package mineplex.servermonitor;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;

public class ServerMonitor
{
	private static Repository _repository = new Repository();
	private static int _count = 0;
	
	public static void main (String args[])
	{		
		_repository.initialize();
		
		while (true)
		{
			if (_count % 10 == 0)
			{
				for (ServerStatusData statusData : _repository.retrieveOldServerStatuses())
				{
					System.out.println("----Old Server Status----");
					killServer(statusData);
				}
				
				List<DynamicServerData> dynamicServers = new ArrayList<DynamicServerData>(_repository.retrieveDynamicServers());
				Collection<ServerGroupData> serverGroups = _repository.retrieveServerGroups();
				HashMap<String, GroupStatusData> groupStatusList = _repository.retrieveGroupStatusData();
				
				for (ServerGroupData serverGroup : serverGroups)
				{
					if (!groupStatusList.containsKey(serverGroup.Name))
					{
						groupStatusList.put(serverGroup.Name, new GroupStatusData());
					}
				
					GroupStatusData groupStatus = groupStatusList.get(serverGroup.Name);
					
					
					
					int serversToAdd = Math.max(serverGroup.RequiredTotalServers - groupStatus.getTotalServers(), serverGroup.RequiredJoinableServers - groupStatus.getJoinableCount());
					int serversToKill = (groupStatus.getTotalServers() > serverGroup.RequiredTotalServers && groupStatus.getJoinableCount() > serverGroup.RequiredJoinableServers) ? Math.min(groupStatus.getJoinableCount() - serverGroup.RequiredJoinableServers, groupStatus.EmptyServers.size()) : 0;

					while (serversToAdd > 0)
					{
						int serverNum = groupStatus.getNextServerNumber();
						Collections.sort(dynamicServers, new DynamicServerSorter());
						DynamicServerData bestServer = getBestDynamicServer(dynamicServers, serverGroup);
						
						if (bestServer == null)
						{
							System.out.println("No best dynamic server available for group " + serverGroup.Name);
							break;
						}
						
						System.out.println("Adding server for Server Group " + serverGroup.Name + " Req Total: " + serverGroup.RequiredTotalServers + " Req Joinable: " + serverGroup.RequiredJoinableServers + " | Actual Total: " + groupStatus.getTotalServers() + " Actual Joinable: " + groupStatus.getJoinableCount());
						startServer(bestServer, serverGroup, serverNum);

					    serversToAdd--;
					}
					
					while (serversToKill > 0)
					{
						System.out.println("Killing excess server for Server Group " + serverGroup.Name + " Req Total: " + serverGroup.RequiredTotalServers + " Req Joinable: " + serverGroup.RequiredJoinableServers + " | Actual Total: " + groupStatus.getTotalServers() + " Actual Joinable: " + groupStatus.getJoinableCount());
						killServer(groupStatus.EmptyServers.get(0));
					    serversToKill--;
					}
				}
			}
			
			try
			{
				Thread.sleep(1000);
			} 
			catch (InterruptedException e)
			{
				e.printStackTrace();
			}
			
			_count++;
			_count %= 10000;
		}
	}

	private static DynamicServerData getBestDynamicServer(Collection<DynamicServerData> dynamicServers,	ServerGroupData serverGroup)
	{
		DynamicServerData bestServer = null;
		
		for (DynamicServerData serverData : dynamicServers)
		{
			if (serverData.AvailableRAM > serverGroup.RequiredRAM && serverData.AvailableCPU > serverGroup.RequiredCPU)
			{
				if (bestServer == null)
				{
					bestServer = serverData;
					
					if (!serverData.ServerGroupCount.containsKey(serverGroup.Name))
						break;
				}
				else if (serverData.ServerGroupCount.containsKey(serverGroup.Name))					
				{
					if (serverData.ServerGroupCount.get(serverGroup.Name) < bestServer.ServerGroupCount.get(serverGroup.Name))
						bestServer = serverData;
				}
			}
		}
		
		return bestServer;
	}
	
	private static void killServer(ServerStatusData serverToKill)
	{
		String cmd = "/home/mineplex/easyRemoteKillServer.sh";
		Process process = null;
		
	    try 
	    {
	    	process = new ProcessBuilder(new String[] {"/bin/sh", "-x", cmd, serverToKill.Address, serverToKill.Name}).start();
	    	process.waitFor(); 
            BufferedReader reader=new BufferedReader(new InputStreamReader(process.getInputStream())); 
            String line = reader.readLine(); 
            
            while(line != null) 
            { 
	            System.out.println(line);
	            line=reader.readLine(); 
            } 
	    }
	    catch (Exception e) 
	    {
	    	e.printStackTrace();
	    }
	    finally
	    {
	    	if (process != null)
	    	{
	    		process.destroy();
	    	}
	    }
	    
	    _repository.removeServerRecord(serverToKill);
	    System.out.println("Sent kill command to " + serverToKill.Address + " for " + serverToKill.Name);
	}
	
	private static void startServer(DynamicServerData serverSpace, ServerGroupData serverGroup, int serverNum)
	{
		String cmd = "/home/mineplex/easyRemoteStartServer.sh";
		Process process = null;
		
	    try 
	    {
	    	process = new ProcessBuilder(new String[] {"/bin/sh", cmd, serverSpace.Address, serverGroup.ScriptName, serverGroup.Prefix + "-" + serverNum, "1", serverSpace.US ? "us" : "eu"}).start();
	    	process.waitFor(); 
            BufferedReader reader=new BufferedReader(new InputStreamReader(process.getInputStream())); 
            String line = reader.readLine();
            
            while(line != null) 
            { 
	            System.out.println(line);
	            line=reader.readLine(); 
            } 
	    }
	    catch (Exception e) 
	    {
	    	e.printStackTrace();
	    }
	    finally
	    {
	    	if (process != null)
	    	{
	    		process.destroy();
	    	}
	    }
	    
	    serverSpace.setServerGroupCount(serverGroup, serverSpace.ServerGroupCount.containsKey(serverGroup.Name) ? (serverSpace.ServerGroupCount.get(serverGroup.Name) + 1) : 1);
	    System.out.println("Sent start command to " + serverSpace.Name + " for " + serverGroup.Prefix + "-" + serverNum);
	}
}