  Copyright ( c ) 2009 Hypothetical Labs , Inc.
 
%% Permission is hereby granted, free of charge, to any person obtaining a copy
%% of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction , including without limitation the rights
%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software , and to permit persons to whom the Software is
%% furnished to do so, subject to the following conditions:
%%
%% The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software .
%%
  THE SOFTWARE IS PROVIDED " AS IS " , WITHOUT WARRANTY OF ANY KIND , EXPRESS OR
%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY , WHETHER IN AN ACTION OF CONTRACT , TORT OR OTHERWISE , ARISING FROM ,
%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
%% THE SOFTWARE.
 
-module(gen_nb_server).
 
-author('').
 
-behaviour(gen_server).
 
%% API
-export([start_link/4]).
 
%% Behavior callbacks
-export([behaviour_info/1]).
 
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
         terminate/2, code_change/3]).
 
-define(SERVER, ?MODULE).
 
-record(state, {cb,
                sock,
                server_state}).
 
%% @hidden
behaviour_info(callbacks) ->
  [{init, 1},
   {handle_call, 3},
   {handle_cast, 2},
   {handle_info, 2},
   {terminate, 2},
   {sock_opts, 0},
   {new_connection, 2}];
 
behaviour_info(_) ->
  undefined.
 
  @spec start_link(CallbackModule , IpAddr , Port , InitParams ) - > Result
  CallbackModule = atom ( )
%% IpAddr = string()
%% Port = integer()
  InitParams = [ any ( ) ]
%% Result = {ok, pid()} | {error, any()}
%% @doc Start server listening on IpAddr:Port
start_link(CallbackModule, IpAddr, Port, InitParams) ->
  gen_server:start_link(?MODULE, [CallbackModule, IpAddr, Port, InitParams], []).
 
%% @hidden
init([CallbackModule, IpAddr, Port, InitParams]) ->
  case CallbackModule:init(InitParams) of
    {ok, ServerState} ->
      case listen_on(CallbackModule, IpAddr, Port) of
        {ok, Sock} ->
          {ok, #state{cb=CallbackModule, sock=Sock, server_state=ServerState}};
        Error ->
          CallbackModule:terminate(Error, ServerState),
          Error
      end;
    Err ->
      Err
  end.
 
%% @hidden
handle_call(Request, From, #state{cb=Callback, server_state=ServerState}=State) ->
  case Callback:handle_call(Request, From, ServerState) of
    {reply, Reply, NewServerState} ->
      {reply, Reply, State#state{server_state=NewServerState}};
    {reply, Reply, NewServerState, Arg} when Arg =:= hibernate orelse is_number(Arg) ->
      {reply, Reply, State#state{server_state=NewServerState}, Arg};
    {noreply, NewServerState} ->
      {noreply, State#state{server_state=NewServerState}};
    {noreply, NewServerState, Arg} when Arg =:= hibernate orelse is_number(Arg) ->
      {noreply, State#state{server_state=NewServerState}, Arg};
    {stop, Reason, NewServerState} ->
      {stop, Reason, State#state{server_state=NewServerState}};
    {stop, Reason, Reply, NewServerState} ->
      {stop, Reason, Reply, State#state{server_state=NewServerState}}
  end.
 
%% @hidden
handle_cast(Msg, #state{cb=Callback, server_state=ServerState}=State) ->
  case Callback:handle_cast(Msg, ServerState) of
    {noreply, NewServerState} ->
      {noreply, State#state{server_state=NewServerState}};
    {noreply, NewServerState, Arg} when Arg =:= hibernate orelse is_number(Arg) ->
      {noreply, State#state{server_state=NewServerState}, Arg};
    {stop, Reason, NewServerState} ->
      {stop, Reason, State#state{server_state=NewServerState}}
  end.
 
