-- 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 select = select;

local match, sub = string.match, string.sub;

local nodeprep = require "prosody.util.encodings".stringprep.nodeprep;

local nameprep = require "prosody.util.encodings".stringprep.nameprep;

local resourceprep = require "prosody.util.encodings".stringprep.resourceprep;

local escapes = {

	[" "] = "\\20"; ['"'] = "\\22";

	["&"] = "\\26"; ["'"] = "\\27";

	["/"] = "\\2f"; [":"] = "\\3a";

	["<"] = "\\3c"; [">"] = "\\3e";

	["@"] = "\\40"; ["\\"] = "\\5c";

};

local unescapes = {};

local backslash_escapes = {};

for k,v in pairs(escapes) do

	unescapes[v] = k;

	backslash_escapes[v] = v:gsub("\\", escapes)

end

local _ENV = nil;

-- luacheck: std none

local function split(jid)

	if jid == nil then return; end

	local node, nodepos = match(jid, "^([^@/]+)@()");

	local host, hostpos = match(jid, "^([^@/]+)()", nodepos);

	local resource = host and match(jid, "^/(.+)$", hostpos);

	if (host == nil) or ((resource == nil) and #jid >= hostpos) then return nil, nil, nil; end

	return node, host, resource;

end

local function bare(jid)

	local node, host = split(jid);

	if node ~= nil and host ~= nil then

		return node.."@"..host;

	end

	return host;

end

local function prepped_split(jid, strict)

	local node, host, resource = split(jid);

	if host ~= nil and host ~= "." then

		if sub(host, -1, -1) == "." then -- Strip empty root label

			host = sub(host, 1, -2);

		end

		host = nameprep(host, strict);

		if host == nil then return; end

		if node ~= nil then

			node = nodeprep(node, strict);

			if node == nil then return; end

		end

		if resource ~= nil then

			resource = resourceprep(resource, strict);

			if resource == nil then return; end

		end

		return node, host, resource;

	end

end

local function join(node, host, resource)

	if host == nil then return end

	if node ~= nil and resource ~= nil then

		return node.."@"..host.."/"..resource;

	elseif node ~= nil then

		return node.."@"..host;

	elseif resource ~= nil then

		return host.."/"..resource;

	end

	return host;

end

local function prep(jid, strict)

	local node, host, resource = prepped_split(jid, strict);

	return join(node, host, resource);

end

local function compare(jid, acl)

	-- compare jid to single acl rule

	-- TODO compare to table of rules?

	local jid_node, jid_host, jid_resource = split(jid);

	local acl_node, acl_host, acl_resource = split(acl);

	if (acl_node == nil or acl_node == jid_node) and

		(acl_host == nil or acl_host == jid_host) and

		(acl_resource == nil or acl_resource == jid_resource) then

		return true

	end

	return false

end

local function node(jid)

	return (select(1, split(jid)));

end

local function host(jid)

	return (select(2, split(jid)));

end

local function resource(jid)

	return (select(3, split(jid)));

end

-- TODO Forbid \20 at start and end of escaped output per XEP-0106 v1.1

local function escape(s) return s and (s:gsub("\\%x%x", backslash_escapes):gsub("[\"&'/:<>@ ]", escapes)); end

local function unescape(s) return s and (s:gsub("\\%x%x", unescapes)); end

return {

	split = split;

	bare = bare;

	prepped_split = prepped_split;

	join = join;

	prep = prep;

	compare = compare;

	node = node;

	host = host;

	resource = resource;

	escape = escape;

	unescape = unescape;

};