local pubsub = require "util.pubsub";

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

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

local jid_join = require "util.jid".join;

local set_new = require "util.set".new;

local st = require "util.stanza";

local calculate_hash = require "util.caps".calculate_hash;

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

local cache = require "util.cache";

local set = require "util.set";

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

local xmlns_pubsub_event = "http://jabber.org/protocol/pubsub#event";

local xmlns_pubsub_owner = "http://jabber.org/protocol/pubsub#owner";

local lib_pubsub = module:require "pubsub";

local empty_set = set_new();

-- username -> util.pubsub service object

local services = {};

-- username -> recipient -> set of nodes

local recipients = {};

-- caps hash -> set of nodes

local hash_map = {};

local host = module.host;

local node_config = module:open_store("pep", "map");

local known_nodes = module:open_store("pep");

local max_max_items = module:get_option_number("pep_max_items", 256);

function module.save()

	return {

		services = services;

		recipients = recipients;

	};

end

function module.restore(data)

	services = data.services;

	recipients = data.recipients;

end

function is_item_stanza(item)

	return st.is_stanza(item) and item.attr.xmlns == xmlns_pubsub and item.name == "item";

end

function check_node_config(node, actor, new_config) -- luacheck: ignore 212/node 212/actor

	if (new_config["max_items"] or 1) > max_max_items then

		return false;

	end

	if new_config["access_model"] ~= "presence"

	and new_config["access_model"] ~= "whitelist"

	and new_config["access_model"] ~= "open" then

		return false;

	end

	return true;

end

local function subscription_presence(username, recipient)

	local user_bare = jid_join(username, host);

	local recipient_bare = jid_bare(recipient);

	if (recipient_bare == user_bare) then return true; end

	return is_contact_subscribed(username, host, recipient_bare);

end

local function nodestore(username)

	-- luacheck: ignore 212/self

	local store = {};

	function store:get(node)

		local data, err = node_config:get(username, node)

		if data == true then

			-- COMPAT Previously stored only a boolean representing 'persist_items'

			data = {

				name = node;

				config = {};

				subscribers = {};

				affiliations = {};

			};

		end

		return data, err;

	end

	function store:set(node, data)

		if data then

			-- Save the data without subscriptions

			local subscribers = {};

			for jid, sub in pairs(data.subscribers) do

				if type(sub) ~= "table" or not sub.presence then

					subscribers[jid] = sub;

				end

			end

			data = {

				name = data.name;

				config = data.config;

				affiliations = data.affiliations;

				subscribers = subscribers;

			};

		end

		return node_config:set(username, node, data);

	end

	function store:users()

		return pairs(known_nodes:get(username) or {});

	end

	return store;

end

local function simple_itemstore(username)

	return function (config, node)

		if config["persist_items"] then

			module:log("debug", "Creating new persistent item store for user %s, node %q", username, node);

			local archive = module:open_store("pep_"..node, "archive");

			return lib_pubsub.archive_itemstore(archive, config, username, node, false);

		else

			module:log("debug", "Creating new ephemeral item store for user %s, node %q", username, node);

			return cache.new(tonumber(config["max_items"]));

		end

	end

end

local function get_broadcaster(username)

	local user_bare = jid_join(username, host);

	local function simple_broadcast(kind, node, jids, item, _, node_obj)

		if node_obj then

			if node_obj.config["notify_"..kind] == false then

				return;

			end

		end

		if kind == "retract" then

			kind = "items"; -- XEP-0060 signals retraction in an <items> container

		end

		local message = st.message({ from = user_bare, type = "headline" })

			:tag("event", { xmlns = xmlns_pubsub_event })

				:tag(kind, { node = node });

		if item then

			item = st.clone(item);

			item.attr.xmlns = nil; -- Clear the pubsub namespace

			if kind == "items" then

				if node_obj and node_obj.config.include_payload == false then

					item:maptags(function () return nil; end);

				end

			end

			message:add_child(item);

		end

		for jid in pairs(jids) do

			module:log("debug", "Sending notification to %s from %s: %s", jid, user_bare, tostring(item));

			message.attr.to = jid;

			module:send(message);

		end

	end

	return simple_broadcast;

end

function get_pep_service(username)

	module:log("debug", "get_pep_service(%q)", username);

	local user_bare = jid_join(username, host);

	local service = services[username];

	if service then

		return service;

	end

	service = pubsub.new({

		node_defaults = {

			["max_items"] = 1;

			["persist_items"] = true;

			["access_model"] = "presence";

		};

		autocreate_on_publish = true;

		autocreate_on_subscribe = true;

		nodestore = nodestore(username);

		itemstore = simple_itemstore(username);

		broadcaster = get_broadcaster(username);

		itemcheck = is_item_stanza;

		get_affiliation = function (jid)

			if jid_bare(jid) == user_bare then

				return "owner";

			end

		end;

		access_models = {

			presence = function (jid)

				if subscription_presence(username, jid) then

					return "member";

				end

				return "outcast";

			end;

		};

		normalize_jid = jid_bare;

		check_node_config = check_node_config;

	});

	local nodes, err = known_nodes:get(username);

	if nodes then

		module:log("debug", "Restoring nodes for user %s", username);

		for node in pairs(nodes) do

			module:log("debug", "Restoring node %q", node);

			service:create(node, true);

		end

	elseif err then

		module:log("error", "Could not restore nodes for %s: %s", username, err);

	else

		module:log("debug", "No known nodes");

	end

	services[username] = service;

	module:add_item("pep-service", { service = service, jid = user_bare });

	return service;

end

function handle_pubsub_iq(event)

