util/stanza.lua

-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

-- 

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

local t_insert      =  table.insert;

local t_concat      =  table.concat;

local t_remove      =  table.remove;

local t_concat      =  table.concat;

local s_format      = string.format;

local s_match       =  string.match;

local tostring      =      tostring;

local setmetatable  =  setmetatable;

local getmetatable  =  getmetatable;

local pairs         =         pairs;

local ipairs        =        ipairs;

local type          =          type;

local next          =          next;

local print         =         print;

local unpack        =        unpack;

local s_gsub        =   string.gsub;

local s_char        =   string.char;

local s_find        =   string.find;

local os            =            os;

local do_pretty_printing = not os.getenv("WINDIR");

local getstyle, getstring;

if do_pretty_printing then

	local ok, termcolours = pcall(require, "util.termcolours");

	if ok then

		getstyle, getstring = termcolours.getstyle, termcolours.getstring;

	else

		do_pretty_printing = nil;

	end

end

local xmlns_stanzas = "urn:ietf:params:xml:ns:xmpp-stanzas";

module "stanza"

stanza_mt = { __type = "stanza" };

stanza_mt.__index = stanza_mt;

function stanza(name, attr)

	local stanza = { name = name, attr = attr or {}, tags = {} };

	return setmetatable(stanza, stanza_mt);

end

function stanza_mt:query(xmlns)

	return self:tag("query", { xmlns = xmlns });

end

function stanza_mt:body(text, attr)

	return self:tag("body", attr):text(text);

end

function stanza_mt:tag(name, attrs)

	local s = stanza(name, attrs);

	local last_add = self.last_add;

	if not last_add then last_add = {}; self.last_add = last_add; end

	(last_add[#last_add] or self):add_direct_child(s);

	t_insert(last_add, s);

	return self;

end

function stanza_mt:text(text)

	local last_add = self.last_add;

	(last_add and last_add[#last_add] or self):add_direct_child(text);

	return self;

end

function stanza_mt:up()

	local last_add = self.last_add;

	if last_add then t_remove(last_add); end

	return self;

end

function stanza_mt:reset()

	self.last_add = nil;

	return self;

end

function stanza_mt:add_direct_child(child)

	if type(child) == "table" then

		t_insert(self.tags, child);

	end

	t_insert(self, child);

end

function stanza_mt:add_child(child)

	local last_add = self.last_add;

	(last_add and last_add[#last_add] or self):add_direct_child(child);

	return self;

end

function stanza_mt:get_child(name, xmlns)

	for _, child in ipairs(self.tags) do

		if (not name or child.name == name)

			and ((not xmlns and self.attr.xmlns == child.attr.xmlns)

				or child.attr.xmlns == xmlns) then

			return child;

		end

	end

end

function stanza_mt:child_with_name(name)

	for _, child in ipairs(self.tags) do

		if child.name == name then return child; end

	end

end

function stanza_mt:child_with_ns(ns)

	for _, child in ipairs(self.tags) do

		if child.attr.xmlns == ns then return child; end

	end

end

function stanza_mt:children()

	local i = 0;

	return function (a)

			i = i + 1

			return a[i];

		end, self, i;

end

function stanza_mt:matching_tags(name, xmlns)

	xmlns = xmlns or self.attr.xmlns;

	local tags = self.tags;

	local start_i, max_i = 1, #tags;

	return function ()

			for i=start_i,max_i do

				v = tags[i];

				if (not name or v.name == name)

				and (not xmlns or xmlns == v.attr.xmlns) then

					start_i = i+1;

					return v;

				end

			end

		end, tags, i;

end

function stanza_mt:childtags()

	local i = 0;

	return function (a)

			i = i + 1

			local v = self.tags[i]

			if v then return v; end

		end, self.tags[1], i;

end

function stanza_mt:maptags(callback)

	local tags, curr_tag = self.tags, 1;

	local n_children, n_tags = #self, #tags;

	local i = 1;

