goext/googleapi/mimeMessage.go

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2023-12-04 13:48:11 +01:00
package googleapi
import (
"gogs.mikescher.com/BlackForestBytes/goext/langext"
"mime"
"strings"
"time"
)
// https://datatracker.ietf.org/doc/html/rfc2822
func encodeMimeMail(from string, recipients []string, cc []string, bcc []string, subject string, body MailBody, attachments []MailAttachment) string {
data := make([]string, 0, 32)
data = append(data, "Date: "+time.Now().Format(time.RFC1123Z))
data = append(data, "MIME-Version: 1.0")
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))
hasInlineAttachments := langext.ArrAny(attachments, func(v MailAttachment) bool { return v.IsInline })
hasNormalAttachments := langext.ArrAny(attachments, func(v MailAttachment) bool { return !v.IsInline })
hasPlain := body.Plain != ""
hasHTML := body.HTML != ""
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 && hasNormalAttachments {
// "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, dumpMailBody(body, hasInlineAttachments, hasNormalAttachments, 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(normalAttachments)-1 {
data = append(data, "")
}
}
data = append(data, "--"+mixedBoundary+"--")
} else if hasNormalAttachments {
// "mixed"
data = append(data, "Content-Type: multipart/mixed; boundary="+mixedBoundary)
data = append(data, "")
data = append(data, dumpMailBody(body, hasInlineAttachments, hasNormalAttachments, mixedBoundary, altBoundary)...)
if hasPlain && hasHTML {
data = append(data, "")
}
for i, attachment := range normalAttachments {
data = append(data, "--"+mixedBoundary)
data = append(data, attachment.dump()...)
if i < len(normalAttachments)-1 {
data = append(data, "")
}
}
data = append(data, "--"+mixedBoundary+"--")
} else if hasInlineAttachments {
// "related"
data = append(data, "Content-Type: multipart/related; boundary="+relatedBoundary)
data = append(data, "")
data = append(data, dumpMailBody(body, hasInlineAttachments, hasNormalAttachments, 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+"--")
} else if hasPlain && hasHTML {
// "alternative"
data = append(data, "Content-Type: multipart/alternative; boundary="+altBoundary)
data = append(data, "")
data = append(data, dumpMailBody(body, hasInlineAttachments, hasNormalAttachments, altBoundary, altBoundary)...)
data = append(data, "")
data = append(data, "--"+altBoundary+"--")
} else if hasPlain {
// "plain"
data = append(data, "Content-Type: text/plain; charset=UTF-8")
data = append(data, "Content-Transfer-Encoding: 7bit")
data = append(data, "")
data = append(data, body.Plain)
} else if hasHTML {
// "plain"
data = append(data, "Content-Type: text/html; charset=UTF-8")
data = append(data, "Content-Transfer-Encoding: 7bit")
data = append(data, "")
data = append(data, body.HTML)
} else {
// "empty??"
}
return strings.Join(data, "\r\n")
}
func dumpMailBody(body MailBody, hasInlineAttachments bool, hasNormalAttachments bool, boundary string, boundaryAlt string) []string {
if body.HTML != "" && body.Plain != "" && !hasInlineAttachments && hasNormalAttachments {
data := make([]string, 0, 16)
data = append(data, "--"+boundary)
data = append(data, "Content-Type: multipart/alternative; boundary="+boundaryAlt)
data = append(data, "")
data = append(data, "--"+boundaryAlt)
data = append(data, "Content-Type: text/plain; charset=UTF-8")
data = append(data, "Content-Transfer-Encoding: 7bit")
data = append(data, "")
data = append(data, body.Plain)
data = append(data, "")
data = append(data, "--"+boundaryAlt)
data = append(data, "Content-Type: text/html; charset=UTF-8")
data = append(data, "Content-Transfer-Encoding: 7bit")
data = append(data, "")
data = append(data, body.HTML)
data = append(data, "")
data = append(data, "--"+boundaryAlt+"--")
return data
}
if body.HTML != "" && body.Plain != "" && hasInlineAttachments {
data := make([]string, 0, 2)
data = append(data, "--"+boundary)
data = append(data, body.HTML)
return data
}
if body.HTML != "" && body.Plain != "" {
data := make([]string, 0, 8)
data = append(data, "--"+boundary)
data = append(data, "Content-Type: text/plain; charset=UTF-8")
data = append(data, "Content-Transfer-Encoding: 7bit")
data = append(data, "")
data = append(data, body.Plain)
data = append(data, "")
data = append(data, "--"+boundary)
data = append(data, "Content-Type: text/html; charset=UTF-8")
data = append(data, "Content-Transfer-Encoding: 7bit")
data = append(data, "")
data = append(data, body.HTML)
return data
}
if body.HTML != "" {
data := make([]string, 0, 2)
data = append(data, "--"+boundary)
data = append(data, "Content-Type: text/html; charset=UTF-8")
data = append(data, "Content-Transfer-Encoding: 7bit")
data = append(data, "")
data = append(data, body.HTML)
return data
}
if body.Plain != "" {
data := make([]string, 0, 2)
data = append(data, "--"+boundary)
data = append(data, "Content-Type: text/plain; charset=UTF-8")
data = append(data, "Content-Transfer-Encoding: 7bit")
data = append(data, "")
data = append(data, body.Plain)
return data
}
data := make([]string, 0, 16)
data = append(data, "--"+boundary)
data = append(data, "Content-Type: text/plain; charset=UTF-8")
data = append(data, "Content-Transfer-Encoding: 7bit")
data = append(data, "")
data = append(data, "") // no content ?!?
return data
}