view mod_muc_inject_mentions/mod_muc_inject_mentions.lua @ 5265:f845c218e52c

mod_http_oauth2: Allow revoking a token without OAuth client credentials If you have a valid token, and you're not supposed to have it, revoking it seems the most responsible thing to do with it, so it should be allowed, while if you are supposed to have it, you should also be allowed to revoke it.
author Kim Alvefur <zash@zash.se>
date Tue, 21 Mar 2023 22:02:38 +0100
parents 33a41503b9e3
children
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module:depends("muc");

local jid_resource = require "util.jid".resource;
local st = require "util.stanza";

local prefixes = module:get_option_set("muc_inject_mentions_prefixes", {})
local suffixes = module:get_option_set("muc_inject_mentions_suffixes", {})
local enabled_rooms = module:get_option("muc_inject_mentions_enabled_rooms", nil)
local disabled_rooms = module:get_option("muc_inject_mentions_disabled_rooms", nil)
local mention_delimiters = module:get_option_set("muc_inject_mentions_mention_delimiters",  {" ", "", "\n", "\t"})
local append_mentions = module:get_option("muc_inject_mentions_append_mentions", false)
local strip_out_prefixes = module:get_option("muc_inject_mentions_strip_out_prefixes", false)
local reserved_nicks = module:get_option("muc_inject_mentions_reserved_nicks", false)
local use_bare_jid = module:get_option("muc_inject_mentions_use_bare_jid", true)
local prefix_mandatory = module:get_option("muc_inject_mentions_prefix_mandatory", false)
local reserved_nicknames = {}

local reference_xmlns = "urn:xmpp:reference:0"

local function update_reserved_nicknames(event)
    local room, data, jid = event.room.jid, event.data, event.jid
    load_room_reserved_nicknames(event.room)
    local nickname = (data or {})["reserved_nickname"]

    if nickname then
        reserved_nicknames[room][nickname] = jid
    else
        local nickname_to_remove
        for _nickname, _jid in pairs(reserved_nicknames[room]) do
            if _jid == jid then
                nickname_to_remove = _nickname
                break
            end
        end
        if nickname_to_remove then
            reserved_nicknames[room][nickname_to_remove] = nil
        end
    end
end

function load_room_reserved_nicknames(room)
    if not reserved_nicknames[room.jid] then
        reserved_nicknames[room.jid] = {}
        for jid, data in pairs(room._affiliations_data or {}) do
            local reserved_nickname = data["reserved_nickname"]
            if reserved_nicknames then
                reserved_nicknames[room.jid][reserved_nickname] = jid
            end
        end
    end
end

local function get_jid(room, nickname)
    local bare_jid = reserved_nicknames[room.jid][nickname]
    if bare_jid and use_bare_jid then
        return bare_jid
    end

    if bare_jid and not use_bare_jid then
        return room.jid .. "/" .. nickname
    end
end

local function get_participants(room)
    if not reserved_nicks then
        local occupants = room._occupants
        local key, occupant = next(occupants)
        return function ()
            while occupant do -- luacheck: ignore
                local nick = jid_resource(occupant.nick);
                local bare_jid = occupant.bare_jid
                key, occupant = next(occupants, key)
                return bare_jid, nick
            end
        end
    else
        local generator = room:each_affiliation()
        local jid, _, affiliation_data = generator(nil, nil)
        return function ()
           while jid do
                local bare_jid, nick = jid, (affiliation_data or {})["reserved_nickname"]
                jid, _, affiliation_data = generator(nil, bare_jid)
                if nick then
                    return bare_jid, nick
                end
           end
        end
    end
end

local function add_mention(mentions, bare_jid, first, last, prefix_indices, has_prefix)
    if strip_out_prefixes then
        if has_prefix then
            table.insert(prefix_indices, first-1)
        end
        first = first - #prefix_indices
        last = last - #prefix_indices
    end
    mentions[first] = {bare_jid=bare_jid, first=first, last=last}
end

local function get_client_mentions(stanza)
    local has_mentions = false
    local client_mentions = {}

    for element in stanza:childtags("reference", reference_xmlns) do
        if element.attr.type == "mention" then
            local key = tonumber(element.attr.begin) + 1 -- count starts at 0
            client_mentions[key] = {bare_jid=element.attr.uri, first=element.attr.begin, last=element.attr["end"]}
            has_mentions = true
        end
    end

    return has_mentions, client_mentions
end

local function is_room_eligible(jid)
    if not enabled_rooms and not disabled_rooms then return true; end

    if enabled_rooms then
        for _, _jid in ipairs(enabled_rooms) do
            if _jid == jid then
                return true
            end
        end
        return false
    end

    if disabled_rooms then
        for _, _jid in ipairs(disabled_rooms) do
            if _jid == jid then
                return false
            end
        end
        return true
    end
end

local function has_nick_prefix(body, first)
    -- There are no configured prefixes
    if not prefixes or #prefixes < 1 then return false end

