/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.hadoop.chukwa.rest.resource;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.ws.rs.Consumes;
  import javax.ws.rs.DELETE;
  import javax.ws.rs.FormParam;
  import javax.ws.rs.GET;
  import javax.ws.rs.POST;
  import javax.ws.rs.PUT;
  import javax.ws.rs.Path;
  import javax.ws.rs.PathParam;
  import javax.ws.rs.WebApplicationException;
  import javax.ws.rs.core.Context;
  import javax.ws.rs.core.Response;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import org.apache.hadoop.chukwa.rest.bean.ReturnCodeBean;
  import org.apache.hadoop.chukwa.rest.bean.ViewBean;
  import org.apache.hadoop.chukwa.datastore.ViewStore;
  import org.apache.hadoop.chukwa.util.ExceptionUtil;
  
  @Path ("/view")
  public class ViewResource {
    protected static final Log log = LogFactory.getLog(ViewResource.class);
  
    @GET
    @Path("vid/{vid}")
    public ViewBean getView(@Context HttpServletRequest request, @PathParam("vid") String vid) {
      ViewStore view;
      ViewBean vr;
      String uid = request.getRemoteUser();
      try {
        view = new ViewStore(uid, vid);
        vr = view.get();
        if(request.getRemoteUser().intern()!=vr.getOwner().intern() && vr.getPermissionType().intern()!="public".intern()) {
      	  throw new WebApplicationException(Response.status(Response.Status.FORBIDDEN).entity("permission denied.").build());
        }
      } catch (IllegalAccessException e) {
        throw new WebApplicationException(Response.status(Response.Status.NOT_FOUND)
            .entity("View does not exist.").build());
      }
      return vr;
    }
    
    @PUT
    @Consumes("application/json")
    public ReturnCodeBean setView(@Context HttpServletRequest request, ViewBean view) {
      try {
        if(request.getRemoteUser().intern()==view.getOwner().intern()) {
          ViewStore vs = new ViewStore(view.getOwner(), view.getName());
          vs.set(view);
        } else {
            throw new WebApplicationException(Response.status(Response.Status.FORBIDDEN)
                .entity("Permission denied.").build());    	  
        }
      } catch (IllegalAccessException e) {
        log.error(ExceptionUtil.getStackTrace(e));
        throw new WebApplicationException(Response.status(Response.Status.NOT_FOUND)
            .entity("View save failed.").build());
      }
      return new ReturnCodeBean(ReturnCodeBean.SUCCESS,"Saved");
    }
  
    @POST
    @Path("permission")
    public ReturnCodeBean changeViewPermission(@Context HttpServletRequest request, @FormParam("owner") String owner, @FormParam("view_vid") String vid, @FormParam("permission") String permission) {
      try {
        if(owner.intern()==request.getRemoteUser().intern()) {
          ViewStore vs = new ViewStore(owner, vid);
          ViewBean view = vs.get();
          vs.delete();
          view.setPermissionType(permission);
          vs.set(view);
        } else {
          throw new Exception("Permission denied.");
        }
      } catch (Exception e) {
        log.error(ExceptionUtil.getStackTrace(e));
        throw new WebApplicationException(Response.status(Response.Status.INTERNAL_SERVER_ERROR)
            .entity("View save failed.").build());      
     }
     return new ReturnCodeBean(ReturnCodeBean.SUCCESS,"Saved");
   }
 
   @POST
   public ReturnCodeBean changeView(@Context HttpServletRequest request, @FormParam("owner") String owner, @FormParam("view_vid") String oldVid, @FormParam("view_name") String name) {
     try {
       ViewStore vs;
       if(oldVid!=null) {
         vs = new ViewStore(owner, oldVid);
       } else {
         vs = new ViewStore(null, "default");
       }
       ViewBean view = vs.get();
       view.setOwner(request.getRemoteUser());
       view.setName(name);
       view.setDescription(name);
       if(oldVid==null) {
         view.setPermissionType("private");
       }
       vs = new ViewStore(request.getRemoteUser(), name);
       vs.set(view);
     } catch (Exception e) {
       log.error(ExceptionUtil.getStackTrace(e));
       throw new WebApplicationException(Response.status(Response.Status.INTERNAL_SERVER_ERROR)
           .entity("View save failed.").build());      
     }
     return new ReturnCodeBean(ReturnCodeBean.SUCCESS,"Saved");
   }
 
   @DELETE
   @Path("delete/{owner}/vid/{vid}")
   public ReturnCodeBean deleteView(@Context HttpServletRequest request, @PathParam("owner") String owner, @PathParam("vid") String vid) {
     try {
       if(owner.intern()==request.getRemoteUser().intern()) {
         ViewStore vs = new ViewStore(owner, vid);
         vs.delete();
       } else {
         throw new WebApplicationException(Response.status(Response.Status.FORBIDDEN)
             .entity("View delete failed.").build());              
       }
     } catch (Exception e) {
       log.error(ExceptionUtil.getStackTrace(e));
       throw new WebApplicationException(Response.status(Response.Status.INTERNAL_SERVER_ERROR)
           .entity("View delete failed.").build());      
     }
     return new ReturnCodeBean(ReturnCodeBean.SUCCESS,"Deleted");
   }
 
   @GET
   @Path("list")
   public String getUserViewList(@Context HttpServletRequest request) {
     String result = "";
     String uid = null;
     try {
       if(uid==null) {
         uid = request.getRemoteUser();
       }
       result = ViewStore.list(uid).toJSONString();
     } catch (Exception e) {
       throw new WebApplicationException(Response.status(Response.Status.NOT_FOUND)
           .entity("View does not exist.").build());
     }
     return result;
   }
 }