feat(backend): track email on new user sign in

backend/api/measure/auth.go

@@ -4,9 +4,11 @@ import (
 	"backend/api/authsession"
 	"backend/api/cipher"
 	"backend/api/server"
+	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"net/http"
 	"strings"
 
@@ -39,6 +41,51 @@ func extractToken(c *gin.Context) (token string) {
 	return
 }
 
+// trackEmail tracks email in third party email list
+func trackEmail(email string) {
+	emailListId := "cm1aew9540002el4efgoa48ne"
+	emailListApiKey := "cm1aew9540003el4e9kefrf4w"
+
+	url := "https://www.waitlist.email/api/subscribers/create"
+
+	requestBody, err := json.Marshal(map[string]string{
+		"waitlist": emailListId,
+		"email":    email,
+	})
+	if err != nil {
+		fmt.Println("Error creating email tracking request body:", err)
+		return
+	}
+
+	req, err := http.NewRequest("POST", url, bytes.NewBuffer(requestBody))
+	if err != nil {
+		fmt.Println("Error creating email tracking request:", err)
+		return
+	}
+
+	// Set headers
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("X-Waitlist-Api-Key", emailListApiKey)
+
+	// Send the request
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		fmt.Println("Error tracking email: ", err)
+		return
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		fmt.Println("Error reading email tracking response:", err)
+		return
+	}
+
+	fmt.Println("Email tracking Response Status:", resp.Status)
+	fmt.Println("Email tracking Response Body:", string(body))
+}
+
 // ValidateAPIKey validates the Measure API key.
 func ValidateAPIKey() gin.HandlerFunc {
 	return func(c *gin.Context) {
@@ -318,6 +365,9 @@ func SigninGitHub(c *gin.Context) {
 				})
 				return
 			}
+
+			// Once new user creation is done, track email
+			trackEmail(ghUser.Email)
 		} else {
 			// update user's last sign in at value
 			if err := msrUser.touchLastSignInAt(ctx); err != nil {
@@ -520,6 +570,9 @@ func SigninGoogle(c *gin.Context) {
 			})
 			return
 		}
+
+		// Once new user creation is done, track email
+		trackEmail(googUser.Email)
 	} else {
 		// update user's last sign in at value
 		if err := msrUser.touchLastSignInAt(ctx); err != nil {