/*
 * Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source 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.
 *
 * Resin Open Source 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, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *
 *   Free Software Foundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package com.caucho.server.security;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;

import javax.servlet.FilterChain;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletResponse;

import com.caucho.server.http.CauchoRequest;
import com.caucho.server.http.CauchoResponse;

public class SecurityFilterChain implements FilterChain {
  private FilterChain _next;

  private ServletContext _webApp;

  private AbstractConstraint []_constraints;
  private HashMap<String,AbstractConstraint[]> _methodMap;

  SecurityFilterChain(FilterChain next)
  {
    _next = next;
  }

  public void setWebApp(ServletContext app)
  {
    _webApp = app;
  }

  public void setConstraints(ArrayList<AbstractConstraint> constraints)
  {
    _constraints = new AbstractConstraint[constraints.size()];

    constraints.toArray(_constraints);
  }

  public void setMethodMap(HashMap<String,AbstractConstraint[]> methodMap)
  {
    _methodMap = methodMap;
  }

  public void destroy()
  {
  }

  @Override
  public void doFilter(ServletRequest request, ServletResponse response)
    throws ServletException, IOException
  {
    // This filter is always called before user filters so we know that
    // the request and response are AbstractRequest and Response.
    CauchoRequest req = (CauchoRequest) request;
    CauchoResponse res = (CauchoResponse) response;

    AbstractConstraint []constraints = null;
    if (_methodMap != null)
      constraints = _methodMap.get(req.getMethod());

    if (constraints == null)
      constraints = _constraints;

    AuthorizationResult result = AuthorizationResult.NONE;

    // XXX: better logging on failure

    boolean isPrivateCache = false;
    if (constraints != null) {
      for (AbstractConstraint constraint : constraints) {
        result = constraint.isAuthorized(req, res, _webApp);

        if (constraint.isPrivateCache())
          isPrivateCache = true;

        if (! result.isFallthrough())
          break;
      }
    }

    if (isPrivateCache)
      res.setPrivateCache(true);

    // server/1af3, server/12d2
    if (req.isLoginRequested() && req.login(result.isFail())) {
      if (result.isResponseSent())
        return;
    }

    if (result.isFail()) {
      if (! result.isResponseSent()
          && ! res.isCommitted()
          && res.getStatus() / 100 == 2) {
        res.sendError(HttpServletResponse.SC_FORBIDDEN);
      }

      return;
    }

    _next.doFilter(request, response);
  }
  
  @Override
  public String toString()
  {
    return getClass().getSimpleName() + "[" + _webApp + "]";
  }
}