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

	local service_name = origin.username;

	if stanza.attr.to ~= nil then

		service_name = jid_split(stanza.attr.to);

	end

	local service = get_pep_service(service_name);

	return lib_pubsub.handle_pubsub_iq(event, service)

end

module:hook("iq/bare/"..xmlns_pubsub..":pubsub", handle_pubsub_iq);

module:hook("iq/bare/"..xmlns_pubsub_owner..":pubsub", handle_pubsub_iq);

module:add_identity("pubsub", "pep", module:get_option_string("name", "Prosody"));

module:add_feature("http://jabber.org/protocol/pubsub#publish");

local function get_caps_hash_from_presence(stanza, current)

	local t = stanza.attr.type;

	if not t then

		local child = stanza:get_child("c", "http://jabber.org/protocol/caps");

		if child then

			local attr = child.attr;

			if attr.hash then -- new caps

				if attr.hash == 'sha-1' and attr.node and attr.ver then

					return attr.ver, attr.node.."#"..attr.ver;

				end

			else -- legacy caps

				if attr.node and attr.ver then

					return attr.node.."#"..attr.ver.."#"..(attr.ext or ""), attr.node.."#"..attr.ver;

				end

			end

		end

		return; -- no or bad caps

	elseif t == "unavailable" or t == "error" then

		return;

	end

	return current; -- no caps, could mean caps optimization, so return current

end

local function resend_last_item(jid, node, service)

	local ok, id, item = service:get_last_item(node, jid);

	service.config.broadcaster("items", node, { [jid] = true }, item);

end

local function update_subscriptions(recipient, service_name, nodes)

	nodes = nodes or empty_set;

	local service_recipients = recipients[service_name];

	if not service_recipients then

		service_recipients = {};

		recipients[service_name] = service_recipients;

	end

	local current = service_recipients[recipient];

	if not current or type(current) ~= "table" then

		current = empty_set;

	end

	if (current == empty_set or current:empty()) and (nodes == empty_set or nodes:empty()) then

		return;

	end

	local service = get_pep_service(service_name);

	for node in current - nodes do

		service:remove_subscription(node, recipient, recipient);

	end

	for node in nodes - current do

		if service:add_subscription(node, recipient, recipient, { presence = true }) then

			resend_last_item(recipient, node, service);

		end

	end

	if nodes == empty_set or nodes:empty() then

		nodes = nil;

	end

	service_recipients[recipient] = nodes;

end

module:hook("presence/bare", function(event)

	-- inbound presence to bare JID received

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

	local t = stanza.attr.type;

	local is_self = not stanza.attr.to;

	local username = jid_split(stanza.attr.to);

	local user_bare = jid_bare(stanza.attr.to);

	if is_self then

		username = origin.username;

		user_bare = jid_join(username, host);

	end

	if not t then -- available presence

		if is_self or subscription_presence(username, stanza.attr.from) then

			local recipient = stanza.attr.from;

			local current = recipients[username] and recipients[username][recipient];

			local hash, query_node = get_caps_hash_from_presence(stanza, current);

			if current == hash or (current and current == hash_map[hash]) then return; end

			if not hash then

				update_subscriptions(recipient, username);

			else

				recipients[username] = recipients[username] or {};

				if hash_map[hash] then

					update_subscriptions(recipient, username, hash_map[hash]);

				else

					recipients[username][recipient] = hash;

					local from_bare = origin.type == "c2s" and origin.username.."@"..origin.host;

					if is_self or origin.type ~= "c2s" or (recipients[from_bare] and recipients[from_bare][origin.full_jid]) ~= hash then

						-- COMPAT from ~= stanza.attr.to because OneTeam can't deal with missing from attribute

						origin.send(

							st.stanza("iq", {from=user_bare, to=stanza.attr.from, id="disco", type="get"})

								:tag("query", {xmlns = "http://jabber.org/protocol/disco#info", node = query_node})

						);

					end

				end

			end

		end

	elseif t == "unavailable" then

		update_subscriptions(stanza.attr.from, username);

	elseif not is_self and t == "unsubscribe" then

		local from = jid_bare(stanza.attr.from);

		local subscriptions = recipients[username];

		if subscriptions then

			for subscriber in pairs(subscriptions) do

				if jid_bare(subscriber) == from then

					update_subscriptions(subscriber, username);

				end

			end

		end

	end

end, 10);

module:hook("iq-result/bare/disco", function(event)

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

	local disco = stanza:get_child("query", "http://jabber.org/protocol/disco#info");

	if not disco then

		return;

	end

	-- Process disco response

	local is_self = stanza.attr.to == nil;

	local user_bare = jid_bare(stanza.attr.to);

	local username = jid_split(stanza.attr.to);

	if is_self then

		username = origin.username;

		user_bare = jid_join(username, host);

	end

	local contact = stanza.attr.from;

	local current = recipients[username] and recipients[username][contact];

	if type(current) ~= "string" then return; end -- check if waiting for recipient's response

	local ver = current;

	if not string.find(current, "#") then

		ver = calculate_hash(disco.tags); -- calculate hash

	end