util.encodings: Spell out all IDNA 2008 options ICU has

[prosody.git] / plugins / muc / muc.lib.lua

-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
-- Copyright (C) 2014 Daurnimator
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local select = select;
local pairs = pairs;
local next = next;
local setmetatable = setmetatable;

local dataform = require "util.dataforms";
local iterators = require "util.iterators";
local jid_split = require "util.jid".split;
local jid_bare = require "util.jid".bare;
local jid_prep = require "util.jid".prep;
local jid_join = require "util.jid".join;
local jid_resource = require "util.jid".resource;
local resourceprep = require "util.encodings".stringprep.resourceprep;
local st = require "util.stanza";
local base64 = require "util.encodings".base64;
local md5 = require "util.hashes".md5;
local new_id = require "util.id".medium;

local log = module._log;

local occupant_lib = module:require "muc/occupant"
local muc_util = module:require "muc/util";
local is_kickable_error = muc_util.is_kickable_error;
local valid_roles, valid_affiliations = muc_util.valid_roles, muc_util.valid_affiliations;

local room_mt = {};
room_mt.__index = room_mt;

function room_mt:__tostring()
        return "MUC room ("..self.jid..")";
end

function room_mt.save()
        -- overridden by mod_muc.lua
end

function room_mt:get_occupant_jid(real_jid)
        return self._jid_nick[real_jid]
end

function room_mt:get_default_role(affiliation)
        local role = module:fire_event("muc-get-default-role", {
                room = self;
                affiliation = affiliation;
                affiliation_rank = valid_affiliations[affiliation or "none"];
        });
        role = role ~= "none" and role or nil; -- coerces `role == false` to `nil`
        return role, valid_roles[role or "none"];
end
module:hook("muc-get-default-role", function(event)
        if event.affiliation_rank >= valid_affiliations.admin then
                return "moderator";
        elseif event.affiliation_rank >= valid_affiliations.none then
                return "participant";
        end
end, -1);

--- Occupant functions
function room_mt:new_occupant(bare_real_jid, nick)
        local occupant = occupant_lib.new(bare_real_jid, nick);
        local affiliation = self:get_affiliation(bare_real_jid);
        occupant.role = self:get_default_role(affiliation);
        return occupant;
end

-- nick is in the form of an in-room JID
function room_mt:get_occupant_by_nick(nick)
        local occupant = self._occupants[nick];
        if occupant == nil then return nil end
        return occupant_lib.copy(occupant);
end

do
        local function next_copied_occupant(occupants, occupant_jid)
                local next_occupant_jid, raw_occupant = next(occupants, occupant_jid);
                if next_occupant_jid == nil then return nil end
                return next_occupant_jid, occupant_lib.copy(raw_occupant);
        end
        -- FIXME Explain what 'read_only' is supposed to be
        function room_mt:each_occupant(read_only) -- luacheck: ignore 212
                return next_copied_occupant, self._occupants, nil;
        end
end

function room_mt:has_occupant()
        return next(self._occupants, nil) ~= nil
end

function room_mt:get_occupant_by_real_jid(real_jid)
        local occupant_jid = self:get_occupant_jid(real_jid);
        if occupant_jid == nil then return nil end
        return self:get_occupant_by_nick(occupant_jid);
end

function room_mt:save_occupant(occupant)
        occupant = occupant_lib.copy(occupant); -- So that occupant can be modified more
        local id = occupant.nick

        -- Need to maintain _jid_nick secondary index
        local old_occupant = self._occupants[id];
        if old_occupant then
                for real_jid in old_occupant:each_session() do
                        self._jid_nick[real_jid] = nil;
                end
        end

        local has_live_session = false
        if occupant.role ~= nil then
                for real_jid, presence in occupant:each_session() do
                        if presence.attr.type == nil then
                                has_live_session = true
                                self._jid_nick[real_jid] = occupant.nick;
                        end
                end
                if not has_live_session then
                        -- Has no live sessions left; they have left the room.
                        occupant.role = nil
                end
        end
        if not has_live_session then
                occupant = nil
        end
        self._occupants[id] = occupant
        return occupant
end

function room_mt:route_to_occupant(occupant, stanza)
        local to = stanza.attr.to;
        for jid in occupant:each_session() do
                stanza.attr.to = jid;
                self:route_stanza(stanza);
        end
        stanza.attr.to = to;
end

-- actor is the attribute table
local function add_item(x, affiliation, role, jid, nick, actor_nick, actor_jid, reason)
        x:tag("item", {affiliation = affiliation; role = role; jid = jid; nick = nick;})
        if actor_nick or actor_jid then
                x:tag("actor", {nick = actor_nick; jid = actor_jid;}):up()
        end
        if reason then
                x:tag("reason"):text(reason):up()
        end
        x:up();
        return x
end

-- actor is (real) jid
function room_mt:build_item_list(occupant, x, is_anonymous, nick, actor_nick, actor_jid, reason)
        local affiliation = self:get_affiliation(occupant.bare_jid) or "none";
        local role = occupant.role or "none";
        if is_anonymous then
                add_item(x, affiliation, role, nil, nick, actor_nick, actor_jid, reason);
        else
                for real_jid in occupant:each_session() do
                        add_item(x, affiliation, role, real_jid, nick, actor_nick, actor_jid, reason);
                end
        end
        return x
end

function room_mt:broadcast_message(stanza)
        if module:fire_event("muc-broadcast-message", {room = self, stanza = stanza}) then
                return true;
        end
        self:broadcast(stanza);
        return true;
end

-- Strip delay tags claiming to be from us
module:hook("muc-occupant-groupchat", function (event)
        local stanza = event.stanza;
        local room = event.room;
        local room_jid = room.jid;

        stanza:maptags(function (child)
                if child.name == "delay" and child.attr["xmlns"] == "urn:xmpp:delay" then
                        if child.attr["from"] == room_jid then
                                return nil;
                        end
                end
                if child.name == "x" and child.attr["xmlns"] == "jabber:x:delay" then
                        if child.attr["from"] == room_jid then
                                return nil;
                        end
                end
                return child;
        end)
end);

-- Broadcast a stanza to all occupants in the room.
-- optionally checks conditional called with (nick, occupant)
function room_mt:broadcast(stanza, cond_func)
        for nick, occupant in self:each_occupant() do
                if cond_func == nil or cond_func(nick, occupant) then
                        self:route_to_occupant(occupant, stanza)
                end
        end
end

local function can_see_real_jids(whois, occupant)
        if whois == "anyone" then
                return true;
        elseif whois == "moderators" then
                return valid_roles[occupant.role or "none"] >= valid_roles.moderator;
        end
end

-- Broadcasts an occupant's presence to the whole room
-- Takes the x element that goes into the stanzas
function room_mt:publicise_occupant_status(occupant, x, nick, actor, reason)
        local base_x = x.base or x;
        -- Build real jid and (optionally) occupant jid template presences
        local base_presence do
                -- Try to use main jid's presence
                local pr = occupant:get_presence();
                if pr and (occupant.role ~= nil or pr.attr.type == "unavailable") then
                        base_presence = st.clone(pr);
                else -- user is leaving but didn't send a leave presence. make one for them
                        base_presence = st.presence {from = occupant.nick; type = "unavailable";};
                end
        end

