<?php

if (!defined('ABSPATH')) {
    exit;
}

/**
 * WC_Gateway_Stripe class.
 *
 * @extends WC_Payment_Gateway
 */
class WC_Gateway_Stripe extends WC_Payment_Gateway_CC {

    /**
     * Should we capture Credit cards
     *
     * @var bool
     */
    public $capture;

    /**
     * Checkout enabled
     *
     * @var bool
     */
    public $stripe_checkout;

    /**
     * Checkout Locale
     *
     * @var string
     */
    public $stripe_checkout_locale;

    /**
     * Credit card image
     *
     * @var string
     */
    public $stripe_checkout_image;

    /**
     * Should we store the users credit cards?
     *
     * @var bool
     */
    public $saved_cards;

    /**
     * API access secret key
     *
     * @var string
     */
    public $secret_key;

    /**
     * Api access publishable key
     *
     * @var string
     */
    public $publishable_key;

    /**
     * Do we accept bitcoin?
     *
     * @var bool
     */
    public $bitcoin;

    /**
     * Is test mode active?
     *
     * @var bool
     */
    public $testmode;

    /**
     * Logging enabled?
     *
     * @var bool
     */
    public $logging;

    /**
     * Constructor
     */
    public function __construct() {
        $this->id = 'stripe';
        $this->method_title = __('Stripe', 'woocommerce-gateway-stripe');
        $this->method_description = __('Stripe works by adding credit card fields on the checkout and then sending the details to Stripe for verification.', 'woocommerce-gateway-stripe');
        $this->has_fields = true;
        $this->view_transaction_url = 'https://dashboard.stripe.com/payments/%s';
        $this->supports = array(
            'subscriptions',
            'products',
            'refunds',
            'subscription_cancellation',
            'subscription_reactivation',
            'subscription_suspension',
            'subscription_amount_changes',
            'subscription_payment_method_change', // Subs 1.n compatibility.
            'subscription_payment_method_change_customer',
            'subscription_payment_method_change_admin',
            'subscription_date_changes',
            'multiple_subscriptions',
            'pre-orders',
            'tokenization',
            'add_payment_method'
        );

        // Load the form fields.
        $this->init_form_fields();

        // Load the settings.
        $this->init_settings();

        // Get setting values.
        $this->title = $this->get_option('title');
        $this->description = $this->get_option('description');
        $this->enabled = $this->get_option('enabled');
        $this->testmode = 'yes' === $this->get_option('testmode');
        $this->capture = 'yes' === $this->get_option('capture', 'yes');
        $this->stripe_checkout = 'yes' === $this->get_option('stripe_checkout');
        $this->stripe_checkout_locale = $this->get_option('stripe_checkout_locale');
        $this->stripe_checkout_image = $this->get_option('stripe_checkout_image', '');
        $this->saved_cards = 'yes' === $this->get_option('saved_cards');
        $this->secret_key = $this->testmode ? $this->get_option('test_secret_key') : $this->get_option('secret_key');
        $this->publishable_key = $this->testmode ? $this->get_option('test_publishable_key') : $this->get_option('publishable_key');
        $this->bitcoin = 'USD' === strtoupper(get_woocommerce_currency()) && 'yes' === $this->get_option('stripe_bitcoin');
        $this->logging = 'yes' === $this->get_option('logging');

        if ($this->stripe_checkout) {
            $this->order_button_text = __('Continue to payment', 'woocommerce-gateway-stripe');
        }

        if ($this->testmode) {
            $this->description .= ' ' . sprintf(__('TEST MODE ENABLED. In test mode, you can use the card number 4242424242424242 with any CVC and a valid expiration date or check the documentation "<a href="%s">Testing Stripe</a>" for more card numbers.', 'woocommerce-gateway-stripe'), 'https://stripe.com/docs/testing');
            $this->description = trim($this->description);
        }

        WC_Stripe_API::set_secret_key($this->secret_key);

        // Hooks.
        add_action('wp_enqueue_scripts', array($this, 'payment_scripts'));
        add_action('admin_notices', array($this, 'admin_notices'));
        add_action('woocommerce_update_options_payment_gateways_' . $this->id, array($this, 'process_admin_options'));
    }

