using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace BizHawk.MultiClient
{
	public class RecentFiles : IEnumerable
	{
		private readonly int MAX_RECENT_FILES;       //Maximum number of files
		private readonly List<string> recentlist;    //List of recent files

		public bool AutoLoad = false;

		public RecentFiles() : this(8) { }
		public RecentFiles(int max)
		{
			recentlist = new List<string>();
			MAX_RECENT_FILES = max;
		}

		public IEnumerator<string> GetEnumerator()
		{
			return recentlist.GetEnumerator();
		}

		System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
		{
			return GetEnumerator();
		}

		public void Clear()
		{
			recentlist.Clear();
		}

		public bool Empty
		{
			get { return recentlist.Count == 0; }
		}

		public int Count
		{
			get { return recentlist.Count; }
		}

		public void Add(string newFile)
		{
			for (int x = 0; x < recentlist.Count; x++)
			{
				if (string.Compare(newFile, recentlist[x]) == 0)
				{
					recentlist.Remove(newFile); //intentionally keeps iterating after this to remove duplicate instances, though those should never exist in the first place
				}
			}
			recentlist.Insert(0, newFile);
			if (recentlist.Count > MAX_RECENT_FILES)
			{
				recentlist.Remove(recentlist[recentlist.Count - 1]);
			}
		}

		public bool Remove(string newFile)
		{
			bool removed = false;
			for (int x = 0; x < recentlist.Count; x++)
			{
				if (string.Compare(newFile, recentlist[x]) == 0)
				{
					recentlist.Remove(newFile); //intentionally keeps iterating after this to remove duplicate instances, though those should never exist in the first place
					removed = true;
				}
			}
			return removed;
		}

		public List<string> GetRecentListTruncated(int length)
		{
			//iterate through list, truncating each item to length, and return the result in a List<string>
			return recentlist.Select(t => t.Substring(0, length)).ToList();
		}

		public string this[int index]
		{
			get
			{
				if (recentlist.Any())
				{
					return recentlist[index];
				}
				else
				{
					return "";
				}
			}
		}

		public ToolStripItem[] GenerateRecentMenu(Action<string> loadFileCallback)
		{
			var items = new List<ToolStripItem>();

			if (Empty)
			{
				var none = new ToolStripMenuItem { Enabled = false, Text = "None" };
				items.Add(none);
			}
			else
			{
				foreach (string filename in recentlist)
				{
					string temp = filename;
					var item = new ToolStripMenuItem { Text = temp };
					item.Click += (o, ev) => loadFileCallback(temp);
					items.Add(item);
				}
			}

			items.Add(new ToolStripSeparator());

			var clearitem = new ToolStripMenuItem { Text = "&Clear" };
			clearitem.Click += (o, ev) => recentlist.Clear();
			items.Add(clearitem);

			return items.ToArray();
		}

		public ToolStripMenuItem GenerateAutoLoadItem()
		{
			var auto = new ToolStripMenuItem { Text = "&Auto-Load", Checked = AutoLoad };
			auto.Click += (o, ev) => ToggleAutoLoad();
			return auto;
		}

		private void ToggleAutoLoad()
		{
			AutoLoad ^= true;
		}
	}
}