        -- Fire event (before full_p and anon_p are created)
        local event = {
                room = self; stanza = base_presence; x = base_x;
                occupant = occupant; nick = nick; actor = actor;
                reason = reason;
        }
        module:fire_event("muc-broadcast-presence", event);

        -- Allow muc-broadcast-presence listeners to change things
        nick = event.nick;
        actor = event.actor;
        reason = event.reason;

        local whois = self:get_whois();

        local actor_nick;
        if actor then
                actor_nick = jid_resource(self:get_occupant_jid(actor));
        end

        local full_p, full_x;
        local function get_full_p()
                if full_p == nil then
                        full_x = st.clone(x.full or base_x);
                        self:build_item_list(occupant, full_x, false, nick, actor_nick, actor, reason);
                        full_p = st.clone(base_presence):add_child(full_x);
                end
                return full_p, full_x;
        end

        local anon_p, anon_x;
        local function get_anon_p()
                if anon_p == nil then
                        anon_x = st.clone(x.anon or base_x);
                        self:build_item_list(occupant, anon_x, true, nick, actor_nick, nil, reason);
                        anon_p = st.clone(base_presence):add_child(anon_x);
                end
                return anon_p, anon_x;
        end

        local self_p, self_x;
        do
                -- Can always see your own full jids
                -- But not allowed to see actor's
                self_x = st.clone(x.self or base_x);
                self:build_item_list(occupant, self_x, false, nick, actor_nick, nil, reason);
                self_p = st.clone(base_presence):add_child(self_x);
        end

        -- General populace
        for occupant_nick, n_occupant in self:each_occupant() do
                if occupant_nick ~= occupant.nick then
                        local pr;
                        if can_see_real_jids(whois, n_occupant) then
                                pr = get_full_p();
                        elseif occupant.bare_jid == n_occupant.bare_jid then
                                pr = self_p;
                        else
                                pr = get_anon_p();
                        end
                        self:route_to_occupant(n_occupant, pr);
                end
        end

        -- Presences for occupant itself
        self_x:tag("status", {code = "110";}):up();
        if occupant.role == nil then
                -- They get an unavailable
                self:route_to_occupant(occupant, self_p);
        else
                -- use their own presences as templates
                for full_jid, pr in occupant:each_session() do
                        pr = st.clone(pr);
                        pr.attr.to = full_jid;
                        pr:add_child(self_x);
                        self:route_stanza(pr);
                end
        end
end

function room_mt:send_occupant_list(to, filter)
        local to_bare = jid_bare(to);
        local is_anonymous = false;
        local whois = self:get_whois();
        if whois ~= "anyone" then
                local affiliation = self:get_affiliation(to);
                if affiliation ~= "admin" and affiliation ~= "owner" then
                        local occupant = self:get_occupant_by_real_jid(to);
                        if not (occupant and can_see_real_jids(whois, occupant)) then
                                is_anonymous = true;
                        end
                end
        end
        for occupant_jid, occupant in self:each_occupant() do
                if filter == nil or filter(occupant_jid, occupant) then
                        local x = st.stanza("x", {xmlns='http://jabber.org/protocol/muc#user'});
                        self:build_item_list(occupant, x, is_anonymous and to_bare ~= occupant.bare_jid); -- can always see your own jids
                        local pres = st.clone(occupant:get_presence());
                        pres.attr.to = to;
                        pres:add_child(x);
                        self:route_stanza(pres);
                end
        end
end

function room_mt:get_disco_info(stanza)
        local node = stanza.tags[1].attr.node or "";
        local reply = st.reply(stanza):tag("query", { xmlns = "http://jabber.org/protocol/disco#info", node = node });
        local event_name = "muc-disco#info";
        local event_data = { room = self, reply = reply, stanza = stanza };

        if node ~= "" then
                event_name = event_name.."/"..node;
        else
                event_data.form = dataform.new {
                        { name = "FORM_TYPE", type = "hidden", value = "http://jabber.org/protocol/muc#roominfo" };
                };
                event_data.formdata = {};
        end
        module:fire_event(event_name, event_data);
        if event_data.form then
                reply:add_child(event_data.form:form(event_data.formdata, "result"));
        end
        return reply;
end
module:hook("muc-disco#info", function(event)
        event.reply:tag("feature", {var = "http://jabber.org/protocol/muc"}):up();
        event.reply:tag("feature", {var = "http://jabber.org/protocol/muc#stable_id"}):up();
        event.reply:tag("feature", {var = "http://jabber.org/protocol/muc#self-ping-optimization"}):up();
end);
module:hook("muc-disco#info", function(event)
        table.insert(event.form, { name = "muc#roominfo_occupants", label = "Number of occupants" });
        event.formdata["muc#roominfo_occupants"] = tostring(iterators.count(event.room:each_occupant()));
end);

function room_mt:get_disco_items(stanza) -- luacheck: ignore 212
        return st.reply(stanza):query("http://jabber.org/protocol/disco#items");
end

function room_mt:handle_kickable(origin, stanza) -- luacheck: ignore 212
        local real_jid = stanza.attr.from;
        local occupant = self:get_occupant_by_real_jid(real_jid);
        if occupant == nil then return nil; end
        local type, condition, text = stanza:get_error();
        local error_message = "Kicked: "..(condition and condition:gsub("%-", " ") or "presence error");
        if text and self:get_whois() == "anyone" then
                error_message = error_message..": "..text;
        end
        occupant:set_session(real_jid, st.presence({type="unavailable"})
                :tag('status'):text(error_message));
        local is_last_session = occupant.jid == real_jid;
        if is_last_session then
                occupant.role = nil;
        end
        local new_occupant = self:save_occupant(occupant);
        local x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user";});
        if is_last_session then
                x:tag("status", {code = "333"});
        end
        self:publicise_occupant_status(new_occupant or occupant, x);
        if is_last_session then
                module:fire_event("muc-occupant-left", {
                                room = self;
                                nick = occupant.nick;
                                occupant = occupant;
                        });
        end
        return true;
end

-- Give the room creator owner affiliation
module:hook("muc-room-pre-create", function(event)
        event.room:set_affiliation(true, jid_bare(event.stanza.attr.from), "owner");
end, -1);