    /**
     * Get_icon function.
     *
     * @access public
     * @return string
     */
    public function get_icon() {
        $ext = version_compare(WC()->version, '2.6', '>=') ? '.svg' : '.png';
        $style = version_compare(WC()->version, '2.6', '>=') ? 'style="margin-left: 0.3em"' : '';

        $icon = '<img src="' . WC_HTTPS::force_https_url(WC()->plugin_url() . '/assets/images/icons/credit-cards/visa' . $ext) . '" alt="Visa" width="32" ' . $style . ' />';
        $icon .= '<img src="' . WC_HTTPS::force_https_url(WC()->plugin_url() . '/assets/images/icons/credit-cards/mastercard' . $ext) . '" alt="Mastercard" width="32" ' . $style . ' />';
        $icon .= '<img src="' . WC_HTTPS::force_https_url(WC()->plugin_url() . '/assets/images/icons/credit-cards/amex' . $ext) . '" alt="Amex" width="32" ' . $style . ' />';

        if ('USD' === get_woocommerce_currency()) {
            $icon .= '<img src="' . WC_HTTPS::force_https_url(WC()->plugin_url() . '/assets/images/icons/credit-cards/discover' . $ext) . '" alt="Discover" width="32" ' . $style . ' />';
            $icon .= '<img src="' . WC_HTTPS::force_https_url(WC()->plugin_url() . '/assets/images/icons/credit-cards/jcb' . $ext) . '" alt="JCB" width="32" ' . $style . ' />';
            $icon .= '<img src="' . WC_HTTPS::force_https_url(WC()->plugin_url() . '/assets/images/icons/credit-cards/diners' . $ext) . '" alt="Diners" width="32" ' . $style . ' />';
        }

        if ($this->bitcoin && $this->stripe_checkout) {
            $icon .= '<img src="' . WC_HTTPS::force_https_url(plugins_url('/assets/images/bitcoin' . $ext, WC_STRIPE_MAIN_FILE)) . '" alt="Bitcoin" width="24" ' . $style . ' />';
        }

        return apply_filters('woocommerce_gateway_icon', $icon, $this->id);
    }

    /**
     * Get Stripe amount to pay
     *
     * @param float  $total Amount due.
     * @param string $currency Accepted currency.
     *
     * @return float|int
     */
    public function get_stripe_amount($total, $currency = '') {
        if (!$currency) {
            $currency = get_woocommerce_currency();
        }
        switch (strtoupper($currency)) {
            // Zero decimal currencies.
            case 'BIF' :
            case 'CLP' :
            case 'DJF' :
            case 'GNF' :
            case 'JPY' :
            case 'KMF' :
            case 'KRW' :
            case 'MGA' :
            case 'PYG' :
            case 'RWF' :
            case 'VND' :
            case 'VUV' :
            case 'XAF' :
            case 'XOF' :
            case 'XPF' :
                $total = absint($total);
                break;
            default :
                $total = round($total, 2) * 100; // In cents.
                break;
        }
        return $total;
    }

    /**
     * Check if SSL is enabled and notify the user
     */
    public function admin_notices() {
        if ('no' === $this->enabled) {
            return;
        }

        // Show message if enabled and FORCE SSL is disabled and WordpressHTTPS plugin is not detected.
        if (( function_exists('wc_site_is_https') && !wc_site_is_https() ) && ( 'no' === get_option('woocommerce_force_ssl_checkout') && !class_exists('WordPressHTTPS') )) {
            echo '<div class="error stripe-ssl-message"><p>' . sprintf(__('Stripe is enabled, but the <a href="%s">force SSL option</a> is disabled; your checkout may not be secure! Please enable SSL and ensure your server has a valid SSL certificate - Stripe will only work in test mode.', 'woocommerce-gateway-stripe'), admin_url('admin.php?page=wc-settings&tab=checkout')) . '</p></div>';
        }
    }

    /**
     * Check if this gateway is enabled
     */
    public function is_available() {
        if ('yes' === $this->enabled) {
            if (!$this->testmode && is_checkout() && !is_ssl()) {
                return false;
            }
            if (!$this->secret_key || !$this->publishable_key) {
                return false;
            }
            return true;
        }
        return false;
    }

