using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.Core;
using Tango.Core.Components;
using Tango.PPC.Common.Connection;

namespace Tango.PPC.Common.RemoteAssistance
{
    /// <summary>
    /// Represents the default remote assistance provider.
    /// </summary>
    /// <seealso cref="Tango.Core.ExtendedObject" />
    /// <seealso cref="Tango.PPC.Common.RemoteAssistance.IRemoteAssistanceProvider" />
    public class DefaultRemoteAssistanceProvider : ExtendedObject, IRemoteAssistanceProvider
    {
        private IMachineProvider _machineProvider;
        private String _installer_path = "C:\\Installers\\TeamViewer_Host.msi";

        private bool _isEnabled;
        /// <summary>
        /// Gets a value indicating whether the remote assistance service is enabled.
        /// </summary>
        public bool IsEnabled
        {
            get { return _isEnabled; }
            private set { _isEnabled = value; RaisePropertyChangedAuto(); }
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="DefaultRemoteAssistanceProvider"/> class.
        /// </summary>
        /// <param name="machineProvider">The machine provider.</param>
        public DefaultRemoteAssistanceProvider(IMachineProvider machineProvider)
        {
            _machineProvider = machineProvider;
        }

        /// <summary>
        /// Enables the remote assistance.
        /// </summary>
        /// <returns></returns>
        public async Task EnableRemoteAssistance()
        {
            if (!IsEnabled)
            {
                try
                {
                    CmdCommand command = new CmdCommand("sc.exe", "config TeamViewer start=auto");
                    command.Timeout = TimeSpan.FromSeconds(10);
                    await command.Run();

                    command = new CmdCommand("net", "start TeamViewer");
                    command.Timeout = TimeSpan.FromSeconds(10);
                    await command.Run();

                    IsEnabled = true;
                }
                catch (Exception ex)
                {
                    LogManager.Log(ex, "Error enabling remote assistance.");
                }
            }
        }

        /// <summary>
        /// Disables the remote assistance.
        /// </summary>
        /// <returns></returns>
        public async Task DisableRemoteAssistance()
        {
            if (IsEnabled)
            {
                try
                {
                    CmdCommand command = new CmdCommand("sc.exe", "config TeamViewer start=disabled");
                    command.Timeout = TimeSpan.FromSeconds(10);
                    await command.Run();

                    command = new CmdCommand("net", "stop TeamViewer");
                    command.Timeout = TimeSpan.FromSeconds(10);
                    await command.Run();
                    IsEnabled = false;
                }
                catch (Exception ex)
                {
                    LogManager.Log(ex, "Error disabling remote assistance.");
                }
            }
        }

        /// <summary>
        /// Installs the remote assistance.
        /// </summary>
        /// <param name="machineSerialNumber">The machine serial number.</param>
        /// <returns></returns>
        public async Task InstallRemoteAssistance(String machineSerialNumber)
        {
            try
            {
                if (!File.Exists(_installer_path))
                {
                    throw new FileNotFoundException($"The remote assistance installer file could not be found at {_installer_path}.");
                }

                if (!(await IsRemoteAssistanceInstalled()))
                {
                    CmdCommand command = new CmdCommand("msiexec.exe", $"/i \"{_installer_path}\" /qn CUSTOMCONFIGID=ke43ann APITOKEN=4765529-gon1LwO1N1TTrlLI21ji ASSIGNMENTOPTIONS=\" --reassign --alias {"TANGO-" + machineSerialNumber} --grant-easy-access\"");
                    command.Timeout = TimeSpan.FromSeconds(30);
                    await command.Run();

                    bool exist = await IsRemoteAssistanceInstalled();

                    if (exist)
                    {
                        await DisableRemoteAssistance();
                    }
                    else
                    {
                        throw new ApplicationException("The remote assistance service was installed but could not be found.");
                    }
                }
                else
                {
                    LogManager.Log("Remote assistance is already installed.");
                }
            }
            catch (Exception ex)
            {
                LogManager.Log(ex, "Error installing remote assistance.");
                throw;
            }
        }

        /// <summary>
        /// Determines whether remote assistance is currently installed.
        /// </summary>
        /// <returns></returns>
        private async Task<bool> IsRemoteAssistanceInstalled()
        {
            bool exist = false;

            for (int i = 0; i < 6; i++)
            {
                LogManager.Log("Checking remote assistance service...");
                await Task.Delay(1000);
                CmdCommand command = new CmdCommand("sc.exe", "query TeamViewer");
                try
                {
                    await command.Run();
                    exist = true;
                    break;
                }
                catch { }
            }

            if (exist)
            {
                LogManager.Log("Remote assistance service found.");
            }
            else
            {
                LogManager.Log("Remote assistance service was not found.");
            }

            return exist;
        }
    }
}