From 405c18d21388f1cc6f8b7349186efb3fa44eef87 Mon Sep 17 00:00:00 2001
From: Drew DeVault <sir@cmpwn.com>
Date: Thu, 19 Nov 2020 10:50:52 -0500
Subject: Convert HTML to plaintext for forwarding & replies

---
 plugins/base/routes.go | 46 ++++++++++++++++++++++++++++++----------------
 1 file changed, 30 insertions(+), 16 deletions(-)

(limited to 'plugins/base/routes.go')

diff --git a/plugins/base/routes.go b/plugins/base/routes.go
index 2107abb..0345189 100644
--- a/plugins/base/routes.go
+++ b/plugins/base/routes.go
@@ -14,12 +14,13 @@ import (
 
 	"git.sr.ht/~emersion/alps"
 	"github.com/emersion/go-imap"
-	imapmove "github.com/emersion/go-imap-move"
-	imapclient "github.com/emersion/go-imap/client"
 	"github.com/emersion/go-message"
 	"github.com/emersion/go-message/mail"
 	"github.com/emersion/go-smtp"
 	"github.com/labstack/echo/v4"
+	"jaytaylor.com/html2text"
+	imapclient "github.com/emersion/go-imap/client"
+	imapmove "github.com/emersion/go-imap-move"
 )
 
 func registerRoutes(p *alps.GoPlugin) {
@@ -759,17 +760,25 @@ func handleReply(ctx *alps.Context) error {
 			return fmt.Errorf("failed to parse part Content-Type: %v", err)
 		}
 
-		if !strings.EqualFold(mimeType, "text/plain") {
-			err := fmt.Errorf("cannot reply to %q part", mimeType)
+		if mimeType == "text/plain" {
+			msg.Text, err = quote(part.Body)
+			if err != nil {
+				return err
+			}
+		} else if mimeType == "text/html" {
+			text, err := html2text.FromReader(part.Body, html2text.Options{})
+			if err != nil {
+				return err
+			}
+			msg.Text, err = quote(strings.NewReader(text))
+			if err != nil {
+				return nil
+			}
+		} else {
+			err := fmt.Errorf("cannot forward %q part", mimeType)
 			return echo.NewHTTPError(http.StatusBadRequest, err)
 		}
 
-		// TODO: strip HTML tags if text/html
-		msg.Text, err = quote(part.Body)
-		if err != nil {
-			return err
-		}
-
 		msg.MessageID = mail.GenerateMessageID()
 		msg.InReplyTo = inReplyTo.Envelope.MessageId
 		// TODO: populate From from known user addresses and inReplyTo.Envelope.To
@@ -819,16 +828,21 @@ func handleForward(ctx *alps.Context) error {
 			return fmt.Errorf("failed to parse part Content-Type: %v", err)
 		}
 
-		if !strings.EqualFold(mimeType, "text/plain") {
+		if mimeType == "text/plain" {
+			msg.Text, err = quote(part.Body)
+			if err != nil {
+				return err
+			}
+		} else if mimeType == "text/html" {
+			msg.Text, err = html2text.FromReader(part.Body, html2text.Options{})
+			if err != nil {
+				return err
+			}
+		} else {
 			err := fmt.Errorf("cannot forward %q part", mimeType)
 			return echo.NewHTTPError(http.StatusBadRequest, err)
 		}
 
-		msg.Text, err = quote(part.Body)
-		if err != nil {
-			return err
-		}
-
 		msg.MessageID = mail.GenerateMessageID()
 		msg.Subject = source.Envelope.Subject
 		if !strings.HasPrefix(strings.ToLower(msg.Subject), "fwd:") &&
-- 
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