refactor: Reorganize SMTP2Shoutrrr code into separate files

email.go

@@ -0,0 +1,65 @@
+package smtp2shoutrrr
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	"log/slog"
+	"mime"
+	"mime/multipart"
+	"net/mail"
+	"strings"
+)
+
+type ReceivedEmail struct {
+	Recipients []string
+	Msg        *mail.Message
+	body       string
+}
+
+func (re *ReceivedEmail) Body() (string, error) {
+	if re.body == "" {
+		contentType := re.Msg.Header.Get("Content-Type")
+
+		if contentType == "" {
+			body, err := io.ReadAll(re.Msg.Body)
+			if err != nil {
+				return "", fmt.Errorf("failed to read email body: %w", err)
+			}
+			re.body = string(body)
+		} else {
+			mediaType, params, err := mime.ParseMediaType(contentType)
+			if err != nil {
+				log.Fatalf("Failed to parse Content-Type: %v", err)
+			}
+
+			if strings.HasPrefix(mediaType, "multipart/alternative") {
+				mr := multipart.NewReader(re.Msg.Body, params["boundary"])
+				for {
+					part, err := mr.NextPart()
+					if err != nil {
+						break
+					}
+					defer part.Close()
+
+					fmt.Printf("Part Content-Type: %s\n", part.Header.Get("Content-Type"))
+
+					if strings.HasPrefix(part.Header.Get("Content-Type"), "text/plain") {
+						body := new(bytes.Buffer)
+						_, err = body.ReadFrom(part)
+						if err != nil {
+							slog.Error("Failed to read part body", slog.String("err", err.Error()))
+							return "", fmt.Errorf("failed to read part body: %w", err)
+						}
+
+						re.body = body.String()
+						break
+					}
+				}
+			}
+		}
+	}
+
+	return re.body, nil
+}