// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Drawing;
using System.Windows.Forms.VisualStyles;
 
namespace System.Windows.Forms;
 
/// <summary>
///  Provides methods used to render a button control in dark mode.
/// </summary>
internal abstract partial class ButtonDarkModeRendererBase : IButtonRenderer
{
    // Define padding values for each renderer type
    private protected abstract Padding PaddingCore { get; }
 
    /// <summary>
    ///  Clears the background with the parent's background color or the control's background color if no parent is available.
    /// </summary>
    /// <param name="graphics">Graphics context to draw on</param>
    private static void ClearBackground(Graphics graphics, Color parentBackgroundColor)
    {
        ArgumentNullException.ThrowIfNull(graphics);
 
        graphics.Clear(parentBackgroundColor);
    }
 
    /// <summary>
    ///  Renders a button with the specified properties and delegates for painting image and field.
    /// </summary>
    public void RenderButton(
        Graphics graphics,
        Rectangle bounds,
        FlatStyle flatStyle,
        PushButtonState state,
        bool isDefault,
        bool focused,
        bool showFocusCues,
        Color parentBackgroundColor,
        Color backColor,
        Action<Rectangle> paintImage,
        Action paintField)
    {
        ArgumentNullException.ThrowIfNull(graphics);
        ArgumentNullException.ThrowIfNull(paintImage);
        ArgumentNullException.ThrowIfNull(paintField);
 
        // Scope the graphics state so all changes are reverted after rendering
        using (new GraphicsStateScope(graphics))
        {
            // Clear the background over the whole button area.
            ClearBackground(graphics, parentBackgroundColor);
 
            // Use padding from ButtonDarkModeRenderer
            Padding padding = PaddingCore;
 
            Rectangle paddedBounds = new(
                x: bounds.X + padding.Left,
                y: bounds.Y + padding.Top,
                width: bounds.Width - padding.Horizontal,
                height: bounds.Height - padding.Vertical);
 
            // Draw button background and get content bounds
            Rectangle contentBounds = DrawButtonBackground(graphics, paddedBounds, state, isDefault, backColor);
 
            // Paint image and field using the provided delegates
            paintImage(contentBounds);
 
            paintField();
 
            if (focused && showFocusCues)
            {
                // Draw focus indicator for other styles
                DrawFocusIndicator(graphics, bounds, isDefault);
            }
        }
    }
 
    public abstract Rectangle DrawButtonBackground(Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault, Color backColor);
 
    public abstract void DrawFocusIndicator(Graphics graphics, Rectangle contentBounds, bool isDefault);
 
    public abstract Color GetTextColor(PushButtonState state, bool isDefault);
 
    public abstract Color GetBackgroundColor(PushButtonState state, bool isDefault);
}