local next = next;

local pairs = pairs;

local setmetatable = setmetatable;

local st = require "util.stanza";

local util = module:require "muc/util";

local function get_filtered_presence(stanza)

	return util.filter_muc_x(st.clone(stanza));

end

local occupant_mt = {};

occupant_mt.__index = occupant_mt;

local function new_occupant(bare_real_jid, nick)

	return setmetatable({

		bare_jid = bare_real_jid;

		nick = nick; -- in-room jid

		sessions = {}; -- hash from real_jid to presence stanzas. stanzas should not be modified

		role = nil;

		jid = nil; -- Primary session

	}, occupant_mt);

end

-- Deep copy an occupant

local function copy_occupant(occupant)

	local sessions = {};

	for full_jid, presence_stanza in pairs(occupant.sessions) do

		-- Don't keep unavailable presences, as they'll accumulate; unless they're the primary session

		if presence_stanza.attr.type ~= "unavailable" or full_jid == occupant.jid then

			sessions[full_jid] = presence_stanza;

		end

	end

	return setmetatable({

		bare_jid = occupant.bare_jid;

		nick = occupant.nick;

		sessions = sessions;

		role = occupant.role;

		jid = occupant.jid;

	}, occupant_mt);

end

-- finds another session to be the primary (there might not be one)

function occupant_mt:choose_new_primary()

	for jid, pr in self:each_session() do

		if pr.attr.type == nil then

			return jid;

		end

	end

	return nil;

end

function occupant_mt:set_session(real_jid, presence_stanza, replace_primary)

	local pr = get_filtered_presence(presence_stanza);

	pr.attr.from = self.nick;

	pr.attr.to = real_jid;

	self.sessions[real_jid] = pr;

	if replace_primary then

		self.jid = real_jid;

	elseif self.jid == nil or (pr.attr.type == "unavailable" and self.jid == real_jid) then

		-- Only leave an unavailable presence as primary when there are no other options

		self.jid = self:choose_new_primary() or real_jid;

	end

end

function occupant_mt:remove_session(real_jid)

	-- Delete original session

	self.sessions[real_jid] = nil;

	if self.jid == real_jid then

		self.jid = self:choose_new_primary();

	end

end

function occupant_mt:each_session()

	return pairs(self.sessions)

end

function occupant_mt:get_presence(real_jid)

	return self.sessions[real_jid or self.jid]

end

return {

	new = new_occupant;

	copy = copy_occupant;

	mt = occupant_mt;

}