fix: raise not found on unsupported language

src/Expressio/Controllers/ExpressionsController.cs

@@ -46,7 +46,7 @@ public async Task<ActionResult<ExpressionDTO>> GetExpression(long id)
 
             if (expression == null)
             {
-                return NotFound();
+                return NotFound($"No expression with the following id: {id}");
             }
 
             return _mapper.Map<Expression, ExpressionDTO>(expression);

src/Expressio/Controllers/MixedExpressionsController.cs

@@ -27,15 +27,29 @@ public MixedExpressionsController(ExpressioContext context, IMapper mapper)
         [HttpGet("random")]
         public async Task<ActionResult<MixedExpressionDTO>> GetRandomMixedExpression(string lang)
         {
-            var mixed_expression = await Task.Run(() => _mixers[lang].Generate());
-            return _mapper.Map<MixedExpression, MixedExpressionDTO>(mixed_expression);
+            if(_mixers.TryGetValue(lang, out Mixer? mixer))
+            {
+                var mixed_expression = await Task.Run(() => mixer.Generate());
+                return _mapper.Map<MixedExpression, MixedExpressionDTO>(mixed_expression);
+            }
+            else
+            {
+                return NotFound($"Language {lang} is not supported");
+            }
         }
 
         [HttpGet("seeded/{seed}")]
         public async Task<ActionResult<MixedExpressionDTO>> GetSeededMixedExpression(int seed, string lang)
         {
-            var mixed_expression = await Task.Run(() => _mixers[lang].Generate(seed));
-            return _mapper.Map<MixedExpression, MixedExpressionDTO>(mixed_expression);
+            if(_mixers.TryGetValue(lang, out Mixer? mixer))
+            {
+                var mixed_expression = await Task.Run(() => mixer.Generate(seed));
+                return _mapper.Map<MixedExpression, MixedExpressionDTO>(mixed_expression);
+            }
+            else
+            {
+                return NotFound($"Language {lang} is not supported");
+            }
         }
     }
 }

src/Expressio/Models/Mixer.cs

@@ -46,4 +46,42 @@ private void PopulateDictionnary()
         foreach(var kv in _dic)
             _weights.AddRange(Enumerable.Repeat(kv.Key, kv.Value.NumberOfPossibilities));
     }
+
+    private class Possibilities
+    {
+        public string Word { get; }
+        private List<Expression> Expressions = new List<Expression>();
+        public int NumberOfPossibilities { 
+            get 
+            {
+                return Expressions.Count * (Expressions.Count - 1);
+            }
+        }
+
+        public Possibilities(string word, Expression expression)
+        {
+            Word = word;
+            Expressions.Add(expression);
+        }
+
+        public void AddExpression(Expression e) 
+        {
+            Expressions.Add(e);
+        }
+
+        public void RemoveDuplicates()
+        {
+            Expressions = Expressions.Distinct().ToList();
+        }
+
+        public MixedExpression Generate(Random rand, int seed)
+        {
+            var expressions = Expressions.OrderBy(e => rand.Next()).Take(2).ToList();
+            return new MixedExpression(
+                $"{expressions.First().SplitFirst(Word)} {expressions.Last().SplitLast(Word)}",
+                [expressions.First(), expressions.Last()],
+                seed
+            );
+        }
+    }
 }