bmc.maui/BuyMeCofee.Maui/Controls/BuyMeACoffeeButton.cs

using BuyMeCofee.Maui.Constants;
using BuyMeCofee.Maui.Enums;
using BuyMeCofee.Maui.Helpers;
using Microsoft.Maui.Controls.Shapes;

namespace BuyMeCofee.Maui.Controls;

/// <summary>
/// A branded Buy Me a Coffee button with the official cup logo and 8 color theme presets.
/// Opens the user's BMC page in the default browser when tapped.
/// </summary>
public class BuyMeACoffeeButton : ContentView
{
    #region Bindable Properties

    public static readonly BindableProperty UsernameProperty =
        BindableProperty.Create(nameof(Username), typeof(string), typeof(BuyMeACoffeeButton),
            string.Empty);

    public static readonly BindableProperty ButtonTextProperty =
        BindableProperty.Create(nameof(ButtonText), typeof(string), typeof(BuyMeACoffeeButton),
            BmcConstants.DefaultButtonText, propertyChanged: OnVisualPropertyChanged);

    public static readonly BindableProperty ThemeProperty =
        BindableProperty.Create(nameof(Theme), typeof(BmcButtonTheme), typeof(BuyMeACoffeeButton),
            BmcButtonTheme.Yellow, propertyChanged: OnThemePropertyChanged);

    public static readonly BindableProperty CustomBackgroundColorProperty =
        BindableProperty.Create(nameof(CustomBackgroundColor), typeof(Color), typeof(BuyMeACoffeeButton),
            null, propertyChanged: OnVisualPropertyChanged);

    public static readonly BindableProperty CustomTextColorProperty =
        BindableProperty.Create(nameof(CustomTextColor), typeof(Color), typeof(BuyMeACoffeeButton),
            null, propertyChanged: OnVisualPropertyChanged);

    public static readonly BindableProperty CornerRadiusProperty =
        BindableProperty.Create(nameof(CornerRadius), typeof(double), typeof(BuyMeACoffeeButton),
            BmcConstants.ButtonCornerRadius, propertyChanged: OnVisualPropertyChanged);

    public static readonly BindableProperty FontSizeProperty =
        BindableProperty.Create(nameof(FontSize), typeof(double), typeof(BuyMeACoffeeButton),
            16.0, propertyChanged: OnVisualPropertyChanged);

    public static readonly BindableProperty CupSizeProperty =
        BindableProperty.Create(nameof(CupSize), typeof(double), typeof(BuyMeACoffeeButton),
            28.0, propertyChanged: OnVisualPropertyChanged);

    #endregion

    #region Properties

    /// <summary>Your Buy Me a Coffee username/slug.</summary>
    public string Username
    {
        get => (string)GetValue(UsernameProperty);
        set => SetValue(UsernameProperty, value);
    }

    /// <summary>Button label text. Default: "Buy me a coffee"</summary>
    public string ButtonText
    {
        get => (string)GetValue(ButtonTextProperty);
        set => SetValue(ButtonTextProperty, value);
    }

    /// <summary>Color theme preset. Default: Yellow (official BMC brand color).</summary>
    public BmcButtonTheme Theme
    {
        get => (BmcButtonTheme)GetValue(ThemeProperty);
        set => SetValue(ThemeProperty, value);
    }

    /// <summary>Custom background color. Only used when Theme is set to Custom.</summary>
    public Color? CustomBackgroundColor
    {
        get => (Color?)GetValue(CustomBackgroundColorProperty);
        set => SetValue(CustomBackgroundColorProperty, value);
    }

    /// <summary>Custom text color. Only used when Theme is set to Custom.</summary>
    public Color? CustomTextColor
    {
        get => (Color?)GetValue(CustomTextColorProperty);
        set => SetValue(CustomTextColorProperty, value);
    }

    /// <summary>Border corner radius. Default: 8</summary>
    public double CornerRadius
    {
        get => (double)GetValue(CornerRadiusProperty);
        set => SetValue(CornerRadiusProperty, value);
    }

