// Copyright (C) 2013 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.googlesource.gerrit.plugins.gitiles;

import com.google.common.collect.Lists;
import com.google.gerrit.extensions.restapi.Url;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.IdentifiedUser;
import com.google.gitiles.BaseServlet;
import com.google.gitiles.GitilesUrls;
import com.google.inject.Inject;
import com.google.inject.Provider;
import java.io.IOException;
import java.util.List;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

class MenuFilter implements Filter {
  private final Provider<CurrentUser> userProvider;
  private final GitilesUrls urls;

  @Inject
  MenuFilter(Provider<CurrentUser> userProvider, GitilesUrls urls) {
    this.userProvider = userProvider;
    this.urls = urls;
  }

  @Override
  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
      throws IOException, ServletException {
    HttpServletRequest req = (HttpServletRequest) request;
    CurrentUser user = userProvider.get();
    List<Object> entries = Lists.newArrayListWithCapacity(3);
    entries.add(BaseServlet.menuEntry("Code Review", urls.getBaseGerritUrl(req)));
    if (user instanceof IdentifiedUser) {
      entries.add(BaseServlet.menuEntry(((IdentifiedUser) user).getName(), null));
      entries.add(BaseServlet.menuEntry("Sign Out", urls.getBaseGerritUrl(req) + "logout"));
    } else {
      entries.add(BaseServlet.menuEntry("Sign In", getLoginRedirectUrl(req)));
    }
    BaseServlet.putSoyData(req, "menuEntries", entries);
    chain.doFilter(request, response);
  }

  @Override
  public void init(FilterConfig filterConfig) throws ServletException {}

  @Override
  public void destroy() {}

  private String getLoginRedirectUrl(HttpServletRequest req) {
    String baseUrl = urls.getBaseGerritUrl(req);
    String loginUrl = baseUrl + "login/";
    String token = req.getRequestURL().toString();
    if (!baseUrl.isEmpty()) {
      token = token.substring(baseUrl.length());
    }

    String queryString = req.getQueryString();
    if (queryString != null && !queryString.isEmpty()) {
      token = token.concat("?" + queryString);
    }
    return (loginUrl + Url.encode(token));
  }
}