using System;
using System.IO;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Threading;
using System.Net.Sockets;
using System.Linq;



namespace LoginServer
{
    public partial class MainForm : Form
    {
        const int port = 10000;

        // For accepting connections
        TcpListener listener = null;
        Thread listenerThread = null;
        List<UserConnection> connections = new List<UserConnection>();
        int loggedInUsers = 0;

        TextBoxStreamWriter textboxWriter = null;      // New StreamWriter object for Console
        TextWriter consoleWriter = null;        // Original Console stream is stored for later restoration

        delegate void UpdateConnectionsStatCallback();
        delegate void IncrementLoggedInUsersStatCallback();
        delegate void DecrementLoggedInUsersStatCallback();

        public MainForm()
        {
            InitializeComponent();
        }

        void MainForm_Load(object sender, EventArgs e)
        {
            // TODO: This line of code loads data into the 'usersDataSet.Users' table. You can move, or remove it, as needed.
            this.usersTableAdapter.Fill(this.usersDataSet.Users);
            // TODO: This line of code loads data into the 'usersDataSet.Users' table. You can move, or remove it, as needed.
            this.usersTableAdapter.Fill(this.usersDataSet.Users);

            // Redirect Console output to consoleTextBox
            consoleWriter = Console.Out;
            textboxWriter = new TextBoxStreamWriter(this, consoleTextBox);
            Console.SetOut(textboxWriter);

            // Begin listening for connections
            listenerThread = new Thread(new ThreadStart(DoListen));
            listenerThread.Start();
        }

        void MainForm_FormClosing(object sender, FormClosingEventArgs e)
        {
            // Reset Console output stream
            Console.SetOut(consoleWriter);
            textboxWriter.Close();

            // Stop listening for connections
            listener.Stop();
        }

        // Thread function, listenes for connections
        void DoListen()
        {
            try
            {
                listener = new TcpListener(System.Net.IPAddress.Any, port);
                listener.Start();

                Console.WriteLine("Listener started");

                do
                {
                    UserConnection client = new UserConnection(listener.AcceptTcpClient());
                    client.LineReceived += new LineReceive(OnLineReceived);
                    connections.Add(client);

                    Console.WriteLine("New connection accepted");
                }
                while (true);
            }
            catch (Exception e)
            {
                Console.WriteLine("Error in listener: " + e.ToString());
            }
        }

        // Called when a UserConnection receives data
        void OnLineReceived(UserConnection sender, string data)
        {
            string[] dataArray = data.Split('\n');
            dataArray = dataArray[0].Split('|');

            switch (dataArray[0])
            {
                case "LOGIN":
                    LoginUser(dataArray[1], dataArray[2], sender);
                    break;

                case "LOGOUT":
                    LogoutUser(sender);
                    break;

                case "CREATEACCOUNT":
                    CreateAccount(dataArray[1], dataArray[2], sender);
                    break;

                case "GETFRIENDS":
                    GetFriends(sender);
                    break;

                default:
                    Console.WriteLine("Unrecognized data received from user");
                    break;
            }
        }

        void LoginUser(string userName, string password, UserConnection sender)
        {
            foreach (DataGridViewRow row in userDataGridView.Rows)
            {
                if (row.Cells[0].Value.Equals(userName) && row.Cells[1].Value.Equals(password) && row.Cells[2].Value.Equals(false))
                {
                    row.Cells[2].Value = true;
                    sender.SendData("LOGINGRANTED");
                    sender.userName = userName;
                    Console.WriteLine("User " + userName + " logged in");

                    IncrementLoggedInUsersStat();

                    return;
                }
            }

            sender.SendData("LOGINDENIED");
        }

        void LogoutUser(UserConnection sender)
        {
            foreach (DataGridViewRow row in userDataGridView.Rows)
            {
                if (row.Cells[0].Value.Equals(sender.userName) && row.Cells[2].Value.Equals(true))
                {
                    Console.WriteLine("User " + sender.userName + " logged out");
                    row.Cells[2].Value = false;
                    DecrementLoggedInUsersStat();
                }
            }
        }

        void CreateAccount(string userName, string password, UserConnection sender)
        {
            foreach (DataGridViewRow row in userDataGridView.Rows)
            {
                if (row.Cells[0].Value.Equals(userName))
                {
                    sender.SendData("CREATEACCOUNTDENIED");
                    return;
                }
            }

            UsersDataSet.UsersRow newRow = usersDataSet.Users.NewUsersRow();
            newRow[0] = userName;
            newRow[1] = password;
            newRow[2] = false;
            newRow[3] = "";
            newRow[4] = 0;
            newRow[5] = 0;
            newRow[6] = 0;
            newRow[7] = 0;
            newRow[8] = 0;
            newRow[9] = 0;
            newRow[10] = 0;
            newRow[11] = 0;

            usersDataSet.Users.Rows.Add(newRow);
            usersTableAdapter.Update(usersDataSet.Users);

            sender.SendData("CREATEACCOUNTGRANTED");
            Console.WriteLine("Account created: " + userName);
        }

        void GetFriends(UserConnection sender)
        {
            foreach (DataGridViewRow row in userDataGridView.Rows)
            {
                if (row.Cells[0].Value.Equals(sender.userName))
                {
                    sender.SendData("RECEIVEFRIENDS|" + row.Cells[3].Value.ToString());
                }
            }
        }

        void HeartbeatTimer_Tick(object sender, EventArgs e)
        {
            List<UserConnection> removeConns = new List<UserConnection>();

            foreach (UserConnection conn in connections)
            {
                if (!conn.active)
                {
                    Console.WriteLine("Cleaning up dropped user");
                    LogoutUser(conn);
                    removeConns.Add(conn);
                }
            }

            foreach (UserConnection conn in removeConns)
            {
                connections.Remove(conn);
            }

            UpdateConnectionsStat();
        }

        void UpdateConnectionsStat()
        {
            if (statsListView.InvokeRequired)
            {
                UpdateConnectionsStatCallback d = new UpdateConnectionsStatCallback(UpdateConnectionsStat);
                Invoke(d);
            }
            else
            {
                statsListView.Items[0].SubItems[1].Text = connections.Count.ToString();
            }
        }

        void IncrementLoggedInUsersStat()
        {
            if (statsListView.InvokeRequired)
            {
                IncrementLoggedInUsersStatCallback d = new IncrementLoggedInUsersStatCallback(IncrementLoggedInUsersStat);
                Invoke(d);
            }
            else
            {
                ++loggedInUsers;
                statsListView.Items[0].SubItems[1].Text = loggedInUsers.ToString();
            }
        }

        void DecrementLoggedInUsersStat()
        {
            if (statsListView.InvokeRequired)
            {
                DecrementLoggedInUsersStatCallback d = new DecrementLoggedInUsersStatCallback(DecrementLoggedInUsersStat);
                Invoke(d);
            }
            else
            {
                --loggedInUsers;
                statsListView.Items[0].SubItems[1].Text = loggedInUsers.ToString();
            }
        }
    }
}