local it = require "util.iterators";

local http = require "util.http";

local sm = require "core.storagemanager";

local st = require "util.stanza";

local xml = require "util.xml";

local tokens = module:depends("tokenauth");

module:depends("storage_xep0227");

local archive_store_name = module:get_option("archive_store", "archive");

local known_stores = {

	accounts = "keyval";

	roster = "keyval";

	private = "keyval";

	pep = "keyval";

	vcard = "keyval";

	[archive_store_name] = "archive";

	pep_data = "archive";

};

local function new_user_xml(username, host)

	local user_xml = st.stanza("server-data", {xmlns='urn:xmpp:pie:0'})

		:tag("host", { jid = host })

			:tag("user", { name = username }):reset();

	return {

		set_user_xml = function (_, store_username, store_host, new_xml)

			if username ~= store_username or store_host ~= host then

				return nil;

			end

			user_xml = new_xml;

			return true;

		end;

		get_user_xml = function (_, store_username, store_host)

			if username ~= store_username or store_host ~= host then

				return nil;

			end

			return user_xml;

		end

	};

end

local function get_selected_stores(query_params)

	local selected_kv_stores, selected_archive_stores, export_pep_data = {}, {}, false;

	if query_params.stores then

		for store_name in query_params.stores:gmatch("[^,]+") do

			local store_type = known_stores[store_name];

			if store_type == "keyval" then

				table.insert(selected_kv_stores, store_name);

			elseif store_type == "archive" then

				if store_name == "pep_data" then

					export_pep_data = true;

				else

					table.insert(selected_archive_stores, store_name);

				end

			else

				module:log("warn", "Unknown store: %s", store_name);

				return 400;

			end

		end

	end

	return {

		keyval = selected_kv_stores;

		archive = selected_archive_stores;

		export_pep_data = export_pep_data;

	};

end

local function get_config_driver(store_name, host)

	-- Fiddling to handle the 'pep_data' storage config override

	if store_name:find("pep_", 1, true) == 1 then

		store_name = "pep_data";

	end

	-- Return driver

	return sm.get_driver(host, store_name);

end

local function handle_export_227(event)

	local session = assert(event.session, "No session found");

	local xep227_driver = sm.load_driver(session.host, "xep0227");

	local username = session.username;

	local user_xml = new_user_xml(session.username, session.host);

	local query_params = http.formdecode(event.request.url.query or "");

	local selected_stores = get_selected_stores(query_params);

	for store_name in it.values(selected_stores.keyval) do

		-- Open the source store that contains the data

		local store = sm.open(session.host, store_name);

		-- Read the current data

		local data, err = store:get(username);

		if data ~= nil or not err then

			-- Initialize the destination store (XEP-0227 backed)

			local target_store = xep227_driver:open_xep0227(store_name, nil, user_xml);

			-- Transform the data and update user_xml (via the _set_user_xml callback)

			if not target_store:set(username, data == nil and {} or data) then

				return 500;

			end

		elseif err then

			return 500;

		end

	end

	if selected_stores.export_pep_data then

		local pep_node_list = sm.open(session.host, "pep"):get(session.username);

		if pep_node_list then

			for node_name in it.keys(pep_node_list) do

				table.insert(selected_stores.archive, "pep_"..node_name);

			end

		end

	end

	for store_name in it.values(selected_stores.archive) do

		local source_driver = get_config_driver(store_name, session.host);

		local source_archive = source_driver:open(store_name, "archive");

		local dest_archive = xep227_driver:open_xep0227(store_name, "archive", user_xml);

		local results_iter, results_err = source_archive:find(username);

		if results_iter then

			local count, errs = 0, 0;

			for id, item, when, with in results_iter do

				local ok, err = dest_archive:append(username, id, item, when, with);

				if ok then

					count = count + 1;

				else

					module:log("warn", "Error: %s", err);

					errs = errs + 1;

				end

				if ( count + errs ) % 100 == 0 then

					module:log("info", "%d items migrated, %d errors", count, errs);

				end

			end

		elseif results_err then

			module:log("warn", "Unable to read from '%s': %s", store_name, results_err);

			return 500;

		end

	end

	local xml_data = user_xml:get_user_xml(username, session.host);