-- check if user is banned
module:hook("muc-occupant-pre-join", function(event)
        local room, stanza = event.room, event.stanza;
        local affiliation = room:get_affiliation(stanza.attr.from);
        if affiliation == "outcast" then
                local reply = st.error_reply(stanza, "auth", "forbidden"):up();
                reply.tags[1].attr.code = "403";
                event.origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
                return true;
        end
end, -10);

module:hook("muc-occupant-pre-join", function(event)
        local nick = jid_resource(event.occupant.nick);
        if not nick:find("%S") then
                event.origin.send(st.error_reply(event.stanza, "modify", "not-allowed", "Invisible Nicknames are forbidden"));
                return true;
        end
end, 1);

module:hook("muc-occupant-pre-change", function(event)
        if not jid_resource(event.dest_occupant.nick):find("%S") then
                event.origin.send(st.error_reply(event.stanza, "modify", "not-allowed", "Invisible Nicknames are forbidden"));
                return true;
        end
end, 1);

function room_mt:handle_first_presence(origin, stanza)
        local real_jid = stanza.attr.from;
        local dest_jid = stanza.attr.to;
        local bare_jid = jid_bare(real_jid);
        if module:fire_event("muc-room-pre-create", {
                        room = self;
                        origin = origin;
                        stanza = stanza;
                }) then return true; end
        local is_first_dest_session = true;
        local dest_occupant = self:new_occupant(bare_jid, dest_jid);

        local orig_nick = dest_occupant.nick;
        if module:fire_event("muc-occupant-pre-join", {
                room = self;
                origin = origin;
                stanza = stanza;
                is_first_session = is_first_dest_session;
                is_new_room = true;
                occupant = dest_occupant;
        }) then return true; end
        local nick_changed = orig_nick ~= dest_occupant.nick;

        dest_occupant:set_session(real_jid, stanza);
        local dest_x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user";});
        dest_x:tag("status", {code = "201"}):up();
        if self:get_whois() == "anyone" then
                dest_x:tag("status", {code = "100"}):up();
        end
        if nick_changed then
                dest_x:tag("status", {code = "210"}):up();
        end
        self:save_occupant(dest_occupant);

        self:publicise_occupant_status(dest_occupant, dest_x);

        module:fire_event("muc-occupant-joined", {
                room = self;
                nick = dest_occupant.nick;
                occupant = dest_occupant;
                stanza = stanza;
                origin = origin;
        });
        module:fire_event("muc-occupant-session-new", {
                room = self;
                nick = dest_occupant.nick;
                occupant = dest_occupant;
                stanza = stanza;
                origin = origin;
                jid = real_jid;
        });
        module:fire_event("muc-room-created", {
                room = self;
                creator = dest_occupant;
                stanza = stanza;
                origin = origin;
        });
        return true;
end

function room_mt:handle_normal_presence(origin, stanza)
        local type = stanza.attr.type;
        local real_jid = stanza.attr.from;
        local bare_jid = jid_bare(real_jid);
        local orig_occupant = self:get_occupant_by_real_jid(real_jid);
        local muc_x = stanza:get_child("x", "http://jabber.org/protocol/muc");

        if orig_occupant == nil and not muc_x and stanza.attr.type == nil then
                module:log("debug", "Attempted join without <x>, possibly desynced");
                origin.send(st.error_reply(stanza, "cancel", "item-not-found",
                        "You are not currently connected to this chat"));
                return true;
        end

        local is_first_dest_session;
        local dest_occupant;
        if type == "unavailable" then
                if orig_occupant == nil then return true; end -- Unavailable from someone not in the room
                -- dest_occupant = nil
        elseif orig_occupant and orig_occupant.nick == stanza.attr.to then -- Just a presence update
                log("debug", "presence update for %s from session %s", orig_occupant.nick, real_jid);
                dest_occupant = orig_occupant;
        else
                local dest_jid = stanza.attr.to;
                dest_occupant = self:get_occupant_by_nick(dest_jid);
                if dest_occupant == nil then
                        log("debug", "no occupant found for %s; creating new occupant object for %s", dest_jid, real_jid);
                        is_first_dest_session = true;
                        dest_occupant = self:new_occupant(bare_jid, dest_jid);
                else
                        is_first_dest_session = false;
                end
        end
        local is_last_orig_session;
        if orig_occupant ~= nil then
                -- Is there are least 2 sessions?
                local iter, ob, last = orig_occupant:each_session();
                is_last_orig_session = iter(ob, iter(ob, last)) == nil;
        end

        local orig_nick = dest_occupant and dest_occupant.nick;

        local event, event_name = {
                room = self;
                origin = origin;
                stanza = stanza;
                is_first_session = is_first_dest_session;
                is_last_session = is_last_orig_session;
        };
        if orig_occupant == nil then
                event_name = "muc-occupant-pre-join";
                event.occupant = dest_occupant;
        elseif dest_occupant == nil then
                event_name = "muc-occupant-pre-leave";
                event.occupant = orig_occupant;
        else
                event_name = "muc-occupant-pre-change";
                event.orig_occupant = orig_occupant;
                event.dest_occupant = dest_occupant;
        end
        if module:fire_event(event_name, event) then return true; end

        local nick_changed = dest_occupant and orig_nick ~= dest_occupant.nick;

        -- Check for nick conflicts
        if dest_occupant ~= nil and not is_first_dest_session
                and bare_jid ~= jid_bare(dest_occupant.bare_jid) then
                -- new nick or has different bare real jid
                log("debug", "%s couldn't join due to nick conflict: %s", real_jid, dest_occupant.nick);
                local reply = st.error_reply(stanza, "cancel", "conflict"):up();
                reply.tags[1].attr.code = "409";
                origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
                return true;
        end

        -- Send presence stanza about original occupant
        if orig_occupant ~= nil and orig_occupant ~= dest_occupant then
                local orig_x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user";});
                local dest_nick;
                if dest_occupant == nil then -- Session is leaving
                        log("debug", "session %s is leaving occupant %s", real_jid, orig_occupant.nick);
                        if is_last_orig_session then
                                orig_occupant.role = nil;
                        end
                        orig_occupant:set_session(real_jid, stanza);
                else
                        log("debug", "session %s is changing from occupant %s to %s", real_jid, orig_occupant.nick, dest_occupant.nick);
                        local generated_unavail = st.presence {from = orig_occupant.nick, to = real_jid, type = "unavailable"};
                        orig_occupant:set_session(real_jid, generated_unavail);
                        dest_nick = jid_resource(dest_occupant.nick);
                        if not is_first_dest_session then -- User is swapping into another pre-existing session
                                log("debug", "session %s is swapping into multisession %s, showing it leave.", real_jid, dest_occupant.nick);
                                -- Show the other session leaving
                                local x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user";});
                                add_item(x, self:get_affiliation(bare_jid), "none");
                                local pr = st.presence{from = dest_occupant.nick, to = real_jid, type = "unavailable"}
                                        :tag("status"):text("you are joining pre-existing session " .. dest_nick):up()
                                        :add_child(x);
                                self:route_stanza(pr);
                        end
                        if is_first_dest_session and is_last_orig_session then -- Normal nick change
                                log("debug", "no sessions in %s left; publicly marking as nick change", orig_occupant.nick);
                                orig_x:tag("status", {code = "303";}):up();
                        else -- The session itself always needs to see a nick change
                                -- don't want to get our old nick's available presence,
                                -- so remove our session from there, and manually generate an unavailable
                                orig_occupant:remove_session(real_jid);
                                log("debug", "generating nick change for %s", real_jid);
                                local x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user";});
                                -- COMPAT: clients get confused if they see other items besides their own
                                -- self:build_item_list(orig_occupant, x, false, dest_nick);
                                add_item(x, self:get_affiliation(bare_jid), orig_occupant.role, real_jid, dest_nick);
                                x:tag("status", {code = "303";}):up();
                                x:tag("status", {code = "110";}):up();
                                self:route_stanza(generated_unavail:add_child(x));
                                dest_nick = nil; -- set dest_nick to nil; so general populace doesn't see it for whole orig_occupant
                        end
                end

