/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2015 wcm.io
    * %%
    * 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.
   * #L%
   */
  package io.wcm.caravan.hal.docs.impl;
  
  import java.io.IOException;
  import java.net.URL;
  import java.util.Map;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.io.FilenameUtils;
  import org.apache.commons.lang3.CharEncoding;
  import org.osgi.framework.Bundle;
  import org.osgi.service.http.HttpContext;
  
  import com.google.common.collect.ImmutableMap;
  
  /**
   * Wraps a defaul HTTP context, but redirects all resource requests to the bundle given in contructor.
   */
  class HttpContextWrapper implements HttpContext {
  
    static final String MIMETYPE_JSON = "application/json";
    static final String MIMETYPE_HTML = "text/html;charset=" + CharEncoding.UTF_8;
  
    /**
     * List of common mime types we should support always.
     */
    private static final Map<String, String> MIME_TYPES = ImmutableMap.<String, String>builder()
        .put("json", MIMETYPE_JSON)
        .put("html", MIMETYPE_HTML)
        .build();
  
    private final HttpContext delegate;
    private final Bundle bundle;
  
    HttpContextWrapper(HttpContext httpContext, Bundle bundle) {
      this.delegate = httpContext;
      this.bundle = bundle;
    }
  
    @Override
    public boolean handleSecurity(HttpServletRequest request, HttpServletResponse response) throws IOException {
      return delegate.handleSecurity(request, response);
    }
  
    @Override
    public URL getResource(String name) {
      return bundle.getResource(name);
    }
  
    @Override
    public String getMimeType(String name) {
      String mimeType = delegate.getMimeType(name);
      if (mimeType == null) {
        String extension = FilenameUtils.getExtension(name);
        if (extension != null) {
          mimeType = MIME_TYPES.get(extension);
        }
      }
      return mimeType;
    }
  
  }