-- Prosody IM

-- Copyright (C) 2008-2009 Matthew Wild

-- Copyright (C) 2008-2009 Waqas Hussain

-- Copyright (C) 2009 Thilo Cestonaro

-- 

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

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

--

local prosody = prosody;

local st = require "util.stanza";

local datamanager = require "util.datamanager";

local bare_sessions = bare_sessions;

local util_Jid = require "util.jid";

local jid_bare = util_Jid.bare;

local jid_split = util_Jid.split;

local load_roster = require "core.rostermanager".load_roster;

local to_number = _G.tonumber;

function findNamedList (privacy_lists, name)

	local ret = nil

	if privacy_lists.lists == nil then

		module:log("debug", "privacy_lists.list is nil. no lists loaded.")

		return nil;

	end

	module:log("debug", "searching for list: %s", name);

	for i=1, #privacy_lists.lists do

		if privacy_lists.lists[i].name == name then

			ret = i;

			break;

		end

	end

	return ret;

end

function isListUsed(origin, name, privacy_lists)	

	if bare_sessions[origin.username.."@"..origin.host].sessions ~= nil then

		for resource, session in pairs(bare_sessions[origin.username.."@"..origin.host].sessions) do

			if resource ~= origin.resource then

				if session.activePrivacyList == name then

					module:log("debug", "List {0} is in use.", name);

					return true;

				elseif session.activePrivacyList == nil and privacy_lists.default == name then

					module:log("debug", "List {0} is in use.", name);

					return true;

				end

			end

		end

	end

	module:log("debug", "List {0} is in NOT use.", name);

	return false;

end

function isAnotherSessionUsingDefaultList(origin)

	local ret = false

	if bare_sessions[origin.username.."@"..origin.host].sessions ~= nil then

		for resource, session in pairs(bare_sessions[origin.username.."@"..origin.host].sessions) do

			if resource ~= origin.resource and session.activePrivacyList == nil then

				module:log("debug", "Default list is used by another resource.");

				ret = true;

				break;

			end

		end

	end

	return ret;

end

function declineList (privacy_lists, origin, stanza, which)

	module:log("info", "User requests to decline the use of privacy list: %s", which);

	if which == "default" then

		if isAnotherSessionUsingDefaultList(origin) then

			return { "cancel", "conflict", "Another session is online and using the default list."};

		end

		privacy_lists.default = nil;

		origin.send(st.reply(stanza));

	elseif which == "active" then

		origin.activePrivacyList = nil;

		origin.send(st.reply(stanza));

	else

		return {"modify", "bad-request", "Neither default nor active list specifed to decline."};

	end

	return true;

end

function activateList (privacy_lists, origin, stanza, which, name)

	module:log("info", "User requests to change the privacy list: %s, to be list named %s", which, name);

	local idx = findNamedList(privacy_lists, name);

	if privacy_lists.default == nil then

		privacy_lists.default = "";

	end

	if origin.activePrivacyList == nil then

		origin.activePrivacyList = "";

	end

	if which == "default" and idx ~= nil then

		if isAnotherSessionUsingDefaultList(origin) then

			return {"cancel", "conflict", "Another session is online and using the default list."};

		end

		privacy_lists.default = name;

		origin.send(st.reply(stanza));

	elseif which == "active" and idx ~= nil then

		origin.activePrivacyList = name;

		origin.send(st.reply(stanza));

	else

		return {"modify", "bad-request", "Either not active or default given or unknown list name specified."};

	end

	return true;

end

function deleteList (privacy_lists, origin, stanza, name)

	module:log("info", "User requests to delete privacy list: %s", name);

	local idx = findNamedList(privacy_lists, name);

	if idx ~= nil then

		if isListUsed(origin, name, privacy_lists) then

			return {"cancel", "conflict", "Another session is online and using the list which should be deleted."};

		end

		if privacy_lists.default == name then

			privacy_lists.default = "";

		end

		if origin.activePrivacyList == name then

			origin.activePrivacyList = "";

		end

		table.remove(privacy_lists.lists, idx);

		origin.send(st.reply(stanza));

		return true;

