local st = require "util.stanza";
local uuid_generate = require "util.uuid".generate;

local xmlns_pubsub = "http://jabber.org/protocol/pubsub";
local xmlns_pubsub_errors = "http://jabber.org/protocol/pubsub#errors";

local _M = {};

local handlers = {};
_M.handlers = handlers;

local pubsub_errors = {
	["conflict"] = { "cancel", "conflict" };
	["invalid-jid"] = { "modify", "bad-request", nil, "invalid-jid" };
	["jid-required"] = { "modify", "bad-request", nil, "jid-required" };
	["nodeid-required"] = { "modify", "bad-request", nil, "nodeid-required" };
	["item-not-found"] = { "cancel", "item-not-found" };
	["not-subscribed"] = { "modify", "unexpected-request", nil, "not-subscribed" };
	["forbidden"] = { "cancel", "forbidden" };
};
local function pubsub_error_reply(stanza, error)
	local e = pubsub_errors[error];
	local reply = st.error_reply(stanza, unpack(e, 1, 3));
	if e[4] then
		reply:tag(e[4], { xmlns = xmlns_pubsub_errors }):up();
	end
	return reply;
end
_M.pubsub_error_reply = pubsub_error_reply;

function handlers.get_items(origin, stanza, items, service)
	local node = items.attr.node;
	local item = items:get_child("item");
	local id = item and item.attr.id;

	if not node then
		return origin.send(pubsub_error_reply(stanza, "nodeid-required"));
	end
	local ok, results = service:get_items(node, stanza.attr.from, id);
	if not ok then
		return origin.send(pubsub_error_reply(stanza, results));
	end

	local data = st.stanza("items", { node = node });
	for _, entry in pairs(results) do
		data:add_child(entry);
	end
	local reply;
	if data then
		reply = st.reply(stanza)
			:tag("pubsub", { xmlns = xmlns_pubsub })
				:add_child(data);
	else
		reply = pubsub_error_reply(stanza, "item-not-found");
	end
	return origin.send(reply);
end

function handlers.get_subscriptions(origin, stanza, subscriptions, service)
	local node = subscriptions.attr.node;
	local ok, ret = service:get_subscriptions(node, stanza.attr.from, stanza.attr.from);
	if not ok then
		return origin.send(pubsub_error_reply(stanza, ret));
	end
	local reply = st.reply(stanza)
		:tag("pubsub", { xmlns = xmlns_pubsub })
			:tag("subscriptions");
	for _, sub in ipairs(ret) do
		reply:tag("subscription", { node = sub.node, jid = sub.jid, subscription = 'subscribed' }):up();
	end
	return origin.send(reply);
end

function handlers.set_create(origin, stanza, create, service)
	local node = create.attr.node;
	local ok, ret, reply;
	if node then
		ok, ret = service:create(node, stanza.attr.from);
		if ok then
			reply = st.reply(stanza);
		else
			reply = pubsub_error_reply(stanza, ret);
		end
	else
		repeat
			node = uuid_generate();
			ok, ret = service:create(node, stanza.attr.from);
		until ok or ret ~= "conflict";
		if ok then
			reply = st.reply(stanza)
				:tag("pubsub", { xmlns = xmlns_pubsub })
					:tag("create", { node = node });
		else
			reply = pubsub_error_reply(stanza, ret);
		end
	end
	return origin.send(reply);
end

function handlers.set_delete(origin, stanza, delete, service)
	local node = delete.attr.node;

	local reply, notifier;
	if not node then
		return origin.send(pubsub_error_reply(stanza, "nodeid-required"));
	end
	local ok, ret = service:delete(node, stanza.attr.from);
	if ok then
		reply = st.reply(stanza);
	else
		reply = pubsub_error_reply(stanza, ret);
	end
	return origin.send(reply);
end

function handlers.set_subscribe(origin, stanza, subscribe, service)
	local node, jid = subscribe.attr.node, subscribe.attr.jid;
	if not (node and jid) then
		return origin.send(pubsub_error_reply(stanza, jid and "nodeid-required" or "invalid-jid"));
	end
	--[[
	local options_tag, options = stanza.tags[1]:get_child("options"), nil;
	if options_tag then
		options = options_form:data(options_tag.tags[1]);
	end
	--]]
	local options_tag, options; -- FIXME
	local ok, ret = service:add_subscription(node, stanza.attr.from, jid, options);
	local reply;
	if ok then
		reply = st.reply(stanza)
			:tag("pubsub", { xmlns = xmlns_pubsub })
				:tag("subscription", {
					node = node,
					jid = jid,
					subscription = "subscribed"
				}):up();
		if options_tag then
			reply:add_child(options_tag);
		end
	else
		reply = pubsub_error_reply(stanza, ret);
	end
	origin.send(reply);
end

function handlers.set_unsubscribe(origin, stanza, unsubscribe, service)
	local node, jid = unsubscribe.attr.node, unsubscribe.attr.jid;
	if not (node and jid) then
		return origin.send(pubsub_error_reply(stanza, jid and "nodeid-required" or "invalid-jid"));
	end
	local ok, ret = service:remove_subscription(node, stanza.attr.from, jid);
	local reply;
	if ok then
		reply = st.reply(stanza);
	else
		reply = pubsub_error_reply(stanza, ret);
	end
	return origin.send(reply);
end

function handlers.set_publish(origin, stanza, publish, service)
	local node = publish.attr.node;
	if not node then
		return origin.send(pubsub_error_reply(stanza, "nodeid-required"));
	end
	local item = publish:get_child("item");
	local id = (item and item.attr.id);
	if not id then
		id = uuid_generate();
		if item then
			item.attr.id = id;
		end
	end
	local ok, ret = service:publish(node, stanza.attr.from, id, item);
	local reply;
	if ok then
		reply = st.reply(stanza)
			:tag("pubsub", { xmlns = xmlns_pubsub })
				:tag("publish", { node = node })
					:tag("item", { id = id });
	else
		reply = pubsub_error_reply(stanza, ret);
	end
	return origin.send(reply);
end

function handlers.set_retract(origin, stanza, retract, service)
	local node, notify = retract.attr.node, retract.attr.notify;
	notify = (notify == "1") or (notify == "true");
	local item = retract:get_child("item");
	local id = item and item.attr.id
	if not (node and id) then
		return origin.send(pubsub_error_reply(stanza, node and "item-not-found" or "nodeid-required"));
	end
	local reply, notifier;
	if notify then
		notifier = st.stanza("retract", { id = id });
	end
	local ok, ret = service:retract(node, stanza.attr.from, id, notifier);
	if ok then
		reply = st.reply(stanza);
	else
		reply = pubsub_error_reply(stanza, ret);
	end
	return origin.send(reply);
end

function handlers.set_purge(origin, stanza, purge, service)
	local node, notify = purge.attr.node, purge.attr.notify;
	notify = (notify == "1") or (notify == "true");
	local reply;
	if not node then
		return origin.send(pubsub_error_reply(stanza, "nodeid-required"));
	end
	local ok, ret = service:purge(node, stanza.attr.from, notify);
	if ok then
		reply = st.reply(stanza);
	else
		reply = pubsub_error_reply(stanza, ret);
	end
	return origin.send(reply);
end

return _M;