<?php

namespace davigil\sources;

require_once('helpers/string.php');
require_once('helpers/cache.php');
require_once('helpers/pit.php');
require_once('helpers/ics.php');
require_once('model.php');


/**
 */
class class_source_ics_feed
	implements interface_source
{
	
	/**
	 */
	private string $url;
	
	
	/**
	 */
	private ?int $lifetime;
	
	
	/**
	 */
	private bool $combine;
	
	
	/**
	 */
	public function __construct(
		string $url,
		?int $lifetime,
		bool $combine
	)
	{
		$this->url = $url;
		$this->lifetime = $lifetime;
		$this->combine = $combine;
		$this->cache_file = \davigil\helpers\call\convey(
			new \davigil\helpers\cache\class_cache_file('data'),
			[
				fn($x) => new \davigil\helpers\cache\class_cache_encoded(
					$x,
					fn($value) => \json_encode($value),
					fn($value_encoded) => \json_decode($value_encoded, true)
				),
			]
		);
		$this->cache_memory = \davigil\helpers\call\convey(
			(new \davigil\helpers\cache\class_cache_memory()),
			[
			]
		);
	}
	
	
	/**
	 */
	private function vcalendar_to_calendar(
		\davigil\helpers\ics\struct_vcalendar $vcalendar
	) : \davigil\model\struct_calendar
	{
		return (
			new \davigil\model\struct_calendar(
				\array_map(
					fn($vevent) => (new \davigil\model\struct_event(
						// id
						$vevent->uid,
						// title
						(
							$this->combine
							?
							\sprintf(
								'%s%s',
								$vevent->summary,
								\implode(
									'',
									\array_map(
										fn($category) => \sprintf(' (%s)', $category),
										$vevent->categories
									)
								)
							)
							:
							$vevent->summary
						),
						// begin
						\davigil\helpers\ics\datetime_to_unix_timestamp($vevent->dtstart->value),
						// end
						(
							($vevent->dtend === null)
							?
							null
							:
							\davigil\helpers\ics\datetime_to_unix_timestamp($vevent->dtend->value)
						),
						// location
						$vevent->location,
						// description
						$vevent->description,
						// 'tags
						(
							$this->combine
							?
							['combined']
							:
							$vevent->categories
						)
					)),
					$vcalendar->events
				)
			)
		);
	}
	
	
	/**
	 */
	private function retrieve(
	)
	{
		$client = new \Sabre\HTTP\Client();
		$request = new \Sabre\HTTP\Request(
			'GET',
			$this->url,
			[],
			null
		);
		$response = $client->send($request);
		$status_code = $response->getStatus();
		switch ($status_code)
		{
			case 200:
			{
				$ics = $response->getBody();
				$vcalendar = \davigil\helpers\ics\vcalendar_decode($ics);
				$calendar = $this->vcalendar_to_calendar($vcalendar);
				$calendar_raw = \davigil\model\calendar_to_raw($calendar);
				return $calendar_raw;
				break;
			}
			default:
			{
				throw (
					new \Exception(
						\sprintf(
							'unhandled response status code: %u',
							$status_code
						)
					)
				);
				break;
			}
		}
	}
	
	
	/**
	 * [implementation]
	 */
	public function get(
		array $parameters
	) : \davigil\model\struct_calendar
	{
		$key = $this->url;
		$f1 = fn() => $this->retrieve();
		$f2 = fn() => \davigil\helpers\cache\get(
			$this->cache_file,
			$key,
			$f1,
			[
				'ttl' => $this->lifetime,
			]
		);
		$f3 = fn() => \davigil\helpers\cache\get(
			$this->cache_memory,
			$key,
			$f2,
			[
				'ttl' => null,
			]
		);
		return \davigil\model\calendar_from_raw(
			($f3)()
		);
	}
	
}

 ?>