using Dalamud.Game.ClientState.Objects.Enums;
using Dalamud.Game.ClientState.Objects.Types;
using Dalamud.Plugin.Services;
using LightlessSync.Services;
using LightlessSync.Services.Mediator;
using Microsoft.Extensions.Logging;
using ObjectKind = LightlessSync.API.Data.Enum.ObjectKind;

namespace LightlessSync.PlayerData.Handlers;

/// <summary>
/// Game object handler for managing game object state and updates
/// </summary>
public sealed class GameObjectHandler : DisposableMediatorSubscriberBase, IHighPriorityMediatorSubscriber
{
    private readonly DalamudUtilService _dalamudUtil;
    private readonly IObjectTable _objectTable;
    private readonly Func<IntPtr> _getAddress;
    private readonly bool _isOwnedObject;
    private readonly PerformanceCollectorService _performanceCollector;
    private readonly Lock _frameworkUpdateGate = new();
    private bool _frameworkUpdateSubscribed;
    private byte _classJob = 0;
    private Task? _delayedZoningTask;
    private bool _haltProcessing = false;
    private CancellationTokenSource _zoningCts = new();

    /// <summary>
    /// Constructor for GameObjectHandler
    /// </summary>
    /// <param name="logger">Logger</param>
    /// <param name="performanceCollector">Performance Collector</param>
    /// <param name="mediator">Lightless Mediator</param>
    /// <param name="dalamudUtil">Dalamud Utilties Service</param>
    /// <param name="objectKind">Object kind of Object</param>
    /// <param name="getAddress">Get Adress</param>
    /// <param name="objectTable">Object table of Dalamud</param>
    /// <param name="ownedObject">Object is owned by user</param>
    public GameObjectHandler(
        ILogger<GameObjectHandler> logger,
        PerformanceCollectorService performanceCollector,
        LightlessMediator mediator,
        DalamudUtilService dalamudUtil,
        ObjectKind objectKind,
        Func<IntPtr> getAddress,
        IObjectTable objectTable,
        bool ownedObject = true) : base(logger, mediator)
    {
        _performanceCollector = performanceCollector;
        ObjectKind = objectKind;
        _dalamudUtil = dalamudUtil;
        _objectTable = objectTable;

        _getAddress = () =>
        {
            _dalamudUtil.EnsureIsOnFramework();
            return getAddress.Invoke();
        };

        _isOwnedObject = ownedObject;
        Name = string.Empty;

        if (ownedObject)
        {
            Mediator.Subscribe<TransientResourceChangedMessage>(this, msg =>
            {
                if (_delayedZoningTask?.IsCompleted ?? true)
                {
                    if (msg.Address != Address) return;
                    Mediator.Publish(new CreateCacheForObjectMessage(this));
                }
            });
        }

        EnableFrameworkUpdates();

        Mediator.Subscribe<ZoneSwitchEndMessage>(this, _ => ZoneSwitchEnd());
        Mediator.Subscribe<ZoneSwitchStartMessage>(this, _ => ZoneSwitchStart());

        Mediator.Subscribe<CutsceneStartMessage>(this, _ => _haltProcessing = true);
        Mediator.Subscribe<CutsceneEndMessage>(this, _ =>
        {
            _haltProcessing = false;
            ZoneSwitchEnd();
        });

        Mediator.Subscribe<PenumbraStartRedrawMessage>(this, msg =>
        {
            if (msg.Address == Address) _haltProcessing = true;
        });
        Mediator.Subscribe<PenumbraEndRedrawMessage>(this, msg =>
        {
            if (msg.Address == Address) _haltProcessing = false;
        });

        Mediator.Publish(new GameObjectHandlerCreatedMessage(this, _isOwnedObject));

        _dalamudUtil.EnsureIsOnFramework();
        CheckAndUpdateObject(allowPublish: true);
    }

    /// <summary>
    /// Draw Condition Enum
    /// </summary>
    public enum DrawCondition
    {
        None,
        ObjectZero,
        DrawObjectZero,
        RenderFlags,
        ModelInSlotLoaded,
        ModelFilesInSlotLoaded
    }

    // Properties
    public IntPtr Address { get; private set; }
    public DrawCondition CurrentDrawCondition { get; set; } = DrawCondition.None;
    public byte Gender { get; private set; }
    public string Name { get; private set; }
    public uint EntityId { get; private set; } = uint.MaxValue;
    public ObjectKind ObjectKind { get; }
    public byte RaceId { get; private set; }
    public byte TribeId { get; private set; }
    private byte[] CustomizeData { get; set; } = new byte[26];
    private IntPtr DrawObjectAddress { get; set; }

    /// <summary>
    /// Act on framework thread after ensuring no draw condition
    /// </summary>
    /// <param name="act">Action of Character</param>
    /// <param name="token">Cancellation Token</param>
    /// <returns>Task Completion</returns>
    public async Task ActOnFrameworkAfterEnsureNoDrawAsync(Action<ICharacter> act, CancellationToken token)
    {
        while (await _dalamudUtil.RunOnFrameworkThread(() =>
        {
            EnsureLatestObjectState();
            if (CurrentDrawCondition != DrawCondition.None) return true;
            var gameObj = _dalamudUtil.CreateGameObject(Address);
            if (gameObj is ICharacter chara)
            {
                act.Invoke(chara);
            }
            return false;
        }).ConfigureAwait(false))
        {
            await Task.Delay(250, token).ConfigureAwait(false);
        }
    }

    /// <summary>
    /// Compare Name And Throw if not equal 
    /// </summary>
    /// <param name="name">Name that will be compared to Object Handler.</param>
    /// <exception cref="InvalidOperationException">Not equal if thrown</exception>
    public void CompareNameAndThrow(string name)
    {
        if (!string.Equals(Name, name, StringComparison.OrdinalIgnoreCase))
        {
            throw new InvalidOperationException("Player name not equal to requested name, pointer invalid");
        }
        if (Address == IntPtr.Zero)
        {
            throw new InvalidOperationException("Player pointer is zero, pointer invalid");
        }
    }

    /// <summary>
    /// Gets the game object from the address
    /// </summary>
    /// <returns>Gane object</returns>
    public IGameObject? GetGameObject()
    {
        return _dalamudUtil.CreateGameObject(Address);
    }

    /// <summary>
    /// Invalidate the object handler
    /// </summary>
    public void Invalidate()
    {
        Address = IntPtr.Zero;
        DrawObjectAddress = IntPtr.Zero;
        EntityId = uint.MaxValue;
        _haltProcessing = false;
    }

    /// <summary>
    /// Refresh the object handler state
    /// </summary>
    public void Refresh()
    {
        _dalamudUtil.RunOnFrameworkThread(CheckAndUpdateObject).GetAwaiter().GetResult();
    }

    /// <summary>
    /// Is Being Drawn Run On Framework Asyncronously
    /// </summary>
    /// <returns>Object is being run in framework</returns>
    public async Task<bool> IsBeingDrawnRunOnFrameworkAsync()
    {
        return await _dalamudUtil.RunOnFrameworkThread(IsBeingDrawn).ConfigureAwait(false);
    }

    /// <summary>
    /// Override ToString method for GameObjectHandler
    /// </summary>
    /// <returns>String</returns>
    public override string ToString()
    {
        var owned = _isOwnedObject ? "Self" : "Other";
        return $"{owned}/{ObjectKind}:{Name} ({Address:X},{DrawObjectAddress:X})";
    }

    /// <summary>
    /// Try Get Object By Address from Object Table
    /// </summary>
    /// <param name="address">Object address</param>
    /// <returns>Game Object of adress</returns>
    private IGameObject? TryGetObjectByAddress(nint address)
    {
        if (address == nint.Zero) return null;

        // Search object table
        foreach (var obj in _objectTable)
        {
            if (obj is null) continue;
            if (obj.Address == address)
                return obj;
        }
        return null;
    }

    /// <summary>
    /// Checks and updates the object state
    /// </summary>
    private void CheckAndUpdateObject() => CheckAndUpdateObject(allowPublish: true);