    /**
     * Initialise Gateway Settings Form Fields
     */
    public function init_form_fields() {
        $this->form_fields = include( 'settings-stripe.php' );

        wc_enqueue_js("
			jQuery( function( $ ) {
				$( '#woocommerce_stripe_stripe_checkout' ).change(function(){
					if ( $( this ).is( ':checked' ) ) {
						$( '#woocommerce_stripe_stripe_checkout_locale, #woocommerce_stripe_stripe_bitcoin, #woocommerce_stripe_stripe_checkout_image' ).closest( 'tr' ).show();
					} else {
						$( '#woocommerce_stripe_stripe_checkout_locale, #woocommerce_stripe_stripe_bitcoin, #woocommerce_stripe_stripe_checkout_image' ).closest( 'tr' ).hide();
					}
				}).change();

				$( '#woocommerce_stripe_secret_key, #woocommerce_stripe_publishable_key' ).change(function(){
					var value = $( this ).val();

					if ( value.indexOf( '_test_' ) >= 0 ) {
						$( this ).css( 'border-color', 'red' ).after( '<span class=\"description stripe-error-description\" style=\"color:red; display:block;\">" . __('This is not a valid live key. Live keys start with "sk_live_" and "pk_live_".', 'woocommerce-gateway-stripe') . "</span>' );
					} else {
						$( this ).css( 'border-color', '' );
						$( '.stripe-error-description', $( this ).parent() ).remove();
					}
				}).change();

				$( '#woocommerce_stripe_test_secret_key, #woocommerce_stripe_test_publishable_key' ).change(function(){
					var value = $( this ).val();

					if ( value.indexOf( '_live_' ) >= 0 ) {
						$( this ).css( 'border-color', 'red' ).after( '<span class=\"description stripe-error-description\" style=\"color:red; display:block;\">" . __('This is not a valid test key. Test keys start with "sk_test_" and "pk_test_".', 'woocommerce-gateway-stripe') . "</span>' );
					} else {
						$( this ).css( 'border-color', '' );
						$( '.stripe-error-description', $( this ).parent() ).remove();
					}
				}).change();
			});
		");
    }

    /**
     * Payment form on checkout page
     */
    public function payment_fields() {
        $user = wp_get_current_user();
        $display_tokenization = $this->supports('tokenization') && is_checkout() && $this->saved_cards;

        if ($user->ID) {
            $user_email = get_user_meta($user->ID, 'billing_email', true);
            $user_email = $user_email ? $user_email : $user->user_email;
        } else {
            $user_email = '';
        }

        if (is_add_payment_method_page()) {
            $pay_button_text = __('Add Card', 'woocommerce-gateway-stripe');
        } else {
            $pay_button_text = '';
        }

        echo '<div
			id="stripe-payment-data"
			data-panel-label="' . esc_attr($pay_button_text) . '"
			data-description=""
			data-email="' . esc_attr($user_email) . '"
			data-amount="' . esc_attr($this->get_stripe_amount(WC()->cart->total)) . '"
			data-name="' . esc_attr(get_bloginfo('name', 'display')) . '"
			data-currency="' . esc_attr(strtolower(get_woocommerce_currency())) . '"
			data-image="' . esc_attr($this->stripe_checkout_image) . '"
			data-bitcoin="' . esc_attr($this->bitcoin ? 'true' : 'false' ) . '"
			data-locale="' . esc_attr($this->stripe_checkout_locale ? $this->stripe_checkout_locale : 'en' ) . '">';

        if ($this->description) {
            echo apply_filters('wc_stripe_description', wpautop(wp_kses_post($this->description)));
        }

        if ($display_tokenization) {
            $this->tokenization_script();
            $this->saved_payment_methods();
        }

        if (!$this->stripe_checkout) {
            $this->form();

            if ($display_tokenization) {
                $this->save_payment_method_checkbox();
            }
        }

