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

namespace Bowin.Common.Utility
{
    public static class EnumerableEx
    {
        public static void ForEach<T>(this IEnumerable<T> sources, Action<T> action)
        {
            foreach (var item in sources)
            {
                action(item);
            }
        }

        public static void ForEach<T>(this IEnumerable<T> sources, Action<T, int> action)
        {
            var index = 0;
            foreach (var item in sources)
            {
                action(item, index++);
            }
        }

        public static void ForEach<T, K>(this IEnumerable<T> sources, Func<T, K> action)
        {
            foreach (var item in sources)
            {
                action(item);
            }
        }

        public static string ToStringEx<T>(this IEnumerable<T> enumerable, string separator)
        {
            return string.Join(separator, enumerable);
        }

        public static string ToStringEx<T>(this IEnumerable<string> enumerable, string separator)
        {
            return string.Join(separator, enumerable);
        }

        public static List<string> MergeInt(this IEnumerable<int?> enumerable, string separator = "-")
        {
            return enumerable.Where(x => x.HasValue).Select(x => x.Value).ToList().MergeInt(separator);
        }
        public static List<string> MergeInt(this IEnumerable<int> enumerable, string separator = "-")
        {
            List<string> result = new List<string>();
            var orderedEnumerable = enumerable.OrderBy(x => x);
            var numberCount = orderedEnumerable.Count();
            if (numberCount == 0) return new List<string>();
            int firstNum = orderedEnumerable.First();
            int lastNum = orderedEnumerable.First();
            for (int i = 1; i < numberCount; i++)
            {
                var curNum = orderedEnumerable.ElementAt(i);
                if (curNum > (lastNum + 1))
                {
                    if (firstNum == lastNum)
                    {
                        result.Add(firstNum.ToString());
                    }
                    else
                    {
                        result.Add(firstNum.ToString() + separator + lastNum.ToString());
                    }
                    firstNum = curNum;
                }

                lastNum = curNum;
            }

            if (firstNum == lastNum)
            {
                result.Add(firstNum.ToString());
            }
            else
            {
                result.Add(firstNum.ToString() + separator + lastNum.ToString());
            }

            return result;
        }
    }
}