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

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

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

    let status = HttpStatus.INTERNAL_SERVER_ERROR;
    let message: string | object = 'Internal server error';
    let code = 'INTERNAL_ERROR';

    if (exception instanceof HttpException) {
      status = exception.getStatus();
      const resp = exception.getResponse();
      message = typeof resp === 'string' ? resp : (resp as any).message ?? resp;
      code = (resp as any).error ?? exception.name;
    } else if (exception instanceof Prisma.PrismaClientKnownRequestError) {
      if (exception.code === 'P2002') {
        status = HttpStatus.CONFLICT;
        message = `Duplicate entry on: ${(exception.meta?.target as string[])?.join(', ')}`;
        code = 'DUPLICATE';
      } else if (exception.code === 'P2025') {
        status = HttpStatus.NOT_FOUND;
        message = 'Record not found';
        code = 'NOT_FOUND';
      } else {
        status = HttpStatus.BAD_REQUEST;
        message = exception.message;
        code = exception.code;
      }
    } else if (exception instanceof Error) {
      message = exception.message;
    }

    this.logger.error(`${request.method} ${request.url} → ${status}: ${JSON.stringify(message)}`);

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