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

namespace Dreadlock.UnitTesting
{
    public class EdgeEnumeratorTests : TestFixture
    {
        public void Works()
        {
            int[] list = { 0, 1, 2, 3, 4, 5, };

            var enumerable = new EdgeEnumerator<int>(list);

            int trailingExpected = 0;
            int leadingExpected = 1;
            int loopCount = 0;

            foreach (var pair in enumerable)
            {
                CheckEqual(trailingExpected++ % 6, pair.Trailing);
                CheckEqual(leadingExpected++ % 6, pair.Leading);
                ++loopCount;
            }

            CheckEqual(list.Length, loopCount);
        }

        public void ZeroLength()
        {
            int[] list = { };

            int loopCount = 0;

            foreach (var pair in new EdgeEnumerator<int>(list))
            {
                ++loopCount;
            }

            CheckEqual(0, loopCount);
        }

        public void OneLength()
        {
            int[] list = { 2, };

            int loopCount = 0;

            foreach (var pair in new EdgeEnumerator<int>(list))
            {
                ++loopCount;
            }

            CheckEqual(1, loopCount);
        }

        public void RecursiveGenerics()
        {
            int[] list = { 0, 1, 2, 3, 4, 5 };

            var edges = new EdgeEnumerator<int>(list);
            var edgePairs = new EdgeEnumerator<EdgeEnumerator<int>.Edge>(edges);

            int leading_leading = 2;
            int leading_trailing = 1;
            int trailing_leading = 1;
            int trailing_trailing = 0;
            int loopCount = 0;

            foreach (var edgePair in edgePairs)
            {
                CheckEqual(leading_leading++ % list.Length, edgePair.Leading.Leading);
                CheckEqual(leading_trailing++ % list.Length, edgePair.Leading.Trailing);
                CheckEqual(trailing_leading++ % list.Length, edgePair.Trailing.Leading);
                CheckEqual(trailing_trailing++ % list.Length, edgePair.Trailing.Trailing);

                ++loopCount;
            }

            CheckEqual(list.Length, loopCount);
        }
    }
}