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;
using IW4MAdmin.Application.API.Master;
using System.Reflection;
using SharedLibraryCore.Database;
using SharedLibraryCore.Events;

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 bool IsInitialized { get; private set; }
        // define what the delagate function looks like
        public delegate void OnServerEventEventHandler(object sender, GameEventArgs e);
        // expose the event handler so we can execute the events
        public OnServerEventEventHandler OnServerEvent { get; set; }
        public DateTime StartTime { get; private set; }

        static ApplicationManager Instance;
        readonly List<AsyncStatus> TaskStatuses;
        List<Command> Commands;
        readonly List<MessageToken> MessageTokens;
        ClientService ClientSvc;
        readonly AliasService AliasSvc;
        readonly PenaltyService PenaltySvc;
        public BaseConfigurationHandler<ApplicationConfiguration> ConfigHandler;
        GameEventHandler Handler;
        ManualResetEventSlim OnQuit;
        readonly IPageList PageList;

        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>();
            ConfigHandler = new BaseConfigurationHandler<ApplicationConfiguration>("IW4MAdminSettings");
            StartTime = DateTime.UtcNow;
            OnQuit = new ManualResetEventSlim();
            PageList = new PageList();
            OnServerEvent += OnServerEventAsync;
            OnServerEvent += EventApi.OnGameEvent;
        }

        private async void OnServerEventAsync(object sender, GameEventArgs args)
        {
            var newEvent = args.Event;

            try
            {
                // if the origin client is not in an authorized state (detected by RCon) don't execute the event
                if (GameEvent.ShouldOriginEventBeDelayed(newEvent))
                {
                    Logger.WriteDebug($"Delaying origin execution of event type {newEvent.Type} for {newEvent.Origin} because they are not authed");
                    if (newEvent.Type == GameEvent.EventType.Command)
                    {
                        await newEvent.Origin.Tell(Utilities.CurrentLocalization.LocalizationIndex["SERVER_DELAYED_EVENT_WAIT"]);
                    }

                    // offload it to the player to keep
                    newEvent.Origin.DelayedEvents.Enqueue(newEvent);
                    return;
                }

                // if the target client is not in an authorized state (detected by RCon) don't execute the event
                if (GameEvent.ShouldTargetEventBeDelayed(newEvent))
                {
                    Logger.WriteDebug($"Delaying target execution of event type {newEvent.Type} for {newEvent.Target} because they are not authed");
                    // offload it to the player to keep
                    newEvent.Target.DelayedEvents.Enqueue(newEvent);
                    return;
                }

                // todo: this is a hacky mess
                if (newEvent.Origin?.DelayedEvents.Count > 0 &&
                    newEvent.Origin?.State == Player.ClientState.Connected)
                {
                    var events = newEvent.Origin.DelayedEvents;

                    // add the delayed event to the queue 
                    while (events.Count > 0)
                    {
                        var oldEvent = events.Dequeue();

                        var e = new GameEvent()
                        {
                            Type = oldEvent.Type,
                            Origin = newEvent.Origin,
                            Data = oldEvent.Data,
                            Extra = oldEvent.Extra,
                            Owner = oldEvent.Owner,
                            Message = oldEvent.Message,
                            Target = oldEvent.Target,
                            OnProcessed = oldEvent.OnProcessed,
                            Remote = oldEvent.Remote
                        };

                        e.Origin = newEvent.Origin;
                        // check if the target was assigned
                        if (e.Target != null)
                        {
                            // update the target incase they left or have newer info
                            e.Target = newEvent.Owner.GetPlayersAsList()
                                .FirstOrDefault(p => p.NetworkId == e.Target.NetworkId);
                            // we have to throw out the event because they left
                            if (e.Target == null)
                            {
                                Logger.WriteWarning($"Delayed event for {e.Origin} was removed because the target has left");
                                continue;
                            }
                        }
                        Logger.WriteDebug($"Adding delayed event of type {e.Type} for {e.Origin} back for processing");
                        this.GetEventHandler().AddEvent(e);
                    }
                }

                await newEvent.Owner.ExecuteEvent(newEvent);

#if DEBUG
                Logger.WriteDebug($"Processed event with id {newEvent.Id}");
#endif
            }

            // this happens if a plugin requires login
            catch (AuthorizationException ex)
            {
                await newEvent.Origin.Tell($"{Utilities.CurrentLocalization.LocalizationIndex["COMMAND_NOTAUTHORIZED"]} - {ex.Message}");
            }

            catch (NetworkException ex)
            {
                Logger.WriteError(ex.Message);
            }

            catch (ServerException ex)
            {
                Logger.WriteWarning(ex.Message);
            }

