Initialize module and dependencies

vendor/github.com/emersion/go-message/mail/writer.go

@@ -0,0 +1,132 @@
+package mail
+
+import (
+	"io"
+	"strings"
+
+	"github.com/emersion/go-message"
+)
+
+func initInlineContentTransferEncoding(h *message.Header) {
+	if !h.Has("Content-Transfer-Encoding") {
+		t, _, _ := h.ContentType()
+		if strings.HasPrefix(t, "text/") {
+			h.Set("Content-Transfer-Encoding", "quoted-printable")
+		} else {
+			h.Set("Content-Transfer-Encoding", "base64")
+		}
+	}
+}
+
+func initInlineHeader(h *InlineHeader) {
+	h.Set("Content-Disposition", "inline")
+	initInlineContentTransferEncoding(&h.Header)
+}
+
+func initAttachmentHeader(h *AttachmentHeader) {
+	disp, _, _ := h.ContentDisposition()
+	if disp != "attachment" {
+		h.Set("Content-Disposition", "attachment")
+	}
+	if !h.Has("Content-Transfer-Encoding") {
+		h.Set("Content-Transfer-Encoding", "base64")
+	}
+}
+
+// A Writer writes a mail message. A mail message contains one or more text
+// parts and zero or more attachments.
+type Writer struct {
+	mw *message.Writer
+}
+
+// CreateWriter writes a mail header to w and creates a new Writer.
+func CreateWriter(w io.Writer, header Header) (*Writer, error) {
+	header = header.Copy() // don't modify the caller's view
+	header.Set("Content-Type", "multipart/mixed")
+
+	mw, err := message.CreateWriter(w, header.Header)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Writer{mw}, nil
+}
+
+// CreateInlineWriter writes a mail header to w. The mail will contain an
+// inline part, allowing to represent the same text in different formats.
+// Attachments cannot be included.
+func CreateInlineWriter(w io.Writer, header Header) (*InlineWriter, error) {
+	header = header.Copy() // don't modify the caller's view
+	header.Set("Content-Type", "multipart/alternative")
+
+	mw, err := message.CreateWriter(w, header.Header)
+	if err != nil {
+		return nil, err
+	}
+
+	return &InlineWriter{mw}, nil
+}
+
+// CreateSingleInlineWriter writes a mail header to w. The mail will contain a
+// single inline part. The body of the part should be written to the returned
+// io.WriteCloser. Only one single inline part should be written, use
+// CreateWriter if you want multiple parts.
+func CreateSingleInlineWriter(w io.Writer, header Header) (io.WriteCloser, error) {
+	header = header.Copy() // don't modify the caller's view
+	initInlineContentTransferEncoding(&header.Header)
+	return message.CreateWriter(w, header.Header)
+}
+
+// CreateInline creates a InlineWriter. One or more parts representing the same
+// text in different formats can be written to a InlineWriter.
+func (w *Writer) CreateInline() (*InlineWriter, error) {
+	var h message.Header
+	h.Set("Content-Type", "multipart/alternative")
+
+	mw, err := w.mw.CreatePart(h)
+	if err != nil {
+		return nil, err
+	}
+	return &InlineWriter{mw}, nil
+}
+
+// CreateSingleInline creates a new single text part with the provided header.
+// The body of the part should be written to the returned io.WriteCloser. Only
+// one single text part should be written, use CreateInline if you want multiple
+// text parts.
+func (w *Writer) CreateSingleInline(h InlineHeader) (io.WriteCloser, error) {
+	h = InlineHeader{h.Header.Copy()} // don't modify the caller's view
+	initInlineHeader(&h)
+	return w.mw.CreatePart(h.Header)
+}
+
+// CreateAttachment creates a new attachment with the provided header. The body
+// of the part should be written to the returned io.WriteCloser.
+func (w *Writer) CreateAttachment(h AttachmentHeader) (io.WriteCloser, error) {
+	h = AttachmentHeader{h.Header.Copy()} // don't modify the caller's view
+	initAttachmentHeader(&h)
+	return w.mw.CreatePart(h.Header)
+}
+
+// Close finishes the Writer.
+func (w *Writer) Close() error {
+	return w.mw.Close()
+}
+
+// InlineWriter writes a mail message's text.
+type InlineWriter struct {
+	mw *message.Writer
+}
+
+// CreatePart creates a new text part with the provided header. The body of the
+// part should be written to the returned io.WriteCloser.
+func (w *InlineWriter) CreatePart(h InlineHeader) (io.WriteCloser, error) {
+	h = InlineHeader{h.Header.Copy()} // don't modify the caller's view
+	initInlineHeader(&h)
+	return w.mw.CreatePart(h.Header)
+}
+
+// Close finishes the InlineWriter.
+func (w *InlineWriter) Close() error {
+	return w.mw.Close()
+}