                self:save_occupant(orig_occupant);
                self:publicise_occupant_status(orig_occupant, orig_x, dest_nick);

                if is_last_orig_session then
                        module:fire_event("muc-occupant-left", {
                                room = self;
                                nick = orig_occupant.nick;
                                occupant = orig_occupant;
                                origin = origin;
                                stanza = stanza;
                        });
                end
        end

        if dest_occupant ~= nil then
                dest_occupant:set_session(real_jid, stanza);
                self:save_occupant(dest_occupant);

                if orig_occupant == nil or muc_x then
                        -- Send occupant list to newly joined or desynced user
                        self:send_occupant_list(real_jid, function(nick, occupant) -- luacheck: ignore 212
                                -- Don't include self
                                return occupant:get_presence(real_jid) == nil;
                        end)
                end
                local dest_x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user";});
                local self_x = st.clone(dest_x);
                if orig_occupant == nil and self:get_whois() == "anyone" then
                        self_x:tag("status", {code = "100"}):up();
                end
                if nick_changed then
                        self_x:tag("status", {code="210"}):up();
                end
                self:publicise_occupant_status(dest_occupant, {base=dest_x,self=self_x});

                if orig_occupant ~= nil and orig_occupant ~= dest_occupant and not is_last_orig_session then
                        -- If user is swapping and wasn't last original session
                        log("debug", "session %s split nicks; showing %s rejoining", real_jid, orig_occupant.nick);
                        -- Show the original nick joining again
                        local pr = st.clone(orig_occupant:get_presence());
                        pr.attr.to = real_jid;
                        local x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user";});
                        self:build_item_list(orig_occupant, x, false);
                        -- TODO: new status code to inform client this was the multi-session it left?
                        pr:add_child(x);
                        self:route_stanza(pr);
                end

                if orig_occupant == nil or muc_x then
                        if is_first_dest_session then
                                module:fire_event("muc-occupant-joined", {
                                        room = self;
                                        nick = dest_occupant.nick;
                                        occupant = dest_occupant;
                                        stanza = stanza;
                                        origin = origin;
                                });
                        end
                        module:fire_event("muc-occupant-session-new", {
                                room = self;
                                nick = dest_occupant.nick;
                                occupant = dest_occupant;
                                stanza = stanza;
                                origin = origin;
                                jid = real_jid;
                        });
                end
        end
        return true;
end

function room_mt:handle_presence_to_occupant(origin, stanza)
        local type = stanza.attr.type;
        if type == "error" then -- error, kick em out!
                return self:handle_kickable(origin, stanza)
        elseif type == nil or type == "unavailable" then
                return self:handle_normal_presence(origin, stanza);
        elseif type ~= 'result' then -- bad type
                if type ~= 'visible' and type ~= 'invisible' then -- COMPAT ejabberd can broadcast or forward XEP-0018 presences
                        origin.send(st.error_reply(stanza, "modify", "bad-request")); -- FIXME correct error?
                end
        end
        return true;
end

function room_mt:handle_iq_to_occupant(origin, stanza)
        local from, to = stanza.attr.from, stanza.attr.to;
        local type = stanza.attr.type;
        local id = stanza.attr.id;
        local occupant = self:get_occupant_by_nick(to);
        if (type == "error" or type == "result") then
                do -- deconstruct_stanza_id
                        if not occupant then return nil; end
                        local from_jid, orig_id, to_jid_hash = (base64.decode(id) or ""):match("^(%Z+)%z(%Z*)%z(.+)$");
                        if not(from == from_jid or from == jid_bare(from_jid)) then return nil; end
                        local from_occupant_jid = self:get_occupant_jid(from_jid);
                        if from_occupant_jid == nil then return nil; end
                        local session_jid
                        for to_jid in occupant:each_session() do
                                if md5(to_jid) == to_jid_hash then
                                        session_jid = to_jid;
                                        break;
                                end
                        end
                        if session_jid == nil then return nil; end
                        stanza.attr.from, stanza.attr.to, stanza.attr.id = from_occupant_jid, session_jid, orig_id;
                end
                log("debug", "%s sent private iq stanza to %s (%s)", from, to, stanza.attr.to);
                self:route_stanza(stanza);
                stanza.attr.from, stanza.attr.to, stanza.attr.id = from, to, id;
                return true;
        else -- Type is "get" or "set"
                local current_nick = self:get_occupant_jid(from);
                if not current_nick then
                        origin.send(st.error_reply(stanza, "cancel", "not-acceptable", "You are not currently connected to this chat"));
                        return true;
                end
                if not occupant then -- recipient not in room
                        origin.send(st.error_reply(stanza, "cancel", "item-not-found", "Recipient not in room"));
                        return true;
                end
                -- XEP-0410 MUC Self-Ping #1220
                if to == current_nick and stanza.attr.type == "get" and stanza:get_child("ping", "urn:xmpp:ping") then
                        self:route_stanza(st.reply(stanza));
                        return true;
                end
                do -- construct_stanza_id
                        stanza.attr.id = base64.encode(occupant.jid.."\0"..stanza.attr.id.."\0"..md5(from));
                end
                stanza.attr.from, stanza.attr.to = current_nick, occupant.jid;
                log("debug", "%s sent private iq stanza to %s (%s)", from, to, occupant.jid);
                local iq_ns = stanza.tags[1].attr.xmlns;
                if iq_ns == 'vcard-temp' or iq_ns == "http://jabber.org/protocol/pubsub" or iq_ns == "urn:ietf:params:xml:ns:vcard-4.0" then
                        stanza.attr.to = jid_bare(stanza.attr.to);
                end
                self:route_stanza(stanza);
                stanza.attr.from, stanza.attr.to, stanza.attr.id = from, to, id;
                return true;
        end
end

function room_mt:handle_message_to_occupant(origin, stanza)
        local from, to = stanza.attr.from, stanza.attr.to;
        local current_nick = self:get_occupant_jid(from);
        local type = stanza.attr.type;
        if not current_nick then -- not in room
                if type ~= "error" then
                        origin.send(st.error_reply(stanza, "cancel", "not-acceptable", "You are not currently connected to this chat"));
                end
                return true;
        end
        if type == "groupchat" then -- groupchat messages not allowed in PM
                origin.send(st.error_reply(stanza, "modify", "bad-request"));
                return true;
        elseif type == "error" and is_kickable_error(stanza) then
                log("debug", "%s kicked from %s for sending an error message", current_nick, self.jid);
                return self:handle_kickable(origin, stanza); -- send unavailable
        end

        local o_data = self:get_occupant_by_nick(to);
        if not o_data then
                origin.send(st.error_reply(stanza, "cancel", "item-not-found", "Recipient not in room"));
                return true;
        end
        log("debug", "%s sent private message stanza to %s (%s)", from, to, o_data.jid);
        stanza:tag("x", { xmlns = "http://jabber.org/protocol/muc#user" }):up();
        stanza.attr.from = current_nick;
        self:route_to_occupant(o_data, stanza)
        -- TODO: Remove x tag?
        stanza.attr.from = from;
        return true;
end

