comparison mod_muc_moderation_delay/delay.lib.lua @ 5938:959382fac20c

mod_muc_moderation_delay: first commit to prosody-modules.
author John Livingston <git@john-livingston.fr>
date Fri, 26 Jul 2024 15:36:05 +0200
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1 -- SPDX-FileCopyrightText: 2024 John Livingston <https://www.john-livingston.fr/>
2 -- SPDX-License-Identifier: AGPL-3.0-only
3 local st = require "util.stanza";
4 local timer = require "util.timer";
5 local get_time = require "util.time".now;
6 local get_moderation_delay = module:require("config").get_moderation_delay;
7
8 local muc_util = module:require "muc/util";
9 local valid_roles = muc_util.valid_roles;
10
11 local moderation_delay_tag = "moderation-delay";
12 local xmlns_fasten = "urn:xmpp:fasten:0";
13 local xmlns_moderated_0 = "urn:xmpp:message-moderate:0";
14 local xmlns_retract_0 = "urn:xmpp:message-retract:0";
15 local xmlns_moderated_1 = "urn:xmpp:message-moderate:1";
16 local xmlns_retract_1 = "urn:xmpp:message-retract:1";
17 local xmlns_st_id = "urn:xmpp:sid:0";
18
19 local queued_stanza_id_timers = {};
20
21 -- tests if a stanza is a retractation message.
22 local function is_retractation_for_stanza_id(stanza)
23 -- XEP 0425 was revised in 2023. For now, mod_muc_moderation uses the previous version.
24 -- But we will make the code compatible with both.
25 local apply_to = stanza:get_child("apply-to", xmlns_fasten);
26 if apply_to and apply_to.attr.id then
27 local moderated = apply_to:get_child("moderated", xmlns_moderated_0);
28 if moderated then
29 local retract = moderated:get_child("retract", xmlns_retract_0);
30 if retract then
31 return apply_to.attr.id;
32 end
33 end
34 end
35
36 local moderated = stanza:get_child("moderated", xmlns_moderated_1);
37 if moderated then
38 if moderated:get_child("retract", xmlns_retract_1) then
39 return moderated.attr.id;
40 end
41 end
42
43 return nil;
44 end
45
46 -- handler for muc-broadcast-message
47 local function handle_broadcast_message(event)
48 local room, stanza = event.room, event.stanza;
49 local delay = get_moderation_delay(room);
50 if delay == nil then
51 -- feature disabled on the room, go for it.
52 return;
53 end
54
55 -- only delay groupchat messages with body.
56 if stanza.attr.type ~= "groupchat" then
57 return;
58 end
59
60 -- detect retractations:
61 local retracted_stanza_id = is_retractation_for_stanza_id(stanza);
62 if retracted_stanza_id then
63 module:log("debug", "Got a retractation message for %s", retracted_stanza_id);
64 if queued_stanza_id_timers[retracted_stanza_id] then
65 module:log("info", "Got a retractation message, for message %s that is currently waiting for broadcast. Cancelling.", retracted_stanza_id);
66 timer.stop(queued_stanza_id_timers[retracted_stanza_id]);
67 queued_stanza_id_timers[retracted_stanza_id] = nil;
68 -- and we continue...
69 end
70 end
71
72 if not stanza:get_child("body") then
73 -- Dont want to delay message without body.
74 -- This is usually messages like "xxx is typing", or any other service message.
75 -- This also should concern retractation messages.
76 -- Clients that will receive retractation messages for message they never got, should just drop them. And that's ok.
77 return;
78 end
79
80 local stanza_id = nil; -- message stanza id... can be nil!
81 local stanza_id_child = stanza:get_child("stanza-id", xmlns_st_id);
82 if not stanza_id_child then
83 -- this can happen when muc is not archived!
84 -- in such case, message retractation is not possible.
85 -- so, this is a normal use case, and we should handle it properly.
86 else
87 stanza_id = stanza_id_child.attr.id;
88 end
89 local id = stanza.attr.id;
90 if not id then
91 -- message should alway have an id, but just in case...
92 module:log("warn", "Message has no id, wont delay it.");
93 return;
94 end
95
96 -- Message must be delayed, except for:
97 -- * room moderators
98 -- * the user that sent the message (if they don't get the echo quickly, their clients could have weird behaviours)
99 module:log("debug", "Message %s / %s must be delayed by %i seconds, sending first broadcast wave.", id, stanza_id, delay);
100 local moderator_role_value = valid_roles["moderator"];
101
102 local cloned_stanza = st.clone(stanza); -- we must clone, to send a copy for the second wave.
103
104 -- first of all, if the initiator occupant is not moderator, me must send to them.
105 -- (delaying the echo message could have some quircks in some xmpp clients)
106 if stanza.attr.from then
107 local from_occupant = room:get_occupant_by_nick(stanza.attr.from);
108 if from_occupant and valid_roles[from_occupant.role or "none"] < moderator_role_value then
109 module:log("debug", "Message %s / %s must be sent separatly to it initialior %s.", id, stanza_id, delay, stanza.attr.from);
110 room:route_to_occupant(from_occupant, stanza);
111 end
112 end
113
114 -- adding a tag, so that moderators can know that this message is delayed.
115 stanza:tag(moderation_delay_tag, {
116 delay = "" .. delay;
117 waiting = string.format("%i", get_time() + delay);
118 }):up();
119
120 -- then, sending to moderators (and only moderators):
121 room:broadcast(stanza, function (nick, occupant)
122 if valid_roles[occupant.role or "none"] >= moderator_role_value then
123 return true;
124 end
125 return false;
126 end);
127
128 local task = timer.add_task(delay, function ()
129 module:log("debug", "Message %s has been delayed, sending to remaining participants.", id);
130 room:broadcast(cloned_stanza, function (nick, occupant)
131 if valid_roles[occupant.role or "none"] >= moderator_role_value then
132 return false;
133 end
134 if nick == stanza.attr.from then
135 -- we already sent it to them (because they are moderator, or because we sent them separately)
136 return false;
137 end
138 return true;
139 end);
140 end);
141 if stanza_id then
142 -- store it, so we can stop timer if there is a retractation.
143 queued_stanza_id_timers[stanza_id] = task;
144 end
145
146 return true; -- stop the default broadcast_message processing.
147 end
148
149 return {
150 handle_broadcast_message = handle_broadcast_message;
151 };