using Avalonia.Media.Imaging;
using DataLayer;
using ReactiveUI;
using System;
using System.Collections.Generic;

namespace LibationAvalonia.ViewModels
{
	public class LiberateButtonStatus : ViewModelBase, IComparable
	{
		public LiberateButtonStatus(bool isSeries, bool isAbsent)
		{
			IsSeries = isSeries;
			IsAbsent = isAbsent;
		}
		public LiberatedStatus BookStatus { get; set; }
		public LiberatedStatus? PdfStatus { get; set; }

		private bool _expanded;
		public bool Expanded
		{
			get => _expanded;
			set
			{
				this.RaiseAndSetIfChanged(ref _expanded, value);
				this.RaisePropertyChanged(nameof(Image));
				this.RaisePropertyChanged(nameof(ToolTip));
			}
		}

		private bool IsAbsent { get; }
		public bool IsSeries { get; }
		public bool IsUnavailable => !IsSeries & IsAbsent & (BookStatus is not LiberatedStatus.Liberated || PdfStatus is not null and not LiberatedStatus.Liberated);
		public Bitmap Image => GetLiberateIcon();
		public string ToolTip => GetTooltip();

		static Dictionary<string, Bitmap> iconCache = new();

		/// <summary> Defines the Liberate column's sorting behavior </summary>
		public int CompareTo(object obj)
		{
			if (obj is not LiberateButtonStatus second) return -1;

			if (IsSeries && !second.IsSeries) return -1;
			else if (!IsSeries && second.IsSeries) return 1;
			else if (IsSeries && second.IsSeries) return 0;
			else if (IsUnavailable && !second.IsUnavailable) return 1;
			else if (!IsUnavailable && second.IsUnavailable) return -1;
			else if (BookStatus == LiberatedStatus.Liberated && second.BookStatus != LiberatedStatus.Liberated) return -1;
			else if (BookStatus != LiberatedStatus.Liberated && second.BookStatus == LiberatedStatus.Liberated) return 1;
			else return BookStatus.CompareTo(second.BookStatus);
		}

		private Bitmap GetLiberateIcon()
		{
			if (IsSeries)
				return Expanded ? GetFromResources("minus") : GetFromResources("plus");

			if (BookStatus == LiberatedStatus.Error)
				return GetFromResources("error");

			string image_lib = BookStatus switch
			{
				LiberatedStatus.Liberated => "green",
				LiberatedStatus.PartialDownload => "yellow",
				LiberatedStatus.NotLiberated => "red",
				_ => throw new Exception("Unexpected liberation state")
			};

			string image_pdf = PdfStatus switch
			{
				LiberatedStatus.Liberated => "_pdf_yes",
				LiberatedStatus.NotLiberated => "_pdf_no",
				LiberatedStatus.Error => "_pdf_no",
				null => "",
				_ => throw new Exception("Unexpected PDF state")
			};

			return GetFromResources($"liberate_{image_lib}{image_pdf}");
		}

		private string GetTooltip()
		{
			if (IsSeries)
				return Expanded ? "Click to Collpase" : "Click to Expand";

			if (IsUnavailable)
				return "This book cannot be downloaded\nbecause it wasn't found during\nthe most recent library scan";

			if (BookStatus == LiberatedStatus.Error)
				return "Book downloaded ERROR";

			string libState = BookStatus switch
			{
				LiberatedStatus.Liberated => "Liberated",
				LiberatedStatus.PartialDownload => "File has been at least\r\npartially downloaded",
				LiberatedStatus.NotLiberated => "Book NOT downloaded",
				_ => throw new Exception("Unexpected liberation state")
			};

			string pdfState = PdfStatus switch
			{
				LiberatedStatus.Liberated => "\r\nPDF downloaded",
				LiberatedStatus.NotLiberated => "\r\nPDF NOT downloaded",
				LiberatedStatus.Error => "\r\nPDF downloaded ERROR",
				null => "",
				_ => throw new Exception("Unexpected PDF state")
			};


			var mouseoverText = libState + pdfState;

			if (BookStatus == LiberatedStatus.NotLiberated ||
				BookStatus == LiberatedStatus.PartialDownload ||
				PdfStatus == LiberatedStatus.NotLiberated)
				mouseoverText += "\r\nClick to complete";

			return mouseoverText;
		}

		private static Bitmap GetFromResources(string rescName)
		{
			if (iconCache.ContainsKey(rescName)) return iconCache[rescName];

			iconCache[rescName] = new Bitmap(App.OpenAsset(rescName + ".png"));
			return iconCache[rescName];
		}
	}
}