get mail body and sender

main.go

@@ -5,7 +5,9 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"strings"
 	"path/filepath"
+	"encoding/base64"
 
 	"golang.org/x/oauth2/google"
 	"google.golang.org/api/gmail/v1"
@@ -15,6 +17,35 @@ import (
 const CREDENTIALS_DIR = "creds"
 const TOKEN_FILE = "token.json"
 const CREDENTIALS_FILE = "credentials.json"
+const USER = "me"
+
+func getEmail(service *gmail.Service, msgID string) *gmail.Message {
+	r, err := service.Users.Messages.Get(USER, msgID).Format("FULL").Do()
+	if err != nil {
+		log.Fatalf("Error when getting mail content: %v", err)
+	}
+	if r == nil {
+		log.Fatalf("Response when getting mail was nil")
+	}
+	return r
+}
+
+func getEmailPlaintext (mail *gmail.Message) (fromAddr string, bodyStr string) {
+	part := mail.Payload.Parts[0].Body.Data
+	body, err := base64.StdEncoding.DecodeString(part)
+	if err != nil {
+		log.Fatalf("Error in message body decoding: %v", err)
+	}
+
+	for _, header := range mail.Payload.Headers {
+		if header.Name == "From" {
+			_, addrPart, _ := strings.Cut(header.Value, "<")
+			fromAddr, _, _ = strings.Cut(addrPart, ">")
+		}
+	}
+
+	return fromAddr, string(body)
+}
 
 func main() {
 	ctx := context.Background()
@@ -36,16 +67,20 @@ func main() {
 	}
 
 	user := "me"
-	r, err := service.Users.Labels.List(user).Do()
+	r, err := service.Users.Messages.List(user).LabelIds("INBOX").Do()
 	if err != nil {
-		log.Fatalf("Unable to retrieve labels: %v", err)
+		log.Fatalf("Unable to retrieve messages: %v", err)
 	}
-	if len(r.Labels) == 0 {
-		fmt.Println("No labels found")
+	if len(r.Messages) == 0 {
+		fmt.Println("No messages found")
 		return
 	}
-	fmt.Println("Labels:")
-	for _, label := range r.Labels {
-		fmt.Printf("- %s\n", label.Name)
+	fmt.Println("Messages:")
+	for _, msg := range r.Messages {
+		fmt.Printf("- %s\n", msg.Id)
+		mail := getEmail(service, msg.Id)
+		fromAddr, msgBody := getEmailPlaintext(mail)
+		fmt.Printf("From: %s\n", fromAddr)
+		fmt.Printf("Message:\n%s\n", msgBody)
 	}
 }