/*
 * Greenshot - a free and open source screenshot tool
 * Copyright (C) 2007-2020 Thomas Braun, Jens Klingen, Robin Krom
 *
 * For more information see: http://getgreenshot.org/
 * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

using Greenshot.IniFile;
using GreenshotPlugin.Core;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;

namespace Greenshot.Forms {
	/// <summary>
	/// the ToolStripMenuSelectList makes it possible to have a single or multi-check menu
	/// </summary>
	public sealed class ToolStripMenuSelectList : ToolStripMenuItem {
		private static readonly CoreConfiguration CoreConfig = IniConfig.GetIniSection<CoreConfiguration>();
		private readonly bool _multiCheckAllowed;
		private bool _updateInProgress;
		private static Image _defaultImage;

		/// <summary>
		/// Occurs when one of the list's child element's Checked state changes.
		/// </summary>
		public new event EventHandler CheckedChanged;
		public object Identifier {
			get;
			private set;
		}

		public ToolStripMenuSelectList(object identifier, bool allowMultiCheck) {
			Identifier = identifier;
			CheckOnClick = false;
			_multiCheckAllowed = allowMultiCheck;
			if (_defaultImage == null || _defaultImage.Size != CoreConfig.ScaledIconSize) {
				_defaultImage?.Dispose();
				_defaultImage = ImageHelper.CreateEmpty(CoreConfig.ScaledIconSize.Width, CoreConfig.ScaledIconSize.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb, Color.Transparent, 96f, 96f);
			}
			Image = _defaultImage;
		}
		public ToolStripMenuSelectList() : this(null,false) {}
		public ToolStripMenuSelectList(object identifier) : this(identifier,false) {}

		/// <summary>
		/// gets or sets the currently checked item
		/// </summary>
		public ToolStripMenuSelectListItem CheckedItem {

			get {
				IEnumerator items = DropDownItems.GetEnumerator();
				while (items.MoveNext()) {
					ToolStripMenuSelectListItem tsmi = (ToolStripMenuSelectListItem)items.Current;
					if (tsmi != null && tsmi.Checked) {
						return tsmi;
					}
				}
				return null;
			}
			set {
				IEnumerator items = DropDownItems.GetEnumerator();
				while (items.MoveNext()) {
					ToolStripMenuSelectListItem tsmi = (ToolStripMenuSelectListItem)items.Current;
					if (tsmi != null && !_multiCheckAllowed && !tsmi.Equals(value)) {
						tsmi.Checked = false;
					} else if (tsmi != null && tsmi.Equals(value)) {
						tsmi.Checked = true;
					}
				}
			}
		}

		/// <summary>
		/// gets or sets the currently checked items
		/// </summary>
		public ToolStripMenuSelectListItem[] CheckedItems {
			get {
				List<ToolStripMenuSelectListItem> sel = new List<ToolStripMenuSelectListItem>();
				IEnumerator items = DropDownItems.GetEnumerator();
				while(items.MoveNext()) {
					ToolStripMenuSelectListItem tsmi = (ToolStripMenuSelectListItem)items.Current;
					if (tsmi != null && tsmi.Checked) {
						sel.Add(tsmi);
					}
				}
				return sel.ToArray();
			}
			set {
				if (!_multiCheckAllowed) {
					throw new ArgumentException("Writing to checkedItems is only allowed in multi-check mode. Either set allowMultiCheck to true or use set SelectedItem instead of SelectedItems.");
				}
				IEnumerator items = DropDownItems.GetEnumerator();
				IEnumerator sel = value.GetEnumerator();
				while (items.MoveNext()) {
					var toolStripMenuSelectListItem = (ToolStripMenuSelectListItem)items.Current;
					if (toolStripMenuSelectListItem == null)
					{
						continue;
					}
					while (sel.MoveNext())
					{
						toolStripMenuSelectListItem.Checked = toolStripMenuSelectListItem.Equals(sel.Current);
						if (!_multiCheckAllowed && !toolStripMenuSelectListItem.Equals(sel.Current)) {
							toolStripMenuSelectListItem.Checked = false;
						} else if (toolStripMenuSelectListItem.Equals(value)) {
							toolStripMenuSelectListItem.Checked = true;
						}
					}
				}
			}
		}

		private void ItemCheckStateChanged(object sender, EventArgs e) {
			if (_updateInProgress) {
				return;
			}
			var toolStripMenuSelectListItem = (ToolStripMenuSelectListItem)sender;
			_updateInProgress = true;
			if (toolStripMenuSelectListItem.Checked && !_multiCheckAllowed) {
				UncheckAll();
				toolStripMenuSelectListItem.Checked = true;
			}
			_updateInProgress = false;
			CheckedChanged?.Invoke(this, new ItemCheckedChangedEventArgs(toolStripMenuSelectListItem));
		}

