ChatService.java

package com.tinkeracademy.projects;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.StatusLine;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;

public class ChatService implements Runnable {
	
	public static final String URL = "http://tinkercloud-1273.appspot.com/chat?channel=summer2016";
	
	public File chatFile = null;
	
	public File userFile = null;
	
	public ScheduledFuture<?> futureTask;
	
	public ArrayList<String> pendingChats = null;
	
	public enum FileType {
		USER,
		CHAT
	}

	public enum ChatStatus {
		YES,
		NO,
		ERROR
	}
	
	public ChatStatus init() {
		if (createFileIfRequired("TinkerAcademyChat.tff", FileType.CHAT) == ChatStatus.ERROR) {
			return ChatStatus.ERROR;
		}
		if (createFileIfRequired("TinkerAcademyUser.tff", FileType.USER) == ChatStatus.ERROR) {
			return ChatStatus.ERROR;
		};
		pendingChats = new ArrayList<String>();
		ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
		futureTask = scheduler.scheduleAtFixedRate(this, 3, 3, TimeUnit.SECONDS);
		return ChatStatus.YES;
	}
	
	public void run() {
		if (pendingChats.isEmpty()) {
			getFromServer();
		} else {
			String line = pendingChats.remove(0);
			postToServer(line);
		}
	}
	
	/**
	 * Posts a single line of chat to the server
	 * 
	 * @param line
	 * @return Chat Status
	 */
	public ChatStatus postToServer(String line)
	{
		HttpClient client = null;
		HttpResponse response = null;
		try {
			HttpPost post = new HttpPost(URL);
			List<NameValuePair> params = new ArrayList<NameValuePair>();
			params.add( new BasicNameValuePair( "chat", line ));
			UrlEncodedFormEntity paramEntity = new UrlEncodedFormEntity( params );
			post.setEntity(paramEntity);
			client = HttpClients.createDefault();
			response = client.execute(post);
			StatusLine statusLine = response.getStatusLine();
			int statusCode = statusLine.getStatusCode();
			if (statusCode == 200) {
				ChatStatus status = processResponse(response);
				return status;
			}
		} catch (Exception e) {
			e.printStackTrace();
			try {
				if (client != null) {
					if (client instanceof CloseableHttpClient) {
						((CloseableHttpClient) client).close();
					}
				}
				if (response != null) {
					if (response instanceof CloseableHttpResponse) {
						((CloseableHttpResponse) response).close();
					}
				}
			} catch(IOException e1) {
				e1.printStackTrace();
			}
		}
		return ChatStatus.ERROR;
	}
	
	public ChatStatus processResponse(HttpResponse response) {
		InputStreamReader reader = null;
		try {
			InputStream input = response.getEntity().getContent();
			reader = new InputStreamReader(input);
			ArrayList<String> lines = new ArrayList<String>();
			ChatStatus status = readLinesFromReader(reader, lines);
			if (status == ChatStatus.YES) {
				return writeLines(chatFile, lines);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return ChatStatus.ERROR;
	}
	
	public ChatStatus getFromServer()
	{
		HttpClient client = null;
		HttpResponse response = null;
		try {
			HttpGet get = new HttpGet(URL);
			client = HttpClients.createDefault();
			response = client.execute(get);
			StatusLine statusLine = response.getStatusLine();
			int statusCode = statusLine.getStatusCode();
			if (statusCode == 200) {
				return processResponse(response);
			}
		} catch(Exception e) {
			e.printStackTrace();
			try {
				if (client != null) {
					if (client instanceof CloseableHttpClient) {
						((CloseableHttpClient) client).close();
					}
				}
				if (response != null) {
					if (response instanceof CloseableHttpResponse) {
						((CloseableHttpResponse) response).close();
					}
				}
			} catch(IOException e1) {
				e1.printStackTrace();
			}
		}
		return ChatStatus.ERROR;
	}
	
	public ChatStatus readLines(File file, ArrayList<String> lines) {
		FileReader fileReader = null;
		try {
			fileReader = new FileReader(file);
			return readLinesFromReader(fileReader, lines);
		} catch(IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if (fileReader != null)
					fileReader.close();
			} catch(IOException e) {
				e.printStackTrace();
			}
		}
		return ChatStatus.ERROR;
	}
	
	public ChatStatus readLinesFromReader(Reader reader, ArrayList<String> lines) {
		BufferedReader bufReader = null;
		try {
			bufReader = new BufferedReader(reader);
			String line = bufReader.readLine();
			while (line != null) {
				lines.add(line);
				line = bufReader.readLine();
			}
			return ChatStatus.YES;
		} catch(IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if (bufReader != null)
					bufReader.close();
			} catch(IOException e) {
				e.printStackTrace();
			}
		}
		return ChatStatus.ERROR;
	}
	
	public ChatStatus writeLines(File file, ArrayList<String> lines) {
		for (String line : lines) {
			ChatStatus status = writeLine(file, line);
			if (status == ChatStatus.ERROR) {
				return status;
			}
		}
		return ChatStatus.YES;
	}
	
	public ChatStatus writeLine(File file, String line) {
		FileWriter fileWriter = null;
		PrintWriter printWriter = null;
		try {
			fileWriter = new FileWriter(file, true);
			printWriter = new PrintWriter(fileWriter);
			printWriter.println(line);
			return ChatStatus.YES;
		} catch(IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if (fileWriter != null) {
					fileWriter.close();
				}
				if (printWriter != null) {
					printWriter.close();
				} 
			} catch(IOException e) {
				e.printStackTrace();
			}
		}
		return ChatStatus.ERROR;
	}
	
	public ChatStatus createFileIfRequired(String name, FileType fileType) {
		String homeDirectory = System.getProperty("user.home");
		File file = new File(homeDirectory, name);
		try {
			if (!file.exists()) {
				if (!file.createNewFile()) {
					return ChatStatus.ERROR;
				}
			}
			if (fileType == FileType.USER) {
				userFile = file;
			} else if (fileType == FileType.CHAT) {
				chatFile = file;
			} else {
				return ChatStatus.ERROR;
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		return ChatStatus.ERROR;
	}
}