import { ExceptionFilter, Catch, ArgumentsHost, HttpException, HttpStatus, Logger } from '@nestjs/common';
import { Request, Response } from 'express';

@Catch()
export class HttpExceptionFilter implements ExceptionFilter {
  private readonly logger = new Logger(HttpExceptionFilter.name);

  catch(exception: unknown, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const response = ctx.getResponse<Response>();
    const request = ctx.getRequest<Request>();

    let status: number;
    let message: string | string[];
    let error: string;

    if (exception instanceof HttpException) {
      status = exception.getStatus();
      const res = exception.getResponse();
      if (typeof res === 'string') {
        message = res;
        error = exception.name;
      } else {
        const obj = res as any;
        message = obj.message || exception.message;
        error = obj.error || exception.name;
      }
    } else if (exception instanceof Error) {
      status = HttpStatus.INTERNAL_SERVER_ERROR;
      message = 'Internal server error';
      error = 'Internal Server Error';
      this.logger.error(`Unhandled: ${exception.message}`, exception.stack);
    } else {
      status = HttpStatus.INTERNAL_SERVER_ERROR;
      message = 'Unknown error';
      error = 'Internal Server Error';
    }

    response.status(status).json({
      success: false,
      statusCode: status,
      error,
      message,
      timestamp: new Date().toISOString(),
      path: request.url,
    });
  }
}