    /// <summary>
    /// Checks and updates the object state with option to allow publish
    /// </summary>
    /// <param name="allowPublish">Allows to publish the object</param>
    private void CheckAndUpdateObject(bool allowPublish)
    {
        var prevAddr = Address;
        var prevDrawObj = DrawObjectAddress;
        string? nameString = null;

        Address = _getAddress();

        IGameObject? obj = null;
        ICharacter? chara = null;

        if (Address != nint.Zero)
        {
            // Try get object
            obj = TryGetObjectByAddress(Address);

            if (obj is not null)
            {
                EntityId = obj.EntityId;

                DrawObjectAddress = Address;

                // Name update
                nameString = obj.Name.TextValue ?? string.Empty;
                if (!string.IsNullOrEmpty(nameString) && !string.Equals(nameString, Name, StringComparison.Ordinal))
                    Name = nameString;

                chara = obj as ICharacter;
            }
            else
            {
                DrawObjectAddress = nint.Zero;
                EntityId = uint.MaxValue;
            }
        }
        else
        {
            DrawObjectAddress = nint.Zero;
            EntityId = uint.MaxValue;
        }

        // Update draw condition
        CurrentDrawCondition = IsBeingDrawnSafe(obj, chara);

        if (_haltProcessing || !allowPublish) return;

        // Determine differences
        bool drawObjDiff = DrawObjectAddress != prevDrawObj;
        bool addrDiff = Address != prevAddr;

        // Name change check
        bool nameChange = false;
        if (nameString is not null)
        {
            nameChange = !string.Equals(nameString, Name, StringComparison.Ordinal);
            if (nameChange) Name = nameString;
        }

        // Customize data change check
        bool customizeDiff = false;
        if (chara is not null)
        {
            // Class job change check
            var classJob = chara.ClassJob.RowId;
            if (classJob != _classJob)
            {
                Logger.LogTrace("[{this}] classjob changed from {old} to {new}", this, _classJob, classJob);
                _classJob = (byte)classJob;
                Mediator.Publish(new ClassJobChangedMessage(this));
            }

            // Customize data comparison
            customizeDiff = CompareAndUpdateCustomizeData(chara.Customize);

            // Census update publish
            if (_isOwnedObject && ObjectKind == ObjectKind.Player && chara.Customize.Length > (int)CustomizeIndex.Tribe)
            {
                var gender = chara.Customize[(int)CustomizeIndex.Gender];
                var raceId = chara.Customize[(int)CustomizeIndex.Race];
                var tribeId = chara.Customize[(int)CustomizeIndex.Tribe];

                if (gender != Gender || raceId != RaceId || tribeId != TribeId)
                {
                    Mediator.Publish(new CensusUpdateMessage(gender, raceId, tribeId));
                    Gender = gender;
                    RaceId = raceId;
                    TribeId = tribeId;
                }
            }
        }


        if ((addrDiff || drawObjDiff || customizeDiff || nameChange) && _isOwnedObject)
        {
            Logger.LogDebug("[{this}] Changed, Sending CreateCacheObjectMessage", this);
            Mediator.Publish(new CreateCacheForObjectMessage(this));
        }
        else if (addrDiff || drawObjDiff)
        {
            if (Address == nint.Zero)
                CurrentDrawCondition = DrawCondition.ObjectZero;
            else if (DrawObjectAddress == nint.Zero)
                CurrentDrawCondition = DrawCondition.DrawObjectZero;

            Logger.LogTrace("[{this}] Changed", this);

            if (_isOwnedObject && ObjectKind != ObjectKind.Player)
                Mediator.Publish(new ClearCacheForObjectMessage(this));
        }
    }

    /// <summary>
    /// Is object being drawn safe check
    /// </summary>
    /// <param name="obj">Object thats being checked</param>
    /// <param name="chara">Character of the object</param>
    /// <returns>Draw Condition of character</returns>
    private DrawCondition IsBeingDrawnSafe(IGameObject? obj, ICharacter? chara)
    {
        // Object zero check
        if (Address == nint.Zero) return DrawCondition.ObjectZero;
        if (obj is null) return DrawCondition.DrawObjectZero;

