From 83488c31fe3e0f814acb3f3909ba5d86e5fa7396 Mon Sep 17 00:00:00 2001
From: Nick Thomas <me@ur.gs>
Date: Sun, 10 Jan 2021 17:12:29 +0000
Subject: [PATCH] Support IMEX messages

---
 delta-connection.c | 56 +++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 50 insertions(+), 6 deletions(-)

diff --git a/delta-connection.c b/delta-connection.c
index 7f33f5b..4729b4f 100644
--- a/delta-connection.c
+++ b/delta-connection.c
@@ -12,6 +12,8 @@
 #include "delta-connection.h"
 #include "libdelta.h"
 
+#define IMEX_RECEIVED_MESSAGE "Setup message received. To apply it, reply with:\nIMEX: %d nnnn-nnnn-nnnn-nnnn-nnnn-nnnn-nnnn-nnnn-nnnn\nNo whitespace in the setup-code!"
+
 void delta_recv_im(DeltaConnectionData *conn, uint32_t msg_id);
 
 void
@@ -141,8 +143,6 @@ delta_event_handler(void *context)
 	dc_event_emitter_t* emitter = dc_get_event_emitter(mailbox);
 	dc_event_t* event;
 
-
-
 	// FIXME: do we still need runthreads?
 	while (conn->runthreads && (event = dc_get_next_event(emitter)) != NULL) {
 		ProcessRequest *pr = NULL;
@@ -177,10 +177,20 @@ delta_event_handler(void *context)
 			break;
 		}
 
-		case DC_EVENT_MSGS_CHANGED:
+		case DC_EVENT_MSGS_CHANGED: {
+			// This event may be issued for a single message, in which case the
+			// message ID is in data2 and we should treat it as an incoming msg
+			uint32_t msg_id = dc_event_get_data2_int(event);
 			pr = delta_build_process_request(conn);
-			purple_timeout_add(0, delta_process_fresh_messages, pr);
+			if (msg_id) {
+				// FIXME: they won't all be incoming. Some will be changed
+				pr->msg_id = msg_id;
+				purple_timeout_add(0, delta_process_incoming_message, pr);
+			} else {
+				purple_timeout_add(0, delta_process_fresh_messages, pr);
+			}
 			break;
+		}
 
 		case DC_EVENT_INCOMING_MSG:
 			// data1 is chat_id, which we don't seem to need yet.
@@ -297,6 +307,25 @@ delta_connection_start_login(PurpleConnection *pc)
 	return;
 }
 
+gboolean delta_try_process_imex(dc_context_t *mailbox, char *text) {
+	if (!g_str_has_prefix(text, "IMEX: ")) {
+		return FALSE;
+	}
+
+	gchar **parts = g_strsplit(text, " ", 3);
+	if (g_strv_length(parts) != 3) {
+		g_strfreev(parts);
+		return FALSE;
+	}
+
+	int msg_id = atoi(parts[1]);
+	gboolean success = dc_continue_key_transfer(mailbox, msg_id, parts[2]);
+
+	g_strfreev(parts);
+
+	return success;
+}
+
 int
 delta_send_im(PurpleConnection *pc, const char *who, const char *message, PurpleMessageFlags flags)
 {
@@ -373,7 +402,9 @@ next:
 	char *stripped_message = purple_markup_strip_html(message);
 	g_assert(stripped_message != NULL);
 	if (strlen(stripped_message) > 0) {
-		dc_send_text_msg(mailbox, chat_id, stripped_message);
+		if (!delta_try_process_imex(mailbox, stripped_message)) {
+			dc_send_text_msg(mailbox, chat_id, stripped_message);
+		}
 	}
 	g_free(stripped_message);
 
@@ -389,7 +420,7 @@ delta_recv_im(DeltaConnectionData *conn, uint32_t msg_id)
 	PurpleConnection *pc = conn->pc;
 	g_assert(pc != NULL);
 
-	dc_msg_t* msg = dc_get_msg(mailbox, msg_id);
+	dc_msg_t *msg = dc_get_msg(mailbox, msg_id);
 	int viewtype = dc_msg_get_viewtype(msg);
 	time_t timestamp = dc_msg_get_timestamp(msg);
 	char *text = dc_msg_get_text(msg);
@@ -404,9 +435,22 @@ delta_recv_im(DeltaConnectionData *conn, uint32_t msg_id)
 	char *who = dc_contact_get_addr(contact);
 	int flags = PURPLE_MESSAGE_RECV;
 
+	// FIXME: as a massive hack, convert IMEX setup messages into a text message
+	// prompting the user how to trigger the IMEX filter in outgoing messages.
+	if (dc_msg_is_setupmessage(msg)) {
+		purple_debug_info(PLUGIN_ID, "Receiving IMEX: ID=%d\n", msg_id);
+		viewtype = DC_MSG_TEXT;
+		g_free(text);
+		text = g_strndup("", 1024);
+		g_assert(text != NULL);
+
+		g_snprintf(text, 1024, IMEX_RECEIVED_MESSAGE, msg_id);
+	}
+
 	switch(viewtype) {
 	case DC_MSG_GIF:
 	case DC_MSG_IMAGE:
+	case DC_MSG_STICKER:
 		flags = flags | PURPLE_MESSAGE_IMAGES;
 		break;
 	case DC_MSG_TEXT: