using System;

namespace Wabbajack.Paths
{
    public static class ArrayExtensions
    {
        public static bool AreEqual<T>(T[] a, int startA, T[] b, int startB, int length)
        {
            if (startA + length > a.Length) return false;
            if (startB + length > b.Length) return false;

            for (var i = 0; i < length; i++)
                if (!a[startA + i]!.Equals(b[startB + i]))
                    return false;
            return true;
        }

        public static int Compare<T>(T[] a, T[] b)
            where T : IComparable<T>
        {
            var idx = 0;
            while (true)
            {
                if (idx == a.Length && idx == b.Length) return 0;
                if (idx == a.Length && idx < b.Length) return -1;
                if (idx == b.Length && idx < a.Length) return 1;

                var comp = a[idx].CompareTo(b[idx]);
                if (comp != 0) return comp;
                idx++;
            }
        }

        public static int CompareString(string[] a, string[] b)
        {
            var idx = 0;
            while (true)
            {
                if (idx == a.Length && idx == b.Length) return 0;
                if (idx == a.Length && idx < b.Length) return -1;
                if (idx == b.Length && idx < a.Length) return 1;

                var comp = string.Compare(a[idx], b[idx], StringComparison.CurrentCultureIgnoreCase);
                if (comp != 0) return comp;
                idx++;
            }
        }

        public static T[] Add<T>(this T[] arr, T itm)
        {
            var newArr = new T[arr.Length + 1];
            Array.Copy(arr, 0, newArr, 0, arr.Length);
            newArr[arr.Length] = itm;
            return newArr;
        }
    }
}