using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.IO;
using System.Threading.Tasks;

using SharedLibraryCore;
using SharedLibraryCore.Interfaces;
using SharedLibraryCore.Commands;
using SharedLibraryCore.Helpers;
using SharedLibraryCore.Exceptions;
using SharedLibraryCore.Objects;
using SharedLibraryCore.Services;
using IW4MAdmin.Application.API;
using Microsoft.Extensions.Configuration;
using WebfrontCore;
using SharedLibraryCore.Configuration;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Text;

namespace IW4MAdmin.Application
{
    public class ApplicationManager : IManager
    {
        private List<Server> _servers;
        public List<Server> Servers => _servers.OrderByDescending(s => s.ClientNum).ToList();
        public Dictionary<int, Player> PrivilegedClients { get; set; }
        public ILogger Logger { get; private set; }
        public bool Running { get; private set; }
        public EventHandler<GameEvent> ServerEventOccurred { get; private set; }
        public DateTime StartTime { get; private set; }

        static ApplicationManager Instance;
        List<AsyncStatus> TaskStatuses;
        List<Command> Commands;
        List<MessageToken> MessageTokens;
        ClientService ClientSvc;
        AliasService AliasSvc;
        PenaltyService PenaltySvc;
        BaseConfigurationHandler<ApplicationConfiguration> ConfigHandler;
        EventApi Api;
        GameEventHandler Handler;
        ManualResetEventSlim OnEvent;
        Timer StatusUpdateTimer;
#if FTP_LOG
        const int UPDATE_FREQUENCY = 700;
#else
        const int UPDATE_FREQUENCY = 2000;
#endif

        private ApplicationManager()
        {
            Logger = new Logger($@"{Utilities.OperatingDirectory}IW4MAdmin.log");
            _servers = new List<Server>();
            Commands = new List<Command>();
            TaskStatuses = new List<AsyncStatus>();
            MessageTokens = new List<MessageToken>();
            ClientSvc = new ClientService();
            AliasSvc = new AliasService();
            PenaltySvc = new PenaltyService();
            PrivilegedClients = new Dictionary<int, Player>();
            Api = new EventApi();
            ServerEventOccurred += Api.OnServerEvent;
            ConfigHandler = new BaseConfigurationHandler<ApplicationConfiguration>("IW4MAdminSettings");
            Console.CancelKeyPress += new ConsoleCancelEventHandler(OnCancelKey);
            StartTime = DateTime.UtcNow;
            OnEvent = new ManualResetEventSlim();
        }

        private void OnCancelKey(object sender, ConsoleCancelEventArgs args)
        {
            Stop();
        }


        public IList<Server> GetServers()
        {
            return Servers;
        }

        public IList<Command> GetCommands()
        {
            return Commands;
        }

        public static ApplicationManager GetInstance()
        {
            return Instance ?? (Instance = new ApplicationManager());
        }

        public void UpdateStatus(object state)
        {
            var taskList = new List<Task>();

            foreach (var server in Servers)
            {
                taskList.Add(Task.Run(() => server.ProcessUpdatesAsync(new CancellationToken())));
            }

            Task.WaitAll(taskList.ToArray());
        }

        public async Task Init()
        {
            // setup the event handler after the class is initialized
            Handler = new GameEventHandler(this);
            #region DATABASE
            var ipList = (await ClientSvc.Find(c => c.Level > Player.Permission.Trusted))
                .Select(c => new
                {
                    c.Password,
                    c.PasswordSalt,
                    c.ClientId,
                    c.Level,
                    c.Name
                });

            foreach (var a in ipList)
            {
                try
                {
                    PrivilegedClients.Add(a.ClientId, new Player()
                    {
                        Name = a.Name,
                        ClientId = a.ClientId,
                        Level = a.Level,
                        PasswordSalt = a.PasswordSalt,
                        Password = a.Password
                    });
                }

                catch (ArgumentException)
                {
                    continue;
                }
            }
            #endregion

            #region CONFIG
            var config = ConfigHandler.Configuration();

