import { NestInterceptor, ExecutionContext, CallHandler } from "@nestjs/common";
import { Observable } from "rxjs";
import { IFileOptions } from "../interfaces/file.interface";
/**
 * Interceptor to handle file uploads using Busboy.
 */
export declare class FormdataInterceptor implements NestInterceptor {
    private readonly fileOptions?;
    private readonly arrayRegexPattern;
    private readonly nestedRegexPattern;
    private httpRequest;
    private busboy;
    /**
     * Constructs a new instance of the FormdataInterceptor class.
     * @param fileOptions - Optional configuration options for file handling.
     */
    constructor(fileOptions?: IFileOptions);
    /**
     * Intercepts the request to handle file uploads if the content type is multipart/form-data.
     * @param context - The execution context.
     * @param next - The next call handler.
     * @returns An Observable that processes the file upload.
     */
    intercept(context: ExecutionContext, next: CallHandler): Promise<Observable<any>>;
    /**
     * Handles multipart/form-data file uploads.
     * @param context - The execution context.
     * @param next - The next call handler.
     * @param request - The HTTP request.
     * @param customFileName - Optional function to customize file names.
     * @param fileSaver - Optional file saver implementation.
     * @returns An Observable that processes the file upload.
     */
    private handleMultipartFormData;
    /**
     * Cleans up the resources used by the `busboy` instance and removes all event listeners.
     */
    private handleDone;
    /**
     * assign save file strategy
     *
     * @param fileSaver  - file saver  strategy
     * @param context - The execution context.
     */
    private assignFile;
    /**
     * Handles a file field by adding FileData to the target object.
     * Automatically uses MultipleFileData for array fields or multiple files with same name.
     * @param target - The target object to set the field value.
     * @param fieldName - The name of the field.
     * @param fileData - The FileData to add.
     */
    private handleFileField;
    /**
     * Handles a field by setting its value in the target object, supporting nested fields and arrays.
     * @param target - The target object to set the field value.
     * @param fieldName - The name of the field.
     * @param value - The value to set.
     */
    private handleField;
    /**
     * Sets a nested value in an object, supporting nested fields and arrays.
     * @param obj - The object to set the nested value in.
     * @param keys - The keys representing the nested path.
     * @param value - The value to set.
     * @param isArray - Whether the field is an array.
     */
    private setNestedValue;
    /**
     * Assigns a value to the specified key in an object, supporting arrays.
     * @param obj - The object to set the value in.
     * @param key - The key to set the value for.
     * @param value - The value to set.
     * @param isArray - Whether the field is an array.
     */
    private assignValue;
    /**
     * Assigns a single value or array value to the specified key in an object.
     * @param obj - The object to set the value in.
     * @param key - The key to set the value for.
     * @param value - The value to set.
     */
    private assignSingleValue;
    /**
     * Assigns a value to an array at the specified key in an object.
     * @param obj - The object to set the value in.
     * @param key - The key to set the value for.
     * @param value - The value to set.
     */
    private assignArrayValue;
}