	end

	return {"modify", "bad-request", "Not existing list specifed to be deleted."};

end

local function sortByOrder(a, b)

	if a.order < b.order then

		return true;

	end

	return false;

end

function createOrReplaceList (privacy_lists, origin, stanza, name, entries, roster)

	module:log("info", "User requests to create / replace list named %s, item count: %d", name, #entries);

	local idx = findNamedList(privacy_lists, name);

	local bare_jid = origin.username.."@"..origin.host;

	if privacy_lists.lists == nil then

		privacy_lists.lists = {};

	end

	if idx == nil then

		idx = #privacy_lists.lists + 1;

	end

	local orderCheck = {};

	local list = {};

	list.name = name;

	list.items = {};

	for _,item in ipairs(entries) do

		if to_number(item.attr.order) == nil or to_number(item.attr.order) < 0 or orderCheck[item.attr.order] ~= nil then

			return {"modify", "bad-request", "Order attribute not valid."};

		end

		if item.attr.type ~= nil and item.attr.type ~= "jid" and item.attr.type ~= "subscription" and item.attr.type ~= "group" then

			return {"modify", "bad-request", "Type attribute not valid."};

		end 

		local tmp = {};

		orderCheck[item.attr.order] = true;

		tmp["type"] = item.attr.type;

		tmp["value"] = item.attr.value;

		tmp["action"] = item.attr.action;

		tmp["order"] = to_number(item.attr.order);

		tmp["presence-in"] = false;

		tmp["presence-out"] = false;

		tmp["message"] = false;

		tmp["iq"] = false;

		if #item.tags > 0 then

			for _,tag in ipairs(item.tags) do

				tmp[tag.name] = true;

			end

		end

		if tmp.type == "group" then

			local found = false;

			local roster = load_roster(origin.username, origin.host);

			for jid,item in pairs(roster) do

				if item.groups ~= nil then

					for group in pairs(item.groups) do

						if group == tmp.value then

							found = true;

							break;

						end

					end

					if found == true then

						break;

					end

				end

			end

			if found == false then

				return {"cancel", "item-not-found", "Specifed roster group not existing."};

			end

		elseif tmp.type == "subscription" then

			if	tmp.value ~= "both" and

				tmp.value ~= "to" and

				tmp.value ~= "from" and

				tmp.value ~= "none" then

				return {"cancel", "bad-request", "Subscription value must be both, to, from or none."};

			end

		end

		if tmp.action ~= "deny" and tmp.action ~= "allow" then

			return {"cancel", "bad-request", "Action must be either deny or allow."};

		end

		list.items[#list.items + 1] = tmp;

	end

	table.sort(list, sortByOrder);

	privacy_lists.lists[idx] = list;

	origin.send(st.reply(stanza));

	if bare_sessions[bare_jid] ~= nil then

		iq = st.iq ( { type = "set", id="push1" } );

		iq:tag ("query", { xmlns = "jabber:iq:privacy" } );

		iq:tag ("list", { name = list.name } ):up();

		iq:up();

		for resource, session in pairs(bare_sessions[bare_jid].sessions) do

			iq.attr.to = bare_jid.."/"..resource

			session.send(iq);

		end

	else

		return {"cancel", "bad-request", "internal error."};

	end

	return true;

end

function getList(privacy_lists, origin, stanza, name)

	module:log("info", "User requests list named: %s", name or "nil");

	local reply = st.reply(stanza);

	reply:tag("query", {xmlns="jabber:iq:privacy"});

	if name == nil then

		reply:tag("active", {name=origin.activePrivacyList or ""}):up();

		reply:tag("default", {name=privacy_lists.default or ""}):up();

		if privacy_lists.lists then

			for _,list in ipairs(privacy_lists.lists) do

				reply:tag("list", {name=list.name}):up();

			end

		end

	else

		local idx = findNamedList(privacy_lists, name);

		module:log("debug", "list idx: %d", idx or -1);

		if idx ~= nil then

			list = privacy_lists.lists[idx];

			reply = reply:tag("list", {name=list.name});

			for _,item in ipairs(list.items) do

				reply:tag("item", {type=item.type, value=item.value, action=item.action, order=item.order});

