Wrote the Trainer.cs methods and fixed a bug in VocabularyItem.cs

VocabularyTrainer/Trainer.cs

@@ -34,7 +34,28 @@ public sealed class Trainer
         var alreadyAsked = new bool[_vocabularyItems.Length];
         for (var i = 0; i < CycleCount; i++)
         {
-            // TODO
+            Console.ForegroundColor = ConsoleColor.Yellow;
+            int nextWord = PickNextWord(alreadyAsked);
+            Console.Write($"{i + 1}: {_vocabularyItems[nextWord].NativeWord, -10} = ");
+            
+            Console.ResetColor();
+            string translationInput = Console.ReadLine()!;
+            alreadyAsked[nextWord] = true;
+
+            bool isTranslationCorrect = _vocabularyItems[nextWord].TestTranslation(translationInput);
+            if (isTranslationCorrect)
+            {
+                Console.ForegroundColor = ConsoleColor.Green;
+                Console.WriteLine("OK!");
+            }
+            else
+            {
+                Console.ForegroundColor = ConsoleColor.Red;
+                Console.WriteLine($"No, {_vocabularyItems[nextWord].NativeWord} = {_vocabularyItems[nextWord].Translation}");
+
+                return;
+            }
+            
             Console.ResetColor();
         }
         Console.WriteLine();
@@ -69,8 +90,42 @@ public sealed class Trainer
     /// <returns>Index of next word to use</returns>
     private int PickNextWord(bool[] alreadyAsked)
     {
-        // TODO
+        //Instead of a while loop trying every combination, we randomize only between the useAble words
-        return -1;
+        int useAbleWords = UseAbleWords(alreadyAsked, out int[] indexOfUseAbleWords);
+        int randomIndex = RandomProvider.Random.Next(0, useAbleWords - 1);
+
+        return indexOfUseAbleWords[randomIndex];
+
+        int UseAbleWords(bool[] alreadyAsked, out int[] indexOfUseAbleWords)
+        {
+            int count = CountUseAbleWords(alreadyAsked);
+            indexOfUseAbleWords = new int[count];
+            int j = 0;
+            for (int i = 0; i < alreadyAsked.Length; i++)
+            {
+                if (!alreadyAsked[i])
+                {
+                    indexOfUseAbleWords[j] = i;
+                    j++;
+                }
+            }
+
+            return count;
+        }
+        
+        int CountUseAbleWords(bool[] alreadyAsked)
+        {
+            int count = 0;
+            for (int i = 0; i < alreadyAsked.Length; i++)
+            {
+                if (!alreadyAsked[i])
+                {
+                    count++;
+                }
+            }
+
+            return count;
+        }
     }
 
     /// <summary>
@@ -78,7 +133,19 @@ public sealed class Trainer
     /// </summary>
     private void Sort()
     {
-        // TODO
+        for (int i = 0; i < _vocabularyItems.Length - 1; i++)
+        {
+            int result = _vocabularyItems[i].CompareTo(_vocabularyItems[i + 1]);
+            if (result > 0)
+            {
+                Swap(i, i + 1);
+            }
+        }
+
+        void Swap(int i, int j)
+        {
+            (_vocabularyItems[i], _vocabularyItems[j]) = (_vocabularyItems[j], _vocabularyItems[i]);
+        }
     }
 
     /// <summary>

VocabularyTrainer/VocabularyItem.cs

@@ -24,7 +24,7 @@ public sealed class VocabularyItem
     public bool TestTranslation(string translationAttempt)
     {
         _countAsked++;
-        if (Translation == translationAttempt)
+        if (string.Equals(Translation, translationAttempt, StringComparison.CurrentCultureIgnoreCase))
         {
             _countCorrect++;
             return true;