const CRON_EXPRESSION = '0 17 * * *';

/**
 * Importiert oder aktualisiert Währungskurse in PocketBase.
 * Das 'updated'-Feld wird durch die Collection als Autodate verwaltet.
 */
function runImport() {
	const ECB_URL =
		'https://www.ecb.europa.eu/stats/eurofxref/eurofxref-daily.xml';
	const COLLECTION_NAME = 'currencies';
	const IMPORT_TIMEOUT_MS = 30000;

	/**
	 * Extrahiert Währungskurse aus dem ECB-XML.
	 *
	 * @param {string} xml - Rohe XML-Antwort.
	 * @returns {Array<{currency: string, rate: number}>}
	 */
	function parseRates(xml) {
		const CURRENCY_RATE_REGEX =
			/<Cube\s+[^>]*currency='([^']+)'[^>]*rate='([^']+)'[^>]*\/>/g;
		const rates = [];
		let match;
		while ((match = CURRENCY_RATE_REGEX.exec(xml)) !== null) {
			rates.push({
				currency: match[1].toLowerCase(),
				rate: parseFloat(match[2]),
			});
		}
		return rates;
	}

	const response = $http.send({
		url: ECB_URL,
		method: 'GET',
		timeout: IMPORT_TIMEOUT_MS,
	});

	if (response.statusCode !== 200) {
		throw new Error(
			'Failed to fetch ECB rates: HTTP ' + response.statusCode,
		);
	}

	const rates = parseRates(response.raw);

	if (rates.length === 0) {
		throw new Error('No rates found in ECB response');
	}

	const collection = $app.findCollectionByNameOrId(COLLECTION_NAME);

	for (const item of rates) {
		let record;
		try {
			record = $app.findRecordById(
				COLLECTION_NAME,
				item.currency,
			);
		} catch (e) {
			record = new Record(collection);
			record.id = item.currency;
		}
		record.set('rate', item.rate);
		$app.save(record);
	}
}

cronAdd('import-currencies', CRON_EXPRESSION, runImport);