package com.yunhai.bschclassmanage.controller.Handler;

import com.yunhai.platform.utils.exception.DException;
import com.yunhai.platform.utils.exception.ErrorCode;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.web.HttpMediaTypeNotSupportedException;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.*;

@Order(Ordered.HIGHEST_PRECEDENCE)
@RestControllerAdvice
public class ValidationExceptionHandler {

    /**
     * 兜底 DException：平台 GlobalExceptionHandler 只返回 code/msg，会丢掉 data。
     * 本项目优先捕获，把业务异常里的 data（如导入错误列表）透传给前端。
     */
    @ExceptionHandler(DException.class)
    public ResponseEntity<Map<String, Object>> handleDException(DException ex) {
        Map<String, Object> response = new LinkedHashMap<>();
        response.put("code", ex.getCode() != null ? ex.getCode().getCode() : ErrorCode.CUSTOM.getCode());
        response.put("msg", ex.getMessage());
        response.put("data", ex.getData());
        response.put("timeNow", LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        return new ResponseEntity<>(response, HttpStatus.OK);
    }

    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<Map<String, Object>> handleValidationExceptions(MethodArgumentNotValidException ex) {
        List<String> msgList = new ArrayList<>();
        ex.getBindingResult().getAllErrors().forEach(error -> {
            String errorMessage = error.getDefaultMessage();
            msgList.add(errorMessage);
        });

        Map<String, Object> response = new LinkedHashMap<>();
        response.put("code", ErrorCode.ERROR.getCode());
        response.put("msg", String.join(";", msgList));
        response.put("data", null);
        response.put("timeNow", LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));

        return new ResponseEntity(response, HttpStatus.BAD_REQUEST);
    }

    /**
     * @RequestBody 反序列化失败（JSON 格式错 / 字段类型不符 / 未知字段被拒）。
     * 不捕获会被平台兜底成 code:6 / 内部服务错误，这里把真实原因透出来。
     */
    @ExceptionHandler(HttpMessageNotReadableException.class)
    public ResponseEntity<Map<String, Object>> handleNotReadable(HttpMessageNotReadableException ex) {
        Map<String, Object> response = new LinkedHashMap<>();
        response.put("code", ErrorCode.ERROR.getCode());
        response.put("msg", "请求体(JSON)解析失败: " + (ex.getRootCause() != null ? ex.getRootCause().getMessage() : ex.getMessage()));
        response.put("data", null);
        response.put("timeNow", LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        return new ResponseEntity(response, HttpStatus.BAD_REQUEST);
    }

    /**
     * Content-Type 不是 application/json（如 text/plain、form 表单、缺省），@RequestBody 无法选择转换器。
     */
    @ExceptionHandler(HttpMediaTypeNotSupportedException.class)
    public ResponseEntity<Map<String, Object>> handleMediaType(HttpMediaTypeNotSupportedException ex) {
        Map<String, Object> response = new LinkedHashMap<>();
        response.put("code", ErrorCode.ERROR.getCode());
        response.put("msg", "请求 Content-Type 不被支持: " + ex.getMessage());
        response.put("data", null);
        response.put("timeNow", LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        return new ResponseEntity(response, HttpStatus.BAD_REQUEST);
    }
}