import { ValidatorFn } from '@angular/forms';

/**
 * Type for custom error messages used for custom validation.
 *
 * ### Import
 *
 * ```typescript
 * import { CustomErrMsg } from '@talenra/ngx-base/user-input-common';
 * ```
 */
interface CustomErrMsg {
    /** The error identifier. */
    code: string;
    /** The error message. */
    text: string;
}

/**
 * Collects custom form-validators which can be used by a reactive form.
 *
 * ```typescript
 * form: FormGroup = new FormGroup({
 *   date: new FormControl(null, [CustomValidators.validPeriodStartYear(2023)])
 * });
 * ```
 *
 * ### Import
 *
 * ```typescript
 * import { CustomValidators } from '@talenra/ngx-base/user-input-common';
 * ```
 */
declare class CustomValidators {
    /**
     * Checks if a date's year is greater than or equal the threshold's year.
     *
     * @param threshold The minimum year
     *
     * @returns Returns a function which in case of an error it returns `{ invalidPeriodStartYear: true }` apart from that `null`.
     */
    static validPeriodStartYear(threshold: number): ValidatorFn;
    /**
     * Checks if the start date is before the end date.
     *
     * @param startDateId Name of the form-control
     * @param endDateId Name of the form-control
     * @param allowSameDay Allows the end date to be on the same day as the start date, default is 'false'
     *
     * @returns Returns a function which in case of an error it returns `{ invalidDateOrder: true }` apart from that `null`.
     */
    static startDateBeforeEndDate(startDateId: string, endDateId: string, allowSameDay?: boolean): ValidatorFn;
}

export { CustomValidators };
export type { CustomErrMsg };