-module(ephraim_conv).
-behaviour(gen_server).

-export([start_link/2]).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
-export([received_message/4]).

-record(conv_state, {
	  conv_ref      :: reference(),
	  event_manager :: pid(),
	  my_jid        :: binary(),
	  jid           :: binary()
	 }).

-spec start_link(pid(), binary()) -> ok.
start_link(EventManager, JID) ->
    ConvRef = make_ref(),
    io:format("Starting conversation ~p with ~p~n", [ConvRef, JID]),

    gen_event:notify(EventManager, {view_update, {conversation, ConvRef, {new, JID}}}),

    {jid,MyJID} = ephraim_config:get(jid),
    gen_server:start_link(?MODULE, #conv_state{conv_ref=ConvRef,event_manager=EventManager,my_jid=list_to_binary(MyJID),jid=JID}, []).

init(State) ->
    process_flag(trap_exit, true),
    {ok, State}.

received_message(Conv, From, Type, Body) ->
    gen_server:cast(Conv, {received_message, From, Type, Body}).

handle_call(_Msg, _From, State) ->
    {noreply, State}.

handle_cast({received_message, From, Type, Body}, State) ->
    gen_event:notify(State#conv_state.event_manager, {view_update, {conversation, State#conv_state.conv_ref, {message, From, Type, Body}}}),
    {noreply, State};
handle_cast(_Msg, State) ->
    {noreply, State}.

handle_info(_Msg, State) ->
    {ok, State}.
terminate(_Reason, State) ->
    io:format("Stopping conversation ~p with ~p~n", [State#conv_state.conv_ref, State#conv_state.jid]),
    ok.
code_change(_OldVersion, State, _Extra) ->
    {ok, State}.


-spec loop(#conv_state{}) -> ok.
loop(State) ->
    receive
        stop ->
	    ok;
	
	{receive_message, Packet} ->
	    Type = exmpp_message:get_type(Packet),
	    Body = exmpp_message:get_body(Packet),
	    if
		Body =/= undefined ->
		    ephraim ! {ui_update, {chat_message, State#conv_state.jid, Type, ephraim:get_alias(State#conv_state.jid), Body}};
		true ->
		    io:format("Received strange message from ~p:~n~p~n", [State#conv_state.jid, Packet])
	    end,
	    loop(State);
	
	{send_message, Type, Message} ->
	    Packet = exmpp_message:normal(Message),
	    Packet2 = exmpp_message:set_type(Packet, Type),
	    Packet3 = exmpp_xml:set_attribute(Packet2, to, State#conv_state.jid),
	    ephraim ! {send_packet, Packet3},
	    ephraim ! {ui_update, {chat_message, State#conv_state.jid, Type, ephraim:get_alias(State#conv_state.my_jid), Message}},
	    loop(State);
	
	Msg ->
	    io:format("ephraim_conv (~p): ~p~n", [State#conv_state.jid, Msg]),
	    loop(State)
    end.