// Fill out your copyright notice in the Description page of Project Settings.


#include "ProjectFishEditor/Public/Thumbnail/ShapeAssetThumbnailRenderer.h"

#include "CanvasItem.h"
#include "CanvasTypes.h"
#include "ProjectFish/DataAsset/ShapeAsset.h"

bool UShapeAssetThumbnailRenderer::CanVisualizeAsset(UObject* Object)
{
	return Cast<UShapeAsset>(Object) != nullptr;
}

void UShapeAssetThumbnailRenderer::Draw(UObject* Object, int32 X, int32 Y, uint32 Width, uint32 Height,
	FRenderTarget* RenderTarget, FCanvas* Canvas, bool bAdditionalViewFamily)
{
	UShapeAsset* BagShapeAsset = Cast<UShapeAsset>(Object);
	if (!BagShapeAsset || !Canvas)
	{
		return;
	}

	DrawBagShape(BagShapeAsset, Canvas, X, Y, Width, Height);
}

void UShapeAssetThumbnailRenderer::DrawBagShape(UShapeAsset* BagShapeAsset, FCanvas* Canvas, int32 X, int32 Y,
	uint32 Width, uint32 Height)
{
	 if (!BagShapeAsset || !Canvas)
    {
        return;
    }

    // Clear the background
    FCanvasBoxItem BackgroundBox(FVector2D(X, Y), FVector2D(Width, Height));
    BackgroundBox.SetColor(FLinearColor(0.1f, 0.1f, 0.1f, 1.0f));
    Canvas->DrawItem(BackgroundBox);

    // Calculate the best fit scale with spacing for separators
    float SeparatorWidth = 2.0f; // White separator width
    float Scale = GetBestFitScale(BagShapeAsset->ShapeWidth, BagShapeAsset->ShapeHeight, Width, Height);
    float CellSize = Scale - SeparatorWidth; // Reduce cell size to make room for separators
    
    // Calculate starting position to center the grid (including separators)
    float GridWidth = BagShapeAsset->ShapeWidth * Scale - SeparatorWidth;
    float GridHeight = BagShapeAsset->ShapeHeight * Scale - SeparatorWidth;
    float StartX = X + (Width - GridWidth) * 0.5f;
    float StartY = Y + (Height - GridHeight) * 0.5f;
    
    // Draw the bag slots (background) with separators
    for (int32 GridY = 0; GridY < BagShapeAsset->ShapeHeight; GridY++)
    {
        for (int32 GridX = 0; GridX < BagShapeAsset->ShapeWidth; GridX++)
        {
            float CellStartX = StartX + GridX * Scale;
            float CellStartY = StartY + GridY * Scale;
    
            bool bIsActive = BagShapeAsset->IsSlotActive(GridX, GridY);
    
            // Draw filled cell (smaller to leave space for separators)
            FCanvasTileItem CellTile(FVector2D(CellStartX, CellStartY), FVector2D(CellSize, CellSize), 
                bIsActive ? FLinearColor(0.2f, 0.8f, 0.2f, 1.0f) : FLinearColor(0.15f, 0.15f, 0.15f, 1.0f));
            CellTile.BlendMode = SE_BLEND_Opaque;
            Canvas->DrawItem(CellTile);
        }
    }
    
    // // Draw white separators
    // // Vertical separators
    // for (int32 GridX = 1; GridX < BagShapeAsset->BagWidth; GridX++)
    // {
    //     float SeparatorX = StartX + GridX * Scale - SeparatorWidth;
    //     FCanvasTileItem VerticalSeparator(FVector2D(SeparatorX, StartY), FVector2D(SeparatorWidth, GridHeight), FLinearColor::White);
    //     VerticalSeparator.BlendMode = SE_BLEND_Opaque;
    //     Canvas->DrawItem(VerticalSeparator);
    // }
    
    // // Horizontal separators
    // for (int32 GridY = 1; GridY < BagShapeAsset->BagHeight; GridY++)
    // {
    //     float SeparatorY = StartY + GridY * Scale - SeparatorWidth;
    //     FCanvasTileItem HorizontalSeparator(FVector2D(StartX, SeparatorY), FVector2D(GridWidth, SeparatorWidth), FLinearColor::White);
    //     HorizontalSeparator.BlendMode = SE_BLEND_Opaque;
    //     Canvas->DrawItem(HorizontalSeparator);
    // }
    
    // // Draw outer border
    // FCanvasBoxItem OuterBorder(FVector2D(StartX, StartY), FVector2D(GridWidth, GridHeight));
    // OuterBorder.SetColor(FLinearColor::White);
    // OuterBorder.LineThickness = 5.0f;
    // Canvas->DrawItem(OuterBorder);
}

float UShapeAssetThumbnailRenderer::GetBestFitScale(int32 BagWidth, int32 BagHeight, uint32 CanvasWidth,
	uint32 CanvasHeight) const
{
	if (BagWidth == 0 || BagHeight == 0)
	{
		return 1.0f;
	}

	// Leave some padding
	float PaddedWidth = CanvasWidth * 0.9f;
	float PaddedHeight = CanvasHeight * 0.9f;

	float ScaleX = PaddedWidth / BagWidth;
	float ScaleY = PaddedHeight / BagHeight;

	// Use the smaller scale to ensure everything fits
	float Scale = FMath::Min(ScaleX, ScaleY);
    
	// Ensure minimum cell size for visibility
	Scale = FMath::Max(Scale, 4.0f);

	return Scale;
}