package net.minecraft;

import java.io.IOException;
import java.net.URL;
import java.time.Instant;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;

public class VersionManager {
	public final List<GameVersion> versions = new ArrayList<>();

	public VersionManager() {
		try {
			downloadVersionList();
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	public GameVersion getVersionForInstant(Instant instant) {
		return versions.stream()
				.filter(v -> !v.isPreleaseOrDemo())
				.filter(v -> v.releasedOn.isBefore(instant))
				.max(Comparator.comparing((GameVersion a) -> a.releasedOn))
				.orElse(null);
	}

	private void downloadVersionList() throws IOException {
		URL versionListURL = new URL("http://files.betacraft.uk/launcher/assets/version_list.txt");
		Scanner scanner = new Scanner(versionListURL.openStream(), "UTF-8");
		while (scanner.hasNextLine()) {
			String[] versionInfo = scanner.nextLine().split("`");
			long compileTimestamp = Long.parseLong(versionInfo[2]);
			long releaseTimestamp = Long.parseLong(versionInfo[3]);
			GameVersion version = new GameVersion(versionInfo[0], versionInfo[1], compileTimestamp, releaseTimestamp);
			versions.add(version);
		}
	}
}