/**
    * 
    */
   package eu.scape_project.watch.rest.resource;
   
   import java.util.Collection;
   
   import javax.ws.rs.DELETE;
   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.QueryParam;
  import javax.ws.rs.core.GenericEntity;
  import javax.ws.rs.core.Response;
  
  import com.wordnik.swagger.core.ApiError;
  import com.wordnik.swagger.core.ApiErrors;
  import com.wordnik.swagger.core.ApiOperation;
  import com.wordnik.swagger.core.ApiParam;
  import com.wordnik.swagger.core.JavaHelp;
  
  import eu.scape_project.watch.dao.EntityDAO;
  import eu.scape_project.watch.dao.EntityTypeDAO;
  import eu.scape_project.watch.domain.Entity;
  import eu.scape_project.watch.domain.EntityType;
  import eu.scape_project.watch.utils.exception.NotFoundException;
  
  import org.apache.log4j.Logger;
  
  /**
   * 
   * REST API for {@link Entity} operations.
   * 
   * @author Luis Faria <lfaria@keep.pt>
   * 
   */
  public class EntityResource extends JavaHelp {
  
    /**
     * Logger.
     */
    private static final Logger LOG = Logger.getLogger(EntityResource.class);
  
    /**
     * Get a {@link Entity} by its unique name. REST interface for
     * {@link EntityDAO#findById(String)}.
     * 
     * @param name
     *          The name of the Entity
     * @return The Entity object with that name or throws
     *         {@link NotFoundException} if none found.
     */
    @GET
    @Path("/{name}")
    @ApiOperation(value = "Find Entity by name", notes = "")
    @ApiErrors(value = {@ApiError(code = NotFoundException.CODE, reason = "Entity not found")})
    public Response getEntityByName(
      @ApiParam(value = "Name of the Entity", required = true) @PathParam("name") final String name) {
  
      final Entity entity = EntityDAO.getInstance().findById(name);
  
      if (entity != null) {
        return Response.ok().entity(entity).build();
      } else {
        throw new NotFoundException("Entity not found: " + name);
      }
    }
  
    /**
     * Get the list of Entities of a defined {@link EntityType}.
     * 
     * @param type
     *          The name of the {@link EntityType}
     * @param start
     *          The index of the first item to retrieve
     * @param max
     *          The maximum number of items to retrieve
     * @return The list of entities filtered by the above constraints
     */
    @GET
    @Path("/list")
    @ApiOperation(value = "List entities", notes = "")
    public Response listEntityOfType(
      @ApiParam(value = "Entity type", required = true) @QueryParam("type") final String type,
      @ApiParam(value = "Index of first item to retrieve", required = true) @QueryParam("start") final int start,
      @ApiParam(value = "Maximum number of items to retrieve", required = true) @QueryParam("max") final int max) {
      final Collection<Entity> list = EntityDAO.getInstance().listWithType(type, start, max);
      return Response.ok().entity(new GenericEntity<Collection<Entity>>(list) {
      }).build();
    }
  
    /**
     * Create a new {@link Entity}.
     * 
     * @param name
     *          The name of the entity
     * @param type
    *          the name of the {@link EntityType} this entity belongs to
    * @return The created Entity or throws {@link NotFoundException} if the type
    *         is not found.
    */
   @POST
   @Path("/{name}")
   @ApiOperation(value = "Create Entity", notes = "This can only be done by a logged user (TODO)")
   @ApiErrors(value = {@ApiError(code = NotFoundException.CODE, reason = "Entity type not found")})
   public Response createEntity(
     @ApiParam(value = "Entity name (must be unique)", required = true) @PathParam("name") final String name,
     @ApiParam(value = "Entity Type (must exist)", required = true) final String type) {
 
     final EntityType entitytype = EntityTypeDAO.getInstance().findById(type);
 
     if (entitytype != null) {
       final Entity entity = new Entity(entitytype, name);
       entity.save();
       return Response.ok().entity(entity).build();
     } else {
       throw new NotFoundException("Entity type not found: " + type);
     }
 
   }
 
   /**
    * Update an existing entity.
    * 
    * @param name
    *          The name of the existing entity
    * @param entity
    *          The new entity that will replace the existing one.
    * @return The entity merged into the KB.
    */
   @PUT
   @Path("/{name}")
   @ApiOperation(value = "Update Entity", notes = "This can only be done by a logged user (TODO)")
   @ApiErrors(value = {@ApiError(code = NotFoundException.CODE, reason = "Entity not found")})
   public Response updateEntity(
     @ApiParam(value = "Name that need to be deleted", required = true) @PathParam("name") final String name,
     @ApiParam(value = "Updated Entity object", required = true) final Entity entity) {
     final Entity original = EntityDAO.getInstance().findById(name);
     if (original != null) {
       original.delete();
       entity.save();
       return Response.ok().entity(entity).build();
     } else {
       throw new NotFoundException("Entity not found: " + name);
     }
   }
 
   /**
    * Delete an existing entity.
    * 
    * @param name
    *          the name of the entity
    * @return The deleted entity or throws {@link NotFoundException} if the
    *         entity to delete is not found
    * 
    */
   @DELETE
   @Path("/{name}")
   @ApiOperation(value = "Delete Entity", notes = "This can only be done by a logged user (TODO)")
   @ApiErrors(value = {@ApiError(code = NotFoundException.CODE, reason = "Entity not found")})
   public Response deleteEntity(
     @ApiParam(value = "The name of the Entity to be deleted", required = true) @PathParam("name") final String name) {
     LOG.info("deleting entity name: " + name);
     final Entity entity = EntityDAO.getInstance().findById(name);
     if (entity != null) {
       entity.delete();
       return Response.ok().entity(entity).build();
     } else {
       throw new NotFoundException("Entity type not found: " + name);
     }
   }
 
 }