From 3d66be6a9f7a1d38117f76b3cd492a2808e89e15 Mon Sep 17 00:00:00 2001
From: Alexander PapaTutuWawa <papatutuwawa@polynom.me>
Date: Fri, 28 May 2021 16:25:35 +0200
Subject: [PATCH] mod_mix_pam: Replace "state" tracking with promises

---
 mod_mix_pam/mod_mix_pam.lua | 80 +++++++++++--------------------------
 1 file changed, 23 insertions(+), 57 deletions(-)

diff --git a/mod_mix_pam/mod_mix_pam.lua b/mod_mix_pam/mod_mix_pam.lua
index b67a228..5ca8101 100644
--- a/mod_mix_pam/mod_mix_pam.lua
+++ b/mod_mix_pam/mod_mix_pam.lua
@@ -70,26 +70,6 @@ function module.load()
     end
 end
 
-local client_state_tracker = {}; -- [stanza ID] -> resource
-local function add_state(id, resource)
-    client_state_tracker[id] = resource;
-    module:log("debug", "Adding a resource %s for id %s", resource, id);
-end
-local function has_state(id)
-    return client_state_tracker[id] ~= nil;
-end
-local function pop_state(id)
-    module:log("debug", "Popping a resource for stanza id %s", id);
-
-    if has_state(id) then
-        local resource = client_state_tracker[id];
-        client_state_tracker[id] = nil;
-        return resource;
-    end
-
-    return nil;
-end
-
 local function handle_client_join(event)
     -- Client requests to join
     module:log("debug", "client-join received");
@@ -115,9 +95,17 @@ local function handle_client_join(event)
     });
     join_iq:add_child(join);
 
-    add_state(stanza.attr.id, origin);
-
-    module:send(join_iq);
+    module:send_iq(join_iq)
+        :next(function(resp)
+                -- Success
+                handle_mix_join(resp, origin);
+            end, function(resp)
+                -- Error
+                -- TODO
+                local error_stanza = resp.stanza;
+                error_stanza.attr.to = origin.full_jid;
+                module:send(error_stanza);
+            end);
     return true;
 end
 
@@ -146,9 +134,16 @@ local function handle_client_leave(event)
     });
     leave_iq:add_child(leave);
 
-    add_state(stanza.attr.id, origin);
-
-    module:send(leave_iq);
+    module:send_iq(leave_iq)
+        :next(function(resp)
+                handle_mix_leave(resp, origin);
+            end, function(resp)
+                -- Error
+                -- TODO
+                local error_stanza = resp.stanza;
+                error_stanza.attr.to = origin.full_jid;
+                module:send(error_stanza);
+            end);
     return true;
 end
 
@@ -163,20 +158,14 @@ module:hook("iq/self", function(event)
     end
 end);
 
-local function handle_mix_join(event)
+local function handle_mix_join(event, origin)
     -- The MIX server responded
     module:log("debug", "Received MIX-JOIN result");
 
     local stanza = event.stanza;
     local spid = stanza:get_child("join", "urn:xmpp:mix:core:1").attr.id;
     local channel_jid = spid.."#"..stanza.attr.from;
-    local origin = pop_state(stanza.attr.id);
     local resource = origin.resource;
-    if resource == nil then
-        module:log("error", "Got a MIX join result for a not-requested id %s", stanza.attr.id);
-        module:log("error", "Maybe the server changed the stanza ID?");
-        return false;
-    end
 
     local client_join = st.iq({
         type = "result";
@@ -200,18 +189,12 @@ local function handle_mix_join(event)
     return true;
 end
 
-local function handle_mix_leave(event)
+local function handle_mix_leave(event, origin)
     -- The MIX server responded
     module:log("debug", "Received MIX-LEAVE result");
 
     local stanza = event.stanza;
-    local origin = pop_state(stanza.attr.id);
     local resource = origin.resource;
-    if resource == nil then
-        module:log("error", "Got a MIX leave result for a not-requested id %s", stanza.attr.id);
-        module:log("error", "Maybe the MIX server changed the stanza ID?");
-        return false;
-    end
 
     local client_leave = st.iq({
         type = "result";
@@ -232,23 +215,6 @@ local function handle_mix_leave(event)
     return true;
 end
 
-module:hook("iq/bare", function(event)
-    -- We handle the MIX results here since IQ stanzas against bare JIDs
-    -- don't make a lot of sense. We first have to translate them into
-    -- full JIDs based on our stanza ID -> resource mapping
-    if event.stanza:get_child("leave", "urn:xmpp:mix:core:1") ~= nil then
-        return handle_mix_leave(event);
-    elseif event.stanza:get_child("join", "urn:xmpp:mix:core:1") ~= nil then
-        return handle_mix_join(event);
-    elseif has_state(event.stanza.attr.id) then
-        local tmp = st.clone(event.stanza);
-        local origin = pop_state(tmp.attr.id);
-        tmp.attr.to = tmp.attr.to.."/"..origin.resource;
-        module:send(tmp);
-        return true;
-    end
-end);
-
 module:hook("roster-get", function(event)
     -- NOTE: Currently this requires a patch to make mod_roster emit
     -- the roster-get event