package com.xuqm.im.controller;

import com.xuqm.common.exception.BusinessException;
import com.xuqm.common.model.ApiResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.security.authorization.AuthorizationDeniedException;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

@RestControllerAdvice
public class GlobalExceptionHandler {

    private static final Logger log = LoggerFactory.getLogger(GlobalExceptionHandler.class);

    @ExceptionHandler(BusinessException.class)
    public ResponseEntity<ApiResponse<Void>> handleBusiness(BusinessException e) {
        return ResponseEntity.status(resolveStatus(e.getCode()))
                .body(ApiResponse.error(e.getCode(), e.getMessage()));
    }

    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<ApiResponse<Void>> handleValidation(MethodArgumentNotValidException e) {
        return ResponseEntity.badRequest().body(ApiResponse.badRequest(e.getBindingResult()
                .getFieldErrors()
                .stream()
                .findFirst()
                .map(error -> error.getDefaultMessage())
                .orElse("参数错误")));
    }

    @ExceptionHandler(IllegalArgumentException.class)
    public ResponseEntity<ApiResponse<Void>> handleIllegalArgument(IllegalArgumentException e) {
        return ResponseEntity.badRequest().body(ApiResponse.badRequest(e.getMessage() == null ? "参数错误" : e.getMessage()));
    }

    @ExceptionHandler(HttpMessageNotReadableException.class)
    public ResponseEntity<ApiResponse<Void>> handleUnreadable(HttpMessageNotReadableException e) {
        return ResponseEntity.badRequest().body(ApiResponse.badRequest("请求体格式错误"));
    }

    @ExceptionHandler(AuthorizationDeniedException.class)
    public ResponseEntity<ApiResponse<Void>> handleAuthorizationDenied(AuthorizationDeniedException e) {
        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
        String principal = authentication == null ? null : String.valueOf(authentication.getPrincipal());
        String authorities = authentication == null ? "[]" : authentication.getAuthorities().toString();
        log.warn("Access denied path={} principal={} authorities={} reason={}",
                "im-service", principal, authorities, e.getMessage());
        return ResponseEntity.status(HttpStatus.FORBIDDEN)
                .body(ApiResponse.error(403, "Forbidden: current token lacks required role"));
    }

    @ExceptionHandler(Exception.class)
    public ResponseEntity<ApiResponse<Void>> handleException(Exception e) {
        log.error("Unhandled exception", e);
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
                .body(ApiResponse.error(500, "服务异常"));
    }

    private HttpStatus resolveStatus(int code) {
        return switch (code) {
            case 400 -> HttpStatus.BAD_REQUEST;
            case 401 -> HttpStatus.UNAUTHORIZED;
            case 403 -> HttpStatus.FORBIDDEN;
            case 404 -> HttpStatus.NOT_FOUND;
            default -> HttpStatus.INTERNAL_SERVER_ERROR;
        };
    }
}