Merge pull request #115 from omise/installment-filter-terms

Installment, display instalment monthly amount & interest fee at the checkout page.

assets/css/omise-css.css

@@ -37,6 +37,16 @@ fieldset.card-exists {
 	font-size: 80%;
 }
 
+#payment .payment_methods li .payment_box fieldset#omise-form-installment .omise-buttom-note {
+	margin-top: 4em;
+}
+
+#payment .payment_methods li .payment_box fieldset#omise-form-installment .omise-installment-interest-rate {
+	color: #aaa;
+	font-size: 80%;
+	line-height: 1;
+}
+
 
 /**
  * 2). Components
@@ -51,7 +61,16 @@ fieldset.card-exists {
 }
 
 /**
- * 2.2). Form, bank list components
+ * 2.2). Components
+ */
+.omise-buttom-note {
+	margin-top: 2em;
+	color: #aaa;
+	font-size: 80%;
+}
+
+/**
+ * 2.3). Form, bank list components
  */
 ul.omise-banks-list {
 	margin: 0;
@@ -149,7 +168,7 @@ ul.omise-banks-list {
 }
 
 /**
- * 2.3). Bank logos
+ * 2.4). Bank logos
  */
 /** BAY **/
 .bank-logo.bay {

composer.json

@@ -0,0 +1,9 @@
+{
+    "name": "omise/omise-woocommerce",
+    "description": "An official payment extension which provides support for Omise payment gateway for store builders working on the WooCommerce platform.",
+    "homepage": "https://www.omise.co/",
+    "license": "MIT",
+    "require-dev": {
+        "phpunit/phpunit": "^8.1"
+    }
+}

includes/backends/class-omise-backend-installment.php

@@ -0,0 +1,127 @@
+<?php
+/**
+ * Note: all calculations in this class are based only on Thailand VAT and fee
+ *       as currently Installment feature supported only for merchants
+ *       that have registered with Omise Thailand account.
+ *
+ * @since 3.4
+ *
+ * @method public initiate
+ * @method public get_available_providers
+ * @method public get_available_plans
+ * @method public calculate_monthly_payment_amount
+ */
+class Omise_Backend_Installment extends Omise_Backend {
+	/**
+	 * @var array  of known installment providers.
+	 */
+	protected static $providers = array();
+
+	public function initiate() {
+		self::$providers = array(
+			'installment_first_choice' => array(
+				'bank_code'          => 'first_choice',
+				'title'              => __( 'Krungsri First Choice', 'omise' ),
+				'interest_rate'      => 1.3,
+				'min_allowed_amount' => 300.00,
+			),
+
+			'installment_bay' => array(
+				'bank_code'          => 'bay',
+				'title'              => __( 'Krungsri', 'omise' ),
+				'interest_rate'      => 0.8,
+				'min_allowed_amount' => 300.00,
+			),
+
+			'installment_ktc' => array(
+				'bank_code'          => 'ktc',
+				'title'              => __( 'Krungthai Card (KTC)', 'omise' ),
+				'interest_rate'      => 0.8,
+				'min_allowed_amount' => 300.00,
+			),
+
+			'installment_bbl' => array(
+				'bank_code'          => 'bbl',
+				'title'              => __( 'Bangkok Bank', 'omise' ),
+				'interest_rate'      => 0.8,
+				'min_allowed_amount' => 500.00,
+			),
+
+			'installment_kbank' => array(
+				'bank_code'          => 'kbank',
+				'title'              => __( 'Kasikorn Bank', 'omise' ),
+				'interest_rate'      => 0.65,
+				'min_allowed_amount' => 500.00,
+			),
+		);
+	}
+
+	/**
+	 * @param  string $currency
+	 * @param  float  $purchase_amount
+	 *
+	 * @return array  of an available installment providers
+	 */
+	public function get_available_providers( $currency, $purchase_amount ) {
+		// Note: as installment payment at the moment only supports for THB currency, so the 
+		//       $purchase_amount is multiplied with 100 to convert the amount into subunit (satang).
+		$providers = $this->capabilities()->getInstallmentBackends( $currency, ( $purchase_amount * 100 ) );
+
+		foreach ( $providers as &$provider ) {
+			$provider_detail = self::$providers[ $provider->_id ];
+
+			$provider->provider_code   = str_replace( 'installment_', '', $provider->_id );
+			$provider->provider_name   = isset( $provider_detail ) ? $provider_detail['title'] : strtoupper( $provider->code );
+			$provider->interest_rate   = $this->capabilities()->is_zero_interest() ? 0 : ( $provider_detail['interest_rate'] );
+			$provider->available_plans = $this->get_available_plans(
+				$purchase_amount,
+				$provider->allowed_installment_terms,
+				$provider->interest_rate,
+				$provider_detail['min_allowed_amount']
+			);
+		}
+
+		return $providers;
+	}
+
+	/**
+	 * @param  float $purchase_amount
+	 * @param  array $allowed_installment_terms
+	 * @param  float $interest_rate
+	 * @param  float $min_allowed_amount
+	 *
+	 * @return array  of an filtered available terms
+	 */
+	public function get_available_plans( $purchase_amount, $allowed_installment_terms, $interest_rate, $min_allowed_amount ) {
+		$plans = array();
+
+		sort( $allowed_installment_terms );
+
+		foreach ( $allowed_installment_terms as $term_length ) {
+			$monthly_amount = $this->calculate_monthly_payment_amount( $purchase_amount, $term_length, $interest_rate );
+
+			if ( $monthly_amount < $min_allowed_amount ) {
+				break;
+			}
+
+			$plans[] = array(
+				'term_length'    => $term_length,
+				'monthly_amount' => $monthly_amount
+			);
+		}
+
+		return $plans;
+	}
+
+	/**
+	 * @param  float $purchase_amount
+	 * @param  int   $term_length      A length of a given installment term.
+	 * @param  float $interest_rate    Its value can be '0' if merchant absorbs an interest.
+	 *
+	 * @return float  of a installment monthly payment (round up to 2 decimals).
+	 */
+	public function calculate_monthly_payment_amount( $purchase_amount, $term_length, $interest_rate ) {
+		$interest = $purchase_amount * $interest_rate * $term_length / 100;
+		return round( ( $purchase_amount + $interest ) / $term_length, 2 );
+	}
+}

