using Godot;
using Rokojori;
using System.Collections.Generic;
using System.Linq;

namespace Rokojori;

[Tool]
[GlobalClass,Icon("res://addons/rokojori_action_library/Icons/UIImage.svg")]
public partial class UISlider:UIImage, UIFocusProcessor
{ 
  public enum Direction
  {
    Vertical,
    Horizontal,
    Both
  }

  [Export]
  public Direction direction = Direction.Vertical;

  [Export]
  public float offsetPerInput = 1f / 20f;


  [Export]
  public Smoothing smoothing;


  [Export]
  public Action onSliderChange; 
  public readonly EventSlot<Vector2> _onSliderChange = new EventSlot<Vector2>();

  [ExportGroup("Testing")]
  // [Export( PropertyHint.Range, "0,1")]
  // public Vector2 editorSliderValue = Vector2.Zero;

  Vector2 _sliderValue;

  [Export( PropertyHint.Range, "0,1")]
  public Vector2 sliderValue
  {
    get { return _sliderValue; }
    set 
    {
      _sliderValue = value;
      SyncSliderValue();
    }
  }

  public float mainValue => direction == Direction.Vertical ? sliderValue.Y : sliderValue.X;

  public Vector2 GetNextSliderMainValue( float value )
  {
    if ( Direction.Vertical == direction )
    {
      return new Vector2( 0.5f, value );
    }
    else
    {
      return new Vector2( value, 0.5f );
    }
  }

  public void SetSliderMainValue( float value )
  {
    if ( Direction.Vertical == direction )
    {
      _sliderValue.Y = value;
    }
    else
    {
      _sliderValue.X = value;
    }

    SyncSliderValue();

    _onSliderChange.DispatchEvent( _sliderValue );
    onSliderChange?.Trigger();
    
  }
 
  void SyncSliderValue()
  {
    SliderShader.sliderValue.Set( Material, sliderValue );
    // this.LogInfo( "Set slider value:", sliderValue, Material );

    // var sm = Material as ShaderMaterial;
    // sm.SetShaderParameter( "sliderValue", sliderValue );
  }

  public override void _Ready()
  {
    base._Ready();

    if ( imageType == null )
    {
      imageType = new SliderUIImageType();
    }

    if ( Texture == null )
    {
      Texture = UI.whiteTexture.Get();
    }
    
    var uiSliderImageType = _imageType as SliderUIImageType;

    if ( uiSliderImageType != null )
    {
      uiSliderImageType.Clear( this );
      uiSliderImageType.Assign( this );

    }

    ComputeUIAncestorDepth();

    SyncSliderValue();


    AssignListener();
  }

  [Export]
  public bool debugInfo = false;

  [Export]
  public string[] propertyInfos = [];


  float lastLeft = 0f;
  float lastRight = 0f;
  float lastUp = 0f;
  float lastDown = 0f;

  public void OnFocusProcess( double delta )
  {
    var settings = GetUI().settings;

    if ( settings == null )
    {
      return;
    }

    if ( Direction.Horizontal == direction )
    {
      
      var offset = 0;

      if ( settings.uiLeft.IsRepeatDown( ref lastLeft ) )
      {
        offset --;
      }

      if ( settings.uiRight.IsRepeatDown( ref lastRight ) )
      {
        offset ++;
      }

      if ( offset != 0 )
      {
        var nextMainValue = MathX.Clamp01( mainValue + offset * offsetPerInput );
        nextValue = NormalizedToButtonPosition( GetNextSliderMainValue( nextMainValue ) );

        if ( ! _updatingPosition )
        {
          _updatingPosition = true; 
          GetUI().onProcess.AddAction( UpdatePosition );
        }

      }
    }  


    // UpdatePosition( (float) delta );
  }

  // public override void _GuiInput( InputEvent inputEvent )
  // {
  //   if ( ! processInputs )
  //   {
  //     return;
  //   }

