local st = require "util.stanza";
local jid = require "util.jid";
local id = require "util.id";

local pubsub = module:depends "pubsub".service;

local xmlns_quick_resp = "urn:xmpp:tmp:quick-response";
local name = module:get_option_string("name", "PubSub Service on "..module.host);
local help = name..[[

Commands:

- `help` - this help message
- `list` - list available nodes
- `subscriptions` - list nodes you are subscribed to
- `subscribe NODE` - subscribe to a node
- `unsubscribe NODE` - unsubscribe from a node]];
if pubsub.get_last_item then -- COMPAT not available in 0.10
	help = help ..  "\n- `last NODE` - send the last item (again)"
end
-- FIXME better word for "node"

local friendly_pubsub_errors = {
	["forbidden"] = "You are not allowed to do that";
	["item-not-found"] = "That node does not exist";
	["internal-server-error"] = "Something went wrong (see server logs)";
	["not-subscribed"] = "You were not subscribed";
};

module:hook("message/host", function (event)
	local stanza = event.stanza;
	local body = stanza:get_child_text("body");
	if not body then return end -- bail out

	local from = stanza.attr.from;

	local reply = st.reply(stanza);
	reply.attr.id = id.medium();

	local command, node_arg = body:match("^(%a+)%s+(.*)");
	command = (command or body):lower();

	if command == "help" then
		reply:body(help):up();
		reply:tag("response", { xmlns = xmlns_quick_resp, value = "list", }):up();
		reply:tag("response", { xmlns = xmlns_quick_resp, value = "subscriptions", }):up();
	elseif command == "list" then
		local ok, nodes = pubsub:get_nodes(from);
		if ok then
			local list = {};
			for node, node_obj in pairs(nodes) do
				table.insert(list, ("- `%s` %s"):format(node, node_obj.config.title or ""));
			end
			reply:body(table.concat(list, "\n"));
		else
			reply:body(friendly_pubsub_errors[nodes] or nodes);
		end
	elseif command == "subscriptions" then
		local ok, subs = pubsub:get_subscriptions(nil, from, from);
		if not ok then
			reply:body(friendly_pubsub_errors[subs] or subs);
		elseif #subs == 0 then
			reply:body("You are not subscribed to anything from this pubsub service");
		else
			local response = {};
			for i = 1, #subs do
				response[i] = string.format("- `%s`", subs[i].node);
				reply:tag("response", { xmlns = xmlns_quick_resp, value = "unsubscribe "..subs[i].node, }):up();
				reply:tag("response", { xmlns = xmlns_quick_resp, value = "last "..subs[i].node, }):up();
			end
			reply:body(table.concat(response, "\n"));
		end
	elseif command == "subscribe" then
		local ok, err = pubsub:add_subscription(node_arg, from, jid.bare(from), { ["pubsub#include_body"] = true });
		reply:body(ok and "OK" or friendly_pubsub_errors[err] or err);
	elseif command == "unsubscribe" then
		local ok, err = pubsub:remove_subscription(node_arg, from, jid.bare(from));
		reply:body(ok and "OK" or friendly_pubsub_errors[err] or err);
	elseif command == "last" and pubsub.get_last_item then
		local ok, item_id, item = pubsub:get_last_item(node_arg, from);
		if not ok then
			reply:body(friendly_pubsub_errors[item_id] or item_id);
		elseif not item_id then
			reply:body("That node does not contain any items");
		else
			pubsub.config.broadcaster("items", node_arg, {
				[from] = { ["pubsub#include_body"] = true }
			}, item, nil, pubsub.nodes[node_arg]);
			reply:body("OK");
		end
	else
		reply:body("Unknown command. `help` to list commands."):up();
		reply:tag("response", { xmlns = xmlns_quick_resp, value = "help", }):up();
	end
	reply:reset();

	if stanza:get_child("no-copy", "urn:xmpp:hints") then
		reply:tag("no-copy", { xmlns = "urn:xmpp:hints" }):up();
	end

	if stanza:get_child("no-store", "urn:xmpp:hints") then
		reply:tag("no-store", { xmlns = "urn:xmpp:hints" }):up();
	end

	module:send(reply);
	return true;
end);