#nullable disable
using System;
using System.ComponentModel;
using ObjCRuntime;
using UIKit;
 
namespace Microsoft.Maui.Controls.Platform.Compatibility
{
	[EditorBrowsable(EditorBrowsableState.Never)]
	public class SafeShellTabBarAppearanceTracker : IShellTabBarAppearanceTracker
	{
		UIColor _defaultBarTint;
		UIColor _defaultTint;
		UIColor _defaultUnselectedTint;
		UITabBarAppearance _tabBarAppearance;
		public virtual void ResetAppearance(UITabBarController controller)
		{
			if (_defaultTint == null)
				return;
 
			var tabBar = controller.TabBar;
			tabBar.BarTintColor = _defaultBarTint;
			tabBar.TintColor = _defaultTint;
			tabBar.UnselectedItemTintColor = _defaultUnselectedTint;
		}
 
		public virtual void SetAppearance(UITabBarController controller, ShellAppearance appearance)
		{
			IShellAppearanceElement appearanceElement = appearance;
			var backgroundColor = appearanceElement.EffectiveTabBarBackgroundColor;
			var foregroundColor = appearanceElement.EffectiveTabBarForegroundColor; // Currently unused
			var disabledColor = appearanceElement.EffectiveTabBarDisabledColor; // Unused on iOS
			var unselectedColor = appearanceElement.EffectiveTabBarUnselectedColor;
			var titleColor = appearanceElement.EffectiveTabBarTitleColor;
 
			var tabBar = controller.TabBar;
 
			if (_defaultTint == null)
			{
				_defaultBarTint = tabBar.BarTintColor;
				_defaultTint = tabBar.TintColor;
				_defaultUnselectedTint = tabBar.UnselectedItemTintColor;
			}
 
			if (OperatingSystem.IsIOSVersionAtLeast(15) || OperatingSystem.IsTvOSVersionAtLeast(15))
				UpdateiOS15TabBarAppearance(controller, appearance);
			else
				UpdateTabBarAppearance(controller, appearance);
		}
 
		public virtual void UpdateLayout(UITabBarController controller)
		{
		}
 
		#region IDisposable Support
 
		protected virtual void Dispose(bool disposing)
		{
		}
 
		public void Dispose()
		{
			Dispose(true);
		}
 
		#endregion
 
		[System.Runtime.Versioning.SupportedOSPlatform("ios15.0")]
		[System.Runtime.Versioning.SupportedOSPlatform("tvos15.0")]
		void UpdateiOS15TabBarAppearance(UITabBarController controller, ShellAppearance appearance)
		{
			IShellAppearanceElement appearanceElement = appearance;
 
			var backgroundColor = appearanceElement.EffectiveTabBarBackgroundColor;
			var foregroundColor = appearanceElement.EffectiveTabBarForegroundColor;
			var unselectedColor = appearanceElement.EffectiveTabBarUnselectedColor;
			var titleColor = appearanceElement.EffectiveTabBarTitleColor;
 
			controller.TabBar
				.UpdateiOS15TabBarAppearance(
					ref _tabBarAppearance,
					null,
					null,
					foregroundColor ?? titleColor,
					unselectedColor,
					backgroundColor,
					titleColor ?? foregroundColor,
					unselectedColor);
		}
 
		void UpdateTabBarAppearance(UITabBarController controller, ShellAppearance appearance)
		{
			IShellAppearanceElement appearanceElement = appearance;
			var backgroundColor = appearanceElement.EffectiveTabBarBackgroundColor;
			var foregroundColor = appearanceElement.EffectiveTabBarForegroundColor;
			var unselectedColor = appearanceElement.EffectiveTabBarUnselectedColor;
			var titleColor = appearanceElement.EffectiveTabBarTitleColor;
 
			var tabBar = controller.TabBar;
 
			if (backgroundColor is not null && backgroundColor.IsNotDefault())
				tabBar.BarTintColor = backgroundColor.ToPlatform();
 
			if (unselectedColor is not null && unselectedColor.IsNotDefault())
			{
				tabBar.UnselectedItemTintColor = unselectedColor.ToPlatform();
				UITabBarItem.Appearance.SetTitleTextAttributes(new UIStringAttributes { ForegroundColor = unselectedColor.ToPlatform() }, UIControlState.Normal);
			}
 
			if (titleColor is not null && titleColor.IsNotDefault() ||
				foregroundColor is not null && foregroundColor.IsNotDefault())
			{
				tabBar.TintColor = (foregroundColor ?? titleColor).ToPlatform();
				UITabBarItem.Appearance.SetTitleTextAttributes(new UIStringAttributes { ForegroundColor = (titleColor ?? foregroundColor).ToPlatform() }, UIControlState.Selected);
			}
		}
	}
}