function room_mt:send_form(origin, stanza)
        origin.send(st.reply(stanza):query("http://jabber.org/protocol/muc#owner")
                :add_child(self:get_form_layout(stanza.attr.from):form())
        );
end

function room_mt:get_form_layout(actor)
        local form = dataform.new({
                title = "Configuration for "..self.jid,
                instructions = "Complete and submit this form to configure the room.",
                {
                        name = 'FORM_TYPE',
                        type = 'hidden',
                        value = 'http://jabber.org/protocol/muc#roomconfig'
                }
        });
        return module:fire_event("muc-config-form", { room = self, actor = actor, form = form }) or form;
end

function room_mt:process_form(origin, stanza)
        local form = stanza.tags[1]:get_child("x", "jabber:x:data");
        if form.attr.type == "cancel" then
                origin.send(st.reply(stanza));
        elseif form.attr.type == "submit" then
                local fields, errors, present;
                if form.tags[1] == nil then -- Instant room
                        fields, present = {}, {};
                else
                        fields, errors, present = self:get_form_layout(stanza.attr.from):data(form);
                        if fields.FORM_TYPE ~= "http://jabber.org/protocol/muc#roomconfig" then
                                origin.send(st.error_reply(stanza, "cancel", "bad-request", "Form is not of type room configuration"));
                                return true;
                        end
                end

                local event = {
                        room = self;
                        origin = origin;
                        stanza = stanza;
                        fields = fields;
                        status_codes = {};
                        actor = stanza.attr.from;
                };
                function event.update_option(name, field, allowed)
                        local new = fields[field];
                        if new == nil then return; end
                        if allowed and not allowed[new] then return; end
                        if new == self["get_"..name](self) then return; end
                        event.status_codes["104"] = true;
                        self["set_"..name](self, new);
                        return true;
                end
                module:fire_event("muc-config-submitted", event);
                for submitted_field in pairs(present) do
                        event.field, event.value = submitted_field, fields[submitted_field];
                        module:fire_event("muc-config-submitted/"..submitted_field, event);
                end
                event.field, event.value = nil, nil;

                self:save(true);
                origin.send(st.reply(stanza));

                if next(event.status_codes) then
                        local msg = st.message({type='groupchat', from=self.jid})
                                :tag('x', {xmlns='http://jabber.org/protocol/muc#user'})
                        for code in pairs(event.status_codes) do
                                msg:tag("status", {code = code;}):up();
                        end
                        msg:up();
                        self:broadcast_message(msg);
                end
        else
                origin.send(st.error_reply(stanza, "cancel", "bad-request", "Not a submitted form"));
        end
        return true;
end

-- Removes everyone from the room
function room_mt:clear(x)
        x = x or st.stanza("x", {xmlns='http://jabber.org/protocol/muc#user'});
        local occupants_updated = {};
        for nick, occupant in self:each_occupant() do -- luacheck: ignore 213
                occupant.role = nil;
                self:save_occupant(occupant);
                occupants_updated[occupant] = true;
        end
        for occupant in pairs(occupants_updated) do
                self:publicise_occupant_status(occupant, x);
                module:fire_event("muc-occupant-left", {
                                room = self;
                                nick = occupant.nick;
                                occupant = occupant;
                        });
        end
end

function room_mt:destroy(newjid, reason, password)
        local x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user"})
                :tag("destroy", {jid=newjid});
        if reason then x:tag("reason"):text(reason):up(); end
        if password then x:tag("password"):text(password):up(); end
        x:up();
        self.destroying = reason or true;
        self:clear(x);
        module:fire_event("muc-room-destroyed", { room = self, reason = reason, newjid = newjid, password = password });
        return true;
end

function room_mt:handle_disco_info_get_query(origin, stanza)
        origin.send(self:get_disco_info(stanza));
        return true;
end

function room_mt:handle_disco_items_get_query(origin, stanza)
        origin.send(self:get_disco_items(stanza));
        return true;
end

function room_mt:handle_admin_query_set_command(origin, stanza)
        local item = stanza.tags[1].tags[1];
        if not item then
                origin.send(st.error_reply(stanza, "cancel", "bad-request"));
                return true;
        end
        if item.attr.jid then -- Validate provided JID
                item.attr.jid = jid_prep(item.attr.jid);
                if not item.attr.jid then
                        origin.send(st.error_reply(stanza, "modify", "jid-malformed"));
                        return true;
                end
        end
        if item.attr.nick then -- Validate provided nick
                item.attr.nick = resourceprep(item.attr.nick);
                if not item.attr.nick then
                        origin.send(st.error_reply(stanza, "modify", "jid-malformed", "invalid nickname"));
                        return true;
                end
        end
        if not item.attr.jid and item.attr.nick then
                -- COMPAT Workaround for Miranda sending 'nick' instead of 'jid' when changing affiliation
                local occupant = self:get_occupant_by_nick(self.jid.."/"..item.attr.nick);
                if occupant then item.attr.jid = occupant.bare_jid; end
        elseif item.attr.role and not item.attr.nick and item.attr.jid then
                -- Role changes should use nick, but we have a JID so pull the nick from that
                local nick = self:get_occupant_jid(item.attr.jid);
                if nick then item.attr.nick = jid_resource(nick); end
        end
        local actor = stanza.attr.from;
        local reason = item:get_child_text("reason");
        local success, errtype, err
        if item.attr.affiliation and item.attr.jid and not item.attr.role then
                local registration_data;
                if item.attr.nick then
                        local room_nick = self.jid.."/"..item.attr.nick;
                        local existing_occupant = self:get_occupant_by_nick(room_nick);
                        if existing_occupant and existing_occupant.bare_jid ~= item.attr.jid then
                                module:log("debug", "Existing occupant for %s: %s does not match %s", room_nick, existing_occupant.bare_jid, item.attr.jid);
                                self:set_role(true, room_nick, nil, "This nickname is reserved");
                        end
                        module:log("debug", "Reserving %s for %s (%s)", item.attr.nick, item.attr.jid, item.attr.affiliation);
                        registration_data = { reserved_nickname = item.attr.nick };
                end
                success, errtype, err = self:set_affiliation(actor, item.attr.jid, item.attr.affiliation, reason, registration_data);
        elseif item.attr.role and item.attr.nick and not item.attr.affiliation then
                success, errtype, err = self:set_role(actor, self.jid.."/"..item.attr.nick, item.attr.role, reason);
        else
                success, errtype, err = nil, "cancel", "bad-request";
        end
        self:save(true);
        if not success then
                origin.send(st.error_reply(stanza, errtype, err));
        else
                origin.send(st.reply(stanza));
        end
        return true;
end

