using System.Collections.Generic;
using System.Reflection;
using Flow.Launcher.Infrastructure;
using NUnit.Framework;
using NUnit.Framework.Legacy;

namespace Flow.Launcher.Test
{
    [TestFixture]
    public class TranslationMappingTest
    {
        [Test]
        public void AddNewIndex_ShouldAddTranslatedIndexPlusLength()
        {
            var mapping = new TranslationMapping();
            mapping.AddNewIndex(5, 3);
            mapping.AddNewIndex(8, 2);

            // 5+3=8, 8+2=10
            ClassicAssert.AreEqual(2, GetOriginalToTranslatedCount(mapping));
            ClassicAssert.AreEqual(8, GetOriginalToTranslatedAt(mapping, 0));
            ClassicAssert.AreEqual(10, GetOriginalToTranslatedAt(mapping, 1));
        }


        [TestCase(0, 0)] // "F" -> "F"
        [TestCase(1, 1)] // "l" -> "l"
        [TestCase(2, 2)] // "o" -> "o"
        [TestCase(3, 3)] // "w" -> "w"
        [TestCase(4, 4)] // " " -> " "
        [TestCase(5, 5)] // "Y" (translated from "用") -> original index 5
        [TestCase(6, 5)] // "o" (translated from "用") -> original index 5
        [TestCase(7, 5)] // "n" (translated from "用") -> original index 5
        [TestCase(8, 5)] // "g" (translated from "用") -> original index 5
        [TestCase(10, 6)] // "H" (translated from "户") -> original index 6
        [TestCase(11, 6)] // "u" (translated from "户") -> original index 6
        public void MapToOriginalIndex_ShouldReturnExpectedIndex(int translatedIndex, int expectedOriginalIndex)
        {
            var mapping = new TranslationMapping();
            // Test case :
            // 0123456
            // Flow 用户
            // 012345678901
            // Flow Yong Hu
            mapping.AddNewIndex(0, 1); // F
            mapping.AddNewIndex(1, 1); // l
            mapping.AddNewIndex(2, 1); // o
            mapping.AddNewIndex(3, 1); // w
            mapping.AddNewIndex(4, 1); // ' '
            mapping.AddNewIndex(5, 4); // 用 -> Yong
            mapping.AddNewIndex(10, 2); // 户 -> Hu

            var result = mapping.MapToOriginalIndex(translatedIndex);
            ClassicAssert.AreEqual(expectedOriginalIndex, result);
        }

        private static int GetOriginalToTranslatedCount(TranslationMapping mapping)
        {
            var field = typeof(TranslationMapping).GetField("_originalToTranslated", BindingFlags.NonPublic | BindingFlags.Instance);
            var list = (List<int>)field.GetValue(mapping);
            return list.Count;
        }

        private static int GetOriginalToTranslatedAt(TranslationMapping mapping, int index)
        {
            var field = typeof(TranslationMapping).GetField("_originalToTranslated", BindingFlags.NonPublic | BindingFlags.Instance);
            var list = (List<int>)field.GetValue(mapping);
            return list[index];
        }
    }
}