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

export const MatchOtherValidator = (otherControlName: string) => {
	let thisControl: UntypedFormControl;
	let otherControl: UntypedFormControl;

	return (control: UntypedFormControl) => {
		if (!control.parent) {
			return null;
		}

		if (!thisControl) {
			thisControl = control;
			otherControl = control.parent.get(otherControlName) as UntypedFormControl;
			if (!otherControl) {
				throw new Error('matchOtherValidator(): other control is not found in parent group');
			}
			otherControl.valueChanges.subscribe(() => {
				thisControl.updateValueAndValidity();
			});
		}

		if (!otherControl) {
			return null;
		}

		if (otherControl.value !== thisControl.value) {
			return {
				matchOther: true
			};
		}

		return null;
	};
};