#nullable enable
using T3.Core.Model;
using T3.Core.Operator;
using T3.Editor.Gui.OutputUi;
using T3.Editor.UiModel.InputsAndTypes;
using T3.Editor.UiModel.Selection;

namespace T3.Editor.UiModel;

public sealed partial class SymbolUi : ISelectionContainer
{
    internal Symbol Symbol => _package.Symbols[_id];
    private SymbolPackage _package;
    private readonly Guid _id;

    internal SymbolUi(Symbol symbol, bool updateConsistency)
    {
        _id = symbol.Id;
        _package = symbol.SymbolPackage;
        if (_package == null)
            throw new ArgumentException("Symbol must have a package");

        InputUis = new OrderedDictionary<Guid, IInputUi>();
        OutputUis = new OrderedDictionary<Guid, IOutputUi>();
        Sections = new OrderedDictionary<Guid, Section>();
        Links = new OrderedDictionary<Guid, ExternalLink>();
        TourPoints = new List<TourPoint>();

        if (updateConsistency)
            UpdateConsistencyWithSymbol();

        ReadOnly = true;
    }

    internal SymbolUi(Symbol symbol,
                      Func<Symbol, List<Child>> childUis,
                      OrderedDictionary<Guid, IInputUi> inputs,
                      OrderedDictionary<Guid, IOutputUi> outputs,
                      OrderedDictionary<Guid, Section> sections,
                      OrderedDictionary<Guid, ExternalLink> links,
                      List<TourPoint> tourPoints,
                      bool updateConsistency) : this(symbol, false)
    {
        _childUis = childUis(symbol).ToDictionary(x => x.Id, x => x);

        InputUis = inputs;
        OutputUis = outputs;
        Sections = sections;
        Links = links;
        TourPoints = tourPoints;
        ReadOnly = true;

        if (updateConsistency)
            UpdateConsistencyWithSymbol(symbol);
    }

    internal void UpdateSymbolPackage(EditorSymbolPackage package)
    {
        if (package == null)
            throw new ArgumentException("Symbol must have a package");
        
        _package = package;
        foreach (var childUi in ChildUis.Values)
        {
            childUi.UpdateSymbolPackage(package);
        }
    }

    IEnumerable<ISelectableCanvasObject> ISelectionContainer.GetSelectables() => GetSelectables();

    internal IEnumerable<ISelectableCanvasObject> GetSelectables()
    {
        foreach (var childUi in ChildUis.Values)
            yield return childUi;

        foreach (var inputUi in InputUis)
            yield return inputUi.Value;

        foreach (var outputUi in OutputUis)
            yield return outputUi.Value;

        foreach (var section in Sections)
            yield return section.Value;
    }

    /// <summary>
    /// Updates the consistency of the symbol ui with the symbol.
    /// Requires providing a symbol as an argument if the symbol is not part of a package - i.e. if it is a pasted symbol
    /// </summary>
    /// <param name="symbol"></param>
    internal void UpdateConsistencyWithSymbol(Symbol? symbol = null)
    {
        symbol ??= Symbol;
        var package = (EditorSymbolPackage)symbol.SymbolPackage;
        // Check if child entries are missing
        foreach (var child in symbol.Children.Values)
        {
            var childId = child.Id;
            if (!ChildUis.TryGetValue(childId, out _))
            {
                if (child.PreviousId != null && ChildUis.TryGetValue(child.PreviousId.Value, out var previousUi))
                {
                    // if we have a previous ui, we can copy the position and other properties from it
                    Log.Debug($"Found a child ui entry that was duplicated for '{child.ReadableName}' - creating a copy");
                    _childUis[childId] = Child.CreateCopy(previousUi, childId, _id, package);
                    _childUis.Remove(child.PreviousId.Value);
                    child.ClearPreviousId();
                }
                else
                {
                    Log.Debug($"Found no symbol child ui entry for symbol child '{child.ReadableName}' - creating a new one");
                    _childUis[childId] = new Child(childId, _id, (EditorSymbolPackage)symbol.SymbolPackage)
                                  {
                                      PosOnCanvas = new Vector2(100, 100),
                                  };
                }
            }
        }

        // check if there are child entries where no symbol child exists anymore
        List<Guid> childIdsToRemove = new(4);

        foreach (var childUi in _childUis.Values)
        {
            if (!symbol.Children.ContainsKey(childUi.Id))
                childIdsToRemove.Add(childUi.Id);
        }

        foreach (var id in childIdsToRemove)
        {
            _childUis.Remove(id);
        }

