backend/source/api/actions/export_ics.ts

/*
This file is part of »zeitbild«.

Copyright 2025 'kcf' <fenris@folksprak.org>

»zeitbild« 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.

»zeitbild« 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 »zeitbild«. If not, see <http://www.gnu.org/licenses/>.
 */


namespace _zeitbild.api
{
	
	/**
	 */
	export function register_export_ics(
		rest_subject : lib_plankton.rest_http.type_rest
	) : void
	{
		register<
			null,
			(
				lib_plankton.ical.type_vcalendar
				|
				string
			)
		>(
			rest_subject,
			lib_plankton.http.enum_method.get,
			"/export/ics",
			{
				"description": "trägt Veranstaltungen aus verschiedenen Kalendern zusammen im ics-Format",
				"query_parameters": () => ([
					{
						"name": "from",
						"required": false,
						"description": "UNIX timestamp",
					},
					{
						"name": "to",
						"required": false,
						"description": "UNIX timestamp",
					},
					{
						"name": "calendar_ids",
						"required": false,
						"description": "comma separated",
					},
				]),
				"output_schema": () => ({
					"nullable": false,
					"type": "string",
				}),
				"response_body_mimetype": "text/calendar",
				"response_body_encode": (output) => Buffer.from(
					(typeof(output) === "string")
					?
					output
					:
					lib_plankton.ical.ics_encode(output)
				),
				"restriction": restriction_web_auth,
				"execution": async (stuff) => {
					const user : {id : _zeitbild.type_user_id; object : _zeitbild.type_user_object;} = await _zeitbild.api.user_from_web_auth(stuff);
					
					const from : lib_plankton.pit.type_pit = (
						("from" in stuff.query_parameters)
						?
						parseInt(stuff.query_parameters["from"])
						:
						lib_plankton.pit.shift_week(
							lib_plankton.pit.now(),
							-2
						)
					);
					const to : lib_plankton.pit.type_pit = (
						("to" in stuff.query_parameters)
						?
						parseInt(stuff.query_parameters["to"])
						:
						lib_plankton.pit.shift_week(
							lib_plankton.pit.now(),
							+6
						)
					);
					const calendar_ids_wanted : (null | Array<_zeitbild.type_calendar_id>) = (
						(
							("calendar_ids" in stuff.query_parameters)
							&&
							(stuff.query_parameters["calendar_ids"] !== null)
						)
						?
						lib_plankton.call.convey(
							stuff.query_parameters["calendar_ids"],
							[
								(x : string) => x.split(","),
								(x : Array<string>) => x.map(parseInt),
								(x : Array<int>) => x.filter(y => (! isNaN(y)))
							]
						)
						:
						null
					);
					
					return (
						_zeitbild.service.calendar.gather_events(
							calendar_ids_wanted,
							from,
							to,
							user.id
						)
						.then(
							(events_extended) => Promise.resolve(
								{
									"status_code": 200,
									"data": _zeitbild.helpers.icalendar_vcalendar_from_own_event_list(
										events_extended
									)
								}
							)
						)
						.catch(
							(reason) => Promise.resolve(
								{
									"status_code": 403,
									"data": String(reason),
								}
							)
						)
					);
				}
			}
		);
	}
	
}