<?php

namespace OCA\Gestion\Helpers;

use DateTime;
use DateTimeZone;
use Exception;

class VCalendarHelpers
{
    
    public static function GetValueFromKeyInVCalendarString(string $key, string $vCalendarString): string
    {
        $value = "";
        preg_match("/$key:(.*)\r\n/", $vCalendarString, $matches);
		if (isset($matches[1])) {
			$value = trim($matches[1]);
		} 
		return $value;
    }

    public static function GetDateStartOrDateEndFromVCalendarString(string $key, string $vCalendarString)
    {
        preg_match("/$key;TZID=([^:]+):(\d+T\d+)/", $vCalendarString, $matches);
        if(!$matches){
            return null;
        }
        try{
            $dateTz = $matches[1];
            $datetimeString = $matches[2];
            $datetimeValue = new DateTime($datetimeString, new DateTimeZone($dateTz));
            return $datetimeValue;
        }
        catch(Exception $e){
            return null;
        }
    }

    public static function GetStartAndEndTimeFromVCalendarString(string $vCalendarString){
        $startTimeValue = "";
        $endTimeValue = "";
        if($vCalendarString != ""){
            $dateStart = self::GetDateStartOrDateEndFromVCalendarString("DTSTART", $vCalendarString);
            if($dateStart != null){
                $startTimeValue = $dateStart->format("H") . "h";
            }
            $dateEnd = self::GetDateStartOrDateEndFromVCalendarString("DTEND", $vCalendarString);
            if($dateEnd != null){
                $endTimeValue = $dateEnd->format("H") . "h";
            }
        }
        return [
            "startTime" => $startTimeValue,
            "endTime"  => $endTimeValue
        ];
    }
    
    public static function ReadVCalendarDataBlob($vCalendarData){
        if (is_resource($vCalendarData)) {
			return stream_get_contents($vCalendarData);
		}
		return $vCalendarData;
    }
}