feat: add part getter

pkg/message/parser.go

@@ -37,6 +37,7 @@ import (
 	"github.com/ProtonMail/proton-bridge/pkg/message/parser"
 	pmmime "github.com/ProtonMail/proton-bridge/pkg/mime"
 	"github.com/ProtonMail/proton-bridge/pkg/pmapi"
+	"github.com/emersion/go-message"
 	"github.com/jaytaylor/html2text"
 )
 
@@ -412,13 +413,41 @@ func (pka *PublicKeyAttacher) Accept(partReader io.Reader, header textproto.MIME
 }
 
 // ======= Parser ==========
+func parseGoMessageHeader(h message.Header) (m *pmapi.Message, err error) {
+	m = pmapi.NewMessage()
+
+	m.Header = make(mail.Header)
+
+	fields := h.Fields()
+
+	for fields.Next() {
+		switch strings.ToLower(fields.Key()) {
+		case "subject":
+			if m.Subject, err = fields.Text(); err != nil {
+				return
+			}
+
+		// TODO: Set these thingies.
+		case "from":
+		case "to":
+		case "reply-to":
+		case "cc":
+		case "bcc":
+		case "date":
+		}
+	}
+
+	return
+}
 
 func ParseGoMessage(r io.Reader) (m *pmapi.Message, mimeBody string, plainContents string, atts []io.Reader, err error) {
+	// Parse the message.
 	p, err := parser.New(r)
 	if err != nil {
 		return
 	}
 
+	// Collect attachments, convert html to plaintext.
 	walker := p.
 		NewWalker().
 		WithContentDispositionHandler("attachment", func(p *parser.Part, _ parser.PartHandler) (err error) {
@@ -431,6 +460,7 @@ func ParseGoMessage(r io.Reader) (m *pmapi.Message, mimeBody string, plainConten
 				plain = string(p.Body)
 			}
 
+			// TODO: Do we need newline here?
 			plainContents += plain
 
 			return
@@ -440,10 +470,10 @@ func ParseGoMessage(r io.Reader) (m *pmapi.Message, mimeBody string, plainConten
 		return
 	}
 
+	// Write out a mime body that doesn't include attachments.
 	writer := p.
 		NewWriter().
 		WithCondition(func(p *parser.Part) (keep bool) {
-			// We don't write if the content disposition says it's an attachment.
 			if disp, _, err := p.Header.ContentDisposition(); err == nil && disp == "attachment" {
 				return false
 			}
@@ -459,6 +489,11 @@ func ParseGoMessage(r io.Reader) (m *pmapi.Message, mimeBody string, plainConten
 
 	mimeBody = buf.String()
 
+	// Parse the header to build a pmapi message.
+	if m, err = parseGoMessageHeader(p.Header()); err != nil {
+		return
+	}
+
 	return
 }
 

pkg/message/parser/parser.go

@@ -1,6 +1,7 @@
 package parser
 
 import (
+	"errors"
 	"io"
 	"io/ioutil"
 
@@ -30,6 +31,25 @@ func (p *Parser) NewWriter() *Writer {
 	return newWriter(p.root)
 }
 
+func (p *Parser) Header() message.Header {
+	return p.root.Header
+}
+
+func (p *Parser) Part(number []int) (part *Part, err error) {
+	part = p.root
+
+	for _, n := range number {
+		if len(part.children) < n {
+			err = errors.New("no such part")
+			return
+		}
+
+		part = part.children[n-1]
+	}
+
+	return
+}
+
 func (p *Parser) parse(r io.Reader) (err error) {
 	e, err := message.Read(r)
 	if err != nil {

pkg/message/parser/part_test.go

@@ -0,0 +1,56 @@
+package parser
+
+import (
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart(t *testing.T) {
+	p := newTestParser(t, "complex_structure.eml")
+
+	wantParts := map[string]string{
+		"":        "multipart/mixed",
+		"1":       "text/plain",
+		"2":       "application/octet-stream",
+		"3":       "multipart/mixed",
+		"3.1":     "text/plain",
+		"3.2":     "application/octet-stream",
+		"4":       "multipart/mixed",
+		"4.1":     "image/gif",
+		"4.2":     "multipart/mixed",
+		"4.2.1":   "text/plain",
+		"4.2.2":   "multipart/alternative",
+		"4.2.2.1": "text/plain",
+		"4.2.2.2": "text/html",
+	}
+
+	for partNumber, wantContType := range wantParts {
+		part, err := p.Part(getPartNumber(partNumber))
+		require.NoError(t, err)
+
+		contType, _, err := part.Header.ContentType()
+		require.NoError(t, err)
+		assert.Equal(t, wantContType, contType)
+	}
+}
+
+func getPartNumber(s string) (part []int) {
+	if s == "" {
+		return
+	}
+
+	for _, number := range strings.Split(s, ".") {
+		i64, err := strconv.ParseInt(number, 10, 64)
+		if err != nil {
+			panic(err)
+		}
+
+		part = append(part, int(i64))
+	}
+
+	return
+}