            // copy over default config if it doesn't exist
            if (config == null)
            {
                var defaultConfig = new BaseConfigurationHandler<DefaultConfiguration>("DefaultSettings").Configuration();
                ConfigHandler.Set((ApplicationConfiguration)new ApplicationConfiguration().Generate());
                var newConfig = ConfigHandler.Configuration();

                newConfig.AutoMessagePeriod = defaultConfig.AutoMessagePeriod;
                newConfig.AutoMessages = defaultConfig.AutoMessages;
                newConfig.GlobalRules = defaultConfig.GlobalRules;
                newConfig.Maps = defaultConfig.Maps;

                if (newConfig.Servers == null)
                {
                    ConfigHandler.Set(newConfig);
                    newConfig.Servers = new List<ServerConfiguration>();

                    do
                    {
                        newConfig.Servers.Add((ServerConfiguration)new ServerConfiguration().Generate());
                    } while (Utilities.PromptBool(Utilities.CurrentLocalization.LocalizationSet["SETUP_SERVER_SAVE"]));

                    config = newConfig;
                    await ConfigHandler.Save();
                }
            }

            else if (config != null)
            {
                if (string.IsNullOrEmpty(config.Id))
                {
                    config.Id = Guid.NewGuid().ToString();
                    await ConfigHandler.Save();
                }

                if (string.IsNullOrEmpty(config.WebfrontBindUrl))
                {
                    config.WebfrontBindUrl = "http://127.0.0.1:1624";
                    await ConfigHandler.Save();
                }
            }

            else if (config.Servers.Count == 0)
                throw new ServerException("A server configuration in IW4MAdminSettings.json is invalid");

            Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
            Utilities.EncodingType = Encoding.GetEncoding(!string.IsNullOrEmpty(config.CustomParserEncoding) ? config.CustomParserEncoding : "windows-1252");

            #endregion
            #region PLUGINS
            SharedLibraryCore.Plugins.PluginImporter.Load(this);

            foreach (var Plugin in SharedLibraryCore.Plugins.PluginImporter.ActivePlugins)
            {
                try
                {
                    await Plugin.OnLoadAsync(this);
                }

                catch (Exception e)
                {
                    Logger.WriteError($"{Utilities.CurrentLocalization.LocalizationSet["SERVER_ERROR_PLUGIN"]} {Plugin.Name}");
                    Logger.WriteDebug($"Exception: {e.Message}");
                    Logger.WriteDebug($"Stack Trace: {e.StackTrace}");
                }
            }
            #endregion

            #region COMMANDS
            if (ClientSvc.GetOwners().Result.Count == 0)
                Commands.Add(new COwner());

            Commands.Add(new CQuit());
            Commands.Add(new CKick());
            Commands.Add(new CSay());
            Commands.Add(new CTempBan());
            Commands.Add(new CBan());
            Commands.Add(new CWhoAmI());
            Commands.Add(new CList());
            Commands.Add(new CHelp());
            Commands.Add(new CFastRestart());
            Commands.Add(new CMapRotate());
            Commands.Add(new CSetLevel());
            Commands.Add(new CUsage());
            Commands.Add(new CUptime());
            Commands.Add(new CWarn());
            Commands.Add(new CWarnClear());
            Commands.Add(new CUnban());
            Commands.Add(new CListAdmins());
            Commands.Add(new CLoadMap());
            Commands.Add(new CFindPlayer());
            Commands.Add(new CListRules());
            Commands.Add(new CPrivateMessage());
            Commands.Add(new CFlag());
            Commands.Add(new CReport());
            Commands.Add(new CListReports());
            Commands.Add(new CListBanInfo());
            Commands.Add(new CListAlias());
            Commands.Add(new CExecuteRCON());
            Commands.Add(new CPlugins());
            Commands.Add(new CIP());
            Commands.Add(new CMask());
            Commands.Add(new CPruneAdmins());
            //Commands.Add(new CKillServer());
            Commands.Add(new CSetPassword());
            Commands.Add(new CPing());

            foreach (Command C in SharedLibraryCore.Plugins.PluginImporter.ActiveCommands)
                Commands.Add(C);
            #endregion

            #region INIT
            async Task Init(ServerConfiguration Conf)
            {
                try
                {
                    var ServerInstance = new IW4MServer(this, Conf);
                    await ServerInstance.Initialize();

                    lock (_servers)
                    {
                        _servers.Add(ServerInstance);
                    }

                    Logger.WriteVerbose($"{Utilities.CurrentLocalization.LocalizationSet["MANAGER_MONITORING_TEXT"]} {ServerInstance.Hostname}");
                    // add the start event for this server
                    Handler.AddEvent(new GameEvent(GameEvent.EventType.Start, "Server started", null, null, ServerInstance));
                }

                catch (ServerException e)
                {
                    Logger.WriteError($"{Utilities.CurrentLocalization.LocalizationSet["SERVER_ERROR_UNFIXABLE"]} [{Conf.IPAddress}:{Conf.Port}]");
                    if (e.GetType() == typeof(DvarException))
                        Logger.WriteDebug($"{Utilities.CurrentLocalization.LocalizationSet["SERVER_ERROR_DVAR"]} {(e as DvarException).Data["dvar_name"]} ({Utilities.CurrentLocalization.LocalizationSet["SERVER_ERROR_DVAR_HELP"]})");
                    else if (e.GetType() == typeof(NetworkException))
                    {
                        Logger.WriteDebug(e.Message);
                    }

