<?php
/**
 * The report behind bin/private-storage-acceptance/wpbr-host-probe.php, the temporary diagnostic used in real-host acceptance.
 *
 * The standalone file only decides whether it may run at all (its name, its age) and who is asking; everything it reports and
 * every request it makes is here, so it is tested like the rest of the plugin. Read-only unless the request carries write=1
 * AND a nonce from the report itself, so a link cannot make an administrator's browser place files. The only host names it
 * asks at are the site's own and up to five declared ones, validated as host names (wpbr_storage_probe_hosts()); the only
 * folder it writes in is one the plugin itself offers as a candidate, and it creates nothing.
 */

if (!defined('ABSPATH')) exit;

/**
 * Temporary diagnostic files left in the WordPress folder (or the one above it), by name.
 *
 * @return string[] Absolute paths.
 */
function wpbr_host_probe_files() {
    $found = array();
    foreach (array(ABSPATH, dirname(rtrim(ABSPATH, '/')) . '/') as $dir) {
        foreach ((array) glob($dir . 'wpbr-host-probe*.php') as $file) {
            if (is_file($file)) $found[] = wp_normalize_path($file);
        }
    }
    return array_values(array_unique($found));
}

/**
 * @param array $request write ('1'), nonce, dir, domain (string|string[])
 * @return array{status:int,body:array}
 */
function wpbr_storage_host_probe_report(array $request) {
    if (!is_user_logged_in() || !current_user_can('manage_options')) {
        return array('status' => 403, 'body' => array('error' => 'Log in as an administrator first.'));
    }
    $write = isset($request['write']) && (string) $request['write'] === '1';
    $nonce = isset($request['nonce']) ? (string) $request['nonce'] : '';
    if ($write && !wp_verify_nonce($nonce, 'wpbr_host_probe')) {
        return array('status' => 403, 'body' => array('error' => 'Placing test files needs the nonce shown in the read-only report. Open the report, then use its write_link.'));
    }
    $want    = isset($request['dir']) ? wpbr_storage_norm(sanitize_text_field((string) $request['dir'])) : '';
    $domains = isset($request['domain']) ? array_map('sanitize_text_field', array_map('strval', (array) $request['domain'])) : array();

    $chain = function ($path) {
        $hops = array();
        $cur  = (string) $path;
        for ($i = 0; $i < 8 && $cur !== '' && @is_link($cur); $i++) {
            $to = @readlink($cur);
            if ($to === false) break;
            $hops[] = $to;
            $cur = ($to !== '' && $to[0] === '/') ? $to : dirname($cur) . '/' . $to;
        }
        $real = $path !== '' ? @realpath($path) : false;
        return array('path' => $path, 'symlink_hops' => $hops, 'real' => $real === false ? null : $real);
    };
    $mounts_text = @is_readable('/proc/mounts') ? (string) @file_get_contents('/proc/mounts') : '';
    $mount_type  = function ($path) use ($mounts_text) {
        $real = $path !== '' ? @realpath($path) : false;
        return $mounts_text !== '' && $real !== false ? wpbr_storage_mount_type($real, $mounts_text) : null;
    };
    $free = function ($path) {
        $p = (string) $path;
        while ($p !== '' && $p !== '/' && !@is_dir($p)) $p = dirname($p);
        $f = function_exists('disk_free_space') ? @disk_free_space($p) : false;
        return $f === false ? null : (int) $f;
    };

    $upload = wp_upload_dir();
    $docs   = wpbr_storage_document_roots();
    $doc    = isset($_SERVER['DOCUMENT_ROOT']) && is_string($_SERVER['DOCUMENT_ROOT']) ? sanitize_text_field(wp_unslash($_SERVER['DOCUMENT_ROOT'])) : '';
    // Which front-proxy headers arrived, never their values: they carry visitors' addresses.
    $seen = array();
    foreach (array('HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED_HOST', 'HTTP_X_FORWARDED_PROTO', 'HTTP_X_REAL_IP', 'HTTP_VIA', 'HTTP_X_FORWARDED_SERVER') as $k) {
        if (!empty($_SERVER[$k])) $seen[] = $k;
    }

    $report = array(
        'generated_at' => gmdate('c'),
        'reminder' => 'This is a temporary diagnostic. Delete the file when you are done (delete=1 with delete_nonce removes it).',
        'environment' => array(
            'php' => PHP_VERSION, 'sapi' => PHP_SAPI, 'uname' => php_uname('s r m'),
            'wp_environment_type' => wp_get_environment_type(),
            'server_software' => isset($_SERVER['SERVER_SOFTWARE']) ? sanitize_text_field(wp_unslash($_SERVER['SERVER_SOFTWARE'])) : null,
            'front_proxy_headers_present' => $seen,
            'open_basedir' => ini_get('open_basedir') ?: null,
            'proc_mounts_readable' => $mounts_text !== '',
            'container_signs' => wpbr_storage_in_container(),
            'multisite' => is_multisite(),
        ),
        'paths' => array(
            'document_root' => $chain($doc),
            'abspath' => $chain(ABSPATH),
            'wp_content' => $chain(WP_CONTENT_DIR),
            'uploads' => $chain($upload['basedir']),
            'roots_the_plugin_knows' => $docs['roots'],
            'mount_types' => array('document_root' => $mount_type($doc), 'uploads' => $mount_type($upload['basedir'])),
        ),
        'plugin' => array(
            'backups_dir' => wpbr_backups_dir(),
            'active_location' => wpbr_storage_active_dir() ?: null,
            'active_problem' => wpbr_storage_active_problem() ?: null,
            'privacy_constants_set' => array('WPBR_PRIVATE_ROOT' => defined('WPBR_PRIVATE_ROOT'), 'WPBR_BACKUPS_DIR' => defined('WPBR_BACKUPS_DIR')),
        ),
        'candidates' => array(),
        'alias_probe' => array('requested' => $write),
        'links' => array(
            'write_link_template' => '?write=1&nonce=' . wp_create_nonce('wpbr_host_probe') . '&dir=<one of the candidate paths>&domain[]=<a mapped host name>',
            'delete_nonce' => wp_create_nonce('wpbr_host_probe_delete'),
        ),
    );

    $found = wpbr_storage_discover(array('probe' => false));
    $by_path = array();
    foreach (array_merge($found['eligible'], $found['rejected']) as $entry) {
        $props = array();
        foreach ($entry['result']['properties'] as $name => $p) {
            $props[$name] = array_intersect_key($p, array_flip(array('status', 'detail', 'basis', 'fstype', 'colocated', 'mode')));
        }
        $report['candidates'][] = array(
            'path' => $entry['path'], 'source' => $entry['source'], 'eligible' => (bool) $entry['result']['ok'],
            'mount_type' => $mount_type($entry['path']), 'free_bytes' => $free($entry['path']), 'properties' => $props,
        );
        $by_path[$entry['path']] = true;
    }

    if ($write) {
        if ($want === '' || !isset($by_path[$want])) {
            $report['alias_probe'] = array('requested' => true, 'error' => 'dir must be one of the candidate paths listed in this report.');
        } else {
            $probe = wpbr_storage_probe_aliases($want, array('hosts' => $domains));
            $report['alias_probe'] = array('requested' => true, 'dir' => $want) + $probe + array(
                'finding' => $probe['result'] === 'exposed'
                    ? 'EXPOSED: ' . implode(', ', $probe['served'])
                    : ($probe['result'] === 'not_exposed_on_tested_addresses' ? 'Not exposed on the addresses tested. This does not show that no mapping exists.' : 'Could not be checked.'),
            );
        }
    }
    return array('status' => 200, 'body' => $report);
}