%%% BEGIN openflax/handler/rewrite.erl %%%
%%%
%%% openflax - Open Source web server for Erlang/OTP
%%% Copyright (c)2004 Cat's Eye Technologies.  All rights reserved.
%%%
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%%% modification, are permitted provided that the following conditions
%%% are met:
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%%%   notice, this list of conditions and the following disclaimer.
%%%
%%%   Redistributions in binary form must reproduce the above copyright
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%%%   distribution.
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%%%   Neither the name of Cat's Eye Technologies nor the names of its
%%%   contributors may be used to endorse or promote products derived
%%%   from this software without specific prior written permission.
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%% @doc URI rewriting handler for OpenFlax.
%%
%% <p>This handler can be invoked from <code>cfg_openflax_dispatch</code>
%% when the URI matches a some pattern.  The URI will be rewritten according
%% to certain rules, and the user agent will be redirected to the new URI.</p>
%%
%% @end

-module(openflax.handler.rewrite).
-vsn('$Id: rewrite.erl 31 2004-04-23 07:00:11Z catseye $').
-author('cpressey@catseye.mine.nu').
-copyright('Copyright (c)2004 Cat`s Eye Technologies. All rights reserved.').

-behaviour(openflax.handler).

-export([start/1, stop/1, serve/1]). % behaviour

-import(lists).
-import(string).
-import(filename).
-import(file).

%% @spec start(conf()) -> conf()
%% @doc Initializes the rewriting handler.

start(_Conf) ->
  openflax.conf:new().

%% @spec stop(conf()) -> conf()
%% @doc Shuts down the rewriting handler.

stop(Conf) ->
  Conf.

%% @spec serve(conf()) -> ok | {error, Reason}
%% @doc Rewrites the URI and redirects the user agent there.

serve(Conf) ->
  % TODO: Obey rules.
  URI = openflax.conf:get_string(sreq_basic_resource, Conf),
  % Find the first hyphen in the URI
  case string:chr(URI, $-) of
    0 ->
      % this shouldn't happen.
      {not_found, Conf};
    HyphenPos ->
      URI0 = string:substr(URI, 1, HyphenPos - 1) ++ "/",
      openflax.app:debug(new_uri, URI0),
      {{moved_permanently, URI0}, Conf}
  end.

%%% END of openflax/handler/rewrite.erl %%%