From 59e83c7cc0c4ef62f293c4080a05485403e5def2 Mon Sep 17 00:00:00 2001
From: Joerg Lehmann <joerg.lehmann@nbit.ch>
Date: Sat, 4 Jan 2020 17:58:40 +0100
Subject: [PATCH] refactor payment process - another step

---
 main.go   |  1 +
 stripe.go | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/main.go b/main.go
index cd762e7..6b5bc1d 100644
--- a/main.go
+++ b/main.go
@@ -89,6 +89,7 @@ func main() {
         http.HandleFunc("/lastmetrics", lastmetricsHandler)
         http.HandleFunc("/save_scale_settings", save_scale_settingsHandler)
         http.HandleFunc("/getstripepaymentintent", getstripepaymentintentHandler)
+        http.HandleFunc("/stripewebhook", stripeWebhookHandler)
 
 	logit("Starting Web Application...")
 	http.ListenAndServe("127.0.0.1:4000", nil)
diff --git a/stripe.go b/stripe.go
index b8bc3f6..d0ff9c3 100644
--- a/stripe.go
+++ b/stripe.go
@@ -3,6 +3,9 @@ package main
 import (
     "fmt"
     "log"
+    "os"
+    "io/ioutil"
+    "encoding/json"
     "net/http"
     "strings"
     "strconv"
@@ -47,6 +50,7 @@ func getstripepaymentintentHandler(response http.ResponseWriter, request *http.R
              Currency: stripe.String(string(stripe.CurrencyCHF)),
              ReceiptEmail: stripe.String(name),
            }
+           params.AddMetadata("charge_data", charge_data[0])
            paymentintent, err := paymentintent.New(params)
            
            if err != nil {
@@ -59,3 +63,42 @@ func getstripepaymentintentHandler(response http.ResponseWriter, request *http.R
 	   fmt.Fprintf(response, "{ \"rc\": 6, \"msg\": \"Only available for logged in users\" }")
         }
 }
+
+func stripeWebhookHandler(w http.ResponseWriter, req *http.Request) {
+    const MaxBodyBytes = int64(65536)
+    req.Body = http.MaxBytesReader(w, req.Body, MaxBodyBytes)
+    payload, err := ioutil.ReadAll(req.Body)
+    if err != nil {
+        fmt.Fprintf(os.Stderr, "Error reading request body: %v\n", err)
+        w.WriteHeader(http.StatusServiceUnavailable)
+        return
+    }
+
+    event := stripe.Event{}
+
+    if err := json.Unmarshal(payload, &event); err != nil {
+        fmt.Fprintf(os.Stderr, "Failed to parse webhook body json: %v\n", err.Error())
+        w.WriteHeader(http.StatusBadRequest)
+        return
+    }
+
+    // Unmarshal the event data into an appropriate struct depending on its Type
+    switch event.Type {
+    case "payment_intent.succeeded":
+        var paymentIntent stripe.PaymentIntent
+        err := json.Unmarshal(event.Data.Raw, &paymentIntent)
+        if err != nil {
+            fmt.Fprintf(os.Stderr, "Error parsing webhook JSON: %v\n", err)
+            w.WriteHeader(http.StatusBadRequest)
+            return
+        }
+        fmt.Printf("PaymentIntent was successful (charge_data: %s, amount: %d)!\n", paymentIntent.Metadata["charge_data"], paymentIntent.Amount)
+    // ... handle other event types
+    default:
+        fmt.Fprintf(os.Stderr, "Unexpected event type: %s\n", event.Type)
+        w.WriteHeader(http.StatusBadRequest)
+        return
+    }
+
+    w.WriteHeader(http.StatusOK)
+}