<?php
// healthcheck.php
// Lightweight readiness probe independent of WordPress code.

header('Content-Type: application/json');
header('Cache-Control: no-store, no-cache, must-revalidate');

$response = [
    'status' => 'ok',
    'php_version' => PHP_VERSION,
    'checks' => [],
];
$httpStatus = 200;

// Filesystem/webroot probe
$webroot = '/var/www/html';
$fsStatus = [
    'name' => 'filesystem',
    'status' => 'ok',
    'detail' => 'Webroot mounted',
];
if (!is_dir($webroot)) {
    $fsStatus['status'] = 'error';
    $fsStatus['detail'] = 'Missing /var/www/html mount';
    $httpStatus = 503;
} elseif (!is_readable($webroot)) {
    $fsStatus['status'] = 'error';
    $fsStatus['detail'] = 'Webroot not readable';
    $httpStatus = 503;
}
$response['checks'][] = $fsStatus;

// Database probe (optional if env vars missing)
$requiredEnv = ['WORDPRESS_DB_HOST', 'WORDPRESS_DB_USER', 'WORDPRESS_DB_PASSWORD', 'WORDPRESS_DB_NAME'];
$dbConfig = [];
$missingEnv = [];
foreach ($requiredEnv as $var) {
    $value = getenv($var);
    if ($value === false || $value === '') {
        $missingEnv[] = $var;
    } else {
        $dbConfig[$var] = $value;
    }
}

$dbStatus = [
    'name' => 'database',
    'status' => 'skipped',
    'detail' => 'Database env vars missing',
];

if (empty($missingEnv)) {
    [$host, $port] = (function (string $rawHost): array {
        if (preg_match('/^\[(.+)\](?::(\d+))?$/', $rawHost, $matches)) {
            return [$matches[1], isset($matches[2]) ? (int) $matches[2] : 3306];
        }
        if (substr_count($rawHost, ':') === 1 && strpos($rawHost, '::') === false) {
            [$h, $p] = explode(':', $rawHost, 2);
            return [$h, (int) $p];
        }
        return [$rawHost, 3306];
    })($dbConfig['WORDPRESS_DB_HOST']);

    $mysqli = @mysqli_init();
    if ($mysqli !== false) {
        @mysqli_options($mysqli, MYSQLI_OPT_CONNECT_TIMEOUT, 3);
        $connected = @$mysqli->real_connect(
            $host,
            $dbConfig['WORDPRESS_DB_USER'],
            $dbConfig['WORDPRESS_DB_PASSWORD'],
            $dbConfig['WORDPRESS_DB_NAME'],
            $port
        );
        if ($connected) {
            $dbStatus['status'] = 'ok';
            $dbStatus['detail'] = 'DB connection OK';
            $mysqli->close();
        } else {
            $dbStatus['status'] = 'error';
            $dbStatus['detail'] = sprintf('DB connect failed: %s', $mysqli->connect_error ?? 'unknown error');
            $httpStatus = 503;
        }
    } else {
        $dbStatus['status'] = 'error';
        $dbStatus['detail'] = 'Unable to init mysqli';
        $httpStatus = 503;
    }
} else {
    $dbStatus['detail'] = 'Missing env: ' . implode(', ', $missingEnv);
}
$response['checks'][] = $dbStatus;

http_response_code($httpStatus);
echo json_encode($response, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES) . "\n";