expose empty server functionality and test it (also introducing a new DC_EVENT_IMAP_FOLDER_EMPTIED event)

deltachat-ffi/deltachat.h

@@ -1513,6 +1513,16 @@ char*           dc_get_mime_headers          (dc_context_t* context, uint32_t ms
  */
 void            dc_delete_msgs               (dc_context_t* context, const uint32_t* msg_ids, int msg_cnt);
 
+/**
+ * Empty IMAP server folder: delete all messages. 
+ *
+ * @memberof dc_context_t
+ * @param context The context object as created by dc_context_new()
+ * @param flags uint32_t with DC_EMPTY_* flags 
+ * @return None.
+ */
+void            dc_empty_server              (dc_context_t* context, const uint32_t flags);
+
 
 /**
  * Forward messages to another chat.
@@ -3929,6 +3939,30 @@ int64_t          dc_lot_get_timestamp     (const dc_lot_t* lot);
  * @{
  */
 
+/**
+ * @defgroup DC_EMPTY
+ *
+ * These constants configure emptying imap folders. 
+ *
+ * @addtogroup DC_EMPTY
+ * @{
+ */
+
+/**
+ * Clear all mvbox messages.
+ */
+#define DC_EMPTY_MVBOX 0x01
+
+/**
+ * Clear all INBOX messages.
+ */
+#define DC_EMPTY_INBOX 0x02
+
+/**
+ * @}
+ */
+
+
 
 /**
  * The library-user may write an informational string to the log.
@@ -3995,6 +4029,16 @@ int64_t          dc_lot_get_timestamp     (const dc_lot_t* lot);
  */
 #define DC_EVENT_IMAP_MESSAGE_MOVED   105
 
+/**
+ * Emitted when an IMAP folder was emptied. 
+ *
+ * @param data1 0
+ * @param data2 (const char*) folder name. 
+ *     Must not be unref'd or modified and is valid only until the callback returns.
+ * @return 0
+ */
+#define DC_EVENT_IMAP_FOLDER_EMPTIED  106
+
 /**
  * Emitted when a new blob file was successfully written 
  *

deltachat-ffi/src/lib.rs

@@ -130,6 +130,7 @@ impl ContextWrapper {
                     | Event::SmtpMessageSent(msg)
                     | Event::ImapMessageDeleted(msg)
                     | Event::ImapMessageMoved(msg)
+                    | Event::ImapFolderEmptied(msg)
                     | Event::NewBlobFile(msg)
                     | Event::DeletedBlobFile(msg)
                     | Event::Warning(msg)
@@ -1286,6 +1287,18 @@ pub unsafe extern "C" fn dc_delete_msgs(
         .unwrap_or(())
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn dc_empty_server(context: *mut dc_context_t, flags: u32) {
+    if context.is_null() || flags == 0 {
+        eprintln!("ignoring careless call to dc_empty_server()");
+        return;
+    }
+    let ffi_context = &*context;
+    ffi_context
+        .with_inner(|ctx| message::dc_empty_server(ctx, flags))
+        .unwrap_or(())
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn dc_forward_msgs(
     context: *mut dc_context_t,

examples/repl/cmdline.rs

@@ -404,6 +404,7 @@ pub unsafe fn dc_cmdline(context: &Context, line: &str) -> Result<(), failure::E
                  checkqr <qr-content>\n\
                  event <event-id to test>\n\
                  fileinfo <file>\n\
+                 emptyserver <flags> (1=MVBOX 2=INBOX)\n\
                  clear -- clear screen\n\
                  exit or quit\n\
                  ============================================="
@@ -976,6 +977,11 @@ pub unsafe fn dc_cmdline(context: &Context, line: &str) -> Result<(), failure::E
                 bail!("Command failed.");
             }
         }
+        "emptyserver" => {
+            ensure!(!arg1.is_empty(), "Argument <flags> missing");
+
+            message::dc_empty_server(context, arg1.parse()?);
+        }
         "" => (),
         _ => bail!("Unknown command: \"{}\" type ? for help.", arg0),
     }

python/src/deltachat/account.py

@@ -135,6 +135,17 @@ class Account(object):
         if not self.is_configured():
             raise ValueError("need to configure first")
 
+    def empty_server_folders(self, inbox=False, mvbox=False):
+        """ empty server folders. """
+        flags = 0
+        if inbox:
+            flags |= const.DC_EMPTY_INBOX
+        if mvbox:
+            flags |= const.DC_EMPTY_MVBOX
+        if not flags:
+            raise ValueError("no flags set")
+        lib.dc_empty_server(self._dc_context, flags)
+
     def get_infostring(self):
         """ return info of the configured account. """
         self.check_is_configured()

python/src/deltachat/const.py

@@ -69,12 +69,15 @@ DC_CERTCK_AUTO = 0
 DC_CERTCK_STRICT = 1
 DC_CERTCK_ACCEPT_INVALID_HOSTNAMES = 2
 DC_CERTCK_ACCEPT_INVALID_CERTIFICATES = 3
+DC_EMPTY_MVBOX = 0x01
+DC_EMPTY_INBOX = 0x02
 DC_EVENT_INFO = 100
 DC_EVENT_SMTP_CONNECTED = 101
 DC_EVENT_IMAP_CONNECTED = 102
 DC_EVENT_SMTP_MESSAGE_SENT = 103
 DC_EVENT_IMAP_MESSAGE_DELETED = 104
 DC_EVENT_IMAP_MESSAGE_MOVED = 105
+DC_EVENT_IMAP_FOLDER_EMPTIED = 106
 DC_EVENT_NEW_BLOB_FILE = 150
 DC_EVENT_DELETED_BLOB_FILE = 151
 DC_EVENT_WARNING = 300
@@ -151,7 +154,7 @@ DC_STR_COUNT = 67
 
