From 475e673b871c62ce4e7a62a4ed7a4b1b7135cf82 Mon Sep 17 00:00:00 2001
From: James Houlahan <james.houlahan@protonmail.com>
Date: Wed, 26 Aug 2020 13:05:45 +0200
Subject: [PATCH] feat: add logging for encoding detection

---
 pkg/message/parser/part.go | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/pkg/message/parser/part.go b/pkg/message/parser/part.go
index 4045bbfd..3f8d7e27 100644
--- a/pkg/message/parser/part.go
+++ b/pkg/message/parser/part.go
@@ -23,6 +23,7 @@ import (
 
 	pmmime "github.com/ProtonMail/proton-bridge/pkg/mime"
 	"github.com/emersion/go-message"
+	"github.com/sirupsen/logrus"
 	"golang.org/x/net/html/charset"
 	"golang.org/x/text/encoding"
 )
@@ -65,6 +66,8 @@ func (p *Part) AddChild(child *Part) {
 }
 
 func (p *Part) ConvertToUTF8() error {
+	logrus.Debug("Converting part to utf-8")
+
 	t, params, err := p.Header.ContentType()
 	if err != nil {
 		return err
@@ -90,16 +93,24 @@ func (p *Part) ConvertToUTF8() error {
 
 func selectSuitableDecoder(p *Part, t string, params map[string]string) *encoding.Decoder {
 	if charset, ok := params["charset"]; ok {
+		logrus.WithField("charset", charset).Debug("The part has a specified charset")
+
 		if decoder, err := pmmime.SelectDecoder(charset); err == nil {
+			logrus.Debug("The charset is known; decoder has been selected")
 			return decoder
 		}
+
+		logrus.Debug("The charset is unknown; no decoder could be selected")
 	}
 
 	if utf8.Valid(p.Body) {
+		logrus.Debug("The part is already valid utf-8, returning noop encoder")
 		return encoding.Nop.NewDecoder()
 	}
 
-	encoding, _, _ := charset.DetermineEncoding(p.Body, t)
+	encoding, name, _ := charset.DetermineEncoding(p.Body, t)
+
+	logrus.WithField("name", name).Debug("Determined encoding by reading body")
 
 	return encoding.NewDecoder()
 }