<?php

namespace Boxzilla\Licensing;

use Boxzilla\Plugin;

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

class UpdateManager
{
    /**
     * @var array
     */
    protected $extensions = [];

    /**
     * @var API
     */
    protected $api;

    /**
     * @var License
     */
    protected $license;

    /**
     * @var array
     */
    protected $available_updates;

    /**
     * @param array $extensions
     * @param API        $api
     * @param License    $license
     */
    public function __construct(array $extensions, API $api, License $license)
    {
        $this->extensions = $extensions;
        $this->license    = $license;
        $this->api        = $api;
    }

    /**
     * Add hooks
     */
    public function init()
    {
        add_filter('pre_set_site_transient_update_plugins', [ $this, 'add_updates' ]);
        add_filter('plugins_api', [ $this, 'get_plugin_info' ], 20, 3);
        add_filter('http_request_args', [ $this, 'add_auth_headers' ], 10, 2);
    }

    /**
     * This adds the license key header to download package requests.
     *
     * @param array $args
     * @param string $url
     *
     * @return mixed
     */
    public function add_auth_headers($args, $url)
    {
        // only act on download request's to the Boxzilla update API
        if (strpos($url, $this->api->url) !== 0 || strpos($url, '/download') === false) {
            return $args;
        }

        // only add if activation key not empty
        if (empty($this->license->activation_key)) {
            return $args;
        }

        if (! isset($args['headers'])) {
            $args['headers'] = [];
        }

        $args['headers']['Authorization'] = "Bearer {$this->license->activation_key}";
        return $args;
    }

    /**
     * @param        $result
     * @param string $action
     * @param object   $args
     *
     * @return object|null
     */
    public function get_plugin_info($result, $action, $args)
    {
        // do nothing for unrelated requests
        if ($action !== 'plugin_information' || ! isset($args->slug)) {
            return $result;
        }

        // only act on our plugins
        if (strpos($args->slug, 'boxzilla-') !== 0) {
            return $result;
        }

        return $this->get_update_info($args->slug);
    }

    /**
     * @param null|object $updates
     * @return object
     */
    public function add_updates($updates)
    {

        // do nothing if no plugins registered
        if (empty($this->extensions)) {
            return $updates;
        }

        // failsafe WP bug
        if (empty($updates) || ! isset($updates->response) || ! is_array($updates->response)) {
            return $updates;
        }

        // fetch available updates
        $available_updates = $this->fetch_updates();

        // merge with other updates
        $updates->response = array_merge($updates->response, $available_updates);

        return $updates;
    }

    /**
     * Fetch array of available updates from remote server
     *
     * @return array
     */
    protected function fetch_updates()
    {
        if (is_array($this->available_updates)) {
            return $this->available_updates;
        }

        // don't try if we failed a request recently.
        $failed_at = get_transient('boxzilla_request_failed');
        if (! empty($failed_at) && ( ( time() - 300 ) < $failed_at )) {
            return [];
        }

        // fetch remote info
        try {
            $remote_plugins = $this->api->get_plugins();
        } catch (API_Exception $e) {
            // set flag for 5 minutes
            set_transient('boxzilla_request_failed', time(), 300);
            return [];
        }

        // filter remote plugins, we only want the ones with an update available
        $this->available_updates = $this->filter_remote_plugins($remote_plugins);

        return $this->available_updates;
    }

    /**
     * @param $remote_plugins
     * @return array
     */
    protected function filter_remote_plugins($remote_plugins)
    {
        $available_updates = [];

        // find new versions
        foreach ($remote_plugins as $remote_plugin) {
            // sanity check
            if (! isset($remote_plugin->new_version)) {
                continue;
            }

            // if plugin is activated, we can access it here
            if (isset($this->extensions[ $remote_plugin->sid ])) {

                /** @var Plugin $local_plugin */
                $local_plugin = $this->extensions[ $remote_plugin->sid ];

                // plugin found and local plugin version not same as remote version?
                if (! $local_plugin || version_compare($local_plugin->version(), $remote_plugin->new_version, '>=')) {
                    continue;
                }

                // add some dynamic data
                $available_updates[ $local_plugin->slug() ] = $this->format_response($local_plugin->slug(), $remote_plugin);
            } else {
                // if plugin is not active, use get_plugin_data for fetching version
                $plugin_file = WP_PLUGIN_DIR . "/{$remote_plugin->slug}/{$remote_plugin->slug}.php";
                if (! file_exists($plugin_file)) {
                    continue;
                }

                $plugin_data = get_plugin_data($plugin_file);

                if (! $plugin_data || version_compare($plugin_data['Version'], $remote_plugin->new_version, '>=')) {
                    continue;
                }

                // add some dynamic data
                $slug                       = plugin_basename($plugin_file);
                $available_updates[ $slug ] = $this->format_response($slug, $remote_plugin);
            }
        }

        return $available_updates;
    }

    /**
     * @param string $slug
     *
     * @return object|null
     */
    public function get_update_info($slug)
    {
        $available_updates = $this->fetch_updates();

        foreach ($available_updates as $plugin_file => $update_info) {
            if ($slug === $update_info->slug) {
                return $update_info;
            }
        }

        return null;
    }

    /**
     * @param $slug
     * @param $response
     *
     * @return mixed
     */
    protected function format_response($slug, $response)
    {
        $response->slug   = dirname($slug);
        $response->plugin = $slug;

        // add some notices if license is inactive
        if (! $this->license->activated) {
            $response->upgrade_notice      = sprintf('You will need to <a href="%s">activate your license</a> to install this plugin update.', admin_url('edit.php?post_type=boxzilla-box&page=boxzilla-settings'));
            $response->sections->changelog = '<p>' . sprintf('You will need to <a href="%s" target="_top">activate your license</a> to install this plugin update.', admin_url('edit.php?post_type=boxzilla-box&page=boxzilla-settings')) . '</p>' . $response->sections->changelog;
            $response->package             = null;
        }

        // cast subkey objects to array as that is what WP expects
        $response->sections     = get_object_vars($response->sections);
        $response->banners      = get_object_vars($response->banners);
        $response->contributors = get_object_vars($response->contributors);
        $response->contributors = array_map(
            function ($v) {
                return get_object_vars($v);
            },
            $response->contributors
        );

        return $response;
    }
}