local print = print;

local assert = assert;

local setmetatable = setmetatable;

local tonumber = tonumber;

local char = string.char;

local coroutine = coroutine;

local lfs = require "lfs";

local loadfile = loadfile;

local pcall = pcall;

local mtools = require "migrator.mtools";

local next = next;

local pairs = pairs;

local json = require "util.json";

local os_getenv = os.getenv;

local error = error;

prosody = {};

local dm = require "util.datamanager"

local function is_dir(path) return lfs.attributes(path, "mode") == "directory"; end

local function is_file(path) return lfs.attributes(path, "mode") == "file"; end

local function clean_path(path)

	return path:gsub("\\", "/"):gsub("//+", "/"):gsub("^~", os_getenv("HOME") or "~");

end

local encode, decode; do

	local urlcodes = setmetatable({}, { __index = function (t, k) t[k] = char(tonumber("0x"..k)); return t[k]; end });

	decode = function (s) return s and (s:gsub("+", " "):gsub("%%([a-fA-F0-9][a-fA-F0-9])", urlcodes)); end

	encode = function (s) return s and (s:gsub("%W", function (c) return format("%%%02x", c:byte()); end)); end

end

local function decode_dir(x)

	if x:gsub("%%%x%x", ""):gsub("[a-zA-Z0-9]", "") == "" then

		return decode(x);

	end

end

local function decode_file(x)

	if x:match(".%.dat$") and x:gsub("%.dat$", ""):gsub("%%%x%x", ""):gsub("[a-zA-Z0-9]", "") == "" then

		return decode(x:gsub("%.dat$", ""));

	end

end

local function prosody_dir(path, ondir, onfile, ...)

	for x in lfs.dir(path) do

		local xpath = path.."/"..x;

		if decode_dir(x) and is_dir(xpath) then

			ondir(xpath, x, ...);

		elseif decode_file(x) and is_file(xpath) then

			onfile(xpath, x, ...);

		end

	end

end

local function handle_root_file(path, name)

	--print("root file: ", decode_file(name))

	coroutine.yield { user = nil, host = nil, store = decode_file(name) };

end

local function handle_host_file(path, name, host)

	--print("host file: ", decode_dir(host).."/"..decode_file(name))

	coroutine.yield { user = nil, host = decode_dir(host), store = decode_file(name) };

end

local function handle_store_file(path, name, store, host)

	--print("store file: ", decode_file(name).."@"..decode_dir(host).."/"..decode_dir(store))

	coroutine.yield { user = decode_file(name), host = decode_dir(host), store = decode_dir(store) };

end

local function handle_host_store(path, name, host)

	prosody_dir(path, function() end, handle_store_file, name, host);

end

local function handle_host_dir(path, name)

	prosody_dir(path, handle_host_store, handle_host_file, name);

end

local function handle_root_dir(path)

	prosody_dir(path, handle_host_dir, handle_root_file);

end

local function decode_user(item)

	local userdata = {

		user = item[1].user;

		host = item[1].host;

		stores = {};

	};

	for i=1,#item do -- loop over stores

		local result = {};

		local store = item[i];

		userdata.stores[store.store] = store.data;

		store.user = nil; store.host = nil; store.store = nil;

	end

	return userdata;

end

local function reader(input)

	local path = clean_path(assert(input.path, "no input.path specified"));

	assert(is_dir(path), "input.path is not a directory");

	local iter = coroutine.wrap(function()handle_root_dir(path);end);

	-- get per-user stores, sorted

	local iter = mtools.sorted {

		reader = function()

			local x = iter();

			while x do

				dm.set_data_path(path);

				local err;

				x.data, err = dm.load(x.user, x.host, x.store);

				if x.data == nil and err then

					local p = dm.getpath(x.user, x.host, x.store);

					print(("Error loading data at path %s for %s@%s (%s store): %s")

						:format(p, x.user or "<nil>", x.host or "<nil>", x.store or "<nil>", err or "<nil>"));

				else

					return x;

				end

				x = iter();

			end

		end;

		sorter = function(a, b)

			local a_host, a_user, a_store = a.host or "", a.user or "", a.store or "";

			local b_host, b_user, b_store = b.host or "", b.user or "", b.store or "";

			return a_host > b_host or (a_host==b_host and a_user > b_user) or (a_host==b_host and a_user==b_user and a_store > b_store);

		end;

	};

	-- merge stores to get users

	iter = mtools.merged(iter, function(a, b)

		return (a.host == b.host and a.user == b.user);

	end);

	return function()

		local x = iter();

		return x and decode_user(x);

	end

end

local function writer(output)

	local path = clean_path(assert(output.path, "no output.path specified"));

	assert(is_dir(path), "output.path is not a directory");

	return function(item)

		if not item then return; end -- end of input

		dm.set_data_path(path);

		for store, data in pairs(item.stores) do

			assert(dm.store(item.user, item.host, store, data));

		end

	end

end

return {

	reader = reader;

	writer = writer;

}