goext/googleapi/sendMail.go

package googleapi

import (
	"gogs.mikescher.com/BlackForestBytes/goext/langext"
	"mime"
	"strings"
	"time"
)

func (c *client) SendMail(from string, recipients []string, cc []string, bcc []string, subject string, body MailBody, attachments []MailAttachment) error {

	data := make([]string, 0, 32)

	data = append(data, "Date: "+time.Now().Format(time.RFC1123Z))
	data = append(data, "From: "+mime.QEncoding.Encode("UTF-8", from))
	data = append(data, "To: "+strings.Join(langext.ArrMap(recipients, func(v string) string { return mime.QEncoding.Encode("UTF-8", v) }), ", "))
	if len(cc) > 0 {
		data = append(data, "To: "+strings.Join(langext.ArrMap(cc, func(v string) string { return mime.QEncoding.Encode("UTF-8", v) }), ", "))
	}
	if len(bcc) > 0 {
		data = append(data, "Bcc: "+strings.Join(langext.ArrMap(bcc, func(v string) string { return mime.QEncoding.Encode("UTF-8", v) }), ", "))
	}
	data = append(data, "Subject: "+mime.QEncoding.Encode("UTF-8", subject))

	hasAttachments := len(attachments) > 0
	hasInlineAttachments := langext.ArrAny(attachments, func(v MailAttachment) bool { return v.IsInline })
	hasPlain := body.Plain != nil
	hasHTML := body.HTML != nil

	mixedBoundary := "--------------" + langext.MustRawHexUUID()
	relatedBoundary := "--------------" + langext.MustRawHexUUID()
	altBoundary := "--------------" + langext.MustRawHexUUID()

	inlineAttachments := langext.ArrFilter(attachments, func(v MailAttachment) bool { return v.IsInline })
	normalAttachments := langext.ArrFilter(attachments, func(v MailAttachment) bool { return !v.IsInline })

	if hasInlineAttachments {
		// "mixed+related"

		data = append(data, "Content-Type: multipart/mixed; boundary="+mixedBoundary)
		data = append(data, "")
		data = append(data, mixedBoundary)

		data = append(data, "Content-Type: multipart/related; boundary="+relatedBoundary)
		data = append(data, "")

		data = append(data, c.dumpHTMLBody(body, hasInlineAttachments, hasAttachments, relatedBoundary, altBoundary)...)
		data = append(data, "")

		for i, attachment := range inlineAttachments {
			data = append(data, relatedBoundary)
			data = append(data, attachment.dump()...)

			if i < len(inlineAttachments)-1 {
				data = append(data, "")
			}
		}

		data = append(data, relatedBoundary)

		for i, attachment := range normalAttachments {
			data = append(data, mixedBoundary)
			data = append(data, attachment.dump()...)

			if i < len(inlineAttachments)-1 {
				data = append(data, "")
			}
		}

		data = append(data, mixedBoundary)

	} else if hasAttachments {
		// "mixed"

		//TODO https://github.dev/muratgozel/MIMEText/blob/master/src/MIMEMessage.ts

	} else if hasPlain && hasHTML {
		// "alternative"

		//TODO https://github.dev/muratgozel/MIMEText/blob/master/src/MIMEMessage.ts

	} else {
		// "plain"

		//TODO https://github.dev/muratgozel/MIMEText/blob/master/src/MIMEMessage.ts

	}

}

func (c *client) dumpHTMLBody(body MailBody, hasInlineAttachments bool, hasAttachments bool, boundary string, boundaryAlt string) []string {

	data := make([]string, 0, 16)

	if body.HTML != nil && body.Plain != nil && hasInlineAttachments {
		data = append(data, boundary)
		data = append(data, *body.HTML)
	} else if body.HTML != nil && body.Plain != nil && hasAttachments {
		data = append(data, boundary)
		data = append(data, "Content-Type: multipart/alternative; boundary="+boundaryAlt)
		data = append(data, "")
		data = append(data, boundaryAlt)
		data = append(data, *body.Plain)
		data = append(data, "")
		data = append(data, boundaryAlt)
		data = append(data, *body.HTML)
		data = append(data, "")
		data = append(data, boundaryAlt)
	} else if body.HTML != nil && body.Plain != nil {
		data = append(data, boundary)
		data = append(data, *body.Plain)
		data = append(data, "")
		data = append(data, boundary)
		data = append(data, *body.HTML)
	} else if body.HTML != nil {
		data = append(data, boundary)
		data = append(data, *body.HTML)
	} else if body.Plain != nil {
		data = append(data, boundary)
		data = append(data, *body.Plain)
	} else {
		data = append(data, boundary)
		data = append(data, "") // no content ?!?
	}

	return data
}