#!/usr/bin/env php
<?php

/**
 * Verify the running PHP environment meets the declared runtime requirements.
 *
 * Reads config/requirements.php and checks the PHP version and that every
 * required extension is loaded. Exits non-zero (failing CI) on any miss.
 *
 * Usage: php scripts/check_requirements.php
 */

/**
 * Parse a php.ini size value (e.g. "128M", "1G", "-1") into bytes.
 * Returns -1 for unlimited.
 */
function parseIniBytes(string $val): int
{
    $val = trim($val);
    if ($val === '' || $val === '-1') {
        return -1;
    }
    $unit = strtolower(substr($val, -1));
    $num = (int)$val;
    return match ($unit) {
        'g' => $num * 1024 * 1024 * 1024,
        'm' => $num * 1024 * 1024,
        'k' => $num * 1024,
        default => $num,
    };
}

$req = require __DIR__ . '/../config/requirements.php';

$errors = [];
$warnings = [];

// PHP version
$minPhp = $req['min_php_version'];
if (version_compare(PHP_VERSION, $minPhp, '<')) {
    $errors[] = sprintf('PHP %s is below the required minimum %s', PHP_VERSION, $minPhp);
}

// Required extensions
foreach ($req['required_extensions'] as $ext) {
    if (!extension_loaded($ext)) {
        $errors[] = sprintf('Missing required PHP extension: %s', $ext);
    }
}

// memory_limit / max_execution_time sanity checks (warnings, not hard
// failures — see config/requirements.php for why these matter).
$memLimitIni = ini_get('memory_limit');
$memLimitBytes = parseIniBytes($memLimitIni);
$minMemBytes = $req['min_memory_limit_mb'] * 1024 * 1024;
if ($memLimitBytes !== -1 && $memLimitBytes < $minMemBytes) {
    $warnings[] = sprintf(
        'memory_limit is %s, below the recommended minimum %dM',
        $memLimitIni,
        $req['min_memory_limit_mb']
    );
}

$maxExecTime = (int)ini_get('max_execution_time');
if ($maxExecTime !== 0 && $maxExecTime < $req['min_max_execution_time']) {
    $warnings[] = sprintf(
        'max_execution_time is %ds, below the recommended minimum %ds',
        $maxExecTime,
        $req['min_max_execution_time']
    );
}

if (!empty($errors)) {
    fwrite(STDERR, "Requirement check FAILED:\n");
    foreach ($errors as $err) {
        fwrite(STDERR, '  - ' . $err . "\n");
    }
    exit(1);
}

foreach ($warnings as $warn) {
    fwrite(STDERR, "Requirement check WARNING: " . $warn . "\n");
}

printf(
    "Requirement check passed: PHP %s (>= %s); extensions: %s\n",
    PHP_VERSION,
    $minPhp,
    implode(', ', $req['required_extensions'])
);
exit(0);