        echo '</div>';
    }

    /**
     * Localize Stripe messages based on code
     *
     * @since 3.0.6
     * @version 3.0.6
     * @return array
     */
    public function get_localized_messages() {
        return apply_filters('wc_stripe_localized_messages', array(
            'invalid_number' => __('The card number is not a valid credit card number.', 'woocommerce-gateway-stripe'),
            'invalid_expiry_month' => __('The card\'s expiration month is invalid.', 'woocommerce-gateway-stripe'),
            'invalid_expiry_year' => __('The card\'s expiration year is invalid.', 'woocommerce-gateway-stripe'),
            'invalid_cvc' => __('The card\'s security code is invalid.', 'woocommerce-gateway-stripe'),
            'incorrect_number' => __('The card number is incorrect.', 'woocommerce-gateway-stripe'),
            'expired_card' => __('The card has expired.', 'woocommerce-gateway-stripe'),
            'incorrect_cvc' => __('The card\'s security code is incorrect.', 'woocommerce-gateway-stripe'),
            'incorrect_zip' => __('The card\'s zip code failed validation.', 'woocommerce-gateway-stripe'),
            'card_declined' => __('The card was declined.', 'woocommerce-gateway-stripe'),
            'missing' => __('There is no card on a customer that is being charged.', 'woocommerce-gateway-stripe'),
            'processing_error' => __('An error occurred while processing the card.', 'woocommerce-gateway-stripe'),
            'invalid_request_error' => __('Could not find payment information.', 'woocommerce-gateway-stripe'),
        ));
    }

    /**
     * payment_scripts function.
     *
     * Outputs scripts used for stripe payment
     *
     * @access public
     */
    public function payment_scripts() {
        $suffix = defined('SCRIPT_DEBUG') && SCRIPT_DEBUG ? '' : '.min';

        if ($this->stripe_checkout) {
            wp_enqueue_script('stripe', 'https://checkout.stripe.com/v2/checkout.js', '', '2.0', true);
            wp_enqueue_script('woocommerce_stripe', plugins_url('assets/js/stripe_checkout' . $suffix . '.js', WC_STRIPE_MAIN_FILE), array('stripe'), WC_STRIPE_VERSION, true);
        } else {
            wp_enqueue_script('stripe', 'https://js.stripe.com/v2/', '', '1.0', true);
            wp_enqueue_script('woocommerce_stripe', plugins_url('assets/js/stripe' . $suffix . '.js', WC_STRIPE_MAIN_FILE), array('jquery-payment', 'stripe'), WC_STRIPE_VERSION, true);
        }

        $stripe_params = array(
            'key' => $this->publishable_key,
            'i18n_terms' => __('Please accept the terms and conditions first', 'woocommerce-gateway-stripe'),
            'i18n_required_fields' => __('Please fill in required checkout fields first', 'woocommerce-gateway-stripe'),
        );

        // If we're on the pay page we need to pass stripe.js the address of the order.
        if (isset($_GET['pay_for_order']) && 'true' === $_GET['pay_for_order']) {
            $order_id = wc_get_order_id_by_order_key(urldecode($_GET['key']));
            $order = wc_get_order($order_id);

            $stripe_params['billing_first_name'] = $order->billing_first_name;
            $stripe_params['billing_last_name'] = $order->billing_last_name;
            $stripe_params['billing_address_1'] = $order->billing_address_1;
            $stripe_params['billing_address_2'] = $order->billing_address_2;
            $stripe_params['billing_state'] = $order->billing_state;
            $stripe_params['billing_city'] = $order->billing_city;
            $stripe_params['billing_postcode'] = $order->billing_postcode;
            $stripe_params['billing_country'] = $order->billing_country;
        }

        $stripe_params['no_prepaid_card_msg'] = __('Sorry, we\'re not accepting prepaid cards at this time.', 'woocommerce-gateway-stripe');
        $stripe_params['allow_prepaid_card'] = apply_filters('wc_stripe_allow_prepaid_card', true) ? 'yes' : 'no';
        $stripe_params['stripe_checkout_require_billing_address'] = apply_filters('wc_stripe_checkout_require_billing_address', false) ? 'yes' : 'no';

        // merge localized messages to be use in JS
        $stripe_params = array_merge($stripe_params, $this->get_localized_messages());

        wp_localize_script('woocommerce_stripe', 'wc_stripe_params', apply_filters('wc_stripe_params', $stripe_params));
    }