	while curr_tag <= n_tags do

		if self[i] == tags[curr_tag] then

			local ret = callback(self[i]);

			if ret == nil then

				t_remove(self, i);

				t_remove(tags, curr_tag);

				n_children = n_children - 1;

				n_tags = n_tags - 1;

			else

				self[i] = ret;

				tags[i] = ret;

			end

			i = i + 1;

			curr_tag = curr_tag + 1;

		end

	end

	return self;

end

local xml_escape

do

	local escape_table = { ["'"] = "&apos;", ["\""] = "&quot;", ["<"] = "&lt;", [">"] = "&gt;", ["&"] = "&amp;" };

	function xml_escape(str) return (s_gsub(tostring(str), "['&<>\"]", escape_table)); end

	_M.xml_escape = xml_escape;

end

local function _dostring(t, buf, self, xml_escape, parentns)

	local nsid = 0;

	local name = t.name

	t_insert(buf, "<"..name);

	for k, v in pairs(t.attr) do

		if s_find(k, "\1", 1, true) then

			local ns, attrk = s_match(k, "^([^\1]*)\1?(.*)$");

			nsid = nsid + 1;

			t_insert(buf, " xmlns:ns"..nsid.."='"..xml_escape(ns).."' ".."ns"..nsid..":"..attrk.."='"..xml_escape(v).."'");

		elseif not(k == "xmlns" and (v == parentns or not v)) then

			t_insert(buf, " "..k.."='"..xml_escape(v).."'");

		end

	end

	local len = #t;

	if len == 0 then

		t_insert(buf, "/>");

	else

		t_insert(buf, ">");

		for n=1,len do

			local child = t[n];

			if child.name then

				self(child, buf, self, xml_escape, t.attr.xmlns);

			else

				t_insert(buf, xml_escape(child));

			end

		end

		t_insert(buf, "</"..name..">");

	end

end

function stanza_mt.__tostring(t)

	local buf = {};

	_dostring(t, buf, _dostring, xml_escape, nil);

	return t_concat(buf);

end

function stanza_mt.top_tag(t)

	local attr_string = "";

	if t.attr then

		for k, v in pairs(t.attr) do if type(k) == "string" then attr_string = attr_string .. s_format(" %s='%s'", k, xml_escape(tostring(v))); end end

	end

	return s_format("<%s%s>", t.name, attr_string);

end

function stanza_mt.get_text(t)

	if #t.tags == 0 then

		local s = {};

		for i, v in ipairs(t) do

			s[i] = tostring(v);

		end

		return t_concat(s);

	end

end

function stanza_mt.get_error(stanza)

	local type, condition, text;

	local error_tag = stanza:get_child("error");

	if not error_tag then

		return nil, nil, nil;

	end

	type = error_tag.attr.type;

	for child in error_tag:childtags() do

		if child.attr.xmlns == xmlns_stanzas then

			if not text and child.name == "text" then

				text = child:get_text();

			elseif not condition then

				condition = child.name;

			end

			if condition and text then

				break;

			end

		end

	end

	return type, condition or "undefined-condition", text;

end

function stanza_mt.__add(s1, s2)

	return s1:add_direct_child(s2);

end

do

	local id = 0;

	function new_id()

		id = id + 1;

		return "lx"..id;

	end

end

function preserialize(stanza)

	local s = { name = stanza.name, attr = stanza.attr };

	for _, child in ipairs(stanza) do

		if child.tags then

			t_insert(s, preserialize(child));

		else

			t_insert(s, tostring(child));

		end

	end

	return s;

end

function deserialize(stanza)

