<?php

namespace Ladon;

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

/**
 * Collects what is installed. Premium plugins and themes that are not on wordpress.org
 * ride along by slug and version just like the rest, Ladon matches them on the feed.
 *
 * On multisite the files are installed once for the whole network, but active state differs
 * per subsite, so active means active anywhere (network-wide or on any subsite) and active_sites
 * names the subsites where a per-site activation is on.
 */
class Inventory
{
    /**
     * @return array<string, mixed>
     */
    public function collect()
    {
        $context = $this->context();

        $data = array(
            'core' => get_bloginfo('version'),
            'php' => $this->phpVersion(),
            'plugins' => $this->plugins($context),
            'themes' => $this->themes($context),
        );

        if ($context['multisite']) {
            $data['multisite'] = true;
            $data['network_sites'] = $context['sites'];
            $data['subsites_scanned'] = $context['scanned'];
        }

        return $data;
    }

    /**
     * A stable fingerprint of the payload, so the plugin and the server both skip no-op reports.
     *
     * @param  array<string, mixed>  $inventory
     */
    public function hash(array $inventory)
    {
        return md5((string) wp_json_encode($this->normalize($inventory)));
    }

    private function phpVersion()
    {
        return defined('PHP_VERSION') ? PHP_VERSION : phpversion();
    }

    /**
     * Where a plugin or theme is active. On a single site this is just the one site.
     *
     * @return array<string, mixed>
     */
    private function context()
    {
        if (!is_multisite()) {
            $url = home_url('/');
            $themes = array(get_stylesheet() => array($url));
            $template = get_template();

            if ($template !== get_stylesheet()) {
                $themes[$template][] = $url;
            }

            return array(
                'multisite' => false,
                'sites' => 1,
                'scanned' => true,
                'networkPlugins' => array(),
                'sitePlugins' => $this->mapFiles((array) get_option('active_plugins', array()), $url),
                'siteThemes' => $themes,
            );
        }

        $networkPlugins = array_keys((array) get_site_option('active_sitewide_plugins', array()));
        $total = (int) get_sites(array('count' => true));
        $cap = (int) apply_filters('ladon_multisite_site_cap', 100);
        $scanned = $total <= $cap;

        $sitePlugins = array();
        $siteThemes = array();

        if ($scanned) {
            foreach (get_sites(array('number' => $cap, 'fields' => 'ids')) as $blogId) {
                $url = get_home_url((int) $blogId, '/');

                foreach ((array) get_blog_option((int) $blogId, 'active_plugins', array()) as $file) {
                    $sitePlugins[(string) $file][] = $url;
                }

                $stylesheet = (string) get_blog_option((int) $blogId, 'stylesheet');
                $template = (string) get_blog_option((int) $blogId, 'template');

                if ($stylesheet !== '') {
                    $siteThemes[$stylesheet][] = $url;
                }

                if ($template !== '' && $template !== $stylesheet) {
                    $siteThemes[$template][] = $url;
                }
            }
        }

        return array(
            'multisite' => true,
            'sites' => $total,
            'scanned' => $scanned,
            'networkPlugins' => array_fill_keys(array_map('strval', $networkPlugins), true),
            'sitePlugins' => $sitePlugins,
            'siteThemes' => $siteThemes,
        );
    }

    /**
     * @param  array<int, string>  $files
     * @return array<string, array<int, string>>
     */
    private function mapFiles(array $files, $url)
    {
        $map = array();

        foreach ($files as $file) {
            $map[(string) $file][] = $url;
        }

        return $map;
    }

    /**
     * @param  array<string, mixed>  $context
     * @return array<int, array<string, mixed>>
     */
    private function plugins(array $context)
    {
        if (!function_exists('get_plugins')) {
            require_once ABSPATH . 'wp-admin/includes/plugin.php';
        }

        $updates = $this->updateVersions('update_plugins');
        $out = array();

        foreach (get_plugins() as $file => $data) {
            $file = (string) $file;
            $slug = $this->slug(strpos($file, '/') !== false ? dirname($file) : basename($file, '.php'));

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

            $networkActive = isset($context['networkPlugins'][$file]);
            $sites = isset($context['sitePlugins'][$file]) ? $context['sitePlugins'][$file] : array();

            $item = array(
                'slug' => $slug,
                'version' => isset($data['Version']) ? (string) $data['Version'] : '',
                'active' => $networkActive || !empty($sites),
            );

            $this->attachScope($item, $context, $networkActive, $sites);

            if (isset($updates[$file])) {
                $item['new_version'] = $updates[$file];
            }

            $out[] = $item;
        }

        return $out;
    }

    /**
     * @param  array<string, mixed>  $context
     * @return array<int, array<string, mixed>>
     */
    private function themes(array $context)
    {
        $updates = $this->updateVersions('update_themes');
        $out = array();

        foreach (wp_get_themes() as $stylesheet => $theme) {
            $stylesheet = (string) $stylesheet;
            $slug = $this->slug($stylesheet);

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

            $sites = isset($context['siteThemes'][$stylesheet]) ? $context['siteThemes'][$stylesheet] : array();

            $item = array(
                'slug' => $slug,
                'version' => (string) $theme->get('Version'),
                'active' => !empty($sites),
            );

            $this->attachScope($item, $context, false, $sites);

            if (isset($updates[$stylesheet])) {
                $item['new_version'] = $updates[$stylesheet];
            }

            $out[] = $item;
        }

        return $out;
    }

    /**
     * Network-active means everywhere, so no list. A per-site activation on multisite lists the sites.
     *
     * @param  array<string, mixed>  $item
     * @param  array<string, mixed>  $context
     * @param  array<int, string>  $sites
     */
    private function attachScope(array &$item, array $context, $networkActive, array $sites)
    {
        if (!$context['multisite'] || $networkActive || empty($sites)) {
            return;
        }

        $sites = array_values(array_unique($sites));
        sort($sites);
        $cap = (int) apply_filters('ladon_multisite_site_cap', 100);

        $item['active_sites'] = array_slice($sites, 0, $cap);
    }

    /**
     * @return array<string, string>
     */
    private function updateVersions($transient)
    {
        $data = get_site_transient($transient);

        if (!is_object($data) || empty($data->response) || !is_array($data->response)) {
            return array();
        }

        $out = array();

        foreach ($data->response as $key => $value) {
            if (is_object($value) && isset($value->new_version)) {
                $out[(string) $key] = (string) $value->new_version;
            } elseif (is_array($value) && isset($value['new_version'])) {
                $out[(string) $key] = (string) $value['new_version'];
            }
        }

        return $out;
    }

    private function slug($value)
    {
        return preg_replace('/[^A-Za-z0-9._-]/', '', (string) $value);
    }

    /**
     * @param  array<string, mixed>  $inventory
     * @return array<string, mixed>
     */
    private function normalize(array $inventory)
    {
        $sort = function (array $items) {
            usort($items, function ($a, $b) {
                return strcmp($a['slug'], $b['slug']);
            });

            return $items;
        };

        $inventory['plugins'] = $sort($inventory['plugins']);
        $inventory['themes'] = $sort($inventory['themes']);

        return $inventory;
    }
}