-- Prosody IM

-- Copyright (C) 2009-2010 Matthew Wild

-- Copyright (C) 2009-2010 Waqas Hussain

-- Copyright (C) 2014 Kim Alvefur

--

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

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

--

-- This module implements XEP-0191: Blocking Command

--

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

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

local st = require"util.stanza";

local st_error_reply = st.error_reply;

local host = module.host;

local storage = module:open_store();

local sessions = prosody.hosts[host].sessions;

-- Cache of blocklists used since module was loaded

local cache = {};

if module:get_option_boolean("blocklist_weak_cache") then

	-- Lower memory usage, more IO and latency

	setmetatable(cache, { __mode = "v" });

end

local null_blocklist = {};

module:add_feature("urn:xmpp:blocking");

local function set_blocklist(username, blocklist)

	local ok, err = storage:set(username, blocklist);

	if not ok then

		return ok, err;

	end

	-- Successful save, update the cache

	cache[username] = blocklist;

	return true;

end

-- Migrates from the old mod_privacy storage

local function migrate_privacy_list(username)

	local migrated_data = { [false] = "not empty" };

	local legacy_data = module:open_store("privacy"):get(username);

	if legacy_data and legacy_data.lists and legacy_data.default then

		legacy_data = legacy_data.lists[legacy_data.default];

		legacy_data = legacy_data and legacy_data.items;

	else

		return migrated_data;

	end

	if legacy_data then

		module:log("info", "Migrating blocklist from mod_privacy storage for user '%s'", username);

		local item, jid;

		for i = 1, #legacy_data do

			item = legacy_data[i];

			if item.type == "jid" and item.action == "deny" then

				jid = jid_prep(item.value);

				if not jid then

					module:log("warn", "Invalid JID in privacy store for user '%s' not migrated: %s", username, tostring(item.value));

				else

					migrated_data[jid] = true;

				end

			end

		end

	end

	set_blocklist(username, migrated_data);

	return migrated_data;

end

local function get_blocklist(username)

	local blocklist = cache[username];

	if not blocklist then

		if not user_exists(username, host) then

			return null_blocklist;

		end

		blocklist = storage:get(username);

		if not blocklist then

			blocklist = migrate_privacy_list(username);

		end

		cache[username] = blocklist;

	end

	return blocklist;

end

module:hook("iq-get/self/urn:xmpp:blocking:blocklist", function (event)

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

	local username = origin.username;

	local reply = st.reply(stanza):tag("blocklist", { xmlns = "urn:xmpp:blocking" });

	local blocklist = get_blocklist(username);

	for jid in pairs(blocklist) do

		if jid then

			reply:tag("item", { jid = jid }):up();

		end

	end

	origin.interested_blocklist = true; -- Gets notified about changes

	return origin.send(reply);

end);

-- Add or remove some jid(s) from the blocklist

-- We want this to be atomic and not do a partial update

local function edit_blocklist(event)

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

	local username = origin.username;

	local action = stanza.tags[1];

	local new = {};

	local jid;

	for item in action:childtags("item") do

		jid = jid_prep(item.attr.jid);

		if not jid then

			return origin.send(st_error_reply(stanza, "modify", "jid-malformed"));

		end

		item.attr.jid = jid; -- echo back prepped

		new[jid] = is_contact_subscribed(username, host, jid) or false;

	end

	local mode = action.name == "block" or nil;

	if mode and not next(new) then

		-- <block/> element does not contain at least one <item/> child element

		return origin.send(st_error_reply(stanza, "modify", "bad-request"));

	end

	local blocklist = get_blocklist(username);

	local new_blocklist = {};

	if mode or next(new) then