package kcauldron.updater;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.List;

import kcauldron.KCauldron;
import kcauldron.updater.KVersionRetriever.IVersionCheckCallback;
import net.minecraft.server.MinecraftServer;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.client.methods.RequestBuilder;
import org.apache.http.impl.client.HttpClientBuilder;
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.CommandSender;

import com.google.common.base.Joiner;

public class KCauldronUpdater implements Runnable, IVersionCheckCallback {
	private static final class LatestVersionCallback extends
			CommandSenderUpdateCallback {
		public LatestVersionCallback(CommandSender sender) {
			super(sender);
		}

		@Override
		public void newVersion(String newVersion) {
			startUpdate(getSender(), newVersion);
		}

		@Override
		public void upToDate() {
			KCauldron.sUpdateInProgress = false;
			CommandSender sender = getSender();
			if (sender != null) {
				sender.sendMessage(ChatColor.DARK_PURPLE + "Current version ("
						+ KCauldron.getCurrentVersion() + ") is up to date");
			}
		}

		@Override
		public void error(Throwable t) {
			super.error(t);
			KCauldron.sUpdateInProgress = false;
		}
	}

	public static void initUpdate(CommandSender sender, String version) {
		if (KCauldron.sUpdateInProgress) {
			sender.sendMessage(ChatColor.RED
					+ "Update stopped: another update in progress");
			return;
		}
		KCauldron.sUpdateInProgress = true;
		if (version == null) {
			sender.sendMessage(ChatColor.DARK_PURPLE
					+ "Fetching latest version...");
			KVersionRetriever.startServer(new LatestVersionCallback(sender),
					false);
		} else {
			startUpdate(sender, version);
		}
	}

	private static void startUpdate(CommandSender sender, String version) {
		if (sender != null) {
			sender.sendMessage(ChatColor.DARK_PURPLE + "Starting update to "
					+ version + "...");
		}
		new KCauldronUpdater(sender, version);
	}

	private final CommandSender mSender;
	private final String mVersion;
	private final Thread mThread;

	public KCauldronUpdater(CommandSender sender, String version) {
		mSender = sender;
		mVersion = version;
		mThread = new Thread(this);
		mThread.setName("KCauldron updater");
		mThread.setPriority(Thread.MIN_PRIORITY);
		mThread.start();
	}

	@Override
	public void run() {
		if (!MinecraftServer.kcauldronConfig.updatecheckerQuite.getValue()) {
			mSender.sendMessage(ChatColor.DARK_PURPLE
					+ "Retrieving latest KBootstrap version...");
		}
		new KVersionRetriever(this, false, false, "pw.prok", "KBootstrap");
	}

	@Override
	public void upToDate() {

	}

	@Override
	public void newVersion(String kbootstrapVersion) {
		boolean quite = MinecraftServer.kcauldronConfig.updatecheckerQuite
				.getValue();
		try {
			if (!quite) {
				mSender.sendMessage(ChatColor.DARK_PURPLE
						+ "Downloading KBootstrap " + kbootstrapVersion + "...");
			}
			File kbootstrap = File.createTempFile("kbootstrap",
					String.valueOf(System.currentTimeMillis()));
			download("https://prok.pw/repo/pw/prok/KBootstrap/"
					+ kbootstrapVersion + "/KBootstrap-" + kbootstrapVersion
					+ "-app.jar", kbootstrap);
			if (!quite) {
				mSender.sendMessage(ChatColor.DARK_PURPLE
						+ "Installing KCauldron " + mVersion
						+ " via KBootstrap " + kbootstrapVersion + "...");
			}

			String javahome = System.getProperty("java.home");
			String javapath = javahome + "/bin/java";

			List<String> command = new ArrayList<String>();
			command.add(javapath);
			command.add("-jar");
			command.add(kbootstrap.getCanonicalPath());
			command.add("--serverDir");
			command.add(KCauldron.getServerLocation().getCanonicalPath());
			command.add("--installKCauldron");
			command.add(mVersion);
			command.add("--serverSymlinks");
			command.add(MinecraftServer.kcauldronConfig.updatecheckerSymlinks
					.getValue());

			Bukkit.getConsoleSender().sendMessage(
					"Starting command: " + Joiner.on(' ').join(command));

			ProcessBuilder builder = new ProcessBuilder(command);
			builder.environment().put("JAVA_HOME", javahome);
			switch (builder.start().waitFor()) {
			case 0:
				mSender.sendMessage(ChatColor.GREEN + "KCauldron " + mVersion
						+ " installed");
				break;
			default:
				mSender.sendMessage(ChatColor.RED
						+ "Failed to install KCauldron " + mVersion);
			}
		} catch (Exception e) {
			if (!quite) {
				e.printStackTrace();
			}
			if (mSender != null) {
				mSender.sendMessage(ChatColor.RED + "Failed update to "
						+ mVersion);
			}
		} finally {
			KCauldron.sUpdateInProgress = false;
		}
	}

	@Override
	public void error(Throwable t) {
		KCauldron.sUpdateInProgress = false;
		t.printStackTrace();
	}

	private static void download(String url, File destination)
			throws IOException {
		HttpUriRequest request = RequestBuilder
				.get()
				.setUri(url)
				.addParameter("hostname",
						MinecraftServer.getServer().getHostname())
				.addParameter("port",
						String.valueOf(MinecraftServer.getServer().getPort()))
				.build();
		HttpResponse response = HttpClientBuilder.create()
				.setUserAgent("KCauldron Updater").build().execute(request);
		if (response.getStatusLine().getStatusCode() != 200) {
			throw new IllegalStateException("Could not download " + url);
		}
		InputStream is = response.getEntity().getContent();
		Files.copy(is, destination.toPath());
		is.close();
	}
}