		/// <summary>
		/// adds an item to the select list
		/// </summary>
		/// <param name="label">the label to be displayed</param>
		/// <param name="image">the icon to be displayed</param>
		/// <param name="data">the data to be returned when an item is queried</param>
		/// <param name="isChecked">whether the item is initially checked</param>
		public void AddItem(string label, Image image, object data, bool isChecked) {
			var toolStripMenuSelectListItem = new ToolStripMenuSelectListItem
			{
				Text = label
			};
			if (image == null) {
				image = _defaultImage;
			}
			toolStripMenuSelectListItem.DisplayStyle = ToolStripItemDisplayStyle.Text;
			toolStripMenuSelectListItem.Image = image;
			toolStripMenuSelectListItem.CheckOnClick = true;
			toolStripMenuSelectListItem.CheckStateChanged += ItemCheckStateChanged;
			toolStripMenuSelectListItem.Data = data;
			if (isChecked) {
				if (!_multiCheckAllowed) {
					_updateInProgress = true;
					UncheckAll();
					_updateInProgress = false;
				}
				toolStripMenuSelectListItem.Checked = true;
			}
			DropDownItems.Add(toolStripMenuSelectListItem);
		}

		/// <summary>
		/// adds an item to the select list
		/// </summary>
		/// <param name="label">the label to be displayed</param>
		/// <param name="image">the icon to be displayed</param>
		public void AddItem(string label, Image image) {
			AddItem(label, image, null, false);
		}

		/// <summary>
		/// adds an item to the select list
		/// </summary>
		/// <param name="label">the label to be displayed</param>
		/// <param name="data">the data to be returned when an item is queried</param>
		public void AddItem(string label, object data) {
			AddItem(label, null, data, false);
		}

		/// <summary>
		/// adds an item to the select list
		/// </summary>
		/// <param name="label">the label to be displayed</param>
		public void AddItem(string label) {
			AddItem(label, null, null, false);
		}


		/// <summary>
		/// adds an item to the select list
		/// </summary>
		/// <param name="label">the label to be displayed</param>
		/// <param name="image">the icon to be displayed</param>
		/// <param name="isChecked">whether the item is initially checked</param>
		public void AddItem(string label, Image image, bool isChecked) {
			AddItem(label, image, null, isChecked);
		}

		/// <summary>
		/// adds an item to the select list
		/// </summary>
		/// <param name="label">the label to be displayed</param>
		/// <param name="data">the data to be returned when an item is queried</param>
		/// <param name="isChecked">whether the item is initially checked</param>
		public void AddItem(string label, object data, bool isChecked) {
			AddItem(label, null, data, isChecked);
		}

		/// <summary>
		/// adds an item to the select list
		/// </summary>
		/// <param name="label">the label to be displayed</param>
		/// <param name="isChecked">whether the item is initially checked</param>
		public void AddItem(string label, bool isChecked) {
			AddItem(label, null, null, isChecked);
		}

		/// <summary>
		/// unchecks all items of the list
		/// </summary>
		public void UncheckAll() {
			IEnumerator items = DropDownItems.GetEnumerator();
			while (items.MoveNext())
			{
				var toolStripMenuSelectListItem = (ToolStripMenuSelectListItem)items.Current;
				if (toolStripMenuSelectListItem != null)
				{
					toolStripMenuSelectListItem.Checked = false;
				}
			}
		}
	}

	/// <summary>
	/// Event class for the CheckedChanged event in the ToolStripMenuSelectList
	/// </summary>
	public class ItemCheckedChangedEventArgs : EventArgs {
		public ToolStripMenuSelectListItem Item {
			get;
			set;
		}
		public ItemCheckedChangedEventArgs(ToolStripMenuSelectListItem item) {
			Item = item;
		}
	}

	/// <summary>
	/// Wrapper around the ToolStripMenuItem, which can contain an object
	/// Also the Checked property hides the normal checked property so we can render our own check
	/// </summary>
	public class ToolStripMenuSelectListItem : ToolStripMenuItem {
		public object Data {
			get;
			set;
		}

	}
}