    /// <summary>Font size for the button text. Default: 16</summary>
    public double FontSize
    {
        get => (double)GetValue(FontSizeProperty);
        set => SetValue(FontSizeProperty, value);
    }

    /// <summary>Cup logo image height. Default: 28</summary>
    public double CupSize
    {
        get => (double)GetValue(CupSizeProperty);
        set => SetValue(CupSizeProperty, value);
    }

    #endregion

    private Border _border = null!;
    private Image _cupImage = null!;
    private Label _textLabel = null!;

    public BuyMeACoffeeButton()
    {
        BuildLayout();
        ApplyTheme();
    }

    private void BuildLayout()
    {
        _cupImage = new Image
        {
            Source = BmcBrandAssets.GetCupLogo(),
            HeightRequest = CupSize,
            Aspect = Aspect.AspectFit,
            VerticalOptions = LayoutOptions.Center,
        };

        _textLabel = new Label
        {
            Text = ButtonText,
            FontSize = FontSize,
            FontAttributes = FontAttributes.Bold,
            VerticalOptions = LayoutOptions.Center,
        };

        var stack = new HorizontalStackLayout
        {
            Spacing = 8,
            HorizontalOptions = LayoutOptions.Center,
            VerticalOptions = LayoutOptions.Center,
            Children = { _cupImage, _textLabel }
        };

        _border = new Border
        {
            StrokeShape = new RoundRectangle { CornerRadius = new Microsoft.Maui.CornerRadius(CornerRadius) },
            Stroke = Colors.Transparent,
            Padding = new Thickness(16, 10),
            Content = stack,
            Shadow = new Shadow
            {
                Brush = new SolidColorBrush(Colors.Black),
                Offset = new Point(0, 2),
                Radius = 4,
                Opacity = 0.25f,
            }
        };

        var tap = new TapGestureRecognizer();
        tap.Tapped += OnTapped;
        _border.GestureRecognizers.Add(tap);

        var hover = new PointerGestureRecognizer();
        hover.PointerEntered += (_, _) => _border.Opacity = 0.85;
        hover.PointerExited += (_, _) => _border.Opacity = 1.0;
        _border.GestureRecognizers.Add(hover);

        Content = _border;
    }

    private void ApplyTheme()
    {
        if (_border is null) return;

        Color bg, text;
        Color stroke = Colors.Transparent;

        if (Theme == BmcButtonTheme.Custom)
        {
            bg = CustomBackgroundColor ?? Color.FromArgb(BmcColors.YellowBg);
            text = CustomTextColor ?? Color.FromArgb(BmcColors.BrandDark);
        }
        else
        {
            var info = BmcThemeResolver.Resolve(Theme);
            bg = info.Background;
            text = info.TextColor;
            stroke = info.StrokeColor;
        }

        _border.BackgroundColor = bg;
        _border.Stroke = new SolidColorBrush(stroke);
        _textLabel.TextColor = text;
    }

    private void UpdateVisuals()
    {
        if (_border is null) return;

        _textLabel.Text = ButtonText;
        _textLabel.FontSize = FontSize;
        _cupImage.HeightRequest = CupSize;

        if (_border.StrokeShape is RoundRectangle rr)
            rr.CornerRadius = new Microsoft.Maui.CornerRadius(CornerRadius);

        ApplyTheme();
    }

    private async void OnTapped(object? sender, TappedEventArgs e)
    {
        if (string.IsNullOrWhiteSpace(Username)) return;

        await _border.ScaleToAsync(0.95, 80, Easing.CubicIn);
        await _border.ScaleToAsync(1.0, 80, Easing.CubicOut);

        await Launcher.Default.OpenAsync(new Uri($"{BmcConstants.BaseUrl}{Username}"));
    }

    private static void OnVisualPropertyChanged(BindableObject bindable, object oldValue, object newValue)
    {
        if (bindable is BuyMeACoffeeButton button)
            button.UpdateVisuals();
    }

    private static void OnThemePropertyChanged(BindableObject bindable, object oldValue, object newValue)
    {
        if (bindable is BuyMeACoffeeButton button)
            button.ApplyTheme();
    }
}