    -- Prefix must have a space before it,
    -- be the first character of the body
    -- or be the first character after a new line
    if not mention_delimiters:contains(body:sub(first - 2, first - 2)) then
        return false
    end

    local prefix = body:sub(first - 1, first - 1)
    for _, _prefix in ipairs(prefixes) do
        if prefix == _prefix then
            return true
        end
    end

    return false
end

local function has_nick_suffix(body, last)
    -- There are no configured suffixes
    if not suffixes or #suffixes < 1 then return false end

    -- Suffix must have a space after it,
    -- be the last character of the body
    -- or be the last character before a new line
    if not mention_delimiters:contains(body:sub(last + 2, last + 2)) then
        return false
    end

    local suffix = body:sub(last+1, last+1)
    for _, _suffix in ipairs(suffixes) do
        if suffix == _suffix then
            return true
        end
    end

    return false
end

local function search_mentions(room, body, client_mentions)
    load_room_reserved_nicknames(room)
    local mentions, prefix_indices = {}, {}
    local current_word = ""
    local current_word_start
    for i = 1, #body+1 do
        local char = body:sub(i,i)
        -- Mention delimiter found, current_word is completed now
        if mention_delimiters:contains(char) and current_word_start then
            -- Check for nickname without prefix
            local jid = get_jid(room, current_word)
            if jid then
                if not prefix_mandatory then
                    add_mention(mentions, jid, current_word_start, i - 1, prefix_indices, false)
                end
            else
                -- Check for nickname with affixes
                local prefix = prefixes:contains(current_word:sub(1,1))
                local suffix = suffixes:contains(current_word:sub(-1))
                if prefix and suffix then
                    jid = get_jid(room, current_word:sub(2, -2))
                    if jid then
                        add_mention(mentions, jid, current_word_start + 1, i - 2, prefix_indices, true)
                    end
                elseif prefix then
                    jid = get_jid(room, current_word:sub(2))
                    if jid then
                        add_mention(mentions, jid, current_word_start + 1, i - 1, prefix_indices, true)
                    end
                elseif suffix and not prefix_mandatory then
                    jid = get_jid(room, current_word:sub(1, -2))
                    if jid then
                        add_mention(mentions, jid, current_word_start, i - 2, prefix_indices, false)
                    end
                end
            end

            current_word = ""
            current_word_start = nil
        elseif not mention_delimiters:contains(char) then
            current_word_start = current_word_start or i
            current_word = current_word .. char
        end
    end

    return mentions, prefix_indices
end

local function muc_inject_mentions(event)
    local room, stanza = event.room, event.stanza;
    local body = stanza:get_child_text("body")

    if not body or #body < 1 then return; end

    -- Inject mentions only if the room is configured for them
    if not is_room_eligible(room.jid) then return; end

    -- Only act on messages that do not include mentions
    -- unless configuration states otherwise.
    local has_mentions, client_mentions = get_client_mentions(stanza)
    if has_mentions and not append_mentions then return; end

    local mentions, prefix_indices = search_mentions(room, body, client_mentions)
    for _, mention in pairs(mentions) do
        -- https://xmpp.org/extensions/xep-0372.html#usecase_mention
        stanza:tag(
            "reference", {
                xmlns=reference_xmlns,
                begin=tostring(mention.first - 1), -- count starts at 0
                ["end"]=tostring(mention.last),
                type="mention",
                uri="xmpp:" .. mention.bare_jid,
            }
        ):up()
    end

    if strip_out_prefixes then
        local body_without_prefixes = ""
        local from = 0
        if #prefix_indices > 0 then
            for _, prefix_index in ipairs(prefix_indices) do
                body_without_prefixes = body_without_prefixes .. body:sub(from, prefix_index-1)
                from = prefix_index + 1
            end
            body_without_prefixes = body_without_prefixes .. body:sub(from, #body)

            -- Replace original body containing prefixes
            stanza:maptags(
                function(tag)
                    if tag.name ~= "body" then
                        return tag
                    end
                    return st.stanza("body"):text(body_without_prefixes)
                end
            )
        end
    end
end

module:hook("muc-occupant-groupchat", muc_inject_mentions)
module:hook("muc-set-affiliation", update_reserved_nicknames)