From 233a0b0631432d4a5530963c9edb1ed6c946a6f3 Mon Sep 17 00:00:00 2001
From: Ambrose Chua <ambrose@makerforce.io>
Date: Mon, 17 Sep 2018 09:27:17 +0800
Subject: [PATCH] Add Slack mechanism

---
 email-collector.go | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/email-collector.go b/email-collector.go
index d870906..45afcdb 100644
--- a/email-collector.go
+++ b/email-collector.go
@@ -1,8 +1,11 @@
 package main // import "github.com/productionwentdown/email-collector"
 
 import (
+	"bytes"
 	"encoding/csv"
+	"encoding/json"
 	"flag"
+	"io/ioutil"
 	"log"
 	"net/http"
 	"os"
@@ -16,11 +19,13 @@ import (
 var filename string
 var listen string
 var redirect string
+var slack string
 
 func main() {
 	flag.StringVar(&filename, "file", "list.csv", "file to append records to")
 	flag.StringVar(&listen, "listen", ":8080", "address to listen to")
 	flag.StringVar(&redirect, "redirect", "/subscribed", "path to redirect to upon success")
+	flag.StringVar(&slack, "slack", "", "optional slack webhook url")
 	flag.Parse()
 
 	csvMutex := &sync.Mutex{}
@@ -58,6 +63,30 @@ func main() {
 		csvWriter.Write([]string{email, time.Now().String()})
 		csvWriter.Flush()
 		csvMutex.Unlock()
+		if len(slack) > 4 {
+			object := map[string]string{
+				"text": "A human (" + email + ") subscribed to the list! Wohoo!",
+			}
+			payload, err := json.Marshal(object)
+			if err != nil {
+				log.Println("json.Marshal failed, not supposed to happen!")
+				w.WriteHeader(500)
+				return
+			}
+			resp, err := http.Post(slack, "application/json", bytes.NewBuffer(payload))
+			if err != nil {
+				log.Println(err)
+				w.WriteHeader(500)
+				return
+			}
+			defer resp.Body.Close()
+			if resp.StatusCode != http.StatusOK {
+				body, _ := ioutil.ReadAll(resp.Body)
+				log.Println(body)
+				w.WriteHeader(500)
+				return
+			}
+		}
 		w.Header().Add("Location", redirect)
 		w.WriteHeader(303)
 	})