    /**
     * Generate the request for the payment.
     * @param  WC_Order $order
     * @param  object $source
     * @return array()
     */
    protected function generate_payment_request($order, $source) {
        $post_data = array();
        $post_data['currency'] = strtolower($order->get_order_currency() ? $order->get_order_currency() : get_woocommerce_currency() );
        $post_data['amount'] = $this->get_stripe_amount($order->get_total(), $post_data['currency']);
        $post_data['description'] = sprintf(__('%s - Order %s', 'woocommerce-gateway-stripe'), wp_specialchars_decode(get_bloginfo('name'), ENT_QUOTES), $order->get_order_number());
        $post_data['capture'] = $this->capture ? 'true' : 'false';

        if (!empty($order->billing_email) && apply_filters('wc_stripe_send_stripe_receipt', false)) {
            $post_data['receipt_email'] = $order->billing_email;
        }

        $post_data['expand[]'] = 'balance_transaction';

        if ($source->customer) {
            $post_data['customer'] = $source->customer;
        }

        if ($source->source) {
            $post_data['source'] = $source->source;
        }

        /**
         * Filter the return value of the WC_Payment_Gateway_CC::generate_payment_request.
         *
         * @since 3.1.0
         * @param array $post_data
         * @param WC_Order $order
         * @param object $source
         */
        return apply_filters('wc_stripe_generate_payment_request', $post_data, $order, $source);
    }

    /**
     * Get payment source. This can be a new token or existing card.
     *
     * @param string $user_id
     * @param bool  $force_customer Should we force customer creation.
     *
     * @throws Exception When card was not added or for and invalid card.
     * @return object
     */
    protected function get_source($user_id, $force_customer = false) {
        $stripe_customer = new WC_Stripe_Customer($user_id);
        $stripe_source = false;
        $token_id = false;

        // New CC info was entered and we have a new token to process
        if (isset($_POST['stripe_token'])) {
            $stripe_token = wc_clean($_POST['stripe_token']);
            $maybe_saved_card = isset($_POST['wc-stripe-new-payment-method']) && !empty($_POST['wc-stripe-new-payment-method']);

            // This is true if the user wants to store the card to their account.
            if (( $user_id && $this->saved_cards && $maybe_saved_card ) || $force_customer) {
                $stripe_source = $stripe_customer->add_card($stripe_token);

                if (is_wp_error($stripe_source)) {
                    throw new Exception($stripe_source->get_error_message());
                }
            } else {
                // Not saving token, so don't define customer either.
                $stripe_source = $stripe_token;
                $stripe_customer = false;
            }
        }

        // Use an existing token, and then process the payment
        elseif (isset($_POST['wc-stripe-payment-token']) && 'new' !== $_POST['wc-stripe-payment-token']) {
            $token_id = wc_clean($_POST['wc-stripe-payment-token']);
            $token = WC_Payment_Tokens::get($token_id);

            if (!$token || $token->get_user_id() !== get_current_user_id()) {
                WC()->session->set('refresh_totals', true);
                throw new Exception(__('Invalid payment method. Please input a new card number.', 'woocommerce-gateway-stripe'));
            }

            $stripe_source = $token->get_token();
        }

        return (object) array(
                    'token_id' => $token_id,
                    'customer' => $stripe_customer ? $stripe_customer->get_id() : false,
                    'source' => $stripe_source,
        );
    }

    /**
     * Get payment source from an order. This could be used in the future for
     * a subscription as an example, therefore using the current user ID would
     * not work - the customer won't be logged in :)
     *
     * Not using 2.6 tokens for this part since we need a customer AND a card
     * token, and not just one.
     *
     * @param object $order
     * @return object
     */
    protected function get_order_source($order = null) {
        $stripe_customer = new WC_Stripe_Customer();
        $stripe_source = false;
        $token_id = false;

        if ($order) {
            if ($meta_value = get_post_meta($order->id, '_stripe_customer_id', true)) {
                $stripe_customer->set_id($meta_value);
            }
            if ($meta_value = get_post_meta($order->id, '_stripe_card_id', true)) {
                $stripe_source = $meta_value;
            }
        }

        return (object) array(
                    'token_id' => $token_id,
                    'customer' => $stripe_customer ? $stripe_customer->get_id() : false,
                    'source' => $stripe_source,
        );
    }

