feat: parse encrypted isphere packet logs

internal/isphere/packetlog/message.go

@@ -0,0 +1,73 @@
+package packetlog
+
+import (
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+type Message struct {
+	ID          string
+	From        string
+	To          string
+	Type        string
+	Body        string
+	Subject     string
+	SendTime    string
+	ReceiptID   string
+	ReceiptType string
+	Consumed    bool
+	Read        bool
+}
+
+type xmppMessage struct {
+	XMLName  xml.Name    `xml:"message"`
+	ID       string      `xml:"id,attr"`
+	From     string      `xml:"from,attr"`
+	To       string      `xml:"to,attr"`
+	Type     string      `xml:"type,attr"`
+	Body     string      `xml:"body"`
+	Subject  string      `xml:"subject"`
+	Receipt  xmppReceipt `xml:"received"`
+	ISphere  xmppISphere `xml:"isphere"`
+	Consumed *struct{}   `xml:"consumed"`
+	Readed   *struct{}   `xml:"readed"`
+}
+
+type xmppReceipt struct {
+	ID   string `xml:"id,attr"`
+	Type string `xml:"type,attr"`
+}
+
+type xmppISphere struct {
+	SendTime string `xml:"sendtime,attr"`
+}
+
+func ParseMessageLog(plaintext string) (Message, error) {
+	start := strings.Index(plaintext, "<message")
+	if start < 0 {
+		return Message{}, errors.New("message stanza not found")
+	}
+	payload := strings.TrimSpace(plaintext[start:])
+	var parsed xmppMessage
+	if err := xml.Unmarshal([]byte(payload), &parsed); err != nil {
+		return Message{}, fmt.Errorf("parse xmpp message: %w", err)
+	}
+	if parsed.ID == "" {
+		return Message{}, errors.New("message id is empty")
+	}
+	return Message{
+		ID:          parsed.ID,
+		From:        parsed.From,
+		To:          parsed.To,
+		Type:        parsed.Type,
+		Body:        strings.TrimSpace(parsed.Body),
+		Subject:     strings.TrimSpace(parsed.Subject),
+		SendTime:    parsed.ISphere.SendTime,
+		ReceiptID:   parsed.Receipt.ID,
+		ReceiptType: parsed.Receipt.Type,
+		Consumed:    parsed.Consumed != nil,
+		Read:        parsed.Readed != nil,
+	}, nil
+}