                    // throw the exception to the main method to stop before instantly exiting
                    throw e;
                }
            }

            await Task.WhenAll(config.Servers.Select(c => Init(c)).ToArray());
            // start polling servers
            StatusUpdateTimer = new Timer(UpdateStatus, null, 0, 10000);

            #endregion

            Running = true;
        }

        private void HeartBeatThread()
        {
            bool successfulConnection = false;
            restartConnection:
            while (!successfulConnection)
            {
                try
                {
                    API.Master.Heartbeat.Send(this, true).Wait();
                    successfulConnection = true;
                }

                catch (Exception e)
                {
                    successfulConnection = false;
                    Logger.WriteWarning($"Could not connect to heartbeat server - {e.Message}");
                }

                Thread.Sleep(30000);
            }

            while (Running)
            {
                Logger.WriteDebug("Sending heartbeat...");
                try
                {
                    API.Master.Heartbeat.Send(this).Wait();
                }
                catch (System.Net.Http.HttpRequestException e)
                {
                    Logger.WriteWarning($"Could not send heartbeat - {e.Message}");
                }

                catch (AggregateException e)
                {
                    Logger.WriteWarning($"Could not send heartbeat - {e.Message}");
                    var exceptions = e.InnerExceptions.Where(ex => ex.GetType() == typeof(RestEase.ApiException));

                    foreach (var ex in exceptions)
                    {
                        if (((RestEase.ApiException)ex).StatusCode == System.Net.HttpStatusCode.Unauthorized)
                        {
                            successfulConnection = false;
                            goto restartConnection;
                        }
                    }
                }

                catch (RestEase.ApiException e)
                {
                    Logger.WriteWarning($"Could not send heartbeat - {e.Message}");
                    if (e.StatusCode == System.Net.HttpStatusCode.Unauthorized)
                    {
                        successfulConnection = false;
                        goto restartConnection;
                    }
                }

                Thread.Sleep(30000);
            }
        }

        public void Start()
        {
            Task.Run(() => HeartBeatThread());
            GameEvent newEvent;
            while (Running)
            {
                // wait for new event to be added
                OnEvent.Wait();
              
                // todo: sequencially or parallelize?
                while ((newEvent = Handler.GetNextEvent()) != null)
                {
                    try
                    {
                        newEvent.Owner.ExecuteEvent(newEvent).Wait();
#if DEBUG
                        Logger.WriteDebug("Processed Event");
#endif
                    }

                    catch (Exception E)
                    {
                        Logger.WriteError($"{Utilities.CurrentLocalization.LocalizationSet["SERVER_ERROR_EXCEPTION"]} {newEvent.Owner}");
                        Logger.WriteDebug("Error Message: " + E.Message);
                        Logger.WriteDebug("Error Trace: " + E.StackTrace);
                        newEvent.OnProcessed.Set();
                        continue;
                    }
                    // tell anyone waiting for the output that we're done
                    newEvent.OnProcessed.Set();
                }

                // signal that all events have been processed
                OnEvent.Reset();
            }
#if !DEBUG
            foreach (var S in Servers)
                S.Broadcast(Utilities.CurrentLocalization.LocalizationSet["BROADCAST_OFFLINE"]).Wait();
#endif
            _servers.Clear();
        }


        public void Stop()
        {
            Running = false;

            // trigger the event processing loop to end
            SetHasEvent();
        }

        public ILogger GetLogger()
        {
            return Logger;
        }

        public IList<MessageToken> GetMessageTokens()
        {
            return MessageTokens;
        }

        public IList<Player> GetActiveClients()
        {
            var ActiveClients = new List<Player>();

            foreach (var server in _servers)
                ActiveClients.AddRange(server.Players.Where(p => p != null));

            return ActiveClients;
        }

        public ClientService GetClientService() => ClientSvc;
        public AliasService GetAliasService() => AliasSvc;
        public PenaltyService GetPenaltyService() => PenaltySvc;
        public IConfigurationHandler<ApplicationConfiguration> GetApplicationSettings() => ConfigHandler;
        public IDictionary<int, Player> GetPrivilegedClients() => PrivilegedClients;
        public IEventApi GetEventApi() => Api;
        public bool ShutdownRequested() => !Running;
        public IEventHandler GetEventHandler() => Handler;

        public void SetHasEvent()
        {
            OnEvent.Set();
        }
    }
}