<?php
namespace App\CMS\Helpers;

use App\CMS\Contracts\Modules\TemplateHandler;
use App\Models\Content\Content;
use App\Models\Module;
use App\Models\User;
use Illuminate\Database\QueryException;
use Illuminate\Support\Facades\Cache;

class CurrentTemplate implements TemplateHandler
{
    protected static $template;
    protected static $initialized = false;

    /**
     * Getter for currently set template
     * @return Module
     * @throws \ErrorException
     */
    public static function get()
    {
        if (!self::$initialized) {
                self::$template = Cache::rememberForever('current-template', function () {
                    $template = Module::where('is_template', true)
                          ->where('enabled', true)
                          ->first();

                    // todo remove after adding $casts into Module model
                    if ($template) {
                        $template->module_settings = json_decode($template->module_settings);
                    }

                    return $template;
                });


            self::$initialized = true;
        }

        return self::$template;
    }

    /**
     * Shortcut for getting template handler
     *
     * @return string
     * @throws \ErrorException
     */
    public static function handler()
    {
        $template = self::get();

        if (!$template) {
            throw new \ErrorException('No template selected, no handler available!');
        }

        return $template->handler;
    }

    /**
     * Reset currently set template and load another one on next call of get() method.
     */
    public static function reset()
    {
        self::$initialized = false;
    }

    /**
     * Register admin menu (or multiple ones)
     *
     * This cannot be in ServiceProvider because Session is started at middleware. And ServiceProvider is called before
     * starting any middleware..
     *
     * @param User $user model of logged user
     */
    public static function registerAdminMenu(User $user)
    {
        call_user_func_array([self::handler(), 'registerAdminMenu'], [$user]);
    }

    /**
     * Get list of registered templates and supported modules.
     *
     * Returned array is expected to be array of arrays with following items: module, namespace and templateName.
     * Example:
     * return [
     *    ['module' => 'Article', 'templateName' => 'article::template.name']
     * ];
     *
     * When no "namespace" is specified, value strtolower(module) is used instaed.
     *
     * @return array
     */
    public static function getPublicTemplatePaths()
    {
        return call_user_func([self::handler(), 'getPublicTemplatePaths']);
    }

    /**
     * Prepare Content object to be rendered using Blade template
     *
     * @param Content $content
     */
    public static function beforeRender(Content & $content)
    {
        call_user_func_array([self::handler(), 'beforeRender'], [&$content]);
    }

    /**
     * Modify input data into format which can be understood by edit template
     *
     * @param Content $content
     */
    public static function beforePopulatingEditForm(Content & $content)
    {
        call_user_func_array([self::handler(), 'beforePopulatingEditForm'], [&$content]);
    }

    /**
     * Slightly modify Content object before saving into database.
     *
     * This way we can do almost whatever we want - even in template
     *
     * @param Content $content
     * @param         $request
     */
    public static function beforeSave(Content & $content, $request)
    {
        call_user_func_array([self::handler(), 'beforeSave'], [&$content, $request]);
    }
}