using Sarand.Net.Mobile.Maui.Layouts;
using Sarand.Net.Mobile.Maui.Views;
using Sarand.Net.Standard.Base.Utils;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Sarand.Net.Mobile.Maui.Controls
{
	//=======================================================================
	public class SamDatePicker : SamContentView
	{
		//-------------------------------------------------------------------
		// Definitions.

		//-------------------------------------------------------------------
		// Data members.
		private bool allowInvalidDate = false;
		private bool invalidDate = true;
		private DateTime previousDate = DateTime.MinValue;
		private SamStackLayout controlLayout = new SamStackLayout() { Orientation = StackOrientation.Horizontal, HorizontalOptions = LayoutOptions.Fill };
		private DatePicker pickerDate = new DatePicker() { IsVisible = false };
		private SamEntry entryDate = new SamEntry() { HorizontalOptions = LayoutOptions.FillAndExpand, VerticalOptions = LayoutOptions.Fill };
		private SamLabel labelResetDate = new SamLabel() { Text = "X", FontAttributes = FontAttributes.Bold, TextColor = Colors.Red, HorizontalOptions = LayoutOptions.Center, VerticalTextAlignment = TextAlignment.Center };

		//-------------------------------------------------------------------
		// Construction.
		public SamDatePicker()
		{
			// Initialise controls.
			// Date picker. Hidden but used to display calendar.
			DefaultFontSize = pickerDate.FontSize;
			pickerDate.Format = "dd-MMM-yyyy";
			pickerDate.DateSelected += PickerDate_DateSelected;
			// Date display entry.
			entryDate.FontSize = pickerDate.FontSize;
			entryDate.FontFamily = pickerDate.FontFamily;
			entryDate.FontAttributes = pickerDate.FontAttributes;
			entryDate.TextColor = pickerDate.TextColor;
			entryDate.Focused += EntryDate_Focused;
			// 'Reset' date label - to invalidate the date value.
			labelResetDate.FontSize = pickerDate.FontSize;
			labelResetDate.FontFamily = pickerDate.FontFamily;

			// 'Reset' label tap gesture.
			var tapGestureRecognizer = new TapGestureRecognizer();
			tapGestureRecognizer.Tapped += LabelValidDate_Tapped;
			labelResetDate.GestureRecognizers.Add(tapGestureRecognizer);

			// Initialise layout.
			Content = controlLayout;
			controlLayout.Children.Add(pickerDate);
			controlLayout.Children.Add(entryDate);
			controlLayout.Children.Add(labelResetDate);

			RefreshDateDisplay();
		}

		//-------------------------------------------------------------------
		// Properties.
		// Configuration.
		public Boolean AllowInvalid
		{
			get { return allowInvalidDate; }
			set
			{
				if (allowInvalidDate = value) return;
				allowInvalidDate = value;
				if (!allowInvalidDate) invalidDate = false;
				RefreshDateDisplay();
			}
		}
		public string Format
		{
			get { return pickerDate.Format; }
			set
			{
				if (pickerDate.Format.Equals(value)) return;
				pickerDate.Format = value;
			}
		}
		public DateTime MinimumDate
		{
			get { return pickerDate.MinimumDate; }
			set { pickerDate.MinimumDate = value; }
		}
		public DateTime MaximumDate
		{
			get { return pickerDate.MaximumDate; }
			set { pickerDate.MaximumDate = value; }
		}
		//-------------------------------------------------------------------
		// Date value.
		public DateTime Date
		{
			get
			{
				if (invalidDate) return DateTime.MinValue;
				return pickerDate.Date;
			}
			set
			{
				if (Date.Equals(value)) return;
				if (!DateUtil.IsValid(value))
				{
					invalidDate = true;
					pickerDate.Date = DateTime.Today;
				}
				else
				{
					invalidDate = false;
					pickerDate.Date = value;
				}
				previousDate = value;
			}
		}
		public String FormattedDate { get { return !invalidDate ? DateUtil.Format(Date, pickerDate.Format) : ""; } }
		//-------------------------------------------------------------------
		// Font.
		public double DefaultFontSize { get; }
		public double FontSize
		{
			get { return pickerDate.FontSize; }
			set
			{
				if (pickerDate.FontSize == value) return;
				pickerDate.FontSize = value;
				entryDate.FontSize = value;
			}
		}
		public String FontFamily
		{
			get { return pickerDate.FontFamily; }
			set
			{
				if (pickerDate.FontFamily == value) return;
				pickerDate.FontFamily = value;
				entryDate.FontFamily = value;
			}
		}
		public FontAttributes FontAttributes
		{
			get { return pickerDate.FontAttributes; }
			set
			{
				if (pickerDate.FontAttributes == value) return;
				pickerDate.FontAttributes = value;
				entryDate.FontAttributes = value;
			}
		}
		public Color TextColor
		{
			get { return pickerDate.TextColor; }
			set
			{
				if (pickerDate.TextColor == value) return;
				pickerDate.TextColor = value;
				entryDate.TextColor = value;
			}
		}

		//-------------------------------------------------------------------
		// Utilities.
		private void RefreshDateDisplay()
		{
			if (allowInvalidDate)
			{
				pickerDate.IsVisible = false;
				entryDate.IsVisible = true;
				labelResetDate.IsVisible = true;
			}
			else
			{
				pickerDate.IsVisible = true;
				entryDate.IsVisible = false;
				labelResetDate.IsVisible = false;
			}
			String dateValue = "";
			if (!invalidDate)
				dateValue = DateUtil.Format(Date, pickerDate.Format);
			entryDate.Text = dateValue;
		}

		//-------------------------------------------------------------------
		//                    C o n t r o l   E v e n t s
		//-------------------------------------------------------------------
		private void PickerDate_DateSelected(object? sender, DateChangedEventArgs e)
		{
			// Date has changed in control.
			invalidDate = !DateUtil.IsValid(e.NewDate);
			RefreshDateDisplay();
			if (DateSelected != null) DateSelected.Invoke(sender, e);
		}
		public event EventHandler<DateChangedEventArgs>? DateSelected;
		//-------------------------------------------------------------------
		private void EntryDate_Focused(object? sender, FocusEventArgs e)
		{
			// Control has gained focus.
			entryDate.Unfocus();
			pickerDate.Focus();
			invalidDate = false;
			RefreshDateDisplay();
		}
		//-------------------------------------------------------------------
		private void LabelValidDate_Tapped(object? sender, EventArgs e)
		{
			// 'Valid' label tapped.
			if (invalidDate) return;
			invalidDate = true;
			DateTime oldDate = previousDate;
			RefreshDateDisplay();
			if (DateSelected != null) DateSelected.Invoke(sender, new DateChangedEventArgs(oldDate, Date));
			previousDate = Date;
		}

		//-------------------------------------------------------------------
	}
	//=======================================================================
}