/**
 * External dependencies
 */
import { __, sprintf } from '@wordpress/i18n';

/**
 * Ensures that a given value contains a string, or throws an error.
 */
export const mustContain = (
	value: string,
	requiredValue: string
): true | never => {
	if ( ! value.includes( requiredValue ) ) {
		throw Error(
			sprintf(
				/* translators: %1$s value passed to filter, %2$s : value that must be included. */
				__(
					'Returned value must include %1$s, you passed "%2$s"',
					'woo-gutenberg-products-block'
				),
				requiredValue,
				value
			)
		);
	}
	return true;
};

/**
 * Converts an input's validityState to a string to display on the frontend.
 *
 * This returns custom messages for invalid/required fields. Other error types use defaults from the browser (these
 * could be implemented in the future but are not currently used by the block checkout).
 */
export const getValidityMessageForInput = (
	label: string,
	inputElement: HTMLInputElement
): string => {
	const { valid, customError, valueMissing, badInput, typeMismatch } =
		inputElement.validity;

	// No errors, or custom error - return early.
	if ( valid || customError ) {
		return inputElement.validationMessage;
	}

	const invalidFieldMessage = sprintf(
		/* translators: %s field label */
		__( 'Please enter a valid %s', 'woo-gutenberg-products-block' ),
		label.toLowerCase()
	);

	if ( valueMissing || badInput || typeMismatch ) {
		return invalidFieldMessage;
	}

	return inputElement.validationMessage || invalidFieldMessage;
};