				if item["message"] then reply:tag("message"):up(); end

				if item["iq"] then reply:tag("iq"):up(); end

				if item["presence-in"] then reply:tag("presence-in"):up(); end

				if item["presence-out"] then reply:tag("presence-out"):up(); end

				reply:up();

			end

		else

			return {"cancel", "item-not-found", "Unknown list specified."};

		end

	end

	origin.send(reply);

	return true;

end

module:hook("iq/bare/jabber:iq:privacy:query", function(data)

	local origin, stanza = data.origin, data.stanza;

	if stanza.attr.to == nil then -- only service requests to own bare JID

		local query = stanza.tags[1]; -- the query element

		local valid = false;

		local privacy_lists = datamanager.load(origin.username, origin.host, "privacy") or {};

		if stanza.attr.type == "set" then

			if #query.tags == 1 then --  the <query/> element MUST NOT include more than one child element 

				for _,tag in ipairs(query.tags) do

					if tag.name == "active" or tag.name == "default" then

						if tag.attr.name == nil then -- Client declines the use of active / default list

							valid = declineList(privacy_lists, origin, stanza, tag.name);

						else -- Client requests change of active / default list

							valid = activateList(privacy_lists, origin, stanza, tag.name, tag.attr.name);

						end

					elseif tag.name == "list" and tag.attr.name then -- Client adds / edits a privacy list

						if #tag.tags == 0 then -- Client removes a privacy list

							valid = deleteList(privacy_lists, origin, stanza, tag.attr.name);

						else -- Client edits a privacy list

							valid = createOrReplaceList(privacy_lists, origin, stanza, tag.attr.name, tag.tags);  -- TODO check if used!

						end

					end

				end

			end

		elseif stanza.attr.type == "get" then

			local name = nil;

			local listsToRetrieve = 0;

			if #query.tags >= 1 then

				for _,tag in ipairs(query.tags) do

					if tag.name == "list" then -- Client requests a privacy list from server

						name = tag.attr.name;

						listsToRetrieve = listsToRetrieve + 1;

					end

				end

			end

			if listsToRetrieve == 0 or listsToRetrieve == 1 then

				valid = getList(privacy_lists, origin, stanza, name);

			end

		end

		if valid ~= true then

			if valid[0] == nil then

				valid[0] = "cancel";

			end

			if valid[1] == nil then

				valid[1] = "bad-request";

			end

			origin.send(st.error_reply(stanza, valid[0], valid[1], valid[2]));

		else

			datamanager.store(origin.username, origin.host, "privacy", privacy_lists);

		end

		return true;

	end

	return false;

end, 500);

function checkIfNeedToBeBlocked(e, session)

	local origin, stanza = e.origin, e.stanza;

	local privacy_lists = datamanager.load(session.username, session.host, "privacy") or {};

	local bare_jid = session.username.."@"..session.host;

	module:log("debug", "checkIfNeedToBeBlocked: username: %s, host: %s", session.username, session.host);

	module:log("debug", "stanza: %s, to: %s, form: %s", stanza.name, stanza.attr.to or "nil", stanza.attr.from or "nil");

	if stanza.attr.to ~= nil and stanza.attr.from ~= nil then

		module:log("debug", "privacy_lists.lists: %s", tostring(privacy_lists.lists));

		module:log("debug", "session.activePrivacyList: %s", tostring(session.activePrivacyList));

		module:log("debug", "privacy_lists.default: %s", tostring(privacy_lists.default));

		if privacy_lists.lists == nil or

		   (session.activePrivacyList == nil or session.activePrivacyList == "") and

		   (privacy_lists.default == nil     or privacy_lists.default == "")

		then 

			module:log("debug", "neither active nor default list set (both are nil) or privacy_lists totally nil. So nothing to do => default is Allow All.");

			return; -- Nothing to block, default is Allow all

		end

	    if jid_bare(stanza.attr.from) == bare_jid and jid_bare(stanza.attr.to) == bare_jid then

            module:log("debug", "Never block communications from one of a user's resources to another.");

            return; -- from one of a user's resource to another => HANDS OFF!

        end