    /**
     * Process the payment
     *
     * @param int  $order_id Reference.
     * @param bool $retry Should we retry on fail.
     * @param bool $force_customer Force user creation.
     *
     * @throws Exception If payment will not be accepted.
     *
     * @return array|void
     */
    public function process_payment($order_id, $retry = true, $force_customer = false) {
        try {
            $order = wc_get_order($order_id);
            $source = $this->get_source(get_current_user_id(), $force_customer);

            if (empty($source->source) && empty($source->customer)) {
                $error_msg = __('Please enter your card details to make a payment.', 'woocommerce-gateway-stripe');
                $error_msg .= ' ' . __('Developers: Please make sure that you are including jQuery and there are no JavaScript errors on the page.', 'woocommerce-gateway-stripe');
                throw new Exception($error_msg);
            }

            // Store source to order meta.
            $this->save_source($order, $source);

            // Handle payment.
            if ($order->get_total() > 0) {

                if ($order->get_total() * 100 < 50) {
                    throw new Exception(__('Sorry, the minimum allowed order total is 0.50 to use this payment method.', 'woocommerce-gateway-stripe'));
                }

                WC_Stripe::log("Info: Begin processing payment for order $order_id for the amount of {$order->get_total()}");

                // Make the request.
                $response = WC_Stripe_API::request($this->generate_payment_request($order, $source));

                if (is_wp_error($response)) {
                    // Customer param wrong? The user may have been deleted on stripe's end. Remove customer_id. Can be retried without.
                    if ('customer' === $response->get_error_code() && $retry) {
                        delete_user_meta(get_current_user_id(), '_stripe_customer_id');
                        return $this->process_payment($order_id, false, $force_customer);
                        // Source param wrong? The CARD may have been deleted on stripe's end. Remove token and show message.
                    } elseif ('source' === $response->get_error_code() && $source->token_id) {
                        $token = WC_Payment_Tokens::get($source->token_id);
                        $token->delete();
                        throw new Exception(__('This card is no longer available and has been removed.', 'woocommerce-gateway-stripe'));
                    }
                    $localized_messages = $this->get_localized_messages();

                    throw new Exception(( isset($localized_messages[$response->get_error_code()]) ? $localized_messages[$response->get_error_code()] : $response->get_error_message()));
                }

                // Process valid response.
                $this->process_response($response, $order);
            } else {
                $order->payment_complete();
            }

            // Remove cart.
            WC()->cart->empty_cart();

            do_action('wc_gateway_stripe_process_payment', $response, $order);

            // Return thank you page redirect.
            return array(
                'result' => 'success',
                'redirect' => $this->get_return_url($order)
            );
        } catch (Exception $e) {
            wc_add_notice($e->getMessage(), 'error');
            WC_Stripe::log(sprintf(__('Error: %s', 'woocommerce-gateway-stripe'), $e->getMessage()));

            if ($order->has_status(array('pending', 'failed'))) {
                $this->send_failed_order_email($order_id);
            }

            do_action('wc_gateway_stripe_process_payment_error', $e, $order);

            return array(
                'result' => 'fail',
                'redirect' => ''
            );
        }
    }

    /**
     * Save source to order.
     *
     * @param WC_Order $order For to which the source applies.
     * @param stdClass $source Source information.
     */
    protected function save_source($order, $source) {
        // Store source in the order.
        if ($source->customer) {
            update_post_meta($order->id, '_stripe_customer_id', $source->customer);
        }
        if ($source->source) {
            update_post_meta($order->id, '_stripe_card_id', $source->source);
        }
    }

    /**
     * Store extra meta data for an order from a Stripe Response.
     */
    public function process_response($response, $order) {
        WC_Stripe::log("Processing response: " . print_r($response, true));

        // Store charge data
        update_post_meta($order->id, '_stripe_charge_id', $response->id);
        update_post_meta($order->id, '_stripe_charge_captured', $response->captured ? 'yes' : 'no' );

