Slimefun4/src/me/mrCookieSlime/Slimefun/GitHub/GitHubConnector.java

package me.mrCookieSlime.Slimefun.GitHub;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.util.HashSet;
import java.util.Set;

import com.google.gson.JsonElement;
import com.google.gson.JsonParser;

public abstract class GitHubConnector implements Runnable {
	
	public static Set<GitHubConnector> connectors = new HashSet<GitHubConnector>();
	
	private File file;

	public GitHubConnector() {
		this.file = new File("plugins/Slimefun/cache/github/" + this.getFileName() + ".json");
		connectors.add(this);
	}
	
	public abstract String getFileName();
	public abstract String getRepository();
	public abstract String getURLSuffix();
	public abstract void onSuccess(JsonElement element);
	public abstract void onFailure();
	
	public void pullFile() {
		System.out.println("[Slimefun - GitHub] Downloading '" + this.getFileName() + ".json' from GitHub...");
		
		try {
			URL website = new URL("https://api.github.com/repos/" + this.getRepository() + this.getURLSuffix());
			
			URLConnection connection = website.openConnection();
            connection.setConnectTimeout(3000);
            connection.addRequestProperty("User-Agent", "Slimefun 4 GitHub Agent (by TheBusyBiscuit)");
            connection.setDoOutput(true);
			
			ReadableByteChannel rbc = Channels.newChannel(connection.getInputStream());
			FileOutputStream fos = new FileOutputStream(file);
			fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
			fos.close();
			System.out.println("[Slimefun - GitHub] Finished download: '" + this.getFileName() + ".json'");
			this.parseData();
		} catch (IOException e) {
			System.err.println("[Slimefun - GitHub] ERROR - Could not connect to GitHub in time.");
			
			if (hasData()) {
				this.parseData();
			}
			else {
				this.onFailure();
			}
		}
	}
	
	public boolean hasData() {
		return this.getFile().exists();
	}
	
	public File getFile() {
		return this.file;
	}

	public void parseData() {
		try {
			BufferedReader reader = new BufferedReader(new FileReader(this.getFile()));
			
			String full = "";
			
			String line;
		    while ((line = reader.readLine()) != null) {
		        full = full + line;
		    }
		    
		    reader.close();
		    
		    JsonElement element = new JsonParser().parse(full);
		    
		    this.onSuccess(element);
		} 
		catch (IOException e) {
			e.printStackTrace();
			this.onFailure();
		}
	}

	@Override
	public void run() {
		this.pullFile();
	}
}