        // Clear membership references to sections that no longer exist (e.g. hand-edited files,
        // paste from a composition whose sections weren't copied along)
        foreach (var childUi in _childUis.Values)
        {
            if (childUi.SectionId != Guid.Empty && !Sections.ContainsKey(childUi.SectionId))
                childUi.SectionId = Guid.Empty;
        }

        foreach (var section in Sections.Values)
        {
            if (section.ParentSectionId != Guid.Empty && !Sections.ContainsKey(section.ParentSectionId))
                section.ParentSectionId = Guid.Empty;
        }

        // check if input UIs are missing
        var existingInputs = InputUis.Values.ToList();
        InputUis.Clear();
        for (int i = 0; i < symbol.InputDefinitions.Count; i++)
        {
            Symbol.InputDefinition input = symbol.InputDefinitions[i];
            var existingInputUi = existingInputs.SingleOrDefault(inputUi => inputUi.Id == input.Id);
            if (existingInputUi == null || existingInputUi.Type != input.DefaultValue.ValueType)
            {
                Log.Debug($"Found no input ui entry for symbol child input '{symbol.Name}.{input.Name}' - creating a new one");
                InputUis.Remove(input.Id);
                var newInputUi = InputUiFactory.Instance.CreateFor(input.DefaultValue.ValueType);
                newInputUi.Parent = this;
                newInputUi.InputDefinition = input;
                newInputUi.PosOnCanvas = GetCanvasPositionForNextInputUi(this);
                InputUis.Add(input.Id, newInputUi);
            }
            else
            {
                existingInputUi.Parent = this;
                InputUis.Add(existingInputUi.Id, existingInputUi); // add at correct position
            }
        }

        // check if there are input entries where no input ui exists anymore
        foreach (var inputUiToRemove in InputUis.Where(kv => !symbol.InputDefinitions.Exists(inputDef => inputDef.Id == kv.Key)).ToList())
        {
            Log.Debug($"InputUi '{inputUiToRemove.Value.Id}' still existed but no corresponding input definition anymore. Removing the ui.");
            InputUis.Remove(inputUiToRemove.Key);
        }

        foreach (var output in symbol.OutputDefinitions)
        {
            if (!OutputUis.TryGetValue(output.Id, out var value) || (value.Type != output.ValueType))
            {
                OutputUis.Remove(output.Id); // if type has changed remove the old entry

                var newOutputUi = OutputUiFactory.Instance.CreateFor(output.ValueType);
                newOutputUi.OutputDefinition = output;
                newOutputUi.PosOnCanvas = ComputeNewOutputUiPositionOnCanvas(_childUis.Values, OutputUis.Values);
                OutputUis.Add(output.Id, newOutputUi);
                FlagAsModified();
            }
        }

        // check if there are input entries where no output ui exists anymore
        foreach (var outputUiToRemove in OutputUis.Where(kv => !Symbol.OutputDefinitions.Exists(outputDef => outputDef.Id == kv.Key)).ToList())
        {
            Log.Debug($"OutputUi '{outputUiToRemove.Value.Id}' still existed but no corresponding input definition anymore. Removing the ui.");
            OutputUis.Remove(outputUiToRemove.Key);
        }
    }

    private static Vector2 ComputeNewOutputUiPositionOnCanvas(IEnumerable<Child> childUis, IEnumerable<IOutputUi> outputUis)
    {
        bool setByOutputs = false;
        var maxPos = new Vector2(float.NegativeInfinity, float.NegativeInfinity);
        foreach (var output in outputUis)
        {
            maxPos = Vector2.Max(maxPos, output.PosOnCanvas);
            setByOutputs = true;
        }

        if (setByOutputs)
            return maxPos + new Vector2(0, 100);

        // FIXME: childUis are always undefined at this point?
        var setByChildren = false;
        var minY = float.PositiveInfinity;
        var maxY = float.NegativeInfinity;

        var maxX = float.NegativeInfinity;

        foreach (var childUi in childUis)
        {
            minY = Math.Min(childUi.PosOnCanvas.Y, minY);
            maxY = Math.Max(childUi.PosOnCanvas.Y, maxY);

            maxX = Math.Max(childUi.PosOnCanvas.X, maxX);
            setByChildren = true;
        }

        if (setByChildren)
            return new Vector2(maxX + 100, (maxY + minY) / 2);

