%% ---
%%  Excerpted from "Programming Erlang"
%%  Copyrights apply to this code. It may not be used to create training 
material, 
%%  courses, books, articles, and the like. Contact us if you are in 
doubt.
%%  We make no guarantees that this code is fit for any purpose. 
%%  Visit http://www.pragmaticprogrammer.com/titles/jaerlang for more book 
information.
%%---
-module(chat_client).

-import(io_widget, 
	[get_state/1, insert_str/2, set_prompt/2, set_state/2, 
	 set_title/2, set_handler/2, update_state/3]).

-export([start/0, test/0, connect/5]).


start() -> 
    connect("localhost", 2223, "AsDT67aQ", "general", "joe").


test() ->
    connect("localhost", 2223, "AsDT67aQ", "general", "joe"),
    connect("localhost", 2223, "AsDT67aQ", "general", "jane"),
    connect("localhost", 2223, "AsDT67aQ", "general", "jim"),
    connect("localhost", 2223, "AsDT67aQ", "general", "sue").
	   

connect(Host, Port, HostPsw, Group, Nick) ->
    spawn(fun() -> handler(Host, Port, HostPsw, Group, Nick) end).
				 
handler(Host, Port, HostPsw, Group, Nick) ->
    process_flag(trap_exit, true),
    Widget = io_widget:start(self()),
    set_title(Widget, Nick),
    set_state(Widget, Nick),
    set_prompt(Widget, [Nick, " > "]),
    set_handler(Widget, fun parse_command/1),
    start_connector(Host, Port, HostPsw),    
    disconnected(Widget, Group, Nick).



disconnected(Widget, Group, Nick) ->
    receive
	{connected, MM} ->
	    insert_str(Widget, "connected to server\nsending data\n"),
	    lib_chan_mm:send(MM, {login, Group, Nick}),
	    wait_login_response(Widget, MM);
	{Widget, destroyed} ->
	    exit(died);
	{status, S} ->
	    insert_str(Widget, to_str(S)),
	    disconnected(Widget, Group, Nick);
	Other ->
	    io:format("chat_client disconnected unexpected:~p~n",[Other]),
	    disconnected(Widget, Group, Nick)
    end.



wait_login_response(Widget, MM) ->
    receive
	{chan, MM, ack} ->
	    active(Widget, MM);
	Other ->
	    io:format("chat_client login unexpected:~p~p~n",[Other,MM]),
	    wait_login_response(Widget, MM)
    end. 



active(Widget, MM) ->
     receive
	 {Widget, Nick, Str} ->
	     lib_chan_mm:send(MM, {relay, Nick, Str}),
	     active(Widget, MM);
	 {chan,MM,{msg,From,Pid,Str}} ->
	     insert_str(Widget, [From,"@",pid_to_list(Pid)," ", Str, 
"\n"]),
	     active(Widget, MM);
	 {'EXIT',Widget,windowDestroyed} ->
	     lib_chan_mm:close(MM);
	 {close, MM} ->
	     exit(serverDied);
	 Other ->
	     io:format("chat_client active unexpected:~p~n",[Other]),
	     active(Widget, MM)
     end. 



start_connector(Host, Port, Pwd) ->
    S = self(),
    spawn_link(fun() -> try_to_connect(S, Host, Port, Pwd) end).
    
try_to_connect(Parent, Host, Port, Pwd) ->
    %% Parent is the Pid of the process that spawned this process
    case lib_chan:connect(Host, Port, chat, Pwd, []) of
	{error, _Why} ->
	    Parent ! {status, {cannot, connect, Host, Port}},
	    sleep(2000),
	    try_to_connect(Parent, Host, Port, Pwd);
	{ok, MM} ->
	    lib_chan_mm:controller(MM, Parent),
	    Parent ! {connected, MM},
	    exit(connectorFinished)
    end.


sleep(T) ->
    receive
    after T -> true
    end.
	    
to_str(Term) ->
    io_lib:format("~p~n",[Term]).

parse_command(Str) -> skip_to_gt(Str).

skip_to_gt(">" ++ T) -> T;
skip_to_gt([_|T])    -> skip_to_gt(T);
skip_to_gt([])       -> exit("no >").