Parsing a CSV file - sorting and aggregating entries

csv-parsing.php

<?php

$filename = './Voters_for_SDC4CRetriever_Official-groupby-email.csv';

$name = null;
$entry_fp = null;
$entry_arr = [];

$fp = fopen($filename, 'r');
while (true) {

	$arr = fgetcsv($fp);

	if ($arr[1] == 'votes' || !$arr) {
		$name = $arr[6];
		$filename = './entries-ip-sort/' . str_replace(' ', '-', $name) . '.csv';

		if ($entry_fp) {

			$csv_str = '';
			$ip_arr = [];
			$ip_list = [];

			foreach($entry_arr as $i => $_arr) {

				$ips = array_map('trim', explode("\n", $_arr[7]));

				foreach($ips as $_i_ip => $ip) {

					if (in_array($i . '.' . $_i_ip, $ip_list) ) {
						continue;
					}
					$ip_list[] = $i . '.' . $_i_ip;

					$ip_entry = $_arr;
					$ip_entry[7] = $ip;
					if ($ip !== '') $ip_entry[8] = '- unique IP';
					$ip_arr[] = $ip_entry;

					if ($ip == '') {
						continue;
					}

					foreach($entry_arr as $_i => $__arr) {
						if ($_i == $i) {
							continue;
						}
						$_ips = array_map('trim', explode("\n", $__arr[7]));

						if (in_array($ip, $_ips)) {

							$ip_key = array_search($ip, $_ips);
							$ip_list[] = $_i . '.' . $ip_key;

							$ip_entry = $__arr; 
							$ip_entry[7] = $ip;
							$ip_entry[8] = '* same IP';
							$ip_arr[] = $ip_entry;
						}
					}

				}
			}

			$sort_ip_arr = [];
			$last_ip = null;
			$tmp_sort_arr = [];
			foreach($ip_arr as $ip_entry) {
				if ($ip_entry[7] == $last_ip) {
					$tmp_sort_arr[] = $ip_entry;
				} else {
					usort($tmp_sort_arr, function($a, $b) {
						return strcmp($a[5], $b[5]);
					});

					var_dump($tmp_sort_arr);

					$sort_ip_arr = array_merge($sort_ip_arr, $tmp_sort_arr);
					$tmp_sort_arr = [];

					$last_ip = $ip_entry[7];
				}
			}

			foreach($sort_ip_arr as $ip_entry) {
				$csv_str .= '"' . implode('","', $ip_entry) . "\"\n";
			}

			fwrite($entry_fp, $csv_str);

			fclose($entry_fp);

		}

		$entry_fp = fopen($filename, 'w+');
		$entry_arr = [];
	}

	if ($entry_fp) {
		$entry_arr[] = $arr;
	}

	if (!$arr) {
		break;
	}
}


if (is_resource($fp)) {
	fclose($fp);
}