feat: updates the media controller class with required implementations.

lesson_26/api/java/api_app/src/main/java/com/codedifferently/lesson26/web/MediaItemsController.java

@@ -4,31 +4,100 @@
 import com.codedifferently.lesson26.library.Library;
 import com.codedifferently.lesson26.library.MediaItem;
 import com.codedifferently.lesson26.library.search.SearchCriteria;
-import java.io.IOException;
+import jakarta.validation.Valid;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
+import java.util.UUID;
 import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.MethodArgumentNotValidException;
 import org.springframework.web.bind.annotation.CrossOrigin;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.ExceptionHandler;
 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.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
 @CrossOrigin
+@RequestMapping("/items")
 public class MediaItemsController {
 
   private final Library library;
-  private final Librarian librarian;
+  private final Librarian librarian = new Librarian("default-librarian", "default-role");
 
-  public MediaItemsController(Library library) throws IOException {
+  public MediaItemsController(Library library) {
     this.library = library;
-    this.librarian = library.getLibrarians().stream().findFirst().orElseThrow();
   }
 
-  @GetMapping("/items")
+  @GetMapping
   public ResponseEntity<GetMediaItemsResponse> getItems() {
     Set<MediaItem> items = library.search(SearchCriteria.builder().build());
     List<MediaItemResponse> responseItems = items.stream().map(MediaItemResponse::from).toList();
+
     var response = GetMediaItemsResponse.builder().items(responseItems).build();
     return ResponseEntity.ok(response);
   }
+
+  @GetMapping("/{id}")
+  public ResponseEntity<MediaItemResponse> getItemById(@PathVariable String id) {
+    try {
+      Set<MediaItem> items = library.search(SearchCriteria.builder().id(id).build());
+      if (items.isEmpty()) {
+        return ResponseEntity.notFound().build();
+      }
+      MediaItemResponse response = MediaItemResponse.from(items.iterator().next());
+      return ResponseEntity.ok(response);
+    } catch (IllegalArgumentException e) {
+      return ResponseEntity.notFound().build();
+    }
+  }
+
+  @PostMapping
+  public ResponseEntity<CreateMediaItemResponse> createItem(
+      @Valid @RequestBody CreateMediaItemRequest request) {
+    try {
+      MediaItem item = MediaItemRequest.asMediaItem(request.getItem());
+      library.addMediaItem(item, librarian);
+      var response = CreateMediaItemResponse.builder().item(MediaItemResponse.from(item)).build();
+      return ResponseEntity.ok(response);
+    } catch (IllegalArgumentException e) {
+      return ResponseEntity.badRequest().build();
+    }
+  }
+
+  @DeleteMapping("/{id}")
+  public ResponseEntity<Void> deleteItemById(@PathVariable String id) {
+    try {
+      UUID uuid = UUID.fromString(id);
+      Set<MediaItem> items = library.search(SearchCriteria.builder().id(id).build());
+      if (items.isEmpty()) {
+        return ResponseEntity.notFound().build();
+      }
+      library.removeMediaItem(uuid, librarian);
+      return ResponseEntity.noContent().build();
+    } catch (IllegalArgumentException e) {
+      return ResponseEntity.notFound().build();
+    }
+  }
+
+  @ExceptionHandler(MethodArgumentNotValidException.class)
+  public ResponseEntity<Map<String, List<Map<String, String>>>> handleValidationErrors(
+      MethodArgumentNotValidException ex) {
+    List<Map<String, String>> errors =
+        ex.getBindingResult().getFieldErrors().stream()
+            .map(
+                fieldError ->
+                    Map.of(
+                        "field", fieldError.getField(),
+                        "message", fieldError.getDefaultMessage()))
+            .toList();
+
+    System.out.println("Validation errors: " + errors);
+
+    return ResponseEntity.badRequest().body(Map.of("errors", errors));
+  }
 }