function room_mt:handle_admin_query_get_command(origin, stanza)
        local actor = stanza.attr.from;
        local affiliation = self:get_affiliation(actor);
        local item = stanza.tags[1].tags[1];
        local _aff = item.attr.affiliation;
        local _aff_rank = valid_affiliations[_aff or "none"];
        local _rol = item.attr.role;
        if _aff and _aff_rank and not _rol then
                -- You need to be at least an admin, and be requesting info about your affiliation or lower
                -- e.g. an admin can't ask for a list of owners
                local affiliation_rank = valid_affiliations[affiliation or "none"];
                if (affiliation_rank >= valid_affiliations.admin and affiliation_rank >= _aff_rank)
                or (self:get_whois() == "anyone") then
                        local reply = st.reply(stanza):query("http://jabber.org/protocol/muc#admin");
                        for jid in self:each_affiliation(_aff or "none") do
                                local nick = self:get_registered_nick(jid);
                                reply:tag("item", {affiliation = _aff, jid = jid, nick = nick }):up();
                        end
                        origin.send(reply:up());
                        return true;
                else
                        origin.send(st.error_reply(stanza, "auth", "forbidden"));
                        return true;
                end
        elseif _rol and valid_roles[_rol or "none"] and not _aff then
                local role = self:get_role(self:get_occupant_jid(actor)) or self:get_default_role(affiliation);
                if valid_roles[role or "none"] >= valid_roles.moderator then
                        if _rol == "none" then _rol = nil; end
                        local reply = st.reply(stanza):query("http://jabber.org/protocol/muc#admin");
                        -- TODO: whois check here? (though fully anonymous rooms are not supported)
                        for occupant_jid, occupant in self:each_occupant() do
                                if occupant.role == _rol then
                                        local nick = jid_resource(occupant_jid);
                                        self:build_item_list(occupant, reply, false, nick);
                                end
                        end
                        origin.send(reply:up());
                        return true;
                else
                        origin.send(st.error_reply(stanza, "auth", "forbidden"));
                        return true;
                end
        else
                origin.send(st.error_reply(stanza, "cancel", "bad-request"));
                return true;
        end
end

function room_mt:handle_owner_query_get_to_room(origin, stanza)
        if self:get_affiliation(stanza.attr.from) ~= "owner" then
                origin.send(st.error_reply(stanza, "auth", "forbidden", "Only owners can configure rooms"));
                return true;
        end

        self:send_form(origin, stanza);
        return true;
end
function room_mt:handle_owner_query_set_to_room(origin, stanza)
        if self:get_affiliation(stanza.attr.from) ~= "owner" then
                origin.send(st.error_reply(stanza, "auth", "forbidden", "Only owners can configure rooms"));
                return true;
        end

        local child = stanza.tags[1].tags[1];
        if not child then
                origin.send(st.error_reply(stanza, "modify", "bad-request"));
                return true;
        elseif child.name == "destroy" then
                local newjid = child.attr.jid;
                local reason = child:get_child_text("reason");
                local password = child:get_child_text("password");
                self:destroy(newjid, reason, password);
                origin.send(st.reply(stanza));
                return true;
        elseif child.name == "x" and child.attr.xmlns == "jabber:x:data" then
                return self:process_form(origin, stanza);
        else
                origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));
                return true;
        end
end

function room_mt:handle_groupchat_to_room(origin, stanza)
        local from = stanza.attr.from;
        local occupant = self:get_occupant_by_real_jid(from);
        if not stanza.attr.id then
                stanza.attr.id = new_id()
        end
        if module:fire_event("muc-occupant-groupchat", {
                room = self; origin = origin; stanza = stanza; from = from; occupant = occupant;
        }) then return true; end
        stanza.attr.from = occupant.nick;
        self:broadcast_message(stanza);
        stanza.attr.from = from;
        return true;
end

-- Role check
module:hook("muc-occupant-groupchat", function(event)
        local role_rank = valid_roles[event.occupant and event.occupant.role or "none"];
        if role_rank <= valid_roles.none then
                event.origin.send(st.error_reply(event.stanza, "cancel", "not-acceptable", "You are not currently connected to this chat"));
                return true;
        elseif role_rank <= valid_roles.visitor then
                event.origin.send(st.error_reply(event.stanza, "auth", "forbidden"));
                return true;
        end
end, 50);

-- hack - some buggy clients send presence updates to the room rather than their nick
function room_mt:handle_presence_to_room(origin, stanza)
        local current_nick = self:get_occupant_jid(stanza.attr.from);
        local handled
        if current_nick then
                local to = stanza.attr.to;
                stanza.attr.to = current_nick;
                handled = self:handle_presence_to_occupant(origin, stanza);
                stanza.attr.to = to;
        end
        return handled;
end

-- Need visitor role or higher to invite
module:hook("muc-pre-invite", function(event)
        local room, stanza = event.room, event.stanza;
        local _from = stanza.attr.from;
        local inviter = room:get_occupant_by_real_jid(_from);
        local role = inviter and inviter.role or room:get_default_role(room:get_affiliation(_from));
        if valid_roles[role or "none"] <= valid_roles.visitor then
                event.origin.send(st.error_reply(stanza, "auth", "forbidden"));
                return true;
        end
end);

function room_mt:handle_mediated_invite(origin, stanza)
        local payload = stanza:get_child("x", "http://jabber.org/protocol/muc#user"):get_child("invite");
        local invitee = jid_prep(payload.attr.to);
        if not invitee then
                origin.send(st.error_reply(stanza, "cancel", "jid-malformed"));
                return true;
        elseif module:fire_event("muc-pre-invite", {room = self, origin = origin, stanza = stanza}) then
                return true;
        end
        local invite = muc_util.filter_muc_x(st.clone(stanza));
        invite.attr.from = self.jid;
        invite.attr.to = invitee;
        invite:tag('x', {xmlns='http://jabber.org/protocol/muc#user'})
                        :tag('invite', {from = stanza.attr.from;})
                                :tag('reason'):text(payload:get_child_text("reason")):up()
                        :up()
                :up();
        if not module:fire_event("muc-invite", {room = self, stanza = invite, origin = origin, incoming = stanza}) then
                self:route_stanza(invite);
        end
        return true;
end

-- COMPAT: Some older clients expect this
module:hook("muc-invite", function(event)
        local room, stanza = event.room, event.stanza;
        local invite = stanza:get_child("x", "http://jabber.org/protocol/muc#user"):get_child("invite");
        local reason = invite:get_child_text("reason");
        stanza:tag('x', {xmlns = "jabber:x:conference"; jid = room.jid;})
                :text(reason or "")
        :up();
end);

-- Add a plain message for clients which don't support invites
module:hook("muc-invite", function(event)
        local room, stanza = event.room, event.stanza;
        if not stanza:get_child("body") then
                local invite = stanza:get_child("x", "http://jabber.org/protocol/muc#user"):get_child("invite");
                local reason = invite:get_child_text("reason") or "";
                stanza:tag("body")
                        :text(invite.attr.from.." invited you to the room "..room.jid..(reason ~= "" and (" ("..reason..")") or ""))
                :up();
        end
end);

function room_mt:handle_mediated_decline(origin, stanza)
        local payload = stanza:get_child("x", "http://jabber.org/protocol/muc#user"):get_child("decline");
        local declinee = jid_prep(payload.attr.to);
        if not declinee then
                origin.send(st.error_reply(stanza, "cancel", "jid-malformed"));
                return true;
        elseif module:fire_event("muc-pre-decline", {room = self, origin = origin, stanza = stanza}) then
                return true;
        end
        local decline = muc_util.filter_muc_x(st.clone(stanza));
        decline.attr.from = self.jid;
        decline.attr.to = declinee;
        decline:tag("x", {xmlns = "http://jabber.org/protocol/muc#user"})
                        :tag("decline", {from = stanza.attr.from})
                                :tag("reason"):text(payload:get_child_text("reason")):up()
                        :up()
                :up();
        if not module:fire_event("muc-decline", {room = self, stanza = decline, origin = origin, incoming = stanza}) then
                declinee = decline.attr.to; -- re-fetch, in case event modified it
                local occupant
                if jid_bare(declinee) == self.jid then -- declinee jid is already an in-room jid
                        occupant = self:get_occupant_by_nick(declinee);
                end
                if occupant then
                        self:route_to_occupant(occupant, decline);
                else
                        self:route_stanza(decline);
                end
        end
        return true;
end

