local pubsub = require "prosody.util.pubsub";

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

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

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

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

local st = require "prosody.util.stanza";

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

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

local cache = require "prosody.util.cache";

local set = require "prosody.util.set";

local new_id = require "prosody.util.id".medium;

local storagemanager = require "prosody.core.storagemanager";

local usermanager = require "prosody.core.usermanager";

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 -> object passed to module:add_items()

local pep_service_items = {};

-- size of caches with full pubsub service objects

local service_cache_size = module:get_option_integer("pep_service_cache_size", 1000, 1);

-- username -> util.pubsub service object

local services = cache.new(service_cache_size, function (username, _)

	local item = pep_service_items[username];

	pep_service_items[username] = nil;

	if item then

		module:remove_item("pep-service", item);

	end

end):table();

-- size of caches with smaller objects

local info_cache_size = module:get_option_integer("pep_info_cache_size", 10000, 1);

-- username -> recipient -> set of nodes

local recipients = cache.new(info_cache_size):table();

-- caps hash -> set of nodes

local hash_map = cache.new(info_cache_size):table();

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, 0);

local function tonumber_max_items(n)

	if n == "max" then

		return max_max_items;

	end

	return tonumber(n);

end

for _, field in ipairs(lib_pubsub.node_config_form) do

	if field.var == "pubsub#max_items" then

		field.range_max = max_max_items;

		break;

	end

end

function module.save()

	return {

		recipients = recipients;

	};

end

function module.restore(data)

	recipients = data.recipients;

end

function is_item_stanza(item)

	return st.is_stanza(item) and item.attr.xmlns == xmlns_pubsub and item.name == "item" and #item.tags == 1;

end

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

	if (tonumber_max_items(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)

		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)

	local driver = storagemanager.get_driver(module.host, "pep_data");

	return function (config, node)

		local max_items = tonumber_max_items(config["max_items"]);

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

		local archive = driver:open("pep_"..node, "archive");

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

	end

end

local function get_broadcaster(username)

	local user_bare = jid_join(username, host);

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

		local expose_publisher;

		if node_obj then

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

				return;

			end

			if node_obj.config.itemreply == "publisher" then

				expose_publisher = true;

			end

		end

		if kind == "retract" then

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

		end

		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

				if not expose_publisher then

					item.attr.publisher = nil;

				end

			end

		end

		local id = new_id();

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

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

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

		if item then

			message:add_child(item);

		end

		for jid in pairs(jids) do

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

			message.attr.to = jid;

			module:send(message);

		end

	end

	return simple_broadcast;

end

local function get_subscriber_filter(username)

	return function (jids, node)

		local broadcast_to = {};

		for jid, opts in pairs(jids) do

			broadcast_to[jid] = opts;

		end

		local service_recipients = recipients[username];

		if service_recipients then

			local service = services[username];

			for recipient, nodes in pairs(service_recipients) do

				if nodes:contains(node) and service:may(node, recipient, "subscribe") then

					broadcast_to[recipient] = true;

				end

			end

		end

		return broadcast_to;

	end

end

-- Read-only service with no nodes where nobody is allowed anything to act as a

-- fallback for interactions with non-existent users

local nobody_service = pubsub.new({

	node_defaults = {

		["max_items"] = 1;

		["persist_items"] = false;

		["access_model"] = "presence";

		["send_last_published_item"] = "on_sub_and_presence";

	};

	autocreate_on_publish = false;

	autocreate_on_subscribe = false;

	get_affiliation = function ()

		return "outcast";

	end;

});

function get_pep_service(username)

	local user_bare = jid_join(username, host);

	local service = services[username];

	if service then

		return service;

	end

	if not usermanager.user_exists(username, host) then

		return nobody_service;

	end

	module:log("debug", "Creating pubsub service for user %q", username);

	service = pubsub.new({

		pep_username = username;

		node_defaults = {

			["max_items"] = 1;

			["persist_items"] = true;

			["access_model"] = "presence";

			["send_last_published_item"] = "on_sub_and_presence";

		};

		max_items = max_max_items;

		autocreate_on_publish = true;

		autocreate_on_subscribe = false;

		nodestore = nodestore(username);

		itemstore = simple_itemstore(username);

		broadcaster = get_broadcaster(username);

		subscriber_filter = get_subscriber_filter(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;

		};

		jid = user_bare;

		normalize_jid = jid_bare;

		check_node_config = check_node_config;

	});

	services[username] = service;

	local item = { service = service, jid = user_bare }

	pep_service_items[username] = item;

	module:add_item("pep-service", item);

	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);

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, config = service:get_node_config(node, true);

	if ok and config.send_last_published_item ~= "on_sub_and_presence" then return end

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

	if not (ok and id) then return; end

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

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 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 nodes - current do

		if service:may(node, recipient, "subscribe") 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 {};