package com.yau.digitalrmb.shared.web;

import com.yau.digitalrmb.shared.api.ApiResponse;
import com.yau.digitalrmb.shared.api.ErrorCode;
import com.yau.digitalrmb.shared.exception.BusinessException;
import com.yau.digitalrmb.platformintegration.application.PlatformTokenException;
import javax.validation.ConstraintViolationException;
import org.slf4j.MDC;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.UUID;

@RestControllerAdvice
public class GlobalExceptionHandler {
    private static final Logger LOGGER = LoggerFactory.getLogger(GlobalExceptionHandler.class);
    @ExceptionHandler({ConstraintViolationException.class, MethodArgumentNotValidException.class})
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    public ApiResponse<Void> handleValidation(Exception exception) {
        return ApiResponse.failure(ErrorCode.VALIDATION_ERROR, exception.getMessage(), traceId());
    }

    @ExceptionHandler(BusinessException.class)
    public ResponseEntity<ApiResponse<Void>> handleBusiness(BusinessException exception) {
        ApiResponse<Void> response = ApiResponse.failure(exception.getErrorCode(), exception.getMessage(), traceId());
        return ResponseEntity.status(httpStatus(exception.getErrorCode())).body(response);
    }

    @ExceptionHandler(PlatformTokenException.class)
    @ResponseStatus(HttpStatus.UNAUTHORIZED)
    public ApiResponse<Void> handlePlatformToken(PlatformTokenException exception) {
        return ApiResponse.failure(ErrorCode.UNAUTHORIZED, "平台登录凭据无效", traceId());
    }

    @ExceptionHandler(Exception.class)
    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
    public ApiResponse<Void> handleUnexpected(Exception exception) {
        LOGGER.error("Unhandled request failure", exception);
        return ApiResponse.failure(ErrorCode.INTERNAL_ERROR, "系统内部错误", traceId());
    }

    private static HttpStatus httpStatus(ErrorCode errorCode) {
        switch (errorCode) {
            case VALIDATION_ERROR:
                return HttpStatus.BAD_REQUEST;
            case UNAUTHORIZED:
                return HttpStatus.UNAUTHORIZED;
            case FORBIDDEN:
                return HttpStatus.FORBIDDEN;
            case RESOURCE_NOT_FOUND:
                return HttpStatus.NOT_FOUND;
            default:
                return HttpStatus.INTERNAL_SERVER_ERROR;
        }
    }

    private String traceId() {
        String traceId = MDC.get(TraceIdFilter.MDC_KEY);
        return traceId == null ? UUID.randomUUID().toString() : traceId;
    }
}