レシピ一覧取得時，最大調理可能数を返すように実装

backend/src/main/java/com/example/todoapp/controller/RecipesController.java

@@ -8,6 +8,7 @@ import java.util.stream.Collectors;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.core.Authentication;
+import org.springframework.security.core.userdetails.UsernameNotFoundException;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.PutMapping;
 import org.springframework.web.bind.annotation.RequestBody;
@@ -18,6 +19,8 @@ import com.example.todoapp.dto.RecipeDetailDTO;
 import com.example.todoapp.dto.RecipeRequestDTO;
 import com.example.todoapp.dto.RecipeResponseDTO;
 import com.example.todoapp.model.Recipes;
+import com.example.todoapp.model.User;
+import com.example.todoapp.repository.UserRepository;
 import com.example.todoapp.service.RecipeService;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestParam;
@@ -36,6 +39,9 @@ public class RecipesController {
     @Autowired
     private RecipeService recipeService;
 
+    @Autowired
+    private UserRepository userRepository;
+
     /**
      * 新しいレシピを作成する
      *
@@ -62,7 +68,12 @@ public class RecipesController {
      */
     @GetMapping("/getAll")
     public ResponseEntity<List<RecipeResponseDTO>> getRecipe(Authentication authentication) {
+        
+        User user = userRepository.findByUsername(authentication.getName())
+            .orElseThrow(() -> new UsernameNotFoundException("User not found"));
+        
         List<Recipes> recipes = recipeService.getAllRecipes();
+
         // エンティティからDTOへの変換
         List<RecipeResponseDTO> responseList = recipes.stream()
             .map(recipe -> {
@@ -70,6 +81,7 @@ public class RecipesController {
                 dto.setRecipeId(recipe.getRecipeId()); 
                 dto.setRecipeName(recipe.getRecipeName());
                 dto.setSummary(recipe.getSummary());
+                dto.setMaxServings(recipeService.getRecipeMaxServings(user.getId(), recipe));
                 return dto;
         })
         .collect(Collectors.toList());

backend/src/main/java/com/example/todoapp/dto/RecipeResponseDTO.java

@@ -28,4 +28,10 @@ public class RecipeResponseDTO {
      * レシピの簡単な説明文
      */
     private String summary;
+
+    /**
+     * 最大調理可能数
+     * そのレシピを何人分調理可能か
+     */
+    private int maxServings;
 }

backend/src/main/java/com/example/todoapp/service/RecipeService.java

@@ -49,6 +49,9 @@ public class RecipeService {
     @Autowired
     private RecipeStuffsRepository recipeStuffsRepository;
 
+    @Autowired
+    private StocksService stockService;
+
     /**
      * レシピを新規登録する
      *
@@ -102,6 +105,34 @@ public class RecipeService {
         return recipesRepository.findAll();
     }
 
+    /**
+     * レシピを指定して，現在の在庫を参照しそのレシピが最大何人分作れるか返す
+     * 
+     * @param userId ユーザーID
+     * @param recipe レシピのエンティティ
+     * @throws RuntimeException レシピが材料を持たないなど，計算に失敗したとき
+     * @return 最大何人分作れるか
+     */
+    public int getRecipeMaxServings(Long userId, Recipes recipe) {
+
+        List<RecipeStuffs> recipeStuffs = recipeStuffsRepository.findByRecipesRecipeId(recipe.getRecipeId());
+
+        //  各材料がその料理のレシピで何人分在庫があるか計算し，それらの最小値が料理全体での人数になる
+        Integer minNServings = null;
+        for (RecipeStuffs recipeStuff : recipeStuffs) {
+            int stockAmount = stockService.calcAmountByStuffId(userId, recipeStuff.getStuff().getStuffId());
+            int nServings = stockAmount / recipeStuff.getAmount(); // 小数点以下切り捨て（整数除算）
+            if (minNServings == null || minNServings > nServings) {
+                minNServings = nServings;
+            }
+        }
+
+        //  recipeStuffs が空の場合などに null のままになる（通常は起こりえない）
+        if (minNServings == null) throw new RuntimeException("Failed to calculate recipeMaxServings");
+
+        return minNServings;
+    }
+
     /**
      * 指定されたIDのレシピ詳細情報を取得する
      *

frontend/src/services/api.ts

@@ -456,7 +456,12 @@ export const recipeApi = {
         errorData?.message
       );
     }
-    return response.json();
+
+    //  デバッグ用に表示
+    const recipes = response.json();
+    console.log('recipes: ', recipes);
+
+    return recipes;
   },
 
   /**

frontend/src/types/types.ts

@@ -142,7 +142,8 @@ export interface Recipe {
 }
 
 export interface RecipeWithId extends Recipe {
-  recipeId: number;
+  recipeId: number; // レシピID
+  maxServings: number; // 最大調理可能数
 }
 
 /**