fixed todo delete progatation in recipe

added count to IngredientController about what recipes we have or dont and 2 small typo mistakes

also added counting ingredients to IngredientService

server/src/main/java/server/api/IngredientController.java

@@ -1,5 +1,6 @@
 package server.api;
 
+
 import commons.Ingredient;
 import commons.ws.Topics;
 import commons.ws.messages.CreateIngredientMessage;
@@ -93,13 +94,22 @@ public class IngredientController {
      *
      * @see Ingredient
      */
-    @GetMapping("/ingredients/{id}")
-    public ResponseEntity<Ingredient> getIngredientById(@PathVariable Long id) {
-        return ingredientService.findById(id)
-                .map(ResponseEntity::ok)
-                .orElseGet(() -> ResponseEntity.notFound().build());
+    @GetMapping("/ingredients/{id}/usage")
+    public ResponseEntity<IngredientUsageResponse> getIngredientUsage(@PathVariable Long id) {
+        if (ingredientService.findById(id).isEmpty()) {
+            return ResponseEntity.notFound().build();
+        }
+
+        // Server-side computation of how many recipes reference this ingredient
+        long usedInRecipes = ingredientService.countUsage(id);
+        return ResponseEntity.ok(new IngredientUsageResponse(id, usedInRecipes));
     }
 
+
+
+
+
+
     /**
      * Update an existing ingredient by its ID.
      * Maps to <code>PATCH /api/ingredients/{id}</code>
@@ -126,7 +136,7 @@ public class IngredientController {
         updated.setId(id);
         return ingredientService.update(id, updated)
                 .map(saved -> {
-                    messagingTemplate.convertAndSend(Topics.INGREDIENTS, new CreateIngredientMessage(saved));
+                    messagingTemplate.convertAndSend(Topics.INGREDIENTS, new UpdateIngredientMessage(saved));
                     return ResponseEntity.ok(saved);
                 })
                 .orElseGet(() -> ResponseEntity.notFound().build());
@@ -139,7 +149,7 @@ public class IngredientController {
      * <p>
      * If an ingredient with the same name already exists,
      * returns 400 Bad Request.
-     *
+     * <p>
      * If the ingredient is created successfully,
      * returns the created ingredient with 200 OK.
      * </p>
@@ -157,7 +167,7 @@ public class IngredientController {
 
         return ingredientService.create(ingredient)
                 .map(saved -> {
-                    messagingTemplate.convertAndSend(Topics.INGREDIENTS, new UpdateIngredientMessage(saved));
+                    messagingTemplate.convertAndSend(Topics.INGREDIENTS, new CreateIngredientMessage(saved));
                     return ResponseEntity.ok(saved);
                 })
                 .orElseGet(() -> ResponseEntity.badRequest().build());
@@ -186,4 +196,6 @@ public class IngredientController {
         messagingTemplate.convertAndSend(Topics.INGREDIENTS, new DeleteIngredientMessage(id));
         return ResponseEntity.ok(true);
     }
+
+    public record IngredientUsageResponse(Long ingredientId, long usedInRecipes){}
 }

server/src/main/java/server/service/IngredientService.java

@@ -4,16 +4,21 @@ import commons.Ingredient;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.stereotype.Service;
 import server.database.IngredientRepository;
+import server.database.RecipeIngredientRepository;
 
 import java.util.List;
 import java.util.Optional;
 
 @Service
 public class IngredientService {
-    IngredientRepository ingredientRepository;
 
-    public IngredientService(IngredientRepository ingredientRepository) {
+    private final IngredientRepository ingredientRepository;
+    private final RecipeIngredientRepository recipeIngredientRepository;
+
+    public IngredientService(IngredientRepository ingredientRepository,
+                             RecipeIngredientRepository recipeIngredientRepository) {
         this.ingredientRepository = ingredientRepository;
+        this.recipeIngredientRepository = recipeIngredientRepository;
     }
 
     public Optional<Ingredient> findById(Long id) {
@@ -30,12 +35,16 @@ public class IngredientService {
 
     /**
      * Creates a new ingredient. Returns empty if the recipe with the same name or id already exists.
+     *
      * @param ingredient Ingredient to be saved in the db.
      * @return The created ingredient (the ingredient arg with a new assigned id) or empty if it already exists in db.
      */
     public Optional<Ingredient> create(Ingredient ingredient) {
-        if (ingredientRepository.existsByName(ingredient.getName()) ||
-                ingredientRepository.existsById(ingredient.getId())) {
+        if (ingredient == null || ingredient.getName() == null) {
+            return Optional.empty();
+        }
+
+        if (ingredientRepository.existsByName(ingredient.getName())) {
             return Optional.empty();
         }
 
@@ -44,7 +53,8 @@ public class IngredientService {
 
     /**
      * Updates an ingredient. The ingredient with the provided id will be replaced (in db) with the provided ingredient.
-     * @param id id of the ingredient to update.
+     *
+     * @param id         id of the ingredient to update.
      * @param ingredient Ingredient to be saved in the db.
      * @return The created ingredient (the ingredient arg with a new assigned id.)
      */
@@ -64,4 +74,10 @@ public class IngredientService {
         return true;
     }
 
+    //actually counting the amount used in recipes
+
+    public long countUsage(long ingredientId) {
+        return recipeIngredientRepository.countByIngredientId(ingredientId);
+
+    }
 }