	if not xml_data or not xml_data:find("host/user") then

		module:log("warn", "No data to export: %s", tostring(xml_data));

		return 204;

	end

	event.response.headers["Content-Type"] = "application/xml";

	return [[<?xml version="1.0" encoding="utf-8" ?>]]..tostring(xml_data);

end

local function is_looking_like_xep227(xml_data)

	if not xml_data or xml_data.name ~= "server-data"

	or xml_data.attr.xmlns ~= "urn:xmpp:pie:0" then

		return false;

	end

	-- Looks like 227, but check it has at least one host + user element

	return not not xml_data:find("host/user");

end

local function handle_import_227(event)

	local session = assert(event.session, "No session found");

	local username = session.username;

	local input_xml_raw = event.request.body;

	local input_xml_parsed = xml.parse(input_xml_raw);

	-- Some sanity checks

	if not input_xml_parsed or not is_looking_like_xep227(input_xml_parsed) then

		module:log("warn", "No data to import");

		return 422;

	end

	-- Set the host and username of the import to the new account's user/host

	input_xml_parsed:find("host").attr.jid = session.host;

	input_xml_parsed:find("host/user").attr.name = username;

	local user_xml = new_user_xml(session.username, session.host);

	user_xml:set_user_xml(username, session.host, input_xml_parsed);

	local xep227_driver = sm.load_driver(session.host, "xep0227");

	for _, store_name in ipairs(selected_stores.keyval) do

		-- Initialize the destination store (XEP-0227 backed)

		local store = xep227_driver:open_xep0227(store_name, nil, user_xml);

		-- Read the current data

		local data, err = store:get(username);

		if data ~= nil or not err then

			local target_store = sm.open(session.host, store_name);

			-- Transform the data and update user_xml (via the _set_user_xml callback)

			if not target_store:set(username, data == nil and {} or data) then

				return 500;

			end

		elseif err then

			return 500;

		end

	end

	if selected_stores.export_pep_data then

		local pep_store = xep227_driver:open_xep0277("pep", nil, user_xml);

		local pep_node_list = pep_store:get(session.username);

		if pep_node_list then

			for node_name in it.keys(pep_node_list) do

				table.insert(selected_stores.archive, "pep_"..node_name);

			end

		end

	end

	for store_name in it.values(selected_stores.archive) do

		local source_archive = xep227_driver:open_xep0227(store_name, "archive", user_xml);

		local dest_driver = get_config_driver(store_name, session.host);

		local dest_archive = dest_driver:open(store_name, "archive");

		local results_iter, results_err = source_archive:find(username);

		if results_iter then

			local count, errs = 0, 0;

			for id, item, when, with in source_archive:find(username) do

				local ok, err = dest_archive:append(username, id, item, when, with);

				if ok then

					count = count + 1;

				else

					module:log("warn", "Error: %s", err);

					errs = errs + 1;

				end

				if ( count + errs ) % 100 == 0 then

					module:log("info", "%d items migrated, %d errors", count, errs);

				end

			end

		elseif results_err then

			module:log("warn", "Unable to read from '%s': %s", store_name, results_err);

			return 500;

		end

	end

	return 200;

end

---

local function check_credentials(request)

	local auth_type, auth_data = string.match(request.headers.authorization or "", "^(%S+)%s(.+)$");

	if not (auth_type and auth_data) then

		return false;

	end

	if auth_type == "Bearer" then

		local token_info = tokens.get_token_info(auth_data);

		if not token_info or not token_info.session then

			return false;

		end

		return token_info.session;

	end

	return nil;

end

local function check_auth(routes)

	local function check_request_auth(event)

		local session = check_credentials(event.request);

		if not session then

			event.response.headers.authorization = ("Bearer realm=%q"):format(module.host.."/"..module.name);

			return false, 401;

		end

		event.session = session;

		return true;

	end

	for route, handler in pairs(routes) do

		routes[route] = function (event, ...)

			local permit, code = check_request_auth(event);

			if not permit then

				return code;

			end

			return handler(event, ...);

		end;

	end

	return routes;

end

module:provides("http", {

	route = check_auth {

		["GET /export"] = handle_export_227;

		["PUT /import"] = handle_import_227;

	};

});