        // Draw Object check
        if (chara is not null && (chara.Customize is null || chara.Customize.Length == 0))
            return DrawCondition.DrawObjectZero;

        return DrawCondition.None;
    }

    /// <summary>
    /// Compare and update customize data of character
    /// </summary>
    /// <param name="customizeData">Customize+ data of object</param>
    /// <returns>Successfully applied or not</returns>
    private bool CompareAndUpdateCustomizeData(ReadOnlySpan<byte> customizeData)
    {
        bool hasChanges = false;

        // Resize if needed
        var len = Math.Min(customizeData.Length, CustomizeData.Length);
        for (int i = 0; i < len; i++)
        {
            var data = customizeData[i];
            if (CustomizeData[i] != data)
            {
                CustomizeData[i] = data;
                hasChanges = true;
            }
        }

        return hasChanges;
    }

    /// <summary>
    /// Framework update method
    /// </summary>
    private void FrameworkUpdate()
    {
        try
        {
            var zoningDelayActive = !(_delayedZoningTask?.IsCompleted ?? true);
            _performanceCollector.LogPerformance(this, $"CheckAndUpdateObject>{(_isOwnedObject ? "Self" : "Other")}+{ObjectKind}/{(string.IsNullOrEmpty(Name) ? "Unk" : Name)}", () => CheckAndUpdateObject(allowPublish: !zoningDelayActive));
        }
        catch (Exception ex)
        {
            Logger.LogWarning(ex, "Error during FrameworkUpdate of {this}", this);
        }
    }

    /// <summary>
    /// Is object being drawn check
    /// </summary>
    /// <returns>Is being drawn</returns>
    private bool IsBeingDrawn()
    {
        EnsureLatestObjectState();

        if (_dalamudUtil.IsAnythingDrawing)
        {
            Logger.LogTrace("[{this}] IsBeingDrawn, Global draw block", this);
            return true;
        }

        Logger.LogTrace("[{this}] IsBeingDrawn, Condition: {cond}", this, CurrentDrawCondition);
        return CurrentDrawCondition != DrawCondition.None;
    }

    /// <summary>
    /// Ensures the latest object state
    /// </summary>
    private void EnsureLatestObjectState()
    {
        if (_haltProcessing || !_frameworkUpdateSubscribed)
        {
            CheckAndUpdateObject();
        }
    }

    /// <summary>
    /// Enables framework updates for the object handler
    /// </summary>
    private void EnableFrameworkUpdates()
    {
        lock (_frameworkUpdateGate)
        {
            if (_frameworkUpdateSubscribed)
            {
                return;
            }

            Mediator.Subscribe<FrameworkUpdateMessage>(this, _ => FrameworkUpdate());
            _frameworkUpdateSubscribed = true;
        }
    }

    /// <summary>
    /// Zone switch end handling
    /// </summary>
    private void ZoneSwitchEnd()
    {
        if (!_isOwnedObject) return;

        try
        {
            _zoningCts?.CancelAfter(2500);
        }
        catch (ObjectDisposedException)
        {
            // ignore canelled after disposed
        }
        catch (Exception ex)
        {
            Logger.LogWarning(ex, "Zoning CTS cancel issue");
        }
    }

    /// <summary>
    /// Zone switch start handling
    /// </summary>
    private void ZoneSwitchStart()
    {
        if (!_isOwnedObject) return;

        _zoningCts = new();
        Logger.LogDebug("[{obj}] Starting Delay After Zoning", this);
        _delayedZoningTask = Task.Run(async () =>
        {
            try
            {
                await Task.Delay(TimeSpan.FromSeconds(120), _zoningCts.Token).ConfigureAwait(false);
            }
            catch
            {
                // ignore cancelled
            }
            finally
            {
                Logger.LogDebug("[{this}] Delay after zoning complete", this);
                _zoningCts.Dispose();
            }
        }, _zoningCts.Token);
    }
}