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

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

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

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

        public async Task UpdateServerStates()
        {
            // store the server hash code and task for it
            var runningUpdateTasks = new Dictionary<int, Task>();

            while (Running)
            {
                // select the server ids that have completed the update task
                var serverTasksToRemove = runningUpdateTasks
                    .Where(ut => ut.Value.Status == TaskStatus.RanToCompletion ||
                        ut.Value.Status == TaskStatus.Canceled ||
                        ut.Value.Status == TaskStatus.Faulted)
                    .Select(ut => ut.Key)
                    .ToList();

                // this is to prevent the log reader from starting before the initial
                // query of players on the server
                if (serverTasksToRemove.Count > 0)
                {
                    IsInitialized = true;
                }

                // remove the update tasks as they have completd
                foreach (int serverId in serverTasksToRemove)
                {
                    runningUpdateTasks.Remove(serverId);
                }

                // select the servers where the tasks have completed
                var serverIds = Servers.Select(s => s.GetHashCode()).Except(runningUpdateTasks.Select(r => r.Key)).ToList();
                foreach (var server in Servers.Where(s => serverIds.Contains(s.GetHashCode())))
                {
                    runningUpdateTasks.Add(server.GetHashCode(), Task.Run(async () =>
                    {
                        try
                        {
                            await server.ProcessUpdatesAsync(new CancellationToken());
                        }

                        catch (Exception e)
                        {
                            Logger.WriteWarning($"Failed to update status for {server}");
                            Logger.WriteDebug($"Exception: {e.Message}");
                            Logger.WriteDebug($"StackTrace: {e.StackTrace}");
                        }
                    }));
                }
#if DEBUG
                Logger.WriteDebug($"{runningUpdateTasks.Count} servers queued for stats updates");
                ThreadPool.GetMaxThreads(out int workerThreads, out int n);
                ThreadPool.GetAvailableThreads(out int availableThreads, out int m);
                Logger.WriteDebug($"There are {workerThreads - availableThreads} active threading tasks");
#endif
#if DEBUG
                await Task.Delay(10000);
#else
                await Task.Delay(ConfigHandler.Configuration().RConPollRate);
#endif
            }
        }

        public async Task Init()
        {
            Running = true;

            #region DATABASE
            using (var db = new DatabaseContext(GetApplicationSettings().Configuration()?.ConnectionString))
            {
                await new ContextSeed(db).Seed();
            }

            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.LocalizationIndex["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($"{Utilities.CurrentLocalization.LocalizationIndex["SERVER_ERROR_PLUGIN"]} {Plugin.Name}");
                    Logger.WriteDebug($"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 CUnflag());
            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());
            Commands.Add(new CSetGravatar());
            Commands.Add(new CNextMap());

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

            #region INIT
            async Task Init(ServerConfiguration Conf)
            {
                // setup the event handler after the class is initialized
                Handler = new GameEventHandler(this);
                try
                {
                    var ServerInstance = new IW4MServer(this, Conf);
                    await ServerInstance.Initialize();

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

                    Logger.WriteVerbose($"{Utilities.CurrentLocalization.LocalizationIndex["MANAGER_MONITORING_TEXT"]} {ServerInstance.Hostname}");
                    // add the start event for this server

                    var e = new GameEvent()
                    {
                        Type = GameEvent.EventType.Start,
                        Data = $"{ServerInstance.GameName} started",
                        Owner = ServerInstance
                    };

                    Handler.AddEvent(e);
                }

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

        private async Task SendHeartbeat(object state)
        {
            var heartbeatState = (HeartbeatState)state;

            while (Running)
            {
                if (!heartbeatState.Connected)
                {
                    try
                    {
                        await Heartbeat.Send(this, true);
                        heartbeatState.Connected = true;
                    }

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

                else
                {
                    try
                    {
                        await Heartbeat.Send(this);
                    }

                    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)
                            {
                                heartbeatState.Connected = false;
                            }
                        }
                    }

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

                }
                await Task.Delay(30000);
            }
        }

        public void Start()
        {
            // this needs to be run seperately from the main thread
#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
#if !DEBUG
            // start heartbeat
            Task.Run(() => SendHeartbeat(new HeartbeatState()));
#endif
            Task.Run(() => UpdateServerStates());
#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed

            while (Running)
            {
                OnQuit.Wait();
                OnQuit.Reset();
            }
            _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 bool ShutdownRequested() => !Running;
        public IEventHandler GetEventHandler() => Handler;

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

        public IList<Assembly> GetPluginAssemblies() => SharedLibraryCore.Plugins.PluginImporter.PluginAssemblies;

        public IPageList GetPageList() => PageList;
    }
}