Experiment: process receipts

FAQ.md

@@ -448,6 +448,7 @@ The low priority status bar notification shows the number of pending operations,
 * *exists*: check if message exists
 * *rule*: execute rule on body text
 * *expunge*: permanently delete messages
+* *report*: process delivery or read receipt (experimental)
 
 Operations are processed only when there is a connection to the email server or when manually synchronizing.
 See also [this FAQ](#user-content-faq16).
@@ -3429,6 +3430,30 @@ Remarks:
 
 <br />
 
+*Process delivery/read receipt (version 1.1797+)*
+
+On receiving a delivery or read receipt, the related message will be looked up in the sent messages folder
+and the following keywords will be set depending on the contents of the report:
+
+```
+$Delivered
+$NotDelivered
+$Displayed
+$NotDisplayed
+```
+
+* Delivered: action = *delivered*, *relayed*, or *expanded*, [see here](https://datatracker.ietf.org/doc/html/rfc3464#section-2.3.3)
+* Displayed: disposition = *displayed*, [see here](https://datatracker.ietf.org/doc/html/rfc3798#section-3.2.6)
+
+It is probably a good idea to enable *Show keywords in message header* in the display settings.
+
+Note that the email server needs to support IMAP flags (keywords) for this feature.
+
+Filter rules will be applied to the received receipt, so it is possible to move/archive the receipt.
+See [this FAQ](#user-content-faq71) for a header condition to recognize receipts.
+
+<br />
+
 <a name="faq126"></a>
 **(126) Can message previews be sent to my wearable?**
 

app/src/main/java/eu/faircode/email/Core.java

@@ -239,6 +239,7 @@ class Core {
 
                         if (message == null &&
                                 !EntityOperation.FETCH.equals(op.name) &&
+                                !EntityOperation.REPORT.equals(op.name) &&
                                 !EntityOperation.SYNC.equals(op.name) &&
                                 !EntityOperation.SUBSCRIBE.equals(op.name) &&
                                 !EntityOperation.PURGE.equals(op.name) &&
@@ -346,6 +347,7 @@ class Core {
 
                                 case EntityOperation.ANSWERED:
                                 case EntityOperation.ADD:
+                                case EntityOperation.REPORT:
                                     // Do nothing
                                     break;
 
@@ -445,6 +447,10 @@ class Core {
                                     onExists(context, jargs, account, folder, message, op, (IMAPFolder) ifolder);
                                     break;
 
+                                case EntityOperation.REPORT:
+                                    onReport(context, jargs, folder, (IMAPStore) istore, (IMAPFolder) ifolder, state);
+                                    break;
+
                                 case EntityOperation.SYNC:
                                     Helper.gc();
                                     onSynchronizeMessages(context, jargs, account, folder, (IMAPStore) istore, (IMAPFolder) ifolder, state);
@@ -1970,6 +1976,43 @@ class Core {
         }
     }
 
+    private static void onReport(Context context, JSONArray jargs, EntityFolder folder, IMAPStore istore, IMAPFolder ifolder, State state) throws JSONException, MessagingException {
+        String msgid = jargs.getString(0);
+        String keyword = jargs.getString(1);
+
+        if (TextUtils.isEmpty(msgid))
+            throw new IllegalArgumentException("msgid missing");
+
+        if (TextUtils.isEmpty(keyword))
+            throw new IllegalArgumentException("keyword missing");
+
+        if (folder.read_only)
+            throw new IllegalArgumentException(folder.name + " read-only");
+
+        if (!ifolder.getPermanentFlags().contains(Flags.Flag.USER))
+            throw new IllegalArgumentException(folder.name + " has no keywords");
+
+        Message[] imessages = ifolder.search(new MessageIDTerm(msgid));
+        if (imessages == null || imessages.length == 0)
+            throw new IllegalArgumentException(msgid + " not found");
+
+        for (Message imessage : imessages) {
+            long uid = ifolder.getUID(imessage);
+            Log.i("Report uid=" + uid + " keyword=" + keyword);
+
+            Flags flags = new Flags(keyword);
+            imessage.setFlags(flags, true);
+
+            try {
+                JSONArray fargs = new JSONArray();
+                fargs.put(uid);
+                onFetch(context, fargs, folder, istore, ifolder, state);
+            } catch (Throwable ex) {
+                Log.w(ex);
+            }
+        }
+    }
+
     static void onSynchronizeFolders(
             Context context, EntityAccount account, Store istore, State state,
             boolean keep_alive, boolean force) throws MessagingException {
@@ -3564,6 +3607,7 @@ class Core {
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
         boolean download_headers = prefs.getBoolean("download_headers", false);
         boolean notify_known = prefs.getBoolean("notify_known", false);
+        boolean experiments = prefs.getBoolean("experiments", false);
         boolean pro = ActivityBilling.isPro(context);
 
