using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using TBF.Resources;

namespace TBF
{
    /// <summary>
    /// Provides login dialog as well as user authorization using TBF.User.Authorize(...)
    /// (i.e. when DialogResult is OK, user was authorized).
    /// </summary>
    public partial class LoginDlg : Form
    {
        // Private fields
        string user;
        string password;
        Grp.GID requiredGroupMembership = Grp.GID.Invalid;
		bool noDatabase;

        /// <summary>
        /// Constructor.
        /// </summary>
        public LoginDlg()
        {
            InitializeComponent();
        }

        /// <summary>
        /// Constructor with a predefined user.
        /// </summary>
        public LoginDlg(string predefinedUser)
            : this()
        {
            user = predefinedUser;
            userNameTextBox.Text = predefinedUser;
        }

		/// <summary>
		/// Constructor with 'no Database' flag.
		/// </summary>
		public LoginDlg(bool noDatabase)
			: this()
		{
			this.noDatabase = noDatabase;
		}

        /// <summary>
        /// Constructor when a specific group membership is required.
        /// </summary>
        public LoginDlg(Grp.GID requiredGroupMembership)
            : this()
        {
            this.requiredGroupMembership = requiredGroupMembership;
        }

        /// <summary>
        /// Constructor with a predefined user when a specific group membership is required.
        /// </summary>
        public LoginDlg(string predefinedUser, Grp.GID requiredGroupMembership)
            : this()
        {
            user = predefinedUser;
            userNameTextBox.Text = predefinedUser;
            this.requiredGroupMembership = requiredGroupMembership;
        }

        private void LoginDlg_Load(object sender, EventArgs e)
        {
            Text = Strings.User_Login;
            label1.Text = Strings.Username;
            label2.Text = Strings.Password;
            okButton.Text = Strings.OkBtnText;
            cancelButton.Text = Strings.CancelBtnText;

            if (user == null) userNameTextBox.Select();
            else passwordTextBox.Select();
        }

        /// <summary>
        /// Try to authorize the user when OK clicked.
        /// </summary>
        private void okButton_Click(object sender, EventArgs e)
        {
            user = userNameTextBox.Text;
            password = passwordTextBox.Text;

			bool authorized = Entities.User.IsPowerUser(user, password);

			if (!authorized && !noDatabase)
			{
				Entities.User loadedUser = Entities.User.LoadUserByName(user);
				if (loadedUser != null)
				{
					if (requiredGroupMembership == Grp.GID.Invalid)
					{
						authorized = loadedUser.Authorize(user, password);
					}
					else
					{
						authorized = loadedUser.Authorize(user, password, requiredGroupMembership);
					}
				}
			}

			if (authorized)
			{
				DialogResult = DialogResult.OK;
				Close();
				if (Program.MainWnd != null) Program.MainWnd.UpdateUser();
				return;
			}

            MessageBox.Show(Strings.Invalid_username_or_password, Strings.Error, MessageBoxButtons.OK);
            DialogResult = DialogResult.None;
            return;
        }

        /// <summary>
        /// Cancel clicked, do not try to authorize.
        /// </summary>
        private void cancelButton_Click(object sender, EventArgs e)
        {
            if (requiredGroupMembership == Grp.GID.Invalid)
            {
                Entities.User.Unauthorize();
            }

            DialogResult = DialogResult.Cancel;
            Close();
            return;
        }
    }
}