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;
using Mesen.GUI.Controls;
using Mesen.GUI.Config;

namespace Mesen.GUI.Debugger.Controls
{
	public partial class ctrlFunctionList : BaseControl
	{
		public event EventHandler OnFindOccurrence;
		public event GoToDestinationEventHandler OnFunctionSelected;

		private List<ListViewItem> _listItems = new List<ListViewItem>();
		private Dictionary<Int32, ListViewItem> _functions = new Dictionary<int, ListViewItem>();

		public ctrlFunctionList()
		{
			InitializeComponent();
		}

		protected override void OnLoad(EventArgs e)
		{
			base.OnLoad(e);
			if(!IsDesignMode) {
				InitShortcuts();
			}
		}

		private void InitShortcuts()
		{
			mnuEditLabel.InitShortcut(this, nameof(DebuggerShortcutsConfig.FunctionList_EditLabel));
			mnuAddBreakpoint.InitShortcut(this, nameof(DebuggerShortcutsConfig.FunctionList_AddBreakpoint));
			mnuFindOccurrences.InitShortcut(this, nameof(DebuggerShortcutsConfig.FunctionList_FindOccurrences));
		}

		private int CompareFunctions(ListViewItem a, ListViewItem b)
		{
			string aText = string.IsNullOrWhiteSpace(a.Text) ? "ZZZZZZZZZZZZZZZZZZZZZZZ" : a.Text;
			string bText = string.IsNullOrWhiteSpace(b.Text) ? "ZZZZZZZZZZZZZZZZZZZZZZZ" : b.Text;
			Int32 aRelative = (Int32)a.SubItems[1].Tag == -1 ? Int32.MaxValue : (Int32)a.SubItems[1].Tag;
			Int32 bRelative = (Int32)b.SubItems[1].Tag == -1 ? Int32.MaxValue : (Int32)b.SubItems[1].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;
				} else {
					return aRelative - bRelative;
				}
			} else {
				return string.Compare(aText, bText);
			}
		}

		public void UpdateFunctionList(bool reset)
		{
			if(reset) {
				_listItems.Clear();
				_functions.Clear();
			}

			Font italicFont = null;
			Font regularFont = null;

			Int32[] entryPoints = InteropEmu.DebugGetFunctionEntryPoints();

			for(int i = 0; i < entryPoints.Length && entryPoints[i] >= 0; i++) {
				Int32 entryPoint = entryPoints[i];
				ListViewItem item;
				if(!_functions.TryGetValue(entryPoint, out item)) {
					CodeLabel label = LabelManager.GetLabel((UInt32)entryPoint, AddressType.PrgRom);
					item = new ListViewItem(label?.Label);
					item.Tag = label;

					item.SubItems.Add("[n/a]");
					item.SubItems[1].Tag = -1;
					item.ForeColor = ThemeHelper.Theme.LabelDisabledForeColor;

					if(italicFont == null) {
						italicFont = new Font(item.Font, FontStyle.Italic);
					}
					item.Font = italicFont;

					item.SubItems.Add("$" + entryPoint.ToString("X4"));
					item.SubItems[2].Tag = entryPoint;

					_listItems.Add(item);
					_functions[entryPoint] = item;
				}

				Int32 relativeAddress = InteropEmu.DebugGetRelativeAddress((UInt32)entryPoint, AddressType.PrgRom);
				if(relativeAddress != (Int32)item.SubItems[1].Tag) {
					if(relativeAddress >= 0) {
						item.SubItems[1].Text = "$" + relativeAddress.ToString("X4");
						item.ForeColor = ThemeHelper.Theme.LabelForeColor;
						if(regularFont == null) {
							regularFont = new Font(item.Font, FontStyle.Regular);
						}
						item.Font = regularFont;
					} else {
						item.SubItems[1].Text = "[n/a]";
						item.ForeColor = ThemeHelper.Theme.LabelDisabledForeColor;
						if(italicFont == null) {
							italicFont = new Font(item.Font, FontStyle.Italic);
						}
						item.Font = italicFont;
					}
					item.SubItems[1].Tag = relativeAddress;
				}
			}