         long uid = ifolder.getUID(imessage);
@@ -3863,6 +3907,22 @@ class Core {
             List<Header> headers = (needsHeaders ? helper.getAllHeaders() : null);
             String body = (needsBody ? helper.getMessageParts().getHtml(context) : null);
 
+            if (experiments && helper.isReport())
+                try {
+                    MessageHelper.Report r = parts.getReport();
+                    EntityFolder s = db.folder().getFolderByType(folder.account, EntityFolder.SENT);
+                    if (r != null && s != null) {
+                        if (r.isDeliveryStatus())
+                            EntityOperation.queue(context, s, EntityOperation.REPORT,
+                                    message.inreplyto, r.isDelivered() ? "$Delivered" : "$NotDelivered");
+                        else if (r.isDispositionNotification())
+                            EntityOperation.queue(context, s, EntityOperation.REPORT,
+                                    message.inreplyto, r.isDisplayed() ? "$Displayed" : "$NotDisplayed");
+                    }
+                } catch (Throwable ex) {
+                    Log.w(ex);
+                }
+
             try {
                 db.beginTransaction();
 

app/src/main/java/eu/faircode/email/DaoOperation.java

@@ -39,6 +39,7 @@ public interface DaoOperation {
             // Other operations: add, delete, seen, answered, flag, keyword, label, subscribe, send
             " WHEN operation.name = '" + EntityOperation.FETCH + "' THEN 2" +
             " WHEN operation.name = '" + EntityOperation.EXISTS + "' THEN 3" +
+            " WHEN operation.name = '" + EntityOperation.REPORT + "' THEN 3" +
             " WHEN operation.name = '" + EntityOperation.COPY + "' THEN 4" +
             " WHEN operation.name = '" + EntityOperation.MOVE + "' THEN 5" +
             " WHEN operation.name = '" + EntityOperation.PURGE + "' THEN 6" +

app/src/main/java/eu/faircode/email/EntityOperation.java

@@ -101,6 +101,7 @@ public class EntityOperation {
     static final String RULE = "rule";
     static final String PURGE = "purge";
     static final String EXPUNGE = "expunge";
+    static final String REPORT = "report";
 
     private static final int MAX_FETCH = 100; // operations
     private static final long FORCE_WITHIN = 30 * 1000; // milliseconds

app/src/main/java/eu/faircode/email/MessageHelper.java

@@ -2598,6 +2598,22 @@ public class MessageHelper {
             return sb.toString();
         }
 
+        Report getReport() throws MessagingException, IOException {
+            for (PartHolder h : extra)
+                if (h.isReport()) {
+                    String result;
+                    Object content = h.part.getContent();
+                    if (content instanceof String)
+                        result = (String) content;
+                    else if (content instanceof InputStream)
+                        result = Helper.readStream((InputStream) content);
+                    else
+                        result = content.toString();
+                    return new Report(h.contentType.getBaseType(), result);
+                }
+            return null;
+        }
+
         List<AttachmentPart> getAttachmentParts() {
             return attachments;
         }
@@ -3789,6 +3805,14 @@ public class MessageHelper {
             this.html = report.toString();
         }
 
+        boolean isDeliveryStatus() {
+            return isDeliveryStatus(type);
+        }
+
+        boolean isDispositionNotification() {
+            return isDispositionNotification(type);
+        }
+
         boolean isDelivered() {
             return ("delivered".equals(action) || "relayed".equals(action) || "expanded".equals(action));
         }