require("std")

local prettytostring = prettytostring

local lfs = require("lfs")

local io = io

local setmetatable = setmetatable

local loadstring = loadstring

local pairs = pairs



module("config")





function new(filepath,default_config)

    local _t

    

    local function save_config()

        local f = io.open(filepath,"w")

        f:write(prettytostring(_t))

        f:close()

        --print(prettytostring(_t))

    end

    

    if lfs.attributes(filepath) then

        local f = io.open(filepath,"r")

        local s = f:read("*a")

        local f2 = loadstring("local t = "..s.." return t")

        f:close()

        _t = f2()

        

        local modified = false

        --make sure all config key have value

        for k,v in pairs(default_config) do

            if _t[k]==nil then

                _t[k]=v

                modified = true

            end

        end

        if modified then save_config() end

    else

        _t = default_config

        save_config()

    end

    

    local proxy = {}

    local proxy_mt =

    {

        __index =

            function(t,k)

                return _t[k]

            end

        ,

        __newindex =

            function(t,k,v)

                _t[k]=v

                save_config()

            end

    }

    setmetatable(proxy,proxy_mt)

    return proxy

end