From fc37fb1eb2a1c8a3c977661579239c8e1ef77b50 Mon Sep 17 00:00:00 2001
From: Shamim Rezaie <shamim@moodle.com>
Date: Thu, 9 Jan 2020 02:57:11 +1100
Subject: [PATCH] MDL-69166 pg_paypal: paypal helper class to work with API

---
 .../gateway/paypal/classes/paypal_helper.php  | 161 ++++++++++++++++++
 1 file changed, 161 insertions(+)
 create mode 100644 payment/gateway/paypal/classes/paypal_helper.php

diff --git a/payment/gateway/paypal/classes/paypal_helper.php b/payment/gateway/paypal/classes/paypal_helper.php
new file mode 100644
index 00000000000..fc8af26d6ed
--- /dev/null
+++ b/payment/gateway/paypal/classes/paypal_helper.php
@@ -0,0 +1,161 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle 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.
+//
+// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Contains helper class to work with PayPal REST API.
+ *
+ * @package    core_payment
+ * @copyright  2020 Shamim Rezaie <shamim@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace pg_paypal;
+
+use curl;
+
+defined('MOODLE_INTERNAL') || die();
+
+require_once($CFG->libdir . '/filelib.php');
+
+class paypal_helper {
+
+    /**
+     * @var string The base API URL
+     */
+    private $baseurl;
+
+    /**
+     * @var string Client ID
+     */
+    private $clientid;
+
+    /**
+     * @var string PayPal App secret
+     */
+    private $secret;
+
+    /**
+     * @var string The oath bearer token
+     */
+    private $token;
+
+    /**
+     * helper constructor.
+     *
+     * @param string $clientid The client id.
+     * @param string $secret PayPal secret.
+     * @param bool $sandbox Whether we are working with the sandbox environment or not.
+     */
+    public function __construct(string $clientid, string $secret, bool $sandbox) {
+        $this->clientid = $clientid;
+        $this->secret = $secret;
+        $this->baseurl = $sandbox ? 'https://api.sandbox.paypal.com' : 'https://api.paypal.com';
+
+        $this->token = $this->get_token();
+    }
+
+    /**
+     * Captures an authorized payment, by ID.
+     *
+     * @param string $authorizationid The PayPal-generated ID for the authorized payment to capture.
+     * @param float $amount The amount to capture.
+     * @param string $currency The currency code for the amount.
+     * @param bool $final Indicates whether this is the final captures against the authorized payment.
+     * @return array|null Formatted API response.
+     */
+    public function capture_authorization(string $authorizationid, float $amount, string $currency, bool $final = true): ?array {
+        $location = "{$this->baseurl}/v2/payments/authorizations/{$authorizationid}/capture";
+
+        $options = [
+            'CURLOPT_RETURNTRANSFER' => true,
+            'CURLOPT_TIMEOUT' => 30,
+            'CURLOPT_HTTP_VERSION' => CURL_HTTP_VERSION_1_1,
+            'CURLOPT_SSLVERSION' => CURL_SSLVERSION_TLSv1_2,
+            'CURLOPT_HTTPHEADER' => [
+                'Content-Type: application/json',
+                "Authorization: Bearer {$this->token}",
+            ],
+        ];
+
+        $command = [
+            'amount' => [
+                'value' => (string) $amount,
+                'currency_code' => $currency,
+            ],
+            'final_capture' => $final,
+        ];
+        $command = json_encode($command);
+
+        $curl = new curl();
+        $result = $curl->post($location, $command, $options);
+
+        return json_decode($result, true);
+    }
+
+    /**
+     * Captures order details from PayPal.
+     *
+     * @param string $orderid The order we want to capture.
+     * @return array|null Formatted API response.
+     */
+    public function capture_order(string $orderid): ?array {
+        $location = "{$this->baseurl}/v2/checkout/orders/{$orderid}/capture";
+
+        $options = [
+            'CURLOPT_RETURNTRANSFER' => true,
+            'CURLOPT_TIMEOUT' => 30,
+            'CURLOPT_HTTP_VERSION' => CURL_HTTP_VERSION_1_1,
+            'CURLOPT_SSLVERSION' => CURL_SSLVERSION_TLSv1_2,
+            'CURLOPT_HTTPHEADER' => [
+                'Content-Type: application/json',
+                "Authorization: Bearer {$this->token}",
+            ],
+        ];
+
+        $command = '{}';
+
+        $curl = new curl();
+        $result = $curl->post($location, $command, $options);
+
+        return json_decode($result, true);
+    }
+
+    /**
+     * Request for PayPal REST oath bearer token.
+     *
+     * @return string
+     */
+    private function get_token(): string {
+        $location = "{$this->baseurl}/v1/oauth2/token";
+
+        $options = [
+            'CURLOPT_RETURNTRANSFER' => true,
+            'CURLOPT_TIMEOUT' => 30,
+            'CURLOPT_HTTP_VERSION' => CURL_HTTP_VERSION_1_1,
+            'CURLOPT_SSLVERSION' => CURL_SSLVERSION_TLSv1_2,
+            'CURLOPT_USERPWD' => "{$this->clientid}:{$this->secret}",
+        ];
+
+        $command = 'grant_type=client_credentials';
+
+        $curl = new curl();
+        $result = $curl->post($location, $command, $options);
+
+        $result = json_decode($result, true);
+
+        return $result['access_token'];
+    }
+}
\ No newline at end of file