includes/backends/class-omise-backend.php

@@ -0,0 +1,25 @@
+<?php
+/**
+ * @since 3.4
+ */
+class Omise_Backend {
+	public function __construct() {
+		$this->initiate();
+	}
+
+	/**
+	 * Class initiation.
+	 *
+	 * @return void
+	 */
+	public function initiate() {
+		return;
+	}
+
+	/**
+	 * @return Omise_Capabilities  Instant.
+	 */
+	public function capabilities() {
+		return Omise_Capabilities::retrieve();
+	}
+}

includes/class-omise-capabilities.php

@@ -45,4 +45,11 @@ public function getInstallmentBackends( $currency = '', $amount = null ) {
 
 		return $this->capabilities->getBackends( $params );
 	}
+
+	/**
+	 * @return bool  True if merchant absorbs the interest or else, false.
+	 */
+	public function is_zero_interest() {
+		return $this->capabilities['zero_interest_installments'];
+	}
 }

includes/gateway/class-omise-payment-installment.php

@@ -33,6 +33,8 @@ public function __construct() {
 			$this->title       = $this->get_option( 'title' );
 			$this->description = $this->get_option( 'description' );
 
+			$this->backend     = new Omise_Backend_Installment;
+
 			add_action( 'woocommerce_update_options_payment_gateways_' . $this->id, array( $this, 'process_admin_options' ) );
 			add_action( 'woocommerce_api_' . $this->id . '_callback', array( $this, 'callback' ) );
 		}
@@ -69,27 +71,15 @@ public function init_form_fields() {
 		 * @inheritdoc
 		 */
 		public function payment_fields() {
-			$provider_names = array(
-				'installment_bay'          => __( 'Krungsri', 'omise' ),
-				'installment_first_choice' => __( 'Krungsri First Choice', 'omise' ),
-				'installment_kbank'        => __( 'Kasikorn Bank', 'omise' ),
-				'installment_bbl'          => __( 'Bangkok Bank', 'omise' ),
-				'installment_ktc'          => __( 'Krungthai Card (KTC)', 'omise' ),
-			);
-
-			$currency             = get_woocommerce_currency();
-			$cart_total           = WC()->cart->total;
-			$capabilities         = Omise_Capabilities::retrieve();
-			$installment_backends = $capabilities->getInstallmentBackends( $currency, $this->format_amount_subunit( $cart_total, $currency ) );
-
-			foreach ( $installment_backends as &$backend ) {
-				$backend->provider_code = str_replace( 'installment_', '', $backend->_id );
-				$backend->provider_name = isset( $provider_names[ $backend->_id ] ) ? $provider_names[ $backend->_id ] : strtoupper( $backend->provider_code );
-			}
+			$currency   = get_woocommerce_currency();
+			$cart_total = WC()->cart->total;
 
