-- mod_http_upload

--

-- Copyright (C) 2015 Kim Alvefur

--

-- This file is MIT/X11 licensed.

-- 

-- Implementation of HTTP Upload file transfer mechanism used by Conversations

--

-- imports

local st = require"util.stanza";

local lfs = require"lfs";

local uuid = require"util.uuid".generate;

local function join_path(a, b)

return a .. package.config:sub(1,1) .. b;

end

-- config

local file_size_limit = module:get_option_number(module.name .. "_file_size_limit", 10 * 1024 * 1024); -- 10 MB

-- depends

module:depends("http");

module:depends("disco");

-- namespace

local xmlns_http_upload = "urn:xmpp:http:upload";

module:add_feature(xmlns_http_upload);

-- state

local pending_slots = module:shared("upload_slots");

local storage_path = join_path(prosody.paths.data, module.name);

lfs.mkdir(storage_path);

-- hooks

module:hook("iq/host/"..xmlns_http_upload..":request", function (event)

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

	local request = stanza.tags[1];

	-- local clients only

	if origin.type ~= "c2s" then

		origin.send(st.error_reply(stanza, "cancel", "not-authorized"));

		return true;

	end

	-- validate

	local filename = request:get_child_text("filename");

	if not filename or filename:find("/") then

		origin.send(st.error_reply(stanza, "modify", "bad-request", "Invalid filename"));

		return true;

	end

	local filesize = tonumber(request:get_child_text("size"));

	if not filesize then

		origin.send(st.error_reply(stanza, "modify", "bad-request", "Missing or invalid file size"));

		return true;

	elseif filesize > file_size_limit then

		origin.send(st.error_reply(stanza, "modify", "not-acceptable", "File too large",

			st.stanza("file-too-large", {xmlns=xmlns_http_upload})

				:tag("max-size"):text(tostring(file_size_limit))));

		return true;

	end

	local reply = st.reply(stanza);

	reply:tag("slot", { xmlns = xmlns_http_upload });

	local random = uuid();

	pending_slots[random.."/"..filename] = origin.full_jid;

	local url = module:http_url() .. "/" .. random .. "/" .. filename;

	reply:tag("get"):text(url):up();

	reply:tag("put"):text(url):up();

	origin.send(reply);

	return true;

end);

-- http service

local function upload_data(event, path)

	if not pending_slots[path] then

		return 401;

	end

	local random, filename = path:match("^([^/]+)/([^/]+)$");

	if not random then

		return 400;

	end

	if #event.request.body > file_size_limit then

		module:log("error", "Uploaded file too large %d bytes", #event.request.body);

		return 400;

	end

	local dirname = join_path(storage_path, random);

	if not lfs.mkdir(dirname) then

		module:log("error", "Could not create directory %s for upload", dirname);

		return 500;

	end

	local full_filename = join_path(dirname, filename);

	local fh, ferr = io.open(full_filename, "w");

	if not fh then

		module:log("error", "Could not open file %s for upload: %s", full_filename, ferr);

		return 500;

	end

	local ok, err = fh:write(event.request.body);

	if not ok then

		module:log("error", "Could not write to file %s for upload: %s", full_filename, err);

		os.remove(full_filename);

		return 500;

	end

	ok, err = fh:close();

	if not ok then

		module:log("error", "Could not write to file %s for upload: %s", full_filename, err);

		os.remove(full_filename);

		return 500;

	end

	module:log("info", "File uploaded by %s to slot %s", pending_slots[path], random);

	pending_slots[path] = nil;

	return 200;

end

	end

end

local function serve_head(event, path)

	return serve_uploaded_files(event, path);

end

module:provides("http", {

	route = {

		["GET /*"] = serve_uploaded_files;

		["HEAD /*"] = serve_head;

		["PUT /*"] = upload_data;

	};

});

module:log("info", "URL: <%s>; Storage path: %s", module:http_url(), storage_path);