feat: adds Trinitie's lesson_23 hw about Web APIs using REST

lesson_23/api/java/api_app/src/main/java/com/codedifferently/lesson23/web/MediaItemsController.java

@@ -4,12 +4,18 @@
 import com.codedifferently.lesson23.library.Library;
 import com.codedifferently.lesson23.library.MediaItem;
 import com.codedifferently.lesson23.library.search.SearchCriteria;
+import jakarta.validation.Valid;
 import java.io.IOException;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.CrossOrigin;
+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.RequestBody;
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
@@ -31,4 +37,40 @@ public ResponseEntity<GetMediaItemsResponse> getItems() {
     var response = GetMediaItemsResponse.builder().items(responseItems).build();
     return ResponseEntity.ok(response);
   }
+
+  @GetMapping("/items/{id}")
+  public ResponseEntity<MediaItemResponse> getItemById(@PathVariable String id) {
+    Set<MediaItem> items = library.search(SearchCriteria.builder().id(id).build());
+    if (items.isEmpty()) {
+      return ResponseEntity.notFound().build();
+    }
+    MediaItem item = items.iterator().next();
+    return ResponseEntity.ok(MediaItemResponse.from(item));
+  }
+
+  @PostMapping("/items")
+  public ResponseEntity<?> addNewItem(
+      @Valid @RequestBody(required = false) CreateMediaItemRequest request) {
+    if (request == null || request.getItem() == null) {
+      return ResponseEntity.badRequest().build();
+    }
+    try {
+      MediaItem item = MediaItemRequest.asMediaItem(request.getItem());
+      library.addMediaItem(item, librarian);
+      return ResponseEntity.ok(Map.of("item", MediaItemResponse.from(item)));
+    } catch (IllegalArgumentException e) {
+      return ResponseEntity.badRequest().build();
+    }
+  }
+
+  @DeleteMapping("/items/{id}")
+  public ResponseEntity<Void> deleteItem(@PathVariable String id) {
+    Set<MediaItem> items = library.search(SearchCriteria.builder().id(id).build());
+    if (items.isEmpty()) {
+      return ResponseEntity.notFound().build();
+    }
+    MediaItem item = items.iterator().next();
+    library.removeMediaItem(item, librarian);
+    return ResponseEntity.noContent().build();
+  }
 }