<?php declare(strict_types=1);

namespace Spatie\CalendarLinks\Generators;

use DateTimeZone;
use Spatie\CalendarLinks\Generator;
use Spatie\CalendarLinks\Link;

/**
 * @see https://github.com/InteractionDesignFoundation/add-event-to-calendar-docs/blob/master/services/outlook-web.md
 * @psalm-type OutlookUrlParameters = array<string, scalar|null>
 */
abstract class BaseOutlook implements Generator
{
    /** @var string {@see https://www.php.net/manual/en/function.date.php} */
    protected $dateFormat = 'Y-m-d';

    /** @var string {@see https://www.php.net/manual/en/function.date.php} */
    protected $dateTimeFormat = 'Y-m-d\TH:i:s\Z';

    /** @psalm-var OutlookUrlParameters */
    protected array $urlParameters = [];

    /** @psalm-param OutlookUrlParameters $urlParameters */
    public function __construct(array $urlParameters = [])
    {
        $this->urlParameters = $urlParameters;
    }

    /** Get base URL for links. */
    abstract public function baseUrl(): string;

    /** {@inheritDoc} */
    public function generate(Link $link): string
    {
        $url = $this->baseUrl();

        if ($link->allDay) {
            $url .= '&startdt='.$link->from->format($this->dateFormat);
            $url .= '&enddt='.$link->to->format($this->dateFormat);
            $url .= '&allday=true';
        } else {
            $url .= '&startdt='.(clone $link->from)->setTimezone(new DateTimeZone('UTC'))->format($this->dateTimeFormat);
            $url .= '&enddt='.(clone $link->to)->setTimezone(new DateTimeZone('UTC'))->format($this->dateTimeFormat);
        }

        $url .= '&subject='.$this->sanitizeString($link->title);

        if ($link->description) {
            $url .= '&body='.$this->sanitizeString($link->description);
        }

        if ($link->address) {
            $url .= '&location='.$this->sanitizeString($link->address);
        }

        foreach ($this->urlParameters as $key => $value) {
            $url .= '&'.urlencode($key).(in_array($value, [null, ''], true) ? '' : '='.$this->sanitizeString((string) $value));
        }

        return $url;
    }

    private function sanitizeString(string $input): string
    {
        return rawurlencode($input);
    }
}