%%%----------------------------------------------------------------------
%%% File    : ejabberd_auth_odbc.erl
%%% Author  : Alexey Shchepin <alexey@process-one.net>
%%% Purpose : Authentification via ODBC
%%% Created : 12 Dec 2004 by Alexey Shchepin <alexey@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2013   ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License
%%% along with this program; if not, write to the Free Software
%%% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
%%% 02111-1307 USA
%%%
%%%----------------------------------------------------------------------

-module(ejabberd_auth_odbc).
-author('alexey@process-one.net').

%% External exports
-export([start/1,
	 set_password/3,
	 check_password/3,
	 check_password/5,
	 try_register/3,
	 dirty_get_registered_users/0,
	 get_vh_registered_users/1,
	 get_vh_registered_users/2,
	 get_vh_registered_users_number/1,
	 get_vh_registered_users_number/2,
	 get_password/2,
	 get_password_s/2,
	 is_user_exists/2,
	 remove_user/2,
	 remove_user/3,
	 store_type/0,
	 plain_password_required/0
	]).

-include("ejabberd.hrl").

%%%----------------------------------------------------------------------
%%% API
%%%----------------------------------------------------------------------
start(_Host) ->
    ok.

plain_password_required() ->
    false.

store_type() ->
	plain.

%% @spec (User, Server, Password) -> true | false | {error, Error}
check_password(User, Server, Password) ->
    case jlib:nodeprep(User) of
	error ->
	    false;
	LUser ->
	    Username = ejabberd_odbc:escape(LUser),
	    LServer = jlib:nameprep(Server),
	    try odbc_queries:get_password(LServer, Username) of
		{selected, ["password"], [{Password}]} ->
		    Password /= ""; %% Password is correct, and not empty
		{selected, ["password"], [{_Password2}]} ->
		    false; %% Password is not correct
		{selected, ["password"], []} ->
		    false; %% Account does not exist
		{error, _Error} ->
		    false %% Typical error is that table doesn't exist
	    catch
		_:_ ->
		    false %% Typical error is database not accessible
	    end
    end.

%% @spec (User, Server, Password, Digest, DigestGen) -> true | false | {error, Error}
check_password(User, Server, Password, Digest, DigestGen) ->
    case jlib:nodeprep(User) of
	error ->
	    false;
	LUser ->
	    Username = ejabberd_odbc:escape(LUser),
	    LServer = jlib:nameprep(Server),
	    try odbc_queries:get_password(LServer, Username) of
		%% Account exists, check if password is valid
		{selected, ["password"], [{Passwd}]} ->
		    DigRes = if
				 Digest /= "" ->
				     Digest == DigestGen(Passwd);
				 true ->
				     false
			     end,
		    if DigRes ->
			    true;
		       true ->
			    (Passwd == Password) and (Password /= "")
		    end;
		{selected, ["password"], []} ->
		    false; %% Account does not exist
		{error, _Error} ->
		    false %% Typical error is that table doesn't exist
	    catch
		_:_ ->
		    false %% Typical error is database not accessible
	    end
    end.

%% @spec (User::string(), Server::string(), Password::string()) ->
%%       ok | {error, invalid_jid}
set_password(User, Server, Password) ->
    case jlib:nodeprep(User) of
	error ->
	    {error, invalid_jid};
	LUser ->
	    Username = ejabberd_odbc:escape(LUser),
	    Pass = ejabberd_odbc:escape(Password),
	    LServer = jlib:nameprep(Server),
	    case catch odbc_queries:set_password_t(LServer, Username, Pass) of
	        {atomic, ok} -> ok;
	        Other -> {error, Other}
	    end
    end.