%% @hidden
handle_info({inet_async, ListSock, _Ref, {ok, CliSocket}}, #state{cb=Callback, server_state=ServerState}=State) ->
  inet_db:register_socket(CliSocket, inet_tcp),
  case Callback:new_connection(CliSocket, ServerState) of
    {ok, NewServerState} ->
      prim_inet:async_accept(ListSock, -1),
      {noreply, State#state{server_state=NewServerState}};
    {stop, Reason, NewServerState} ->
      {stop, Reason, State#state{server_state=NewServerState}}
  end;
 
handle_info(Info, #state{cb=Callback, server_state=ServerState}=State) ->
  case Callback:handle_info(Info, ServerState) of
    {noreply, NewServerState} ->
      {noreply, State#state{server_state=NewServerState}};
    {noreply, NewServerState, Arg} when Arg =:= hibernate orelse is_number(Arg) ->
      {noreply, State#state{server_state=NewServerState}, Arg};
    {stop, Reason, NewServerState} ->
      {stop, Reason, State#state{server_state=NewServerState}}
  end.
 
%% @hidden
terminate(Reason, #state{cb=Callback, sock=Sock, server_state=ServerState}) ->
  gen_tcp:close(Sock),
  Callback:terminate(Reason, ServerState),
  ok.
 
%% @hidden
code_change(_OldVsn, State, _Extra) ->
  {ok, State}.
 
  Internal functions
 
%% @hidden
  @spec listen_on(CallbackModule , IpAddr , Port ) - > Result
  CallbackModule = atom ( )
%% IpAddr = string()
%% Port = integer()
%% Result = {ok, port()} | {error, any()}
listen_on(CallbackModule, IpAddr, Port) ->
  SockOpts = [{ip, convert(IpAddr)}|CallbackModule:sock_opts()],
  case gen_tcp:listen(Port, SockOpts) of
    {ok, LSock} ->
      {ok, _Ref} = prim_inet:async_accept(LSock, -1),
      {ok, LSock};
    Err ->
      Err
  end.
 
%% @hidden
   convert(Addr ) - > Result
%% Addr = string()
%% Result = {integer(), integer(), integer(), integer()}
  @doc Converts text IP addresses " 0.0.0.0 " to tuples { 0 , 0 , 0 , 0 }
convert(Addr) ->
  T = string:tokens(Addr, "."),
  list_to_tuple([list_to_integer(X) || X <- T]).

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in

 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 API
 Behavior callbacks
 gen_server callbacks
 @hidden
 IpAddr = string()
 Port = integer()
 Result = {ok, pid()} | {error, any()}
 @doc Start server listening on IpAddr:Port
 @hidden
 @hidden
 @hidden
 @hidden
 @hidden
 @hidden
 @hidden
 IpAddr = string()
 Port = integer()
 Result = {ok, port()} | {error, any()}
 @hidden
 Addr = string()
 Result = {integer(), integer(), integer(), integer()}
  Copyright ( c ) 2009 Hypothetical Labs , Inc.
 
  in the Software without restriction , including without limitation the rights
  copies of the Software , and to permit persons to whom the Software is
  all copies or substantial portions of the Software .
  THE SOFTWARE IS PROVIDED " AS IS " , WITHOUT WARRANTY OF ANY KIND , EXPRESS OR
  LIABILITY , WHETHER IN AN ACTION OF CONTRACT , TORT OR OTHERWISE , ARISING FROM ,
 
-module(gen_nb_server).
 
-author('').
 
-behaviour(gen_server).
 
-export([start_link/4]).
 
-export([behaviour_info/1]).
 
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
         terminate/2, code_change/3]).
 
-define(SERVER, ?MODULE).
 
-record(state, {cb,
                sock,
                server_state}).
 
behaviour_info(callbacks) ->
  [{init, 1},
   {handle_call, 3},
   {handle_cast, 2},
   {handle_info, 2},
   {terminate, 2},
   {sock_opts, 0},
   {new_connection, 2}];
 
behaviour_info(_) ->
  undefined.
 