			lstFunctions.BeginUpdate();
			_listItems.Sort(CompareFunctions);
			lstFunctions.VirtualMode = true;
			lstFunctions.VirtualListSize = _listItems.Count;
			lstFunctions.EndUpdate();
		}

		private ListViewItem GetSelectedItem()
		{
			return _listItems[lstFunctions.SelectedIndices[0]];
		}

		private void lstFunctions_DoubleClick(object sender, EventArgs e)
		{
			if(lstFunctions.SelectedIndices.Count > 0) {
				Int32 relativeAddress = (Int32)GetSelectedItem().SubItems[1].Tag;
				Int32 absoluteAddress = (Int32)GetSelectedItem().SubItems[2].Tag;
				OnFunctionSelected?.Invoke(new GoToDestination() {
					AddressInfo = new AddressTypeInfo() { Address = absoluteAddress, Type = AddressType.PrgRom },
					CpuAddress = relativeAddress
				});
			}
		}

		private void mnuEditLabel_Click(object sender, EventArgs e)
		{
			if(lstFunctions.SelectedIndices.Count > 0) {
				CodeLabel label = GetSelectedItem().Tag as CodeLabel;
				if(label != null) {
					ctrlLabelList.EditLabel(label.Address, label.AddressType);
				} else {
					ctrlLabelList.EditLabel((UInt32)(Int32)GetSelectedItem().SubItems[2].Tag, AddressType.PrgRom);
				}
			}
		}

		private void mnuFindOccurrences_Click(object sender, EventArgs e)
		{
			if(lstFunctions.SelectedIndices.Count > 0) {
				int relativeAddress = (int)GetSelectedItem().SubItems[1].Tag;
				if(relativeAddress >= 0) {
					CodeLabel label = GetSelectedItem().Tag as CodeLabel;
					if(label != null) {
						OnFindOccurrence?.Invoke(label.Label, null);
					} else {
						OnFindOccurrence?.Invoke("$" + ((int)GetSelectedItem().SubItems[1].Tag).ToString("X4"), null);
					}
				}
			}
		}
		
		private void lstFunctions_SelectedIndexChanged(object sender, EventArgs e)
		{
			mnuEditLabel.Enabled = lstFunctions.SelectedIndices.Count == 1;
			mnuFindOccurrences.Enabled = lstFunctions.SelectedIndices.Count == 1;
			if(lstFunctions.SelectedIndices.Count == 1) {
				int relativeAddress = (int)GetSelectedItem().SubItems[1].Tag;
				if(relativeAddress < 0) {
					mnuFindOccurrences.Enabled = false;
				}
			}
		}

		private void mnuAddBreakpoint_Click(object sender, EventArgs e)
		{
			if(lstFunctions.SelectedIndices.Count > 0) {
				int absoluteAddress = (int)GetSelectedItem().SubItems[2].Tag;
				BreakpointManager.AddBreakpoint(new Breakpoint() {
					MemoryType = DebugMemoryType.PrgRom,
					BreakOnExec = true,
					BreakOnRead = false,
					BreakOnWrite = false,
					Address = (UInt32)absoluteAddress,
					StartAddress = (UInt32)absoluteAddress,
					EndAddress = (UInt32)absoluteAddress,
					AddressType = BreakpointAddressType.SingleAddress
				});
			}
		}

		private void lstFunctions_RetrieveVirtualItem(object sender, RetrieveVirtualItemEventArgs e)
		{
			e.Item = _listItems[e.ItemIndex];
		}

		private void lstFunctions_SearchForVirtualItem(object sender, SearchForVirtualItemEventArgs e)
		{
			for(int i = 0; i < _listItems.Count; i++) {
				if(_listItems[i].Text.StartsWith(e.Text, StringComparison.InvariantCultureIgnoreCase)) {
					e.Index = i;
					return;
				}
			}
		}
	}
}