implement main functionality

src/main/java/ua/com/dxrkness/controller/S3FileHandler.java

@@ -1,4 +1,102 @@
 package ua.com.dxrkness.controller;
 
+import jakarta.servlet.ServletException;
+import org.springframework.http.MediaType;
+import org.springframework.stereotype.Component;
+import org.springframework.web.servlet.function.ServerRequest;
+import org.springframework.web.servlet.function.ServerResponse;
+import software.amazon.awssdk.services.s3.model.S3Exception;
+import ua.com.dxrkness.model.DirectoryPath;
+import ua.com.dxrkness.service.S3Service;
+
+import java.io.IOException;
+import java.net.URI;
+import java.util.Optional;
+
+@Component
 public class S3FileHandler {
+    private final S3Service service;
+
+    public S3FileHandler(S3Service service) {
+        this.service = service;
+    }
+
+    public ServerResponse createDirectory(ServerRequest request) throws ServletException, IOException {
+        return Optional.of(request.body(DirectoryPath.class))
+                .map(DirectoryPath::path)
+                .map(body -> {
+                    try {
+                        service.createDirectory(body);
+                        return ServerResponse.created(body).build();
+                    } catch (S3Exception exception) {
+                        return ServerResponse.badRequest().build();
+                    }
+                }).get();
+    }
+
+    public ServerResponse downloadFile(ServerRequest request) throws ServletException, IOException {
+        return Optional.of(request.body(DirectoryPath.class))
+                .map(DirectoryPath::path)
+                .map(URI::toString)
+                .map(service::downloadFile)
+                .map(reader -> {
+                    try (reader) {
+                        return ServerResponse
+                                .ok()
+                                .contentType(MediaType.APPLICATION_OCTET_STREAM)
+                                .body(reader.readAllBytes());
+                    } catch (IOException e) {
+                        return ServerResponse.badRequest().build();
+                    }
+                }).get();
+    }
+
+    public ServerResponse uploadFile(ServerRequest request) throws ServletException, IOException {
+        return Optional.of(request.multipartData())
+                .map(data -> data.getFirst("file"))
+                .map(file -> {
+                    try {
+                        final var path = request.param("path")
+                                .map(URI::create)
+                                .orElse(URI.create(""));
+
+                        service.uploadFile(file, path);
+                        return ServerResponse
+                                .created(URI.create("/files"))
+                                .body(new DirectoryPath(
+                                        path.resolve(
+                                                file.getSubmittedFileName()
+                                        )
+                                ));
+                    } catch (IOException e) {
+                        return ServerResponse.badRequest().build();
+                    }
+                })
+                .get();
+    }
+
+    public ServerResponse listing(ServerRequest request) throws ServletException, IOException {
+        return Optional.of(request.body(DirectoryPath.class))
+                .map(key -> service.listing(key.path()))
+                .map(objects -> ServerResponse.ok().body(objects))
+                .get();
+    }
+
+    public ServerResponse delete(ServerRequest request) throws ServletException, IOException {
+        return Optional.of(request.body(DirectoryPath.class))
+                .map(DirectoryPath::path)
+                .map(path -> {
+                    try {
+                        service.delete(path