        //Log.Warning("Assuming default output position");
        return new Vector2(300, 200);
    }

    private static Vector2 GetCanvasPositionForNextInputUi(SymbolUi symbolUi)
    {
        if (symbolUi.Symbol.InputDefinitions.Count == 0)
        {
            return new Vector2(-200, 0);
        }

        IInputUi? lastInputUi = null;

        foreach (var inputDef in symbolUi.Symbol.InputDefinitions)
        {
            if (symbolUi.InputUis.TryGetValue(inputDef.Id, out var ui))
                lastInputUi = ui;
        }

        if (lastInputUi == null)
            return new Vector2(-200, 0);

        return lastInputUi.PosOnCanvas + new Vector2(0, lastInputUi.Size.Y + 50);
    }

    internal void ClearModifiedFlag()
    {
        _hasBeenModified = false;
    }

    internal string Description { get; set; } = string.Empty;
    internal SymbolTags Tags { get; set; }

    /// <summary>
    /// Per-symbol render export configuration. Null if no render settings have been configured.
    /// Serialized to .t3ui files.
    /// </summary>
    internal Gui.Windows.RenderExport.RenderSettings? RenderSettings { get; set; }

    /// <summary>
    /// Per-symbol live-recording configuration (audio / IO / MIDI / OSC toggles for the
    /// timeline Record button). Null if no recording settings have been customised.
    /// Serialized to .t3ui files.
    /// </summary>
    internal Gui.Windows.TimeLine.RecordingSettings? RecordingSettings { get; set; }

    /// <summary>
    /// Per-symbol output window states (one per OutputWindow instance).
    /// Serialized to .t3ui files.
    /// </summary>
    internal List<Gui.Windows.Output.OutputWindowState>? OutputWindowStates { get; set; }

    /// <summary>
    /// Per-symbol timeline state (zoom, scroll, loop range, mode).
    /// Serialized to .t3ui files.
    /// </summary>
    internal Gui.Windows.TimeLine.TimelineState? TimelineState { get; set; }

    /// <summary>
    /// ImGui docking layout string for this project (stored on root op only).
    /// Serialized to .t3ui files.
    /// </summary>
    internal string? WindowLayout { get; set; }

    /// <summary>
    /// ImGui version that produced the WindowLayout, for compatibility checks.
    /// </summary>
    internal string? WindowLayoutImGuiVersion { get; set; }

    /// <summary>
    /// Window visibility state per window title (stored on root op only).
    /// </summary>
    internal Dictionary<string, bool>? WindowVisibility { get; set; }

    [Flags]
    internal enum SymbolTags
    {
        None = 0,
        Essential = 1 << 0,
        Example = 1 << 1,
        Project = 1 << 2,
        Advanced = 1 << 3,
        Internal = 1 << 4,
        Private = 1 << 5,
        Experimental = 1 << 6,
        Research = 1 << 7,
        NeedsFix = 1 << 10,
        HasUpdate = 1 << 11,
        Obsolete = 1 << 12,
    }

    internal bool ReadOnly;
    private bool _hasBeenModified;
    internal bool HasBeenModified => _hasBeenModified;
    internal bool NeedsSaving => _hasBeenModified && !ReadOnly;
    private Dictionary<Guid, Child> _childUis = new();
    internal IReadOnlyDictionary<Guid, Child> ChildUis => _childUis;
    internal OrderedDictionary<Guid, ExternalLink> Links { get; private set; }
    internal List<TourPoint> TourPoints { get; private set; }
    
    internal OrderedDictionary<Guid, IInputUi> InputUis { get; private set; }
    internal OrderedDictionary<Guid, IOutputUi> OutputUis { get; private set; }
    internal OrderedDictionary<Guid, Section> Sections { get; private set; }

    internal void ReplaceWith(SymbolUi newSymbolUi)
    {
        _childUis = newSymbolUi._childUis;
        InputUis = newSymbolUi.InputUis;
        OutputUis = newSymbolUi.OutputUis;
        Sections = newSymbolUi.Sections;
        Links = newSymbolUi.Links;
        Description = newSymbolUi.Description;
    }

    public override string ToString()
    {
        return $"{Symbol.Name} UI";
    }
}