  //   if ( ! HasFocus() )
  //   {     
  //     return;
  //   }

  //   var settings = GetUI()?.settings;

  //   if ( settings == null )
  //   {
  //     return;
  //   }

  //   if ( Direction.Horizontal == direction )
  //   {
  //     var offset = 0;

  //     // this.LogInfo( Sensor.GetInputEventInfo( inputEvent ) );
  //     // this.LogInfo( 
  //     //   "Is Horizontal", 
  //     //  "Left:", settings.uiLeft.IsSensor( inputEvent ), "Left Down:", settings.uiLeft.IsDown( inputEvent ), 
  //     //  "Right:", settings.uiRight.IsSensor( inputEvent ), "Right Down:", settings.uiRight.IsDown( inputEvent )  
  //     // );

  //     if ( settings.uiLeft.IsDown( inputEvent ) )
  //     {
  //       offset --;
  //     }

  //     if ( settings.uiRight.IsDown( inputEvent ) )
  //     {
  //       offset ++;
  //     }

  //     if ( offset != 0 )
  //     {
  //       //  this.LogInfo( "Offset", offset );

  //       var nextValue = MathX.Clamp01( mainValue + offset * offsetPerInput );
  //       SetSliderMainValue( nextValue );
  //     }
  //   }  

  //   if ( Direction.Vertical == direction )
  //   {
  //     var offset = 0;

  //     if ( settings.uiUp?.isActive ?? false )
  //     {
  //       offset --;
  //     }

  //     if ( settings.uiDown?.isActive ?? false )
  //     {
  //       offset ++;
  //     }

  //     var nextValue = MathX.Clamp01( mainValue + offset * offsetPerInput );
  //     SetSliderMainValue( nextValue );
  //   } 
  // }

  public override void _Process( double delta )
  {
    // ProcessInputs();

    if ( ! debugInfo )
    {
      return;
    }

    

    
    var it = imageType as SliderUIImageType;

    if ( it == null )
    {
      return;
    }

    var propNames = it.GetNumberShaderProperties();

    var tw = Texture.GetWidth();
    var th = Texture.GetHeight();

    var w = UINumber.Compute( this, UIStyleNumberProperty.Width, tw, tw / 100f );
    var h = UINumber.Compute( this, UIStyleNumberProperty.Height, th, th / 100f );

    var infos = new List<string>();
    
    for ( int i = 0; i < propNames.Length; i++ )
    {
      var n = propNames[ i ];
      var p = it.GetUIStyleNumberProperty( UIStyleNumberProperty.FloatShaderProperty, n );

      if ( p == null )
      {
        continue;
      }

      var relative = 100f;
      
      if ( n.EndsWith( "X" ) )
      {
        relative = w;
      }
      else if ( n.EndsWith( "Y" ) )
      {
        relative = h;
      }


      var value = UINumber.Compute( this, UIStyleNumberProperty.FloatShaderProperty, n, 0, relative );
      infos.Add( "[" + n + "] (" + p.value._FFF() + " * " + p.unit +") :" + value._FFF() );
    }

    propertyInfos = infos.ToArray();

    this.LogInfo( propertyInfos );


    debugInfo = false;
    
  }



  UIDragging.UIDraggingCallbacks leftMouseCallbacks;
  Vector2 cachedMouseOffset;
  Vector2 cachedButtonPosition;

  bool _dragging = false;
  bool _updatingPosition = false;

  string scrollID = IDGenerator.GenerateID();

  float ComputeShaderProperty( string n, float relative = 100 )
  {
    return UINumber.Compute( this, UIStyleNumberProperty.FloatShaderProperty, n, 0, relative );
  }

