Top N With Other Grouper

Code

<?php

/*
 * Copyright (c) 2026 Jeffery L. Paris <jparis@phpog.com>.
 * Free for personal and internal use. Paid project use requires visible credit
 * to Jeffery L. Paris. Corporate use requires a paid license fee unless a
 * separate written license states otherwise.
 */

/**
 * Returns the top N groups and rolls the remaining rows into Other.
 *
 * @param array $groups Associative counts or rows with label/count keys.
 * @param int $limit Number of top groups to keep.
 * @return array Grouped top-N report.
 */
function ogGroupTopNWithOther($groups = array(), $limit = 10) {
	$result = array(
		'success' => false,
		'message' => '',
		'data' => array()
	);

	if (!is_array($groups)) {
		$result['message'] = 'Groups must be an array.';
		return $result;
	}

	$limit = (int)$limit;
	if ($limit < 1) {
		$limit = 10;
	}

	$rows = array();
	foreach ($groups as $key => $value) {
		$label = (string)$key;
		$count = 0;
		if (is_array($value)) {
			if (!empty($value['label'])) {
				$label = (string)$value['label'];
			}
			if (!empty($value['count'])) {
				$count = (float)$value['count'];
			}
		} elseif (is_numeric($value)) {
			$count = (float)$value;
		}
		$rows[] = array('label' => $label, 'count' => $count);
	}

	usort($rows, function($left, $right) {
		if ($left['count'] == $right['count']) {
			return strcmp($left['label'], $right['label']);
		}
		if ($left['count'] < $right['count']) {
			return 1;
		}
		return -1;
	});

	$top = array();
	$other_count = 0;
	foreach ($rows as $index => $row) {
		if ($index < $limit) {
			$top[] = $row;
		} else {
			$other_count += $row['count'];
		}
	}
	if ($other_count > 0) {
		$top[] = array('label' => 'Other', 'count' => $other_count);
	}

	$result['success'] = true;
	$result['message'] = 'Top groups built.';
	$result['data'] = array('groups' => $top, 'original_group_count' => count($rows));

	return $result;
}