content: package act.view;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2017 ActFramework
   * %%
   * 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%
   */
  
  import act.app.ActionContext;
  import act.util.ActContext;
  import org.osgl.$;
  import org.osgl.http.H;
  import org.osgl.util.C;
  import org.osgl.util.E;
  import org.osgl.util.S;
  
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.Set;
  
  import static org.osgl.http.H.Format.*;
  
  /**
   * Resolve template path for {@link ActContext}
   */
  public class TemplatePathResolver {
  
      private static final Set<H.Format> supportedFormats = new HashSet<>();
  
      public final String resolve(ActContext context) {
          String path = context.templatePath();
          return resolveTemplatePath(path, context);
      }
  
      public final String resolveWithContextMethodPath(ActContext context) {
          String methodPath = context.methodPath();
          String path = context.templatePath();
          String[] sa = path.split("\\.");
          int level = sa.length + 1;
          S.Buffer sb;
          if (S.notBlank(methodPath)) {
              while (--level > 0) {
                  methodPath = S.beforeLast(methodPath, ".");
              }
              sb = S.newBuffer(methodPath);
          } else {
              sb = S.newBuffer();
          }
          if (!path.startsWith("/")) {
              sb.append("/");
          }
          path = sb.append(path).toString().replace('.', '/');
          return resolveTemplatePath(path, context);
      }
  
      /**
       * Sub class shall use this method to implement template path resolving logic.
       *
       * The default implementation will append the template file suffix based on the
       * {@link ActionContext#accept() accepted format}. E.g. if accepted format is
       * `text/html`, then it will append `.html` to the path specified if suffix
       * is not presented in the path
       *
       * @param path the template path string
       * @param context the act context
       * @return the template path amended by the logic described above
       */
      protected String resolveTemplatePath(String path, ActContext context) {
          return amendSuffix(path, context);
      }
  
      protected String amendSuffix(String path, ActContext context) {
          if (path.contains(".")) {
              return path;
          }
          H.Format fmt = context.accept();
          if (UNKNOWN == fmt) {
              fmt = HTML;
          }
          if (isAcceptFormatSupported(fmt)) {
              return S.concat(path, ".", fmt.name());
          }
          if (context instanceof ActionContext) {
              ActionContext actionContext = $.cast(context);
              H.Request req = actionContext.req();
              throw E.unsupport("Error handling %s request to %s - Request accept not supported: %s", req.method(), req.url(), fmt);
          }
          throw E.unsupport("Request accept not supported: %s",  fmt);
      }
  
      public static void registerSupportedFormats(H.Format ... fmts) {
          supportedFormats.addAll(C.listOf(fmts));
      }
  
      public static void registerSupportedFormats(Collection<H.Format> fmts) {
          supportedFormats.addAll(fmts);
      }
  
      public static boolean isAcceptFormatSupported(H.Format fmt) {
          return (UNKNOWN == fmt || HTML == fmt || JSON == fmt || XML == fmt || TXT == fmt || CSV == fmt) || supportedFormats.contains(fmt);
      }
  }
  