export interface HoneypotInputProps {
    /**
     * The name expected to be used by the honeypot input field.
     */
    nameFieldName: string;
    /**
     * The name expected to be used by the honeypot valid from input field.
     */
    validFromFieldName: string | null;
    /**
     * The encrypted value of the current timestamp.
     */
    encryptedValidFrom: string;
}
export interface HoneypotConfig {
    /**
     * Enable randomization of the name field name, this way the honeypot field
     * name will be different for each request.
     */
    randomizeNameFieldName?: boolean;
    /**
     * The name of the field that will be used for the honeypot input.
     */
    nameFieldName?: string;
    /**
     * The name of the field that will be used for the honeypot valid from input.
     */
    validFromFieldName?: string | null;
    /**
     * The seed used for the encryption of the valid from timestamp.
     */
    encryptionSeed?: string;
}
/**
 * The error thrown when the Honeypot fails, meaning some automated bot filled
 * the form and the request is probably spam.
 */
export declare class SpamError extends Error {
    readonly name = "SpamError";
}
/**
 * Module used to implement a Honeypot.
 * A Honeypot is a visually hidden input that is used to detect spam bots. This
 * field is expected to be left empty by users because they don't see it, but
 * bots will fill it falling in the honeypot trap.
 */
export declare class Honeypot {
    private generatedEncryptionSeed;
    protected config: HoneypotConfig;
    constructor(config?: HoneypotConfig);
    /**
     * Get the HoneypotInputProps to be used in your forms.
     * @param options The options for the input props.
     * @param options.validFromTimestamp Since when the timestamp is valid.
     * @returns The props to be used in the form.
     */
    getInputProps({ validFromTimestamp, }?: {
        validFromTimestamp?: number | undefined;
    }): Promise<HoneypotInputProps>;
    check(formData: FormData): Promise<void>;
    protected get nameFieldName(): string;
    protected get validFromFieldName(): string | null;
    protected get encryptionSeed(): string;
    protected getRandomizedNameFieldName(nameFieldName: string, formData: FormData): string | undefined;
    protected shouldCheckHoneypot(formData: FormData, nameFieldName: string): boolean;
    protected randomValue(): string;
    protected encrypt(value: string): Promise<string>;
    protected decrypt(value: string): Promise<string>;
    protected isFuture(timestamp: number): boolean;
    protected isValidTimeStamp(timestampp: number): boolean;
}