 			Omise_Util::render_view(
 				'templates/payment/form-installment.php',
-				array( 'installment_backends' => $installment_backends )
+				array(
+					'installment_backends' => $this->backend->get_available_providers( $currency, $cart_total ),
+					'is_zero_interest'     => $this->backend->capabilities()->is_zero_interest()
+				)
 			);
 		}
 

includes/gateway/class-omise-payment.php

@@ -27,6 +27,13 @@ abstract class Omise_Payment extends WC_Payment_Gateway {
 	 */
 	public $id = 'omise';
 
+	/**
+	 * @since 3.4
+	 *
+	 * @var   \Omise_Backend
+	 */
+	protected $backend;
+
 	/**
 	 * @see omise/includes/class-omise-setting.php
 	 *

omise-woocommerce.php

@@ -117,6 +117,8 @@ private function define_constants() {
 	private function include_classes() {
 		defined( 'OMISE_WOOCOMMERCE_PLUGIN_PATH' ) || define( 'OMISE_WOOCOMMERCE_PLUGIN_PATH', __DIR__ );
 
+		require_once OMISE_WOOCOMMERCE_PLUGIN_PATH . '/includes/backends/class-omise-backend.php';
+		require_once OMISE_WOOCOMMERCE_PLUGIN_PATH . '/includes/backends/class-omise-backend-installment.php';
 		require_once OMISE_WOOCOMMERCE_PLUGIN_PATH . '/includes/classes/class-omise-charge.php';
 		require_once OMISE_WOOCOMMERCE_PLUGIN_PATH . '/includes/classes/class-omise-card-image.php';
 		require_once OMISE_WOOCOMMERCE_PLUGIN_PATH . '/includes/events/class-omise-event-charge-capture.php';

phpunit.xml

@@ -0,0 +1,18 @@
+<phpunit
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/8.1/phpunit.xsd"
+	backupGlobals="true"
+	backupStaticAttributes="false"
+	colors="true"
+	stopOnError="false"
+	stopOnFailure="false"
+	stopOnIncomplete="false"
+	stopOnSkipped="false"
+	stopOnRisky="false"
+	verbose="true">
+	<testsuites>
+		<testsuite name="Omise WooCommerce Test Suite">
+			<directory suffix="-test.php">tests/unit</directory>
+		</testsuite>
+	</testsuites>
+</phpunit>

templates/payment/form-installment.php

@@ -10,15 +10,39 @@
 							<span class="title"><?php echo $backend->provider_name; ?></span><br/>
 							<select id="<?php echo $backend->_id; ?>_installment_terms" name="<?php echo $backend->_id; ?>_installment_terms" class="installment-term-select-box">
 								<option>Select term</option>
-								<?php foreach ( $backend->allowed_installment_terms as $term ) : ?>
-									<option value="<?php echo $term; ?>"><?php echo $term; ?> <?php echo __('months'); ?></option>
+								<?php foreach ( $backend->available_plans as $installment_plan ) : ?>
+									<option value="<?php echo $installment_plan['term_length']; ?>">
+										<?php
+										echo sprintf(
+											__( '%d months', 'omise', 'omise_installment_term_option' ),
+											$installment_plan['term_length']
+										);
+										?>
+
+										<?php
+										echo sprintf(
+											__( '( %s / months )', 'omise', 'omise_installment_payment_per_month' ),
+											wc_price( $installment_plan['monthly_amount'] )
+										);
+										?>
+									</option>
 								<?php endforeach; ?>
 							</select>
+							<?php if ( ! $viewData['is_zero_interest'] ): ?>
+								<br/><span class="omise-installment-interest-rate">
+									<?php echo sprintf( __( '( interest %g%% )', 'omise' ), $backend->interest_rate ); ?>
+								</span>
+							<?php endif; ?>
 						</div>
 					</label>
 				</li>
 			<?php endforeach; ?>
 		</ul>
+		<div class="omise-buttom-note">
+			<p>
+				<?php echo $viewData['is_zero_interest'] ? __( 'All installment payments are interest free', 'omise' ) : __( 'Monthly payment rates shown may be inaccurate as interest rates are subject to change by its bank issuer.', 'omise' ); ?>
+			</p>
+		</div>
 	</fieldset>
 <?php else: ?>
 	<p>

tests/unit/class-omise-unit-test.php

@@ -0,0 +1,16 @@
+<?php
+
+class Omise_Unit_Test {
+	public static function include_class( $path ): void {
+		require_once __DIR__ . '/../../includes/' . $path;
+	}
+}
+
+/**
+ * Mock WordPress __() function.
+ *
+ * @see wp-includes/l10n.php
+ */
+function __( $text, $domain = 'default' ) {
+	return $text;
+}