package com.ctrip.apollo.common.controller;

 import org.springframework.http.HttpHeaders;

 import org.springframework.http.HttpStatus;

 import org.springframework.http.ResponseEntity;

 import org.springframework.web.HttpMediaTypeException;

 import org.springframework.web.HttpRequestMethodNotSupportedException;

 import org.springframework.web.bind.annotation.ControllerAdvice;

 import org.springframework.web.bind.annotation.ExceptionHandler;

 import org.springframework.web.client.HttpStatusCodeException;

 import com.ctrip.apollo.core.exception.AbstractBaseException;

 import com.ctrip.apollo.core.exception.BadRequestException;

 import com.ctrip.apollo.core.exception.NotFoundException;

 import com.dianping.cat.Cat;

 import com.google.gson.Gson;

 import com.google.gson.reflect.TypeToken;

 import java.lang.reflect.Type;

 import java.time.LocalDateTime;

 import java.time.format.DateTimeFormatter;

 import java.util.LinkedHashMap;

 import java.util.Map;

 import javax.servlet.ServletException;

 import javax.servlet.http.HttpServletRequest;

 import static org.springframework.http.HttpStatus.BAD_REQUEST;

 import static org.springframework.http.HttpStatus.INTERNAL_SERVER_ERROR;

 import static org.springframework.http.HttpStatus.NOT_FOUND;

 import static org.springframework.http.MediaType.APPLICATION_JSON;

 @ControllerAdvice

 public class GlobalDefaultExceptionHandler {

   private Gson gson = new Gson();

   private static Type mapType = new TypeToken<Map<String, Object>>() {}.getType();

   @ExceptionHandler(Exception.class)

   public ResponseEntity<Map<String, Object>> exception(HttpServletRequest request, Exception ex) {

     return handleError(request, INTERNAL_SERVER_ERROR, ex);

   }

   private ResponseEntity<Map<String, Object>> handleError(HttpServletRequest request,

       HttpStatus status, Throwable ex) {

     return handleError(request, status, ex, ex.getMessage());

   }

   private ResponseEntity<Map<String, Object>> handleError(HttpServletRequest request,

       HttpStatus status, Throwable ex, String message) {

     ex = resolveError(ex);

     if (ex.getCause() instanceof HttpStatusCodeException) {

       return restTemplateException(request, (HttpStatusCodeException) ex.getCause());

     }

     Cat.logError(ex);

     Map<String, Object> errorAttributes = new LinkedHashMap<>();

     errorAttributes.put("status", status.value());

     errorAttributes.put("message", message);

     errorAttributes.put("timestamp",

         LocalDateTime.now().format(DateTimeFormatter.ISO_LOCAL_DATE_TIME));

     errorAttributes.put("exception", resolveError(ex).getClass().getName());

     errorAttributes.put("stackTrace", ex.getStackTrace());

     if (ex instanceof AbstractBaseException) {

       errorAttributes.put("errorCode", ((AbstractBaseException) ex).getErrorCode());

     }

     HttpHeaders headers = new HttpHeaders();

     headers.setContentType(APPLICATION_JSON);

     return new ResponseEntity<>(errorAttributes, headers, status);

   }

   @ExceptionHandler({HttpRequestMethodNotSupportedException.class, HttpMediaTypeException.class})

   public ResponseEntity<Map<String, Object>> methodNotSupportedException(HttpServletRequest request,

       ServletException ex) {

     return handleError(request, BAD_REQUEST, ex);

   }

   @ExceptionHandler(NotFoundException.class)

   public ResponseEntity<Map<String, Object>> notFound(HttpServletRequest request,

       NotFoundException ex) {

     return handleError(request, NOT_FOUND, ex);

   }

   @ExceptionHandler(BadRequestException.class)

   public ResponseEntity<Map<String, Object>> badRequest(HttpServletRequest request,

       BadRequestException ex) {

     return handleError(request, BAD_REQUEST, ex);

   }

   @ExceptionHandler(HttpStatusCodeException.class)

   public ResponseEntity<Map<String, Object>> restTemplateException(HttpServletRequest request,

       HttpStatusCodeException ex) {

     Map<String, Object> errorAttributes = gson.fromJson(ex.getResponseBodyAsString(), mapType);

     HttpHeaders headers = new HttpHeaders();

     headers.setContentType(APPLICATION_JSON);

     return new ResponseEntity<>(errorAttributes, headers, ex.getStatusCode());

   }

   private Throwable resolveError(Throwable ex) {

     while (ex instanceof ServletException && ex.getCause() != null) {

       ex = ((ServletException) ex).getCause();

     }

     return ex;

   }

 }