        // Store other data such as fees
        if (isset($response->balance_transaction) && isset($response->balance_transaction->fee)) {
            // Fees and Net needs to both come from Stripe to be accurate as the returned
            // values are in the local currency of the Stripe account, not from WC.
            $fee = !empty($response->balance_transaction->fee) ? number_format($response->balance_transaction->fee / 100, 2, '.', '') : 0;
            $net = !empty($response->balance_transaction->net) ? number_format($response->balance_transaction->net / 100, 2, '.', '') : 0;
            update_post_meta($order->id, 'Stripe Fee', $fee);
            update_post_meta($order->id, 'Net Revenue From Stripe', $net);
        }

        if ($response->captured) {
            $order->payment_complete($response->id);

            $message = sprintf(__('Stripe charge complete (Charge ID: %s)', 'woocommerce-gateway-stripe'), $response->id);
            $order->add_order_note($message);
            WC_Stripe::log('Success: ' . $message);
        } else {
            add_post_meta($order->id, '_transaction_id', $response->id, true);

            if ($order->has_status(array('pending', 'failed'))) {
                $order->reduce_order_stock();
            }

            $order->update_status('on-hold', sprintf(__('Stripe charge authorized (Charge ID: %s). Process order to take payment, or cancel to remove the pre-authorization.', 'woocommerce-gateway-stripe'), $response->id));
            WC_Stripe::log("Successful auth: $response->id");
        }

        return $response;
    }

    /**
     * Add payment method via account screen.
     * We don't store the token locally, but to the Stripe API.
     * @since 3.0.0
     */
    public function add_payment_method() {
        if (empty($_POST['stripe_token']) || !is_user_logged_in()) {
            wc_add_notice(__('There was a problem adding the card.', 'woocommerce-gateway-stripe'), 'error');
            return;
        }

        $stripe_customer = new WC_Stripe_Customer(get_current_user_id());
        $card = $stripe_customer->add_card(wc_clean($_POST['stripe_token']));

        if (is_wp_error($card)) {
            $localized_messages = $this->get_localized_messages();
            $error_msg = __('There was a problem adding the card.', 'woocommerce-gateway-stripe');

            // loop through the errors to find matching localized message
            foreach ($card->errors as $error => $msg) {
                if (isset($localized_messages[$error])) {
                    $error_msg = $localized_messages[$error];
                }
            }

            wc_add_notice($error_msg, 'error');
            return;
        }

        return array(
            'result' => 'success',
            'redirect' => wc_get_endpoint_url('payment-methods'),
        );
    }

    /**
     * Refund a charge
     * @param  int $order_id
     * @param  float $amount
     * @return bool
     */
    public function process_refund($order_id, $amount = null, $reason = '') {
        $order = wc_get_order($order_id);

        if (!$order || !$order->get_transaction_id()) {
            return false;
        }

        $body = array();

        if (!is_null($amount)) {
            $body['amount'] = $this->get_stripe_amount($amount);
        }

        if ($reason) {
            $body['metadata'] = array(
                'reason' => $reason,
            );
        }

        WC_Stripe::log("Info: Beginning refund for order $order_id for the amount of {$amount}");

        $response = WC_Stripe_API::request($body, 'charges/' . $order->get_transaction_id() . '/refunds');

        if (is_wp_error($response)) {
            WC_Stripe::log("Error: " . $response->get_error_message());
            return $response;
        } elseif (!empty($response->id)) {
            $refund_message = sprintf(__('Refunded %s - Refund ID: %s - Reason: %s', 'woocommerce-gateway-stripe'), wc_price($response->amount / 100), $response->id, $reason);
            $order->add_order_note($refund_message);
            WC_Stripe::log("Success: " . html_entity_decode(strip_tags($refund_message)));
            return true;
        }
    }

    /**
     * Sends the failed order email to admin
     *
     * @version 3.1.0
     * @since 3.1.0
     * @param int $order_id
     * @return null
     */
    public function send_failed_order_email($order_id) {
        $emails = WC()->mailer()->get_emails();
        if (!empty($emails) && !empty($order_id)) {
            $emails['WC_Email_Failed_Order']->trigger($order_id);
        }
    }

}