using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Sarand.Net.Standard.Base.Utils
{
	//=======================================================================
	public static class ListUtil
	{
		//-------------------------------------------------------------------
		public static void ClearAndDispose<T>(this IList<T> values) where T : IDisposable
		{
			while (values.Count > 0)
			{
				T value = values[0];
				values.RemoveAt(0);
				value.Dispose();
			}
		}

		//-------------------------------------------------------------------
		/// <summary>Is the list empty</summary>
		public static Boolean IsEmpty<T>(this IEnumerable<T> items)
		{
			return items.Count() == 0;
		}

		//-------------------------------------------------------------------
		/// <summary>
		/// Is the value in the list of items.
		/// <para>NB String values are compared case-sensitive.</para>
		/// <para>Use InCI() for case-insensitive string comparison.</para>
		/// </summary>
		public static Boolean In<T>(this T item, IEnumerable<T> items)
		{
			return items.Contains(item);
		}
		/// <summary>Is the String in the list of items [case-insensitive]</summary>
		public static Boolean InCI(this String item, IEnumerable<String> items)
		{
			return items.ContainsCI(item);
		}

		//-------------------------------------------------------------------
		public enum Equality
		{
			/// <summary>Exact - exact match between items in each list.</summary>
			Exact = 0x01,
			/// <summary>Unique values only - ignores number of instances of each value.</summary>
			UniqueValuesOnly = 0x02,
		}
		/// <summary>
		/// Compare content of two lists.
		/// <para>- Exact ensures precise number and sequence of elements.</para>
		/// <para>- Unique allows any number and sequence as long as each item is present in both lists.</para>
		/// </summary>
		public static bool Equals<T>(this IList<T> sourceList, IList<T> targetList, Equality equality)
		{
			bool sameLength = (sourceList.Count == targetList.Count);
			if (equality == Equality.Exact)
			{
				// List must contain exactly the same members in each position.
				if (!sameLength) return false;
				for (int idx = 0; idx < sourceList.Count; idx++)
				{
					if (!sourceList[idx].Equals(targetList[idx])) return false;
				}
				return true;
			}
			// Compare just the unique values.
			if (sourceList.Except(targetList).Any()) return false;
			if (targetList.Except(sourceList).Any()) return false;
			return true;
		}

		//-------------------------------------------------------------------
		/// <summary>
		/// Remove the specified range of items from the list to a new list.
		/// </summary>
		public static List<T> ExtractRange<T>(this List<T> values, int index, int count)
		{
			List<T> extractedValues = new List<T>();
			if (values.Any())
			{
				count = Math.Min(values.Count(), count);
				extractedValues.AddRange(values.GetRange(index, count));
				values.RemoveRange(index, count);
			}
			return extractedValues;
		}

		//-------------------------------------------------------------------
	}
	//=======================================================================
}