<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Response;
use Illuminate\Contracts\Foundation\Application;

class CookieConsentMiddleware
{
    protected $app;

    public function __construct(Application $app)
    {
        $this->app = $app;
    }

    public function handle($request, Closure $next)
    {
        $response = $next($request);

        if (! $response instanceof Response) {
            return $response;
        }

        if (! $this->containsBodyTag($response)) {
            return $response;
        }

        return $this->addCookieConsentScriptToResponse($response);
    }

    /**
     * Add the cookie script before the closing body tag
     *
     * @param \Illuminate\Http\Response $response
     * @return \Illuminate\Http\Response $response
     */
    protected function addCookieConsentScriptToResponse(Response $response)
    {
        // Get content
        $content = $response->getContent();

        // Get closing body tag position
        $closingBodyTagPosition = $this->getLastClosingBodyTagPosition($content);

        // Add script to content
        $newContent = '';
        $newContent .= substr($content, 0, $closingBodyTagPosition);
        $newContent .= view('site.partials.cookieIndex')->render();
        $newContent .= substr($content, $closingBodyTagPosition);

        return $response->setContent($newContent);
    }

    /**
     * Check for body-tag
     *
     * @param Response $response
     * @return bool
     */
    protected function containsBodyTag(Response $response)
    {
        return $this->getLastClosingBodyTagPosition($response->getContent()) !== false;
    }

    /**
     * Get position body tag
     *
     * @param string $content
     * @return int
     */
    protected function getLastClosingBodyTagPosition($content = '')
    {
        return strripos($content, '</body>');
    }
}