package common.http.error;
   
   import common.http.interceptor.HttpServletBiConsumer;
   import common.http.interceptor.ServletInterceptor;
   import usecase.auth.AuthenticationRequiredException;
   import usecase.auth.AuthorizationException;
   import usecase.auth.BannedUserException;
   
   import javax.json.Json;
  import javax.json.JsonObject;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import javax.validation.ConstraintViolation;
  import javax.validation.ConstraintViolationException;
  import java.io.IOException;
  import java.io.PrintWriter;
  import java.time.format.DateTimeFormatter;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  import java.util.stream.Collectors;
  
  import static javax.servlet.http.HttpServletResponse.*;
  
  /**
   * @see JSONError
   */
  public class JSONErrorInterceptor extends ServletInterceptor<JSONError> {
  
      @Override
      protected void init(JSONError annotation) {
  
      }
  
      @Override
      public void handle(HttpServletRequest req, HttpServletResponse resp, HttpServletBiConsumer next) throws ServletException, IOException {
          try{
              next.handle(req,resp);
          } catch (IllegalArgumentException e) {
              sendJSONError(resp, SC_BAD_REQUEST, e.getMessage());
          } catch (ConstraintViolationException e) {
              List<String> collect = e.getConstraintViolations().stream()
                      .map(ConstraintViolation::getMessage)
                      .collect(Collectors.toList());
  
              sendJSONError(resp,SC_BAD_REQUEST,collect);
          } catch (AuthenticationRequiredException e) {
              sendJSONError(resp,SC_UNAUTHORIZED, e.getMessage());
          } catch (BannedUserException e){
              if (e.getDuration() != null){
                  String end  = DateTimeFormatter.ISO_INSTANT.format(e.getDuration());
                  sendJSONError(resp,SC_FORBIDDEN, "Sei bannato fino a " + end);
              } else {
                  sendJSONError(resp, SC_FORBIDDEN);
              }
          } catch (AuthorizationException e) {
              sendJSONError(resp,SC_FORBIDDEN, e.getMessage());
          } catch (RuntimeException | ServletException | IOException e){
              sendJSONError(resp,SC_INTERNAL_SERVER_ERROR, "Internal server error");
              req.getServletContext().log(e.getMessage(), e);
          }
      }
  
      private void sendJSONError(HttpServletResponse resp, int code, Collection<String> messages) throws IOException {
          JsonObject errors = Json.createObjectBuilder().add("errors", Json.createArrayBuilder(messages)).build();
          resp.setStatus(code);
          resp.setContentType("application/json");
          PrintWriter writer = resp.getWriter();
          writer.print(errors.toString());
          writer.flush();
  
      }
  
      private void sendJSONError(HttpServletResponse resp, int code, String message) throws IOException {
          List<String> singleton = message == null ? Collections.emptyList() : List.of(message);
          sendJSONError(resp, code, singleton);
      }
  
      private void sendJSONError(HttpServletResponse resp, int code) throws IOException{
          sendJSONError(resp,code,Collections.emptyList());
      }
  
      @Override
      public int priority() {
          return 2;
      }
  }