<?php
/**
 * iCalcreator, the PHP class package managing iCal (rfc2445/rfc5445) calendar information.
 *
 * This file is a part of iCalcreator.
 *
 * @author    Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
 * @copyright 2007-2024 Kjell-Inge Gustafsson, kigkonsult AB, All rights reserved
 * @link      https://kigkonsult.se
 * @license   Subject matter of licence is the software iCalcreator.
 *            The above copyright, link, package and version notices,
 *            this licence notice and the invariant [rfc5545] PRODID result use
 *            as implemented and invoked in iCalcreator shall be included in
 *            all copies or substantial portions of the iCalcreator.
 *
 *            iCalcreator is free software: you can redistribute it and/or modify
 *            it under the terms of the GNU Lesser General Public License as
 *            published by the Free Software Foundation, either version 3 of
 *            the License, or (at your option) any later version.
 *
 *            iCalcreator is distributed in the hope that it will be useful,
 *            but WITHOUT ANY WARRANTY; without even the implied warranty of
 *            MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *            GNU Lesser General Public License for more details.
 *
 *            You should have received a copy of the GNU Lesser General Public License
 *            along with iCalcreator. If not, see <https://www.gnu.org/licenses/>.
 */
declare( strict_types = 1 );
namespace Kigkonsult\Icalcreator\Util;

use Exception;
use InvalidArgumentException;
use Kigkonsult\Icalcreator\IcalInterface;
use Kigkonsult\Icalcreator\Pc;
use Kigkonsult\Icalcreator\Vcalendar;

use function clearstatcache;
use function file_put_contents;
use function filesize;
use function filter_var;
use function gzencode;
use function header;
use function sprintf;
use function strcasecmp;
use function strlen;
use function substr;
use function sys_get_temp_dir;
use function tempnam;
use function unlink;
use function utf8_encode;

/**
 * iCalcreator http support class
 *
 * @since 2.41.88 - 2024-01-18
 */
class HttpFactory
{
    /**
     * HTTP headers
     *
     * @var string[] $headers
     */
    private static array $headers = [
        'Content-Encoding: gzip',
        'Vary: *',
        'Content-Length: %s',
        'Content-Type: text/calendar; charset=utf-8',
        'Content-Disposition: attachment; filename="%s"',
        'Content-Disposition: inline; filename="%s"',
        'Cache-Control: max-age=10',
    ];

    /**
     * Return created, updated and/or parsed calendar, sending a HTTP redirect header.
     *
     * @param Vcalendar    $calendar
     * @param null|bool    $utf8Encode
     * @param null|bool    $gzip
     * @param null|bool    $cdType true : Content-Disposition: attachment... (default), false : ...inline...
     * @param null|string  $fileName
     * @return bool true on success, false on error
     * @throws Exception
     * @since  2.29.15 - 2020-01-19
     */
    public static function returnCalendar(
        Vcalendar $calendar,
        ? bool $utf8Encode = false,
        ? bool $gzip       = false,
        ? bool $cdType     = true,
        ? string $fileName = null
    ) : bool
    {
        static $ICR = 'iCr';
        if( empty( $fileName ) ) {
            $fileName = self::getFakedFilename();
        }
        $output     = $calendar->createCalendar();
        if( $utf8Encode ?? false ) {
            $output = utf8_encode( $output );
        }
        $fsize = null;
        if( $gzip ?? false ) {
            $output = gzencode( $output, 9 );
            $fsize  = strlen((string) $output );
            header( self::$headers[0] );
            header( self::$headers[1] );
        }
        elseif( false !== ( $temp = tempnam( sys_get_temp_dir(), $ICR ))) {
            if( false !== file_put_contents( $temp, $output )) {
                $fsize = @filesize( $temp );
            }
            unlink( $temp );
            clearstatcache();
        } // end else
        if( ! empty( $fsize )) {
            header( sprintf( self::$headers[2], $fsize ));
        }
        header( self::$headers[3] );
        $cdTix = $cdType ? 4 : 5;
        header( sprintf( self::$headers[$cdTix], $fileName ));
        header( self::$headers[6] );
        echo $output;
        return true;
    }

    /**
     * Return faked filename
     *
     * @return string
     * @since  2.29.4 - 2019-07-02
     */
    private static function getFakedFilename() : string
    {
        static $DOTICS = '.ics';
        return date( DateTimeFactory::$YmdHis, (int) microtime( true )) . $DOTICS;
    }

    /**
     * Assert URL
     *
     * @param string $url
     * @return void
     * @throws InvalidArgumentException
     * @since  2.41.68 - 2022-09-26
     */
    public static function assertUrl( string $url ) : void
    {
        static $UC   = '_';
        static $URN  = 'urn';
        static $HTTP = 'http://';
        static $MSG  = 'URL validity error #%d, \'%s\'';
        $url2 = str_contains( $url, $UC )
            ? str_replace( $UC, StringFactory::$MINUS, $url )
            : $url;
        switch( true ) {
            case ( false !== filter_var( $url2, FILTER_VALIDATE_URL )) :
                return;
            case ( empty( parse_url( $url2, PHP_URL_SCHEME )) &&
                ( false !== filter_var( $HTTP . $url2, FILTER_VALIDATE_URL ))) :
                return;
            case ( 0 !== strcasecmp( $URN, substr( $url, 0, 3 ))) :
                throw new InvalidArgumentException( sprintf( $MSG, 2, $url ));
            default :
                throw new InvalidArgumentException( sprintf( $MSG, 1, $url ));
        } // end switch
    }

    /**
     * Set calendar component property uri; URL, TZURL, SOURCE
     *
     * @param null|Pc  $propValue
     * @param Pc       $value
     * @return void
     * @throws InvalidArgumentException
     * @since 2.41.88 - 2024-01-18
     */
    public static function urlSet( ? Pc & $propValue, Pc $value ) : void
    {
        $pcValue = $value->getValue();
        if( ! empty( $pcValue )) {
            StringFactory::checkFixUrlDecode( $pcValue );
            self::assertUrl( $pcValue );
            $value->setValue( $pcValue );
            $value->removeParam(IcalInterface::VALUE );
        }
        $propValue = $value;
    }
}