using System;
using System.Collections;
using System.Collections.Generic;
using AppKit;
using Foundation;

namespace Cauldron.Macos.SourceList
{
	public class SourceListDataSource : NSOutlineViewDataSource
	{
		#region Private Variables

		private SourceListView _controller;

		#endregion

		#region Public Variables

		public List<SourceListItem> Items = new();

		#endregion

		#region Constructors

		public SourceListDataSource(SourceListView controller)
		{
			// Initialize
			this._controller = controller;
		}

		#endregion

		#region Override Properties

		public override nint GetChildrenCount(NSOutlineView outlineView, Foundation.NSObject item)
		{
			if (item == null)
			{
				return Items.Count;
			}
			else
			{
				return ((SourceListItem)item).Count;
			}
		}

		public override bool ItemExpandable(NSOutlineView outlineView, Foundation.NSObject item)
		{
			return ((SourceListItem)item).HasChildren;
		}

		public override NSObject GetChild(NSOutlineView outlineView, nint childIndex, Foundation.NSObject item)
		{
			if (item == null)
			{
				return Items[(int)childIndex];
			}
			else
			{
				return ((SourceListItem)item)[(int)childIndex];
			}
		}

		public override NSObject GetObjectValue(NSOutlineView outlineView, NSTableColumn tableColumn, NSObject item)
		{
			return new NSString(((SourceListItem)item).Title);
		}

		#endregion

		#region Internal Methods

		internal SourceListItem ItemForRow(int row)
		{
			int index = 0;

			// Look at each group
			foreach (SourceListItem item in Items)
			{
				// Is the row inside this group?
				if (row >= index && row <= (index + item.Count))
				{
					return item[row - index - 1];
				}

				// Move index
				index += item.Count + 1;
			}

			// Not found 
			return null;
		}

		#endregion
	}
}