-- Add a plain message for clients which don't support declines
module:hook("muc-decline", function(event)
        local room, stanza = event.room, event.stanza;
        if not stanza:get_child("body") then
                local decline = stanza:get_child("x", "http://jabber.org/protocol/muc#user"):get_child("decline");
                local reason = decline:get_child_text("reason") or "";
                stanza:body(decline.attr.from.." declined your invite to the room "
                        ..room.jid..(reason ~= "" and (" ("..reason..")") or ""));
        end
end);

function room_mt:handle_message_to_room(origin, stanza)
        local type = stanza.attr.type;
        if type == "groupchat" then
                return self:handle_groupchat_to_room(origin, stanza)
        elseif type == "error" and is_kickable_error(stanza) then
                return self:handle_kickable(origin, stanza)
        elseif type == nil or type == "normal" then
                local x = stanza:get_child("x", "http://jabber.org/protocol/muc#user");
                if x then
                        local payload = x.tags[1];
                        if payload == nil then --luacheck: ignore 542
                                -- fallthrough
                        elseif payload.name == "invite" and payload.attr.to then
                                return self:handle_mediated_invite(origin, stanza)
                        elseif payload.name == "decline" and payload.attr.to then
                                return self:handle_mediated_decline(origin, stanza)
                        end
                        origin.send(st.error_reply(stanza, "cancel", "bad-request"));
                        return true;
                end

                local form = stanza:get_child("x", "jabber:x:data");
                local form_type = dataform.get_type(form);
                if form_type == "http://jabber.org/protocol/muc#request" then
                        self:handle_role_request(origin, stanza, form);
                        return true;
                end
        end
end

function room_mt:route_stanza(stanza) -- luacheck: ignore 212
        module:send(stanza);
end

function room_mt:get_affiliation(jid)
        local node, host, resource = jid_split(jid);
        -- Affiliations are granted, revoked, and maintained based on the user's bare JID.
        local bare = node and node.."@"..host or host;
        local result = self._affiliations[bare];
        if not result and self._affiliations[host] == "outcast" then result = "outcast"; end -- host banned
        return result;
end

-- Iterates over jid, affiliation pairs
function room_mt:each_affiliation(with_affiliation)
        local _affiliations, _affiliation_data = self._affiliations, self._affiliation_data;
        return function(_, jid)
                local affiliation;
                repeat -- Iterate until we get a match
                        jid, affiliation = next(_affiliations, jid);
                until with_affiliation == nil or jid == nil or affiliation == with_affiliation
                return jid, affiliation, _affiliation_data[jid];
        end, nil, nil;
end

function room_mt:set_affiliation(actor, jid, affiliation, reason, data)
        if not actor then return nil, "modify", "not-acceptable"; end;

        local node, host, resource = jid_split(jid);
        if not host then return nil, "modify", "not-acceptable"; end
        jid = jid_join(node, host); -- Bare
        local is_host_only = node == nil;

        if valid_affiliations[affiliation or "none"] == nil then
                return nil, "modify", "not-acceptable";
        end
        affiliation = affiliation ~= "none" and affiliation or nil; -- coerces `affiliation == false` to `nil`

        local target_affiliation = self._affiliations[jid]; -- Raw; don't want to check against host
        local is_downgrade = valid_affiliations[target_affiliation or "none"] > valid_affiliations[affiliation or "none"];

        if actor == true then
                actor = nil -- So we can pass it safely to 'publicise_occupant_status' below
        else
                local actor_affiliation = self:get_affiliation(actor);
                if actor_affiliation == "owner" then
                        if jid_bare(actor) == jid and is_downgrade then -- self change
                                -- need at least one owner
                                local is_last = true;
                                for j in self:each_affiliation("owner") do
                                        if j ~= jid then is_last = false; break; end
                                end
                                if is_last then
                                        return nil, "cancel", "conflict";
                                end
                        end
                        -- owners can do anything else
                elseif affiliation == "owner" or affiliation == "admin"
                        or actor_affiliation ~= "admin"
                        or target_affiliation == "owner" or target_affiliation == "admin" then
                        -- Can't demote owners or other admins
                        return nil, "cancel", "not-allowed";
                end
        end

        -- Set in 'database'
        self._affiliations[jid] = affiliation;
        if not affiliation or data == false or (data ~= nil and next(data) == nil) then
                module:log("debug", "Clearing affiliation data for %s", jid);
                self._affiliation_data[jid] = nil;
        elseif data then
                module:log("debug", "Updating affiliation data for %s", jid);
                self._affiliation_data[jid] = data;
        end

        -- Update roles
        local role = self:get_default_role(affiliation);
        local role_rank = valid_roles[role or "none"];
        local occupants_updated = {}; -- Filled with old roles
        for nick, occupant in self:each_occupant() do -- luacheck: ignore 213
                if occupant.bare_jid == jid or (
                        -- Outcast can be by host.
                        is_host_only and affiliation == "outcast" and select(2, jid_split(occupant.bare_jid)) == host
                ) then
                        -- need to publicize in all cases; as affiliation in <item/> has changed.
                        occupants_updated[occupant] = occupant.role;
                        if occupant.role ~= role and (
                                is_downgrade or
                                valid_roles[occupant.role or "none"] < role_rank -- upgrade
                        ) then
                                occupant.role = role;
                                self:save_occupant(occupant);
                        end
                end
        end