  Vector2 sliderSize 
  {
    get 
    {
      var tw = Texture.GetWidth();
      var th = Texture.GetHeight();

      var w = UINumber.Compute( this, UIStyleNumberProperty.Width, tw, tw / 100f );
      var h = UINumber.Compute( this, UIStyleNumberProperty.Height, th, th / 100f );

      var valueX = ComputeShaderProperty( SliderShader.sliderSizeX.propertyName, w );
      var valueY = ComputeShaderProperty( SliderShader.sliderSizeY.propertyName, h );

      return new Vector2( valueX, valueY );
    }
  }

  Vector2 sliderSizeMargins
  {
    get 
    {
      var tw = Texture.GetWidth();
      var th = Texture.GetHeight();

      var w = UINumber.Compute( this, UIStyleNumberProperty.Width, tw, tw / 100f );
      var h = UINumber.Compute( this, UIStyleNumberProperty.Height, th, th / 100f );

      var valueX = ComputeShaderProperty( SliderShader.sliderSizeMarginX.propertyName, w );
      var valueY = ComputeShaderProperty( SliderShader.sliderSizeMarginY.propertyName, h );

      return new Vector2( valueX, valueY );
    }
  }

  Vector2 sliderRange => Size - ( sliderSize + sliderSizeMargins );
  Vector2 sliderOffset => sliderSize;
  
  Vector2 buttonPositionMin
  {
    get { return NormalizedToButtonPosition( Vector2.Zero ); }
  }

  Vector2 buttonPositionMax
  {
    get { return NormalizedToButtonPosition( Vector2.One ); }
  }


  Vector2 NormalizedToButtonPosition( Vector2 normalized )
  {
    return normalized * sliderRange + sliderOffset;
  }

  Vector2 ButtonPositionToNormalized( Vector2 buttonPosition )
  {
    return ( buttonPosition - sliderOffset ) / sliderRange;
  }


  bool _listenerAssigned = false;

  void AssignListener()
  {
    if ( _listenerAssigned )
    {
      return;
    }

    leftMouseCallbacks = UIDragging.OnLeftMouseButton( this,
      ( ev )=>
      {
        if ( ev.isStart )
        { 
          if ( ! ( _updatingPosition || _dragging ) )
          {
            cachedButtonPosition = NormalizedToButtonPosition( sliderValue );
            smoothing?.SetCurrent( cachedButtonPosition );

            _dragging = true;
            _updatingPosition = true;

            ev.ui.onProcess.AddAction( UpdatePosition );
          }

        } 
        else if ( ev.isEnd )
        {
          _dragging = false;
        }

        var nextPosition = cachedButtonPosition + ev.distanceToStart;
        nextValue = nextPosition.Clamp( buttonPositionMin, buttonPositionMax );                 
      
      }
    );

    _listenerAssigned = true;
  }

  Vector2 nextValue;

  Vector2 GetButtonScrollRange()
  {
    return Vector2.Zero;
    // return ( Size - button.Size ).Max( Vector2.Zero );
  }

  Vector2 cachedOffset = Vector2.Zero;

  void UpdatePosition( float delta )
  {
    
    var value = Smoothing.Apply( smoothing, nextValue, delta );

    // this.LogInfo( "UpdatePosition:", value );

    var uiStyleContainer = ( UIStylePropertyContainerNode ) this;
    
    uiStyleContainer.SetLayoutDirtyFlag();

    if ( ! _dragging && ( value - nextValue ).Length() < 1 )
    { 
      var ui = UIHolder.GetUI( this );
      ui.onProcess.RemoveAction( UpdatePosition );
      _updatingPosition = false;
      // this.LogInfo( "Removed Processing" );

      value = nextValue;

      uiStyleContainer.RemoveUISelectorFlag( UISelectorFlag.Scrolling, scrollID );
      
    }

    var currentSliderValue = ButtonPositionToNormalized( value );

    if ( Direction.Vertical == direction )
    {
      currentSliderValue.X = 0.5f;
    }
    else if ( Direction.Horizontal == direction )
    {
      currentSliderValue.Y = 0.5f;
    }

    _sliderValue = currentSliderValue;
    SyncSliderValue();

    onSliderChange?.Trigger();
    _onSliderChange.DispatchEvent( _sliderValue );
    
  }

}