module:set_global();

local jid_bare = require "util.jid".bare;

local jid_split = require "util.jid".split;

local stat, mkdir = require "lfs".attributes, require "lfs".mkdir;

-- Get a filesystem-safe string

local function fsencode_char(c)

	return ("%%%02x"):format(c:byte());

end

local function fsencode(s)

	return (s:gsub("[^%w._-@]", fsencode_char):gsub("^%.", "_"));

end

local log_base_path = module:get_option("message_logging_dir", prosody.paths.data.."/message_logs");

mkdir(log_base_path);

local function get_host_path(host)

	return log_base_path.."/"..fsencode(host);

end

local function get_user_path(jid)

	local username, host = jid_split(jid);

	local base = get_host_path(host)..os.date("/%Y-%m-%d");

	if not stat(base) then

		mkdir(base);

	end

	return base.."/"..fsencode(username)..".msglog";

end

local open_files_mt = { __index = function (open_files, jid)

	local f, err = io.open(get_user_path(jid), "a+");

	if not f then

		module:log("error", "Failed to open message log for writing [%s]: %s", jid, err);

	end

	rawset(open_files, jid, f);

	return f;

end };

-- [user@host] = filehandle

local open_files = setmetatable({}, open_files_mt);

function close_open_files()

	module:log("debug", "Closing all open files");

	for jid, filehandle in pairs(open_files) do

		filehandle:close();

		open_files[jid] = nil;

	end

end

module:hook_global("logging-reloaded", close_open_files);

local function write_to_log(log_jid, jid, prefix, body)

	if not body then return; end

	local f = open_files[log_jid];

	if not f then return; end

	body = body:gsub("\n", "\n    "); -- Indent newlines

	f:write(os.date("%H:%M:%S "), prefix or "", prefix and ": " or "", jid, ": ", body, "\n");

	f:flush();

end

local function handle_incoming_message(event)

	local origin, stanza = event.origin, event.stanza;

	local message_type = stanza.attr.type;

	if message_type == "error" then return; end

	local from, to = jid_bare(stanza.attr.from), jid_bare(stanza.attr.to or stanza.attr.from);

	if message_type == "groupchat" then

		from = from.." <"..(select(3, jid_split(stanza.attr.from)) or "")..">";

	end

	write_to_log(to, from, "RECV", stanza:get_child_text("body"));

end

local function handle_outgoing_message(event)

	local origin, stanza = event.origin, event.stanza;

	local message_type = stanza.attr.type;

	if message_type == "error" then return; end

	local from, to = jid_bare(stanza.attr.from), jid_bare(stanza.attr.to or origin.full_jid);

	write_to_log(from, to, "SEND", stanza:get_child_text("body"));

end

local function handle_muc_message(event)

	local stanza = event.stanza;

	if stanza.attr.type ~= "groupchat" then return; end

	local room = event.room or hosts[select(2, jid_split(stanza.attr.to))].modules.muc.rooms[stanza.attr.to];

	if not room then return; end

	local nick = select(3, jid_split(room._jid_nick[stanza.attr.from]));

	if not nick then return; end

	write_to_log(room.jid, jid_bare(stanza.attr.from).." <"..nick..">", "MESG", stanza:get_child_text("body"));

end

function module.add_host(module)

	local host_base_path = get_host_path(module.host);

	if not stat(host_base_path) then

		mkdir(host_base_path);

	end

	if hosts[module.host].modules.muc then

		module:hook("message/bare", handle_muc_message, 1);

	else

		module:hook("message/bare", handle_incoming_message, 1);

		module:hook("message/full", handle_incoming_message, 1);

		module:hook("pre-message/bare", handle_outgoing_message, 1);

		module:hook("pre-message/full", handle_outgoing_message, 1);

		module:hook("pre-message/host", handle_outgoing_message, 1);

	end

end

function module.command(arg)

	local command = table.remove(arg, 1);

	if command == "path" then

		print(get_user_path(arg[1]));

	else

		io.stderr:write("Unrecognised command: ", command);

		return 1;

	end

	return 0;

end

function module.save()

	return { open_files = open_files };

end

function module.restore(saved)

	open_files = setmetatable(saved.open_files or {}, open_files_mt);

end