Files
EMLy/backend/utils/mail/eml_reader.go
Flavio Fois 0cda0a26fc v1.2.2
2026-02-04 19:57:31 +01:00

125 lines
2.8 KiB
Go

package internal
import (
"fmt"
"io"
"net/mail"
"os"
"strings"
"unicode/utf8"
"emly/backend/utils"
"golang.org/x/text/encoding/charmap"
"golang.org/x/text/transform"
)
type EmailAttachment struct {
Filename string `json:"filename"`
ContentType string `json:"contentType"`
Data []byte `json:"data"`
}
type EmailData struct {
From string `json:"from"`
To []string `json:"to"`
Cc []string `json:"cc"`
Bcc []string `json:"bcc"`
Subject string `json:"subject"`
Body string `json:"body"`
Attachments []EmailAttachment `json:"attachments"`
IsPec bool `json:"isPec"`
HasInnerEmail bool `json:"hasInnerEmail"`
}
func ReadEmlFile(filePath string) (*EmailData, error) {
file, err := os.Open(filePath)
if err != nil {
return nil, fmt.Errorf("failed to open file: %w", err)
}
defer file.Close()
email, err := utils.Parse(file)
if err != nil {
return nil, fmt.Errorf("failed to parse email: %w", err)
}
// Format addresses
formatAddress := func(addr []*mail.Address) []string {
var result []string
for _, a := range addr {
result = append(result, convertToUTF8(a.String()))
}
return result
}
// Determine body (prefer HTML)
body := email.HTMLBody
if body == "" {
body = email.TextBody
}
// Process attachments and detect PEC
var attachments []EmailAttachment
var hasDatiCert, hasSmime, hasInnerEmail bool
for _, att := range email.Attachments {
data, err := io.ReadAll(att.Data)
if err != nil {
continue // Handle error or skip? Skipping for now.
}
// PEC Detection Logic
filenameLower := strings.ToLower(att.Filename)
if filenameLower == "daticert.xml" {
hasDatiCert = true
}
if filenameLower == "smime.p7s" {
hasSmime = true
}
if strings.HasSuffix(filenameLower, ".eml") {
hasInnerEmail = true
}
attachments = append(attachments, EmailAttachment{
Filename: att.Filename,
ContentType: att.ContentType,
Data: data,
})
}
isPec := hasDatiCert && hasSmime
// Format From
var from string
if len(email.From) > 0 {
from = email.From[0].String()
}
return &EmailData{
From: convertToUTF8(from),
To: formatAddress(email.To),
Cc: formatAddress(email.Cc),
Bcc: formatAddress(email.Bcc),
Subject: convertToUTF8(email.Subject),
Body: convertToUTF8(body),
Attachments: attachments,
IsPec: isPec,
HasInnerEmail: hasInnerEmail,
}, nil
}
func convertToUTF8(s string) string {
if utf8.ValidString(s) {
return s
}
// If invalid UTF-8, assume Windows-1252 (superset of ISO-8859-1)
decoder := charmap.Windows1252.NewDecoder()
decoded, _, err := transform.String(decoder, s)
if err != nil {
return s // Return as-is if decoding fails
}
return decoded
}