%% @spec (User, Server, Password) -> {atomic, ok} | {atomic, exists} | {error, invalid_jid}
try_register(User, Server, Password) ->
    case jlib:nodeprep(User) of
	error ->
	    {error, invalid_jid};
	LUser ->
	    Username = ejabberd_odbc:escape(LUser),
	    Pass = ejabberd_odbc:escape(Password),
	    LServer = jlib:nameprep(Server),
	    case catch odbc_queries:add_user(LServer, Username, Pass) of
		{updated, 1} ->
		    {atomic, ok};
		_ ->
		    {atomic, exists}
	    end
    end.

dirty_get_registered_users() ->
    Servers = ejabberd_config:get_vh_by_auth_method(odbc),
    lists:flatmap(
      fun(Server) ->
	      get_vh_registered_users(Server)
      end, Servers).

get_vh_registered_users(Server) ->
    LServer = jlib:nameprep(Server),
    case catch odbc_queries:list_users(LServer) of
	{selected, ["username"], Res} ->
	    [{U, LServer} || {U} <- Res];
	_ ->
	    []
    end.

get_vh_registered_users(Server, Opts) ->
    LServer = jlib:nameprep(Server),
    case catch odbc_queries:list_users(LServer, Opts) of
	{selected, ["username"], Res} ->
	    [{U, LServer} || {U} <- Res];
	_ ->
	    []
    end.

get_vh_registered_users_number(Server) ->
    LServer = jlib:nameprep(Server),
    case catch odbc_queries:users_number(LServer) of
	{selected, [_], [{Res}]} ->
	    list_to_integer(Res);
	_ ->
	    0
    end.

get_vh_registered_users_number(Server, Opts) ->
    LServer = jlib:nameprep(Server),
    case catch odbc_queries:users_number(LServer, Opts) of
	{selected, [_], [{Res}]} ->
	    list_to_integer(Res);
	_Other ->
	    0
    end.

get_password(User, Server) ->
    case jlib:nodeprep(User) of
	error ->
	    false;
	LUser ->
	    Username = ejabberd_odbc:escape(LUser),
	    LServer = jlib:nameprep(Server),
	    case catch odbc_queries:get_password(LServer, Username) of
		{selected, ["password"], [{Password}]} ->
		    Password;
		_ ->
		    false
	    end
    end.

get_password_s(User, Server) ->
    case jlib:nodeprep(User) of
	error ->
	    "";
	LUser ->
	    Username = ejabberd_odbc:escape(LUser),
	    LServer = jlib:nameprep(Server),
	    case catch odbc_queries:get_password(LServer, Username) of
		{selected, ["password"], [{Password}]} ->
		    Password;
		_ ->
		    ""
	    end
    end.

%% @spec (User, Server) -> true | false | {error, Error}
is_user_exists(User, Server) ->
    case jlib:nodeprep(User) of
	error ->
	    false;
	LUser ->
	    Username = ejabberd_odbc:escape(LUser),
	    LServer = jlib:nameprep(Server),
	    try odbc_queries:get_password(LServer, Username) of
		{selected, ["password"], [{_Password}]} ->
		    true; %% Account exists
		{selected, ["password"], []} ->
		    false; %% Account does not exist
		{error, Error} ->
		    {error, Error} %% Typical error is that table doesn't exist
	    catch
		_:B ->
		    {error, B} %% Typical error is database not accessible
	    end
    end.

%% @spec (User, Server) -> ok | error
%% @doc Remove user.
%% Note: it may return ok even if there was some problem removing the user.
remove_user(User, Server) ->
    case jlib:nodeprep(User) of
	error ->
	    error;
	LUser ->
	    Username = ejabberd_odbc:escape(LUser),
	    LServer = jlib:nameprep(Server),
	    catch odbc_queries:del_user(LServer, Username),
		ok
    end.

%% @spec (User, Server, Password) -> ok | error | not_exists | not_allowed
%% @doc Remove user if the provided password is correct.
remove_user(User, Server, Password) ->
    case jlib:nodeprep(User) of
	error ->
	    error;
	LUser ->
	    Username = ejabberd_odbc:escape(LUser),
	    Pass = ejabberd_odbc:escape(Password),
	    LServer = jlib:nameprep(Server),
	    F = fun() ->
			Result = odbc_queries:del_user_return_password(
				   LServer, Username, Pass),
			case Result of
			    {selected, ["password"], [{Password}]} ->
				ok;
			    {selected, ["password"], []} ->
				not_exists;
			    _ ->
				not_allowed
			end
		end,
	    {atomic, Result} = odbc_queries:sql_transaction(LServer, F),
	    Result
    end.