pkg/message/parser/testdata/complex_structure.eml

@@ -0,0 +1,91 @@
+Subject: Sample mail
+From: John Doe <jdoe@machine.example>
+To: Mary Smith <mary@example.net>
+Date: Fri, 21 Nov 1997 09:55:06 -0600
+Content-Type: multipart/mixed; boundary="0000MAIN"
+
+main summary
+
+--0000MAIN
+Content-Type: text/plain
+
+1. main message
+
+--0000MAIN
+Content-Type: application/octet-stream
+Content-Disposition: inline; filename="main_signature.sig"
+Content-Transfer-Encoding: base64
+
+aWYgeW91IGFyZSByZWFkaW5nIHRoaXMsIGhpIQ==
+
+--0000MAIN
+Subject: Inside mail 3
+From: Mary Smith <mary@example.net>
+To: John Doe <jdoe@machine.example>
+Date: Fri, 20 Nov 1997 09:55:06 -0600
+Content-Type: multipart/mixed; boundary="0003MSG"
+
+3. message summary
+
+--0003MSG
+Content-Type: text/plain
+
+3.1 message text
+
+--0003MSG
+Content-Type: application/octet-stream
+Content-Disposition: attachment; filename="msg_3_signature.sig"
+Content-Transfer-Encoding: base64
+
+aWYgeW91IGFyZSByZWFkaW5nIHRoaXMsIGhpIQ==
+
+--0003MSG--
+
+--0000MAIN
+Content-Type: multipart/mixed; boundary="0004ATTACH"
+
+4 attach summary
+
+--0004ATTACH
+Content-Type: image/gif
+Content-Disposition: attachment; filename="att4.1_gif.sig"
+Content-Transfer-Encoding: base64
+
+aWYgeW91IGFyZSByZWFkaW5nIHRoaXMsIGhpIQ==
+
+--0004ATTACH
+Subject: Inside mail 4.2
+From: Mary Smith <mary@example.net>
+To: John Doe <jdoe@machine.example>
+Date: Fri, 10 Nov 1997 09:55:06 -0600
+Content-Type: multipart/mixed; boundary="0042MSG"
+
+4.2 message summary
+
+--0042MSG
+Content-Type: text/plain
+
+4.2.1 message text
+
+--0042MSG
+Content-Type: multipart/alternative; boundary="0422ALTER"
+
+4.2.2 alternative summary
+
+--0422ALTER
+Content-Type: text/plain
+
+4.2.2.1 plain text
+
+--0422ALTER
+Content-Type: text/html
+
+<h1>4.2.2.2 html text</h1>
+
+--0422ALTER--
+
+--0042MSG--
+
+--0004ATTACH--
+
+--0000MAIN--

pkg/message/parser/testdata/text_html.eml

@@ -1,9 +1,9 @@
-From: Sender <sender@pm.me>
-To: Receiver <receiver@pm.me>
-Content-Type: multipart/mixed; boundary=longrandomstring
-
---longrandomstring
-Content-Type: text/html
-
-<html><body>This is body of <b>HTML mail</b> with attachment</body></html>
---longrandomstring--
+From: Sender <sender@pm.me>
+To: Receiver <receiver@pm.me>
+Content-Type: multipart/mixed; boundary=longrandomstring
+
+--longrandomstring
+Content-Type: text/html
+
+<html><body>This is body of <b>HTML mail</b> with attachment</body></html>
+--longrandomstring--

pkg/message/parser/testdata/text_html_octet_attachment.eml

@@ -1,15 +1,15 @@
-From: Sender <sender@pm.me>
-To: Receiver <receiver@pm.me>
-Content-Type: multipart/mixed; boundary=longrandomstring
-
---longrandomstring
-Content-Type: text/html
-
-<html><body>This is body of <b>HTML mail</b> with attachment</body></html>
---longrandomstring
-Content-Type: application/octet-stream
-Content-Transfer-Encoding: base64
-Content-Disposition: attachment
-
-aWYgeW91IGFyZSByZWFkaW5nIHRoaXMsIGhpIQ==
---longrandomstring--
+From: Sender <sender@pm.me>
+To: Receiver <receiver@pm.me>
+Content-Type: multipart/mixed; boundary=longrandomstring
+
+--longrandomstring
+Content-Type: text/html
+
+<html><body>This is body of <b>HTML mail</b> with attachment</body></html>
+--longrandomstring
+Content-Type: application/octet-stream
+Content-Transfer-Encoding: base64
+Content-Disposition: attachment
+
+aWYgeW91IGFyZSByZWFkaW5nIHRoaXMsIGhpIQ==
+--longrandomstring--

pkg/message/parser/writer_test.go

@@ -2,6 +2,7 @@ package parser
 
 import (
 	"bytes"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -15,7 +16,7 @@ func TestParserWrite(t *testing.T) {
 	buf := new(bytes.Buffer)
 
 	assert.NoError(t, w.Write(buf))
-	assert.Equal(t, s("text_html_octet_attachment.eml"), buf.String())
+	assert.Equal(t, s("text_html_octet_attachment.eml"), crlf(buf.String()))
 }
 
 func TestParserWriteNoAttachments(t *testing.T) {
@@ -35,5 +36,9 @@ func TestParserWriteNoAttachments(t *testing.T) {
 	buf := new(bytes.Buffer)
 
 	assert.NoError(t, w.Write(buf))
-	assert.Equal(t, s("text_html.eml"), buf.String())
+	assert.Equal(t, s("text_html.eml"), crlf(buf.String()))
+}
+
+func crlf(s string) string {
+	return strings.ReplaceAll(s, "\r\n", "\n")
 }