using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Collections;

namespace Mesen.GUI.Debugger.Controls
{
	public partial class ctrlFunctionList : UserControl
	{
		public event EventHandler OnFunctionSelected;
		public ctrlFunctionList()
		{
			InitializeComponent();
		}

		private class FunctionComparer : IComparer
		{
			int IComparer.Compare(object x, object y)
			{
				ListViewItem a = x as ListViewItem;
				ListViewItem b = y as ListViewItem;

				string aText = string.IsNullOrWhiteSpace(a.Text) ? "ZZZZZZZZZZZZZZZZZZZZZZZ" : a.Text;
				string bText = string.IsNullOrWhiteSpace(b.Text) ? "ZZZZZZZZZZZZZZZZZZZZZZZ" : b.Text;
				Int32 aRelative = (Int32)a.Tag == -1 ? Int32.MaxValue : (Int32)a.Tag;
				Int32 bRelative = (Int32)b.Tag == -1 ? Int32.MaxValue : (Int32)b.Tag;
				Int32 aAbsolute = (Int32)a.SubItems[2].Tag;
				Int32 bAbsolute = (Int32)b.SubItems[2].Tag;

				if(a.Text == b.Text) {
					if(a.Tag == b.Tag) {
						return aAbsolute > bAbsolute ? 1 : -1;
					} else {
						return aRelative > bRelative ? 1 : -1;
					}
				} else {
					return string.Compare(aText, bText);
				}
			}
		}

		private Dictionary<Int32, ListViewItem> _functions = new Dictionary<int, ListViewItem>(); 
		public void UpdateFunctionList(bool reset)
		{
			if(reset) {
				lstFunctions.Items.Clear();
				_functions.Clear();
			}

			Int32[] entryPoints = InteropEmu.DebugGetFunctionEntryPoints();
			bool updating = false;

			for(int i = 0; entryPoints[i] >= 0; i++) {
				Int32 entryPoint = entryPoints[i];
				ListViewItem item;
				if(!_functions.TryGetValue(entryPoint, out item)) {
					if(!updating) {
						updating = true;
						lstFunctions.BeginUpdate();
						lstFunctions.ListViewItemSorter = null;
					}

					CodeLabel label = LabelManager.GetLabel((UInt32)entryPoint, AddressType.PrgRom);
					item = lstFunctions.Items.Add(label?.Label);
					item.Tag = -1;
					item.SubItems.Add("");
					item.SubItems.Add("$" + entryPoint.ToString("X4"));
					item.SubItems[2].Tag = entryPoint;

					_functions[entryPoint] = item;
				}

				Int32 relativeAddress = InteropEmu.DebugGetRelativeAddress((UInt32)entryPoint, AddressType.PrgRom);
				if(relativeAddress != (Int32)item.Tag) {
					if(!updating) {
						updating = true;
						lstFunctions.BeginUpdate();
						lstFunctions.ListViewItemSorter = null;
					}

					if(relativeAddress >= 0) {
						item.SubItems[1].Text = "$" + relativeAddress.ToString("X4");
						item.ForeColor = Color.Black;
						item.Font = new Font(item.Font, FontStyle.Regular);
					} else {
						item.SubItems[1].Text = "[n/a]";
						item.ForeColor = Color.Gray;
						item.Font = new Font(item.Font, FontStyle.Italic);
					}
					item.Tag = relativeAddress;
				}
			}

			if(updating) {
				lstFunctions.ListViewItemSorter = new FunctionComparer();
				lstFunctions.Sort();
				lstFunctions.EndUpdate();
			}
		}

		private void lstFunctions_DoubleClick(object sender, EventArgs e)
		{
			if(lstFunctions.SelectedItems.Count > 0) {
				Int32 relativeAddress = (Int32)lstFunctions.SelectedItems[0].Tag;

				if(relativeAddress >= 0) {
					OnFunctionSelected?.Invoke(relativeAddress, e);
				}
			}
		}
	}
}