Convert HTML to plaintext for forwarding & replies

go.mod

@@ -23,9 +23,12 @@ require (
 	github.com/labstack/echo/v4 v4.1.16
 	github.com/labstack/gommon v0.3.0
 	github.com/microcosm-cc/bluemonday v1.0.2
+	github.com/olekukonko/tablewriter v0.0.4 // indirect
+	github.com/ssor/bom v0.0.0-20170718123548-6386211fdfcf // indirect
 	github.com/yuin/gopher-lua v0.0.0-20191220021717-ab39c6098bdb
 	gitlab.com/golang-commonmark/linkify v0.0.0-20200225224916-64bca66f6ad3
 	golang.org/x/crypto v0.0.0-20200510223506-06a226fb4e37 // indirect
 	golang.org/x/net v0.0.0-20200506145744-7e3656a0809f
+	jaytaylor.com/html2text v0.0.0-20200412013138-3577fbdbcff7
 	layeh.com/gopher-luar v1.0.7
 )

go.sum

@@ -103,6 +103,8 @@ github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hd
 github.com/mattn/go-isatty v0.0.9/go.mod h1:YNRxwqDuOph6SZLI9vUUz6OYw3QyUt7WiY2yME+cCiQ=
 github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
+github.com/mattn/go-runewidth v0.0.7 h1:Ei8KR0497xHyKJPAv59M1dkC+rOZCMBJ+t3fZ+twI54=
+github.com/mattn/go-runewidth v0.0.7/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/microcosm-cc/bluemonday v1.0.2 h1:5lPfLTTAvAbtS0VqT+94yOtFnGfUWYyx0+iToC3Os3s=
@@ -112,6 +114,8 @@ github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJ
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
+github.com/olekukonko/tablewriter v0.0.4 h1:vHD/YYe1Wolo78koG299f7V/VAS08c6IpCLn+Ejf/w8=
+github.com/olekukonko/tablewriter v0.0.4/go.mod h1:zq6QwlOf5SlnkVbMSr5EoBv3636FWnp+qbPhuoO21uA=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -133,6 +137,8 @@ github.com/prometheus/procfs v0.1.3 h1:F0+tqvhOksq22sc6iCHF5WGlWjdwj92p0udFh1VFB
 github.com/prometheus/procfs v0.1.3/go.mod h1:lV6e/gmhEcM9IjHGsFOCxxuZ+z1YqCvr4OA4YeYWdaU=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
+github.com/ssor/bom v0.0.0-20170718123548-6386211fdfcf h1:pvbZ0lM0XWPBqUKqFU8cmavspvIl9nulOYwdy6IFRRo=
+github.com/ssor/bom v0.0.0-20170718123548-6386211fdfcf/go.mod h1:RJID2RhlZKId02nZ62WenDCkgHFerpIOmW0iT7GKmXM=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
@@ -205,5 +211,7 @@ gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.5/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+jaytaylor.com/html2text v0.0.0-20200412013138-3577fbdbcff7 h1:mub0MmFLOn8XLikZOAhgLD1kXJq8jgftSrrv7m00xFo=
+jaytaylor.com/html2text v0.0.0-20200412013138-3577fbdbcff7/go.mod h1:OxvTsCwKosqQ1q7B+8FwXqg4rKZ/UG9dUW+g/VL2xH4=
 layeh.com/gopher-luar v1.0.7 h1:53iv6CCkRs5wyofZ+qVXcyAYQOIG52s6pt4xkqZdq7k=
 layeh.com/gopher-luar v1.0.7/go.mod h1:TPnIVCZ2RJBndm7ohXyaqfhzjlZ+OA2SZR/YwL8tECk=

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:") &&