local dump = require "util.serialization".serialize;

local load = require "util.envload".envloadfile;

local dm = require "core.storagemanager".olddm;

local driver = {};

local map = {};

local map_mt = { __index = map };

map.remove = {};

function map:get(user, key)

	module:log("debug", "map:get(%s, %s)", tostring(user), tostring(key))

	local filename = dm.getpath(user, module.host, self.store, "map");

	module:log("debug", "File is %s", filename);

	local env = {};

	if _VERSION == "Lua 5.1" then -- HACK

		env._ENV = env; -- HACK

	end -- SO MANY HACKS

	local chunk, err = load(filename, env);

	if not chunk then return chunk, err; end

	local ok, err = pcall(chunk);

	if not ok then return ok, err; end

	if _VERSION == "Lua 5.1" then -- HACK

		env._ENV = nil; -- HACK

	end -- HACKS EVERYWHERE

	if key == nil then

		return env;

	end

	return env[key];

end

function map:set_keys(user, keyvalues)

	local keys, values = {}, {};

	if _VERSION == "Lua 5.1" then

		assert(keyvalues._ENV == nil, "'_ENV' is a restricted key");

	end

	for key, value in pairs(keyvalues) do

		module:log("debug", "user %s sets %q to %s", user, key, tostring(value))

			key = "_ENV[" .. dump(key) .. "]";

		end

		table.insert(keys, key);

		if value == self.remove then

			table.insert(values, "nil")

		else

			table.insert(values, dump(value))

		end

	end

	local data = table.concat(keys, ", ") .. " = " .. table.concat(values, ", ") .. ";\n";

	return dm.append_raw(user, module.host, self.store, "map", data);

end

function map:set(user, key, value)

	if _VERSION == "Lua 5.1" then

		assert(key ~= "_ENV", "'_ENV' is a restricted key");

	end

	if key == nil then

		local filename = dm.getpath(user, module.host, self.store, "map");

		os.remove(filename);

		return true;

	end

	if type(key) ~= "string" or not key:find("^[%w_][%w%d_]*$") or key == "_ENV" then

		key = "_ENV[" .. dump(key) .. "]";

	end

	local data = key .. " = " .. dump(value) .. ";\n";

	return dm.append_raw(user, module.host, self.store, "map", data);

end

local keyval = {};

local keyval_mt = { __index = keyval };

function keyval:get(user)

	return map.get(self, user);

end

function keyval:set(user, data)

	map.set(self, user);

	if data then

		for k, v in pairs(data) do

			map.set(self, user, k, v);

		end

	end

	return true;

end

-- TODO some kind of periodic compaction thing?

function map:_compact(user)

	local data = self:get(user);

	return keyval.set(self, user, data);

end

function driver:open(store, typ)

	if typ == "map" then

		return setmetatable({ store = store, }, map_mt);

	elseif typ == nil or typ == "keyval" then

		return setmetatable({ store = store, }, keyval_mt);

	end

	return nil, "unsupported-store";

end

module:provides("storage", driver);