<?php

function on_post() {
    $WEBSITE_CATEGORY = 'page_url';
    $DOWNLOADS_FOLDER = getenv('ARCHIVES_DIR');
    $website_url = $_POST[$WEBSITE_CATEGORY];
    $currentPage = new DownloadPage($website_url, $DOWNLOADS_FOLDER);
}

class DownloadPage {
    private $zip_location;
    private $zip_name;
    private $page_url;
    private $page_contents;

    function __construct($page_url, $zip_location) {
        $this->zip_location = $zip_location;
        $this->page_url = $page_url;
        list($website_exists, $this->page_url) = $this->does_website_exist($this->page_url);
        if ($website_exists) {
            $this->zip_name = Database\Webpage::create($zip_location, $page_url, 1) . '.zip';
            $this->page_contents = file_get_contents($this->page_url);
            $zip = $this->create_zip_archive();
        } else {
            echo "Website does not exist";
        }
    }

    function set_zip_location($zip_location) {
        $this->zip_location = $zip_location;
    }
    function set_zip_name($zip_name) {
        $this->zip_name = $zip_name;
    }
    function set_page_url($page_url) {
        $this->page_url = $page_url;
    }
    function apply_correct_protocol($url, $protocol) {
        if (str_contains($url, $protocol)) {
            return $url;
        }

        return $protocol . $url;
    }

    function does_website_exist($url) {

        // Check if the site exists with https
        $https_url = $this->apply_correct_protocol($url, "https://");
        if ($https_url != $url) {
            $url_headers = @get_headers($https_url);
            if ($url_headers && $url_headers[0] != 'HTTP/1.1 404 Not Found') {
                return array(true, $https_url);
            }
        }

        // Check if the site exists with http
        $http_url = $this->apply_correct_protocol($url, "http://");
        if ($http_url != $url) {
            $url_headers = @get_headers($http_url);
            if ($url_headers && $url_headers[0] != 'HTTP/1.1 404 Not Found') {
                return array(true, $http_url);
            }
        }

        // Check if the site exists as is
        // Will take effect when the user has entered the https/http protocol with the site
        $url_headers = @get_headers($url);
        if ($url_headers && $url_headers[0] != 'HTTP/1.1 404 Not Found') {
            return array(true, $url);
        }

        return array(false, $url);
    }

    function create_zip_archive() {
        // Creates and returns a zip object resulted from zipping the page that was downloaded
        $zip = new ZipArchive();
        if ($zip->open($this->zip_location . '/' . $this->zip_name, ZipArchive::CREATE) === TRUE) {
            $zip->addFromString('index.html', $this->page_contents);
            $zip->close();
            echo "Archived {$this->page_url}";
        } else {
            echo "Zip archive could not be open";
        }

        return $zip;
    }
}