State

export interface FormValidationResult<E> {
  formValue: FormValue;
  formErrors: FieldErrorsMap<E>;
}

type Validate<V> =
  V extends FormValueValidator<infer E>
    ? {
        validate(): FieldErrorsMap<E>;
      }
    : {};

type ValidateAsync<V> =
  V extends AsyncFormValueValidator<infer E>
    ? {
        validateAsync(signal: AbortSignal): Promise<FieldErrorsMap<E>>;
      }
    : {};

export type FormState<T, V extends Validator> = {
  readonly context: FormContext;
  readonly validation: Action<
    [event: SubmitEvent],
    FormValidationResult<AnyFormValueValidatorError<V>>,
    unknown
  >;
  readonly fieldsValidation: Action<
    [config: Config, value: FieldValue],
    FieldError<AnyFieldValueValidatorError<V>>[],
    unknown
  >;
  /**
   * An accessor that maintains form state consistency:
   *
   * - A snapshot of the form state is returned on access
   * - Default values from JSON Schema are taken into account during assignment
   *
   * You can gain direct access to the internal state by hacking types:
   *
   * `(form.context as FormInternalContext<typeof validator>).value`
   */
  value: T | undefined;
  isSubmitted: boolean;
  isChanged: boolean;
  errors: FieldErrorsMap<PossibleError<V>>;
  submit(e: SubmitEvent): Promise<void>;
  reset(e: Event): void;
} & Validate<V> &
  ValidateAsync<V>;