ACF Repeater validator for relay prices

relay-price-validation.php

<?php
/**
 * based on https://gist.github.com/sudarshann/66c55e48f1e36fb5412261d869976dc7
 *
 * sorry for german wordings inside!
 */
class AndrekellingthemeAcfValidateStaffelpreis {
	public function __construct() {
		add_filter('acf/validate_value/name=prices', [$this, 'acf_validate_staffelpreis'], 10, 4);
	}

	function acf_validate_staffelpreis($valid, $value, $field, $input_name) {
		// Bail early if value is already invalid.
		if ($valid !== true) {
			return $valid;
		}

		$result = self::validate_staffelpreis($value, $field['key']);
		if( !empty($result) ){
			return $result;
		}

		return true;
	}

	function validate_staffelpreis($current_rows, $fieldKey) {
		$lowDayCount = 0;
		$tagespreis = (float) get_field('tagesmiete', $_POST['post_id']);
		$highPrice = $tagespreis;
		$index = 0;
		// acf_reset_validation_errors is not correctly removing error messages in any case. especially when editing another field, then the error message is on.
		acf_reset_validation_errors();

		foreach ($current_rows as $current_row) {
			$current = array_values($current_row);
			$currentKeys = array_keys($current_row);
			$currentDayCount = (float) $current[0];
			$currentPrice = (float) $current[1];

			$fieldSelectorDay = "acf[$fieldKey][row-$index][$currentKeys[0]]";
			$fieldSelectorPrice = "acf[$fieldKey][row-$index][$currentKeys[1]]";
			$index++;

			if(1 >= $currentDayCount){
				acf_add_validation_error($fieldSelectorDay , 'Dieser Tag-wert ist nicht korrekt.' );
				return 'Tage-wert muss größer 1 sein.';
			}
			if($lowDayCount >= $currentDayCount){
				acf_add_validation_error($fieldSelectorDay , 'Dieser Tag-wert scheint nicht korrekt.' );
				return 'Tage-wert muss ansteigend verlaufen, also größer werden.';
			}

			$lowDayCount = $currentDayCount;
			if($tagespreis <= $currentPrice){
				acf_add_validation_error($fieldSelectorPrice , 'Dieser Preis ist nicht korrekt.' );
				return 'Preis-wert muss kleiner als der Tagespreis sein.';
			}
			if($highPrice <= $currentPrice){
				acf_add_validation_error($fieldSelectorPrice , 'Dieser Preis scheint nicht korrekt.' );
				return 'Preis-wert muss absteigend verlaufen, also kleiner werden.';
			}
			$highPrice = $currentPrice;
		}

		return false;
	}
}

To make this repeater fields values valid under each other in that post.

It's about relay prices.

prices is the repeater field.
In there we have 2 subfields per row. Which are day and price

• days shall increase per row
  • and be higher than 1
• price shall decrease per row
  • and be higher than the one day price "tagesmiete"