PaymentConnector for abstraction

LNPay.cpp

@@ -0,0 +1,137 @@
+/**
+ * LNPay Payment Connector
+ *
+ * @author Tim Kijewski <bootstrapbandit7@gmail.com>
+ *
+ */
+
+#include <String.h>
+#include <ArduinoJson.h>
+#include <WiFiClientSecure.h>
+#include <HTTPClient.h>
+
+#include "PaymentConnector.h"
+
+  //API Setup
+  String api_key = "<public_api_key>"; // Can be found here: https://lnpay.co/dashboard/integrations
+  String wallet_key = "<wallet_access_key>"; // Can be found here: https://lnpay.co/dashboard/advanced-wallets
+
+
+  //Endpoint Setup
+  String api_endpoint = "https://lnpay.co/v1";
+  String invoice_create_endpoint = "/wallet/" + wallet_key + "/invoice";
+  String invoice_check_endpoint = "/lntx/{{tx_id}}"; //append LNTX ID to the end (e.g. /user/lntx/lntx_mfEKSse22)
+
+  //HTTP client
+  HTTPClient http;
+
+
+  //Constructor
+  PaymentConnector::PaymentConnector (String currency_pair) {
+    _currency_pair = currency_pair;
+  }
+
+
+  /**
+   * PaymentConnector::createRequest
+   * 
+   * @param String method - GET,POST
+   * @param String path - REST path to be appended to api_endpoint
+   * @param String data - string of data for POST requests
+   * 
+   * @return String - response data from request
+   * 
+   */
+  String PaymentConnector::createRequest(String method,String path, String data)
+  {
+    String payload;
+    int httpCode;
+
+    Serial.println("PaymentConnector::createRequest BEGIN-------");
+    Serial.println("METHOD:" + method);
+    Serial.println("URL:" + api_endpoint + path);
+    Serial.println("DATA:" + data);
+
+    http.begin(api_endpoint + path); //Getting fancy to response size
+    http.addHeader("Content-Type","application/json");
+    http.addHeader("X-Api-Key",api_key);
+
+    if (method.equals("POST"))
+      httpCode = http.POST(data); //Make the request
+    else if (method.equals("GET")) {
+      httpCode = http.GET(); //Make the request
+    } else {
+      Serial.println("This HTTP method usage is not defined");
+    }
+
+    if (httpCode > 0) { //Check for the returning code
+      payload = http.getString();
+      Serial.println("RESPONSE:" + payload);
+    } else {
+      Serial.println("Error on HTTP request");
+    }
+    http.end(); //Free the resources
+    Serial.println("PaymentConnector::createRequest END--------");
+
+    return payload;
+  }
+
+
+  /**
+   * PaymentConnector::createInvoice
+   * 
+   * @param int num_satoshis - number of satoshis for invoice
+   * @param String memo - Memo for invoice
+   * 
+   * @return createInvoiceResponse - object containing both a payment_request AND an ID for lookup
+   * 
+   */
+  createInvoiceResponse PaymentConnector::createInvoice(int num_satoshis, String memo) {
+    String toPost = "{  \"num_satoshis\" : " + (String) num_satoshis +", \"memo\" :\""+ memo + String(random(1,1000)) + "\"}";
+
+    String payload = PaymentConnector::createRequest((String)"POST",invoice_create_endpoint,toPost);
+
+    const size_t capacity = JSON_OBJECT_SIZE(2) + 500;
+    DynamicJsonDocument doc(capacity);
+    deserializeJson(doc, payload);
+    Serial.println(payload);
+
+    const char* payment_request = doc["payment_request"]; 
+    const char* id = doc["id"]; 
+    String payreq = (String) payment_request;
+    String lntx_id = (String) id;
+    Serial.println(payreq);
+    Serial.println(lntx_id);
+
+    createInvoiceResponse cir;
+
+    cir.payment_request = payreq;
+    cir.payment_id = lntx_id;
+
+    return cir;
+  }
+
+  /**
+   * PaymentConnector::checkIfPaymentIsSettled
+   * 
+   * @param String id - provided from the PaymentConnector::createInvoice call to check if settled
+   * 
+   * @return int - 1 or 0 depending on settled
+   * 
+   */
+  int PaymentConnector::checkIfPaymentIsSettled(String id) {
+    invoice_check_endpoint.replace("{{tx_id}}",id);
+    String payload = PaymentConnector::createRequest((String)"GET",invoice_check_endpoint);
+
+    const size_t capacity = JSON_OBJECT_SIZE(2) + 500;
+    DynamicJsonDocument doc(capacity);
+    deserializeJson(doc, payload);
+
+    const char* settled = doc["settled"]; 
+    int settledInt = (int) settled;
+    if (settledInt == 1){
+      return 1;
+    } else{
+      return 0;
+    }
+  }

PaymentConnector.h

@@ -0,0 +1,29 @@
+/**
+ * createInvoiceResponse
+ * 
+ * @param String payment_request - Payment request to be saved from the createInvoice request
+ * @param String payment_id - to be used to poll for invoice settled or not
+ * 
+ * 
+ */
+class createInvoiceResponse {
+  public: 
+    String payment_request;
+    String payment_id;
+};
+
+/**
+ * PaymentConnector
+ * 
+ * Skeleton for functions required to make a PaymentConnector
+ * 
+ */
+class PaymentConnector {
+  public:
+    PaymentConnector(String currency_pair);
+    createInvoiceResponse createInvoice(int num_satoshis, String memo);
+    int checkIfPaymentIsSettled(String id);
+    String createRequest(String method, String path, String data = "");
+  private:
+    String _currency_pair;
+};

main.ino

@@ -0,0 +1,42 @@
+#include <M5Stack.h>
+#include <WiFiClientSecure.h>
+#include "PaymentConnector.h"
+
+PaymentConnector lnpay("BTCUSD");
+
+void setup() {
+  Serial.begin(115200);
+  M5.begin();
+  Wire.begin();
+  WiFi.begin("SSID", "PASSWORD");
+  int i = 0;
+  while (WiFi.status() != WL_CONNECTED) {
+    if(i >= 5){
+     M5.Lcd.fillScreen(BLACK);
+     M5.Lcd.setCursor(55, 80);
+     M5.Lcd.setTextSize(2);
+     M5.Lcd.setTextColor(TFT_RED);
+     M5.Lcd.println("WIFI NOT CONNECTED");
+    }
+    i++;
+  }
+
+
+
+
+}
+
+void loop() {
+  // put your main code here, to run repeatedly:
+
+
+  //createInvoiceResponse resp = lnpay.createInvoice(20,"Memo!");
+
+  int settled = 0;
+  while (!settled) {
+    settled = lnpay.checkIfPaymentIsSettled(resp.payment_id);
+    Serial.println("SETTLED:" + settled);
+    delay(1000);
+  }
+
+}