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

namespace Rokojori;

[Tool]
[GlobalClass]
public partial class UIAppSettings:UIRegion
{ 
  [ExportToolButton( "Create App Settings UI")]
  public Callable createAppSettingsUI => Callable.From(
    ()=>
    {
      CreateAppSettingsUI();
    }
  );

  [Export]
  public AppSettings appSettings;

  [Export]
  public UIAppSettingsGenerator generator;

  public enum MenuChangeMode
  {
    None,
    Clamped,
    Wrapped
  }

  [Export]
  public MenuChangeMode menuChangeMode = MenuChangeMode.Wrapped;

  [Export]
  public Action onConfirm;

  [Export]
  public Action onCancel;

  [Export]
  public Action onReady;


  [ExportGroup( "References")]

  [Export]
  public Node background = null;

  [Export]
  public UIAppSettingsHeader header = null;

  [Export]
  public UIAppSettingsCategoryPage[] pages = [];



  public override void _Process( double delta )
  {
    ProcessMenuInputs();
    ProcessMainInputs();
  }

  void ProcessMenuInputs()
  {
    if ( MenuChangeMode.None == menuChangeMode )
    {
      return;
    }

    var settings = GetUI().settings;
    var wrapped = MenuChangeMode.Wrapped == menuChangeMode;

    if ( settings == null )
    {
      return;
    }

    if ( settings.uiPreviousMenu?.isDown ?? false )
    { 
      ChangeMenu( -1, wrapped );
    } 

    if ( settings.uiNextMenu?.isDown ?? false )
    { 
      ChangeMenu( 1, wrapped );
    }

  }

  void ProcessMainInputs()
  {
     var settings = GetUI().settings;
    
    if ( settings == null )
    {
      return;
    }

    if ( settings.uiConfirm?.isDown ?? false )
    {
      onConfirm?.Trigger();
      onReady?.Trigger();
    }
    
    if ( settings.uiCancel?.isDown ?? false )
    {
      onCancel?.Trigger();
      onReady?.Trigger();
    }

  }

  void ChangeMenu( int offset, bool wrap )
  {
    var selectedPageIndex = pages.FindIndex( p => p.Visible );
    var nextIndex = selectedPageIndex + offset;

    nextIndex = wrap ? MathX.Repeat( nextIndex, pages.Length ) : Mathf.Clamp( nextIndex, 0, pages.Length -1  );

    
    var nextSelectedPage = pages[ nextIndex ];
    var category = nextSelectedPage.category;

    var selector = header.GetAll<SelectSettingsPage>().Find( selector => selector.category == category );
    // var selector = nextSelectedPage.Get<SelectSettingsPage>();

    this.LogInfo( 
      "SelectedPageIndex:", selectedPageIndex, "nextIndex:", nextIndex, 
      HierarchyName.Of( nextSelectedPage ), 
      HierarchyName.Of( selector ) 
    );

    selector.Trigger();
  }

  void CreateAppSettingsUI()
  {
    this.DestroyChildren();

    background = null;
    header = null;    
    pages = [];

    var resolvedSettings = appSettings ?? Unique<App>.Get().settings; 

    background = generator.background.GenerateBackground( this ) as Node;

    resolvedSettings.categories.ForEach( CreateCategory );
    
    CreateHeader( resolvedSettings );

    

    pages.ForEach( p => p.SetVisibility( p.category == appSettings.categories[ 0 ] ) );
  }

  void CreateHeader( AppSettings settings )
  {
    header = generator.header.GenerateHeader( this, settings );
  }

  void CreateCategory( AppSettingsCategory category )
  {
    var page = generator.catergoryPage.GenerateCategoryPage( this, category );
    pages = pages.Add( page );
  }
}