// countries.js — country data and helpers

/**
 * @typedef {{ name: string, x: number, y: number }} City
 * @typedef {{ name: string, hint: string, cities: City[] }} Country
 */

const Countries = (() => {
	/** @type {Country[]} */
	const COUNTRIES_DATA = [
		{
			name: "Switzerland",
			hint: "Alpine country in Central Europe",
			cities: [
				{ name: "Bern", x: 48, y: 58 },
				{ name: "Zürich", x: 58, y: 38 },
				{ name: "Geneva", x: 22, y: 72 },
			],
		},
		{
			name: "Norway",
			hint: "Scandinavian country with long coastline",
			cities: [
				{ name: "Oslo", x: 55, y: 72 },
				{ name: "Bergen", x: 32, y: 60 },
				{ name: "Tromsø", x: 62, y: 18 },
			],
		},
		{
			name: "Italy",
			hint: "Boot-shaped peninsula in Southern Europe",
			cities: [
				{ name: "Rome", x: 52, y: 58 },
				{ name: "Milan", x: 42, y: 22 },
				{ name: "Naples", x: 58, y: 72 },
			],
		},
		{
			name: "Japan",
			hint: "Island nation in East Asia",
			cities: [
				{ name: "Tokyo", x: 72, y: 48 },
				{ name: "Osaka", x: 58, y: 58 },
				{ name: "Sapporo", x: 70, y: 22 },
			],
		},
		{
			name: "Brazil",
			hint: "Largest country in South America",
			cities: [
				{ name: "Brasília", x: 58, y: 52 },
				{ name: "São Paulo", x: 60, y: 68 },
				{ name: "Manaus", x: 38, y: 38 },
			],
		},
		{
			name: "Australia",
			hint: "Continent and country in the Southern Hemisphere",
			cities: [
				{ name: "Canberra", x: 72, y: 72 },
				{ name: "Sydney", x: 78, y: 68 },
				{ name: "Perth", x: 22, y: 65 },
			],
		},
		{
			name: "France",
			hint: "Western Europe, roughly hexagonal shape",
			cities: [
				{ name: "Paris", x: 50, y: 32 },
				{ name: "Lyon", x: 58, y: 55 },
				{ name: "Marseille", x: 58, y: 72 },
			],
		},
		{
			name: "India",
			hint: "Large peninsula in South Asia",
			cities: [
				{ name: "New Delhi", x: 46, y: 28 },
				{ name: "Mumbai", x: 32, y: 55 },
				{ name: "Chennai", x: 52, y: 72 },
			],
		},
		{
			name: "Canada",
			hint: "Second largest country in the world",
			cities: [
				{ name: "Ottawa", x: 62, y: 52 },
				{ name: "Vancouver", x: 22, y: 55 },
				{ name: "Toronto", x: 60, y: 58 },
			],
		},
		{
			name: "Germany",
			hint: "Central European country",
			cities: [
				{ name: "Berlin", x: 58, y: 28 },
				{ name: "Munich", x: 48, y: 68 },
				{ name: "Hamburg", x: 42, y: 18 },
			],
		},
	];

	/** @type {Country[]} */
	let _data = [];

	/**
	 * Load country data into memory. Safe to call multiple times.
	 * Returns a Promise for future compatibility with a real API fetch.
	 * @returns {Promise<Country[]>}
	 */
	function loadCountries() {
		if (!_data.length) _data = COUNTRIES_DATA;
		return Promise.resolve(_data);
	}

	/**
	 * Return a random subset of countries.
	 * @param {number} count
	 * @returns {Country[]}
	 */
	function getRandomCountries(count = 3) {
		return [..._data].sort(() => Math.random() - 0.5).slice(0, count);
	}

	/**
	 * Get city list for a specific country by name.
	 * @param {string} countryName
	 * @returns {City[]}
	 */
	function getCities(countryName) {
		const country = _data.find((c) => c.name === countryName);
		return country ? country.cities : [];
	}

	return { loadCountries, getRandomCountries, getCities };
})();