	-- Set metatable

	if stanza then

		local attr = stanza.attr;

		for i=1,#attr do attr[i] = nil; end

		local attrx = {};

		for att in pairs(attr) do

			if s_find(att, "|", 1, true) and not s_find(att, "\1", 1, true) then

				local ns,na = s_match(att, "^([^|]+)|(.+)$");

				attrx[ns.."\1"..na] = attr[att];

				attr[att] = nil;

			end

		end

		for a,v in pairs(attrx) do

			attr[a] = v;

		end

		setmetatable(stanza, stanza_mt);

		for _, child in ipairs(stanza) do

			if child.tags then

				deserialize(child);

			end

		end

		if not stanza.tags then

			-- Rebuild tags

			local tags = {};

			for _, child in ipairs(stanza) do

				if type(child) == "table" then

					t_insert(tags, child);

				end

			end

			stanza.tags = tags;

		end

	end

	return stanza;

end

function clone(stanza)

	local lookup_table = {};

	local function _copy(object)

		if type(object) ~= "table" then

			return object;

		elseif lookup_table[object] then

			return lookup_table[object];

		end

		local new_table = {};

		lookup_table[object] = new_table;

		for index, value in pairs(object) do

			new_table[_copy(index)] = _copy(value);

		end

		return setmetatable(new_table, getmetatable(object));

	end

	return _copy(stanza)

end

function message(attr, body)

	if not body then

		return stanza("message", attr);

	else

		return stanza("message", attr):tag("body"):text(body):up();

	end

end

function iq(attr)

	if attr and not attr.id then attr.id = new_id(); end

	return stanza("iq", attr or { id = new_id() });

end

function reply(orig)

	return stanza(orig.name, orig.attr and { to = orig.attr.from, from = orig.attr.to, id = orig.attr.id, type = ((orig.name == "iq" and "result") or orig.attr.type) });

end

do

	local xmpp_stanzas_attr = { xmlns = xmlns_stanzas };

	function error_reply(orig, type, condition, message)

		local t = reply(orig);

		t.attr.type = "error";

		t:tag("error", {type = type}) --COMPAT: Some day xmlns:stanzas goes here

			:tag(condition, xmpp_stanzas_attr):up();

		if (message) then t:tag("text", xmpp_stanzas_attr):text(message):up(); end

		return t; -- stanza ready for adding app-specific errors

	end

end

function presence(attr)

	return stanza("presence", attr);

end

if do_pretty_printing then

	local style_attrk = getstyle("yellow");

	local style_attrv = getstyle("red");

	local style_tagname = getstyle("red");

	local style_punc = getstyle("magenta");

	local attr_format = " "..getstring(style_attrk, "%s")..getstring(style_punc, "=")..getstring(style_attrv, "'%s'");

	local top_tag_format = getstring(style_punc, "<")..getstring(style_tagname, "%s").."%s"..getstring(style_punc, ">");

	--local tag_format = getstring(style_punc, "<")..getstring(style_tagname, "%s").."%s"..getstring(style_punc, ">").."%s"..getstring(style_punc, "</")..getstring(style_tagname, "%s")..getstring(style_punc, ">");

	local tag_format = top_tag_format.."%s"..getstring(style_punc, "</")..getstring(style_tagname, "%s")..getstring(style_punc, ">");

	function stanza_mt.pretty_print(t)

		local children_text = "";

		for n, child in ipairs(t) do

			if type(child) == "string" then

				children_text = children_text .. xml_escape(child);

			else

				children_text = children_text .. child:pretty_print();

			end

		end

		local attr_string = "";

		if t.attr then

			for k, v in pairs(t.attr) do if type(k) == "string" then attr_string = attr_string .. s_format(attr_format, k, tostring(v)); end end

		end

		return s_format(tag_format, t.name, attr_string, children_text, t.name);

	end

	function stanza_mt.pretty_top_tag(t)

		local attr_string = "";

		if t.attr then

			for k, v in pairs(t.attr) do if type(k) == "string" then attr_string = attr_string .. s_format(attr_format, k, tostring(v)); end end

		end

		return s_format(top_tag_format, t.name, attr_string);

	end

else

	-- Sorry, fresh out of colours for you guys ;)

	stanza_mt.pretty_print = stanza_mt.__tostring;

	stanza_mt.pretty_top_tag = stanza_mt.top_tag;

end

return _M;