst_set_session_data() {

	if ( isset( $_REQUEST['taxregion'] ) ) {
		
	    // Save to the session variable
		$_SESSION['taxregion'] = $_REQUEST['taxregion'];
		
	}
}
add_action( 'pmpro_checkout_preheader', 'agst_set_session_data', 20 );

/**
 * Remove the taxregion session variable after the checkout
 */
function agst_pmpro_after_checkout() {
 
	if ( isset( $_SESSION['taxregion'] ) ) {
		unset( $_SESSION['taxregion'] );
	}
}

add_action( "pmpro_after_checkout", "agst_pmpro_after_checkout", 10 );