using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net.Sockets;
using System.Runtime.Serialization.Formatters.Binary;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Xml.Serialization;

namespace MainClient
{
	public partial class Form1 : Form
	{
		// connects to remote TCP server
		// network stream sends and recieves data
		public TcpClient clientSocket;
		public NetworkStream serverStream = default(NetworkStream);
		string readData = null; // store and read data from network
		Thread ctThread;  // used to run loop later
		String name = null; // name of client	
		List<string> nowChatting = new List<string>(); // list of users connected
		List<string> chat = new List<string>(); // chat log

		// Takes the name from login and changes form name.
		public void setName(String title)
		{
			this.Text = title;
			name = title;
		}

		public Form1()
		{
			InitializeComponent();
		}

		// Connects the client to the server using port 5000.
		// Displays a message if successful.
		// Adds the name of the user to the client list.
		private void btnConnect_Click(object sender, EventArgs e)
		{

				clientSocket = new TcpClient();
				try
				{
					clientSocket.Connect("127.0.0.1", 5000);
					readData = "Connected to Server ";
					msg();

					serverStream = clientSocket.GetStream();

					byte[] outStream = Encoding.ASCII.GetBytes(name + "$");
					serverStream.Write(outStream, 0, outStream.Length);
					serverStream.Flush();
					btnConnect.Enabled = false;

					ctThread = new Thread(getMessage);
					ctThread.Start();
				}
				catch (Exception er)
				{
					MessageBox.Show("Server Not Started");
				}
			}		

		// Allows the client to send a message.
		// Clears the chatbox after sending the message.
		// Adds the message to the chat list.
		private void btnSend_Click(object sender, EventArgs e)
		{		
				try
				{
					if (!input.Text.Equals(""))
					{
						chat.Add("gChat");
						chat.Add(input.Text);
						byte[] outStream = ObjectToByteArray(chat);

						serverStream.Write(outStream, 0, outStream.Length);
						serverStream.Flush();
						input.Text = "";
						chat.Clear();
					}
				}
				catch (Exception er)
				{
					btnConnect.Enabled = true;
				}			
		}

		// Disconnects the client from the server after displaying a confirmation message.
		private void btndisconnect_Click(object sender, EventArgs e)
		{
			MessageBox.Show("Are you sure you want to disconnect?");
			Application.Exit();
		}

		// Adds the users in the parts list to the client list.
		public void getUsers(List<string> parts)
		{
			this.Invoke((MethodInvoker)delegate
			{
				listBox1.Items.Clear();
				for (int i = 1; i < parts.Count; i++)
				{
					listBox1.Items.Add(parts[i]);

				}
			});
		}

		private void getMessage()
		{
			try
			{
				while (true)
				{
					serverStream = clientSocket.GetStream(); // gets network stream
					byte[] inStream = new byte[10025]; // create a buffer to store incomming message
					serverStream.Read(inStream, 0, inStream.Length); // read message into buffer
					List<string> parts = null; // create a list to store the parts of the incomming message

					// Check if the client socket is still connected
					if (!SocketConnected(clientSocket))
					{
						// If not, show a message box, exit current thread, close the socket, and enable the connect button
						MessageBox.Show("Disconnected from server");
						ctThread.Abort();
						clientSocket.Close();
						btnConnect.Enabled = true;
					}

					// Deserialize the incoming message and process it based on its type
					parts = (List<string>)ByteArrayToObject(inStream);
					switch (parts[0])
					{
						case "userList":
							getUsers(parts);
							break;
						case "gChat":
							readData = "" + parts[1];
							msg();
							break;
					}

					// Check if the message is empty
					if (readData[0].Equals('\0'))
					{
						// If so, display a message and enable the connect button
						readData = "try to reconnect";
						msg();

						this.Invoke((MethodInvoker)delegate // cross threads
						{
							btnConnect.Enabled = true;
						});

						ctThread.Abort();
						clientSocket.Close();
						break;
					}
					chat.Clear(); // Clear the chat buffer
				}
			}
			catch (Exception e)
			{
				// If exception occurs, exit the thread, close the socket, and enable the connect button
				ctThread.Abort();
				clientSocket.Close();
				btnConnect.Enabled = true;
				Console.WriteLine(e);
			}
		}

		// Displays message in the thread
		private void msg()
		{
			if (this.InvokeRequired)
				this.Invoke(new MethodInvoker(msg));
			else
				history.Text = history.Text + Environment.NewLine + " - " + readData;
		}

		// Serializes an object to a byte array
		public byte[] ObjectToByteArray(object _Object)
		{
			using (var stream = new MemoryStream())
			{
				var formatter = new BinaryFormatter();
				formatter.Serialize(stream, _Object);
				return stream.ToArray();
			}
		}

		// Deserializes a byte array to an object
		public Object ByteArrayToObject(byte[] arrBytes)
		{
			using (var memStream = new MemoryStream())
			{
				var binForm = new BinaryFormatter();
				memStream.Write(arrBytes, 0, arrBytes.Length);
				memStream.Seek(0, SeekOrigin.Begin);
				var obj = binForm.Deserialize(memStream);
				return obj;
			}
		}

		// Checks if the client socket is still connected to the server
		bool SocketConnected(TcpClient s)
		{
			bool flag = false;
			try
			{
				bool part1 = s.Client.Poll(10, SelectMode.SelectRead);
				bool part2 = (s.Available == 0);
				if (part1 && part2)
				{
					this.Invoke((MethodInvoker)delegate // cross threads
					{
						btnConnect.Enabled = true;
					});
					flag = false;
				}
				else
				{
					flag = true;
				}
			}
			catch (Exception er)
			{
				Console.WriteLine();
			}
			return flag;
		}
	}
}