feat: RecipeController with GET, POST, PUT, DELETE

TODO: WebSockets updates should be propagated after POST/PUT/DELETE operations

server/src/main/java/server/api/RecipeController.java

@@ -0,0 +1,121 @@
+package server.api;
+
+import commons.Recipe;
+
+import org.springframework.data.domain.PageRequest;
+import org.springframework.http.ResponseEntity;
+
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import server.database.RecipeRepository;
+
+import java.util.List;
+import java.util.Optional;
+
+@RestController
+@RequestMapping("/recipe")
+public class RecipeController {
+    private final RecipeRepository recipeRepository; // JPA repository used in this controller
+
+    public RecipeController(RecipeRepository recipeRepository) {
+        this.recipeRepository = recipeRepository;
+    }
+
+    /**
+     * Mapping for <code>GET /recipe/{id}</code>
+     * <p>
+     *     Gets a specific recipe by its unique id.
+     * </p>
+     * @param id id of the recipe
+     * @return The recipe if it exists in the repository; otherwise returns 404 Not Found status
+     */
+    @GetMapping("/recipe/{id}")
+    public ResponseEntity<Recipe> getRecipe(@PathVariable Long id) {
+        if (!recipeRepository.existsById(id)) {
+            return ResponseEntity.notFound().build();
+        }
+        return ResponseEntity.ok(recipeRepository.findById(id).get());
+    }
+
+    /**
+     * Mapping for <code>GET /recipes(?limit=)</code>
+     * <p>
+     * If the limit parameter is unspecified, return all recipes in the repository.
+     * @param limit Integer limit of items you want to get
+     * @return The list of recipes
+     */
+    @GetMapping("/recipes")
+    public ResponseEntity<List<Recipe>> getRecipes(@RequestParam Optional<Integer> limit) {
+        if (limit.isPresent()) {
+            return ResponseEntity.ok(
+                    recipeRepository.findAll(
+                            PageRequest.of(0, limit.get())
+                    ).toList());
+        }
+        return ResponseEntity.ok(recipeRepository.findAll());
+    }
+
+    /**
+     * Mapping for <code>POST /recipe/{id}</code>
+     * @param id The recipe id to replace
+     * @param recipe The new recipe to be replaced from the original
+     * @return The changed recipe; returns 400 Bad Request if the recipe does not exist
+     */
+    @PostMapping("/recipe/{id}")
+    public ResponseEntity<Recipe> updateRecipe(@PathVariable Long id, @RequestBody Recipe recipe) {
+        if (!recipeRepository.existsById(id)) {
+            return ResponseEntity.badRequest().build();
+        }
+
+        // TODO: Send WS update to all subscribers with the updated recipe
+
+        return ResponseEntity.ok(recipeRepository.save(recipe));
+    }
+
+    /**
+     * Mapping for <code>PUT /recipe/new</code>
+     * <p>
+     *     Inserts a new recipe into the repository
+     * </p>
+     * @param recipe The new recipe as a request body
+     * @return 200 OK with the recipe you added; or 400 Bad Request if the recipe already exists
+     */
+    @PutMapping("/recipe/new")
+    public ResponseEntity<Recipe> createRecipe(@RequestBody Recipe recipe) {
+        if (recipeRepository.existsById(recipe.getId())) {
+            return ResponseEntity.badRequest().build();
+        }
+
+        // TODO: Send WS update to all subscribers with the new recipe
+
+        return ResponseEntity.ok(recipeRepository.save(recipe));
+    }
+
+    /**
+     * Mapping for <code>DELETE /recipe/{id}</code>
+     * <p>
+     *     Deletes a recipe identified by its <code>id</code>.
+     * </p>
+     * @param id The id of the recipe to be deleted.
+     * @return 200 OK with the recipe that was deleted; or 400 Bad Request if the recipe doesn't exist.
+     */
+    @DeleteMapping("/recipe/{id}")
+    public ResponseEntity<Recipe> deleteRecipe(@PathVariable Long id) {
+        if (!recipeRepository.existsById(id)) {
+            return ResponseEntity.badRequest().build();
+        }
+        Recipe removedRecipe = recipeRepository.findById(id).get();
+        recipeRepository.delete(removedRecipe);
+
+        // TODO: Send WS update to propagate deletion
+        return ResponseEntity.ok(removedRecipe);
+    }
+}