<?php
// File: case_data.php

function getCaseData() {
    return [
        1 => [
            "title" => "Case 1: Title",
            "isPro" => false,
            // other case data...
        ]
		// etc
    ];
}

function getAvailableCases($isPro) {
    $allCases = getCaseData();
    foreach ($allCases as &$case) {
        $case['isAccessible'] = !($case['isPro'] ?? false) || $isPro;
    }
    return $allCases;
}