#!/usr/bin/env escript

main([]) ->
    try
        {ok,DefaultDirName}=file:get_cwd(),
        NodeName = input("Please enter a node name", make_nodename() ),
        Cookie = input("Please enter a network cookie", "oreo" ),
        DirName = input("Please enter a directory name", DefaultDirName ),
        WebUiPort = input("Please enter the WEB UI port", "9090" ),
        file_substitute(filename:join(["priv","templates","simmanager.config.template"]),
            filename:join(["config","simmanager.config"]),
            [{"$$PROJECT_HOME$$",DirName},{"$$WEB_UI_PORT$$",WebUiPort}]),
        file_substitute(filename:join(["priv","templates","simmanager.args.template"]),
            filename:join(["config","simmanager.args"]),
            [{"$$NODE_NAME$$",NodeName},{"$$COOKIE$$",Cookie}]),
        file:make_dir(filename:join(["priv","mnesia"]))
    catch
        _:_ ->
            usage()
    end;
main(_) ->
    usage().

usage() ->
    io:format("usage: mqtt_config <project_home_prefix>~n"),
    halt(1).

find_hostname()->
    {ok,Hostname}=inet:gethostname(),
    {ok,{hostent,_RealHostname,_,inet,4,[A|_]}}=inet_res:gethostbyname(Hostname),
    {ok,{hostent,VerifiedHostName,_,inet,4,_}}=inet_res:gethostbyaddr(A),
    VerifiedHostName.

make_nodename()->
    "simmanager@" ++ find_hostname().

replace([],FinalBlob)->
    FinalBlob;
replace([{Variable,Value}|T],Blob) when is_integer(Value)->
    replace(T,string:replace(Blob,Variable,integer_to_list(Value),all));
replace([{Variable,Value}|T],Blob) when is_list(Value)->
    replace(T,string:replace(Blob,Variable,Value,all)).

file_substitute(FileNameIn,FileNameOut,VariableList)->
    {ok,FileBin}=file:read_file(FileNameIn),
    FileBlob=binary_to_list(FileBin),
    NewBlob=replace(VariableList,FileBlob),
    file:write_file(FileNameOut,list_to_binary(NewBlob)).

input(Prompt,Default)->
    InputData=string:trim(io:get_line( Prompt ++ " [" ++ Default ++ "] :")),
    case InputData=="" of
        true -> Default;
        false -> InputData
    end.