 
 def read_event_defines(f):
-    rex = re.compile(r'#define\s+((?:DC_EVENT|DC_QR|DC_MSG|DC_LP|DC_CERTCK|DC_STATE|DC_STR|'
+    rex = re.compile(r'#define\s+((?:DC_EVENT|DC_QR|DC_MSG|DC_LP|DC_EMPTY|DC_CERTCK|DC_STATE|DC_STR|'
                      r'DC_CONTACT_ID|DC_GCL|DC_CHAT|DC_PROVIDER)_\S+)\s+([x\d]+).*')
     for line in f:
         m = rex.match(line)

python/tests/conftest.py

@@ -180,6 +180,12 @@ def acfactory(pytestconfig, tmpdir, request, session_liveconfig):
             ac.start_threads(mvbox=mvbox, sentbox=sentbox)
             return ac
 
+        def get_one_online_account(self):
+            ac1 = self.get_online_configuring_account()
+            wait_successful_IMAP_SMTP_connection(ac1)
+            wait_configuration_progress(ac1, 1000)
+            return ac1
+
         def get_two_online_accounts(self):
             ac1 = self.get_online_configuring_account()
             ac2 = self.get_online_configuring_account()

python/tests/test_account.py

@@ -493,6 +493,18 @@ class TestOnlineAccount:
         assert msg_in.text == "message2"
         assert msg_in.is_forwarded()
 
+    def test_send_self_message_and_empty_folder(self, acfactory, lp):
+        ac1 = acfactory.get_one_online_account()
+        lp.sec("ac1: create self chat")
+        chat = ac1.create_chat_by_contact(ac1.get_self_contact())
+        chat.send_text("hello")
+        ac1._evlogger.get_matching("DC_EVENT_SMTP_MESSAGE_SENT")
+        ac1.empty_server_folders(inbox=True, mvbox=True)
+        ev = ac1._evlogger.get_matching("DC_EVENT_IMAP_FOLDER_EMPTIED")
+        assert ev[2] == "DeltaChat"
+        ev = ac1._evlogger.get_matching("DC_EVENT_IMAP_FOLDER_EMPTIED")
+        assert ev[2] == "INBOX"
+
     def test_send_and_receive_message_markseen(self, acfactory, lp):
         ac1, ac2 = acfactory.get_two_online_accounts()
 

src/events.rs

@@ -54,6 +54,12 @@ pub enum Event {
     #[strum(props(id = "105"))]
     ImapMessageMoved(String),
 
+    /// Emitted when an IMAP folder was emptied
+    ///
+    /// @return 0
+    #[strum(props(id = "106"))]
+    ImapFolderEmptied(String),
+
     /// Emitted when an new file in the $BLOBDIR was created
     ///
     /// @return 0

src/imap.rs

@@ -651,7 +651,8 @@ impl Imap {
         }
 
         // deselect existing folder, if needed (it's also done implicitly by SELECT, however, without EXPUNGE then)
-        if self.config.read().unwrap().selected_folder_needs_expunge {
+        let needs_expunge = { self.config.read().unwrap().selected_folder_needs_expunge };
+        if needs_expunge {
             if let Some(ref folder) = self.config.read().unwrap().selected_folder {
                 info!(context, "Expunge messages in \"{}\".", folder);
 
@@ -659,16 +660,19 @@ impl Imap {
                 // https://tools.ietf.org/html/rfc3501#section-6.4.2
                 if let Some(ref mut session) = &mut *self.session.lock().unwrap() {
                     match session.close() {
-                        Ok(_) => {}
+                        Ok(_) => {
+                            info!(context, "close/expunge succeeded");
+                        }
                         Err(err) => {
                             warn!(context, "failed to close session: {:?}", err);
+                            return 0;
                         }
                     }
                 } else {
                     return 0;
                 }
-                self.config.write().unwrap().selected_folder_needs_expunge = true;
             }
+            self.config.write().unwrap().selected_folder_needs_expunge = false;
         }
 
         // select new folder
@@ -1510,10 +1514,10 @@ impl Imap {
             if self.select_folder::<String>(context, None) == 0 {
                 warn!(
                     context,
-                    "could not perform expunge on empty folder {}", folder
+                    "could not perform expunge on empty-marked folder {}", folder
                 );
             } else {
-                info!(context, "Emptying folder '{}' done.", folder);
+                emit_event!(context, Event::ImapFolderEmptied(folder.to_string()));
             }
         }
     }

src/message.rs

@@ -1276,6 +1276,12 @@ pub fn update_server_uid(
     }
 }
 
+#[allow(dead_code)]
+pub fn dc_empty_server(context: &Context, flags: u32) {
+    job_kill_action(context, Action::EmptyServer);
+    job_add(context, Action::EmptyServer, flags as i32, Params::new(), 0);
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;