  @spec start_link(CallbackModule , IpAddr , Port , InitParams ) - > Result
  CallbackModule = atom ( )
  InitParams = [ any ( ) ]
start_link(CallbackModule, IpAddr, Port, InitParams) ->
  gen_server:start_link(?MODULE, [CallbackModule, IpAddr, Port, InitParams], []).
 
init([CallbackModule, IpAddr, Port, InitParams]) ->
  case CallbackModule:init(InitParams) of
    {ok, ServerState} ->
      case listen_on(CallbackModule, IpAddr, Port) of
        {ok, Sock} ->
          {ok, #state{cb=CallbackModule, sock=Sock, server_state=ServerState}};
        Error ->
          CallbackModule:terminate(Error, ServerState),
          Error
      end;
    Err ->
      Err
  end.
 
handle_call(Request, From, #state{cb=Callback, server_state=ServerState}=State) ->
  case Callback:handle_call(Request, From, ServerState) of
    {reply, Reply, NewServerState} ->
      {reply, Reply, State#state{server_state=NewServerState}};
    {reply, Reply, NewServerState, Arg} when Arg =:= hibernate orelse is_number(Arg) ->
      {reply, Reply, State#state{server_state=NewServerState}, Arg};
    {noreply, NewServerState} ->
      {noreply, State#state{server_state=NewServerState}};
    {noreply, NewServerState, Arg} when Arg =:= hibernate orelse is_number(Arg) ->
      {noreply, State#state{server_state=NewServerState}, Arg};
    {stop, Reason, NewServerState} ->
      {stop, Reason, State#state{server_state=NewServerState}};
    {stop, Reason, Reply, NewServerState} ->
      {stop, Reason, Reply, State#state{server_state=NewServerState}}
  end.
 
handle_cast(Msg, #state{cb=Callback, server_state=ServerState}=State) ->
  case Callback:handle_cast(Msg, ServerState) of
    {noreply, NewServerState} ->
      {noreply, State#state{server_state=NewServerState}};
    {noreply, NewServerState, Arg} when Arg =:= hibernate orelse is_number(Arg) ->
      {noreply, State#state{server_state=NewServerState}, Arg};
    {stop, Reason, NewServerState} ->
      {stop, Reason, State#state{server_state=NewServerState}}
  end.
 
handle_info({inet_async, ListSock, _Ref, {ok, CliSocket}}, #state{cb=Callback, server_state=ServerState}=State) ->
  inet_db:register_socket(CliSocket, inet_tcp),
  case Callback:new_connection(CliSocket, ServerState) of
    {ok, NewServerState} ->
      prim_inet:async_accept(ListSock, -1),
      {noreply, State#state{server_state=NewServerState}};
    {stop, Reason, NewServerState} ->
      {stop, Reason, State#state{server_state=NewServerState}}
  end;
 
handle_info(Info, #state{cb=Callback, server_state=ServerState}=State) ->
  case Callback:handle_info(Info, ServerState) of
    {noreply, NewServerState} ->
      {noreply, State#state{server_state=NewServerState}};
    {noreply, NewServerState, Arg} when Arg =:= hibernate orelse is_number(Arg) ->
      {noreply, State#state{server_state=NewServerState}, Arg};
    {stop, Reason, NewServerState} ->
      {stop, Reason, State#state{server_state=NewServerState}}
  end.
 
terminate(Reason, #state{cb=Callback, sock=Sock, server_state=ServerState}) ->
  gen_tcp:close(Sock),
  Callback:terminate(Reason, ServerState),
  ok.
 
code_change(_OldVsn, State, _Extra) ->
  {ok, State}.
 
  Internal functions
 
  @spec listen_on(CallbackModule , IpAddr , Port ) - > Result
  CallbackModule = atom ( )
listen_on(CallbackModule, IpAddr, Port) ->
  SockOpts = [{ip, convert(IpAddr)}|CallbackModule:sock_opts()],
  case gen_tcp:listen(Port, SockOpts) of
    {ok, LSock} ->
      {ok, _Ref} = prim_inet:async_accept(LSock, -1),
      {ok, LSock};
    Err ->
      Err
  end.
 
   convert(Addr ) - > Result
  @doc Converts text IP addresses " 0.0.0.0 " to tuples { 0 , 0 , 0 , 0 }
convert(Addr) ->
  T = string:tokens(Addr, "."),
  list_to_tuple([list_to_integer(X) || X <- T]).