        -- Tell the room of the new occupant affiliations+roles
        local x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user"});
        if not role then -- getting kicked
                if affiliation == "outcast" then
                        x:tag("status", {code="301"}):up(); -- banned
                else
                        x:tag("status", {code="321"}):up(); -- affiliation change
                end
        end
        local is_semi_anonymous = self:get_whois() == "moderators";

        if next(occupants_updated) ~= nil then
                for occupant, old_role in pairs(occupants_updated) do
                        self:publicise_occupant_status(occupant, x, nil, actor, reason);
                        if occupant.role == nil then
                                module:fire_event("muc-occupant-left", {
                                                room = self;
                                                nick = occupant.nick;
                                                occupant = occupant;
                                        });
                        elseif is_semi_anonymous and
                                (old_role == "moderator" and occupant.role ~= "moderator") or
                                (old_role ~= "moderator" and occupant.role == "moderator") then -- Has gained or lost moderator status
                                -- Send everyone else's presences (as jid visibility has changed)
                                for real_jid in occupant:each_session() do
                                        self:send_occupant_list(real_jid, function(occupant_jid, occupant) --luacheck: ignore 212 433
                                                return occupant.bare_jid ~= jid;
                                        end);
                                end
                        end
                end
        else
                -- Announce affiliation change for a user that is not currently in the room,
                -- XEP-0045 (v1.31.2) example 195
                -- add_item(x, affiliation, role, jid, nick, actor_nick, actor_jid, reason)
                local announce_msg = st.message({ from = self.jid })
                        :add_child(add_item(st.clone(x), affiliation, nil, jid, nil, nil, nil, reason));
                local min_role = is_semi_anonymous and "moderator" or "none";
                self:broadcast(announce_msg, muc_util.only_with_min_role(min_role));
        end

        self:save(true);

        module:fire_event("muc-set-affiliation", {
                room = self;
                actor = actor;
                jid = jid;
                affiliation = affiliation or "none";
                reason = reason;
                previous_affiliation = target_affiliation;
                data = data and data or nil; -- coerce false to nil
                in_room = next(occupants_updated) ~= nil;
        });

        return true;
end

function room_mt:get_affiliation_data(jid, key)
        local data = self._affiliation_data[jid];
        if not data then return nil; end
        if key then
                return data[key];
        end
        return data;
end

function room_mt:get_role(nick)
        local occupant = self:get_occupant_by_nick(nick);
        return occupant and occupant.role or nil;
end

function room_mt:may_set_role(actor, occupant, role)
        local event = {
                room = self,
                actor = actor,
                occupant = occupant,
                role = role,
        };

        module:fire_event("muc-pre-set-role", event);
        if event.allowed ~= nil then
                return event.allowed, event.error, event.condition;
        end

        -- Can't do anything to other owners or admins
        local occupant_affiliation = self:get_affiliation(occupant.bare_jid);
        if occupant_affiliation == "owner" or occupant_affiliation == "admin" then
                return nil, "cancel", "not-allowed";
        end

        -- If you are trying to give or take moderator role you need to be an owner or admin
        if occupant.role == "moderator" or role == "moderator" then
                local actor_affiliation = self:get_affiliation(actor);
                if actor_affiliation ~= "owner" and actor_affiliation ~= "admin" then
                        return nil, "cancel", "not-allowed";
                end
        end

        -- Need to be in the room and a moderator
        local actor_occupant = self:get_occupant_by_real_jid(actor);
        if not actor_occupant or actor_occupant.role ~= "moderator" then
                return nil, "cancel", "not-allowed";
        end

        return true;
end

function room_mt:set_role(actor, occupant_jid, role, reason)
        if not actor then return nil, "modify", "not-acceptable"; end

        local occupant = self:get_occupant_by_nick(occupant_jid);
        if not occupant then return nil, "modify", "item-not-found"; end

        if valid_roles[role or "none"] == nil then
                return nil, "modify", "not-acceptable";
        end
        role = role ~= "none" and role or nil; -- coerces `role == false` to `nil`

        if actor == true then
                actor = nil -- So we can pass it safely to 'publicise_occupant_status' below
        else
                local allowed, err, condition = self:may_set_role(actor, occupant, role)
                if not allowed then
                        return allowed, err, condition;
                end
        end

        local x = st.stanza("x", {xmlns = "http://jabber.org/protocol/muc#user"});
        if not role then
                x:tag("status", {code = "307"}):up();
        end
        occupant.role = role;
        self:save_occupant(occupant);
        self:publicise_occupant_status(occupant, x, nil, actor, reason);
        if role == nil then
                module:fire_event("muc-occupant-left", {
                                room = self;
                                nick = occupant.nick;
                                occupant = occupant;
                        });
        end
        return true;
end

local whois = module:require "muc/whois";
room_mt.get_whois = whois.get;
room_mt.set_whois = whois.set;

local _M = {}; -- module "muc"

function _M.new_room(jid, config)
        return setmetatable({
                jid = jid;
                _jid_nick = {};
                _occupants = {};
                _data = config or {};
                _affiliations = {};
                _affiliation_data = {};
        }, room_mt);
end

local new_format = module:get_option_boolean("new_muc_storage_format", false);

function room_mt:freeze(live)
        local frozen, state;
        if new_format then
                frozen = {
                        _jid = self.jid;
                        _data = self._data;
                };
                for user, affiliation in pairs(self._affiliations) do
                        frozen[user] = affiliation;
                end
        else
                frozen = {
                        jid = self.jid;
                        _data = self._data;
                        _affiliations = self._affiliations;
                        _affiliation_data = self._affiliation_data;
                };
        end
        if live then
                state = {};
                for nick, occupant in self:each_occupant() do
                        state[nick] = {
                                bare_jid = occupant.bare_jid;
                                role = occupant.role;
                                jid = occupant.jid;
                        }
                        for jid, presence in occupant:each_session() do
                                state[jid] = st.preserialize(presence);
                        end
                end
                local history = self._history;
                if history and history[1] ~= nil then
                        state._last_message = st.preserialize(history[#history].stanza);
                        state._last_message_at = history[#history].timestamp;
                end
        end
        return frozen, state;
end

function _M.restore_room(frozen, state)
        local room_jid = frozen._jid or frozen.jid;
        local room = _M.new_room(room_jid, frozen._data);

        if state and state._last_message and state._last_message_at then
                room._history = {
                        { stanza = st.deserialize(state._last_message),
                          timestamp = state._last_message_at, },
                };
        end

        local occupants = {};
        local room_name, room_host = jid_split(room_jid);

        room._affiliation_data = frozen._affiliation_data or {};

        if frozen.jid and frozen._affiliations then
                -- Old storage format
                room._affiliations = frozen._affiliations;
        else
                -- New storage format
                for jid, data in pairs(frozen) do
                        local node, host, resource = jid_split(jid);
                        if host:sub(1,1) ~= "_" and not resource and type(data) == "string" then
                                -- bare jid: affiliation
                                room._affiliations[jid] = data;
                        end
                end
        end
        for jid, data in pairs(state or frozen) do
                local node, host, resource = jid_split(jid);
                if node or host:sub(1,1) ~= "_" then
                        if host == room_host and node == room_name and resource and type(data) == "table" then
                                -- full room jid: bare real jid and role
                                local nick = jid;
                                local occupant = occupants[nick] or occupant_lib.new(data.bare_jid, nick);
                                occupant.bare_jid = data.bare_jid;
                                occupant.role = data.role;
                                occupant.jid = data.jid; -- Primary session JID
                                occupants[nick] = occupant;
                        elseif type(data) == "table" and data.name == "presence" then
                                -- full user jid: presence
                                local nick = data.attr.from;
                                local occupant = occupants[nick] or occupant_lib.new(nil, nick);
                                local presence = st.deserialize(data);
                                occupant:set_session(jid, presence);
                                occupants[nick] = occupant;
                        end
                end
        end

        for _, occupant in pairs(occupants) do
                room:save_occupant(occupant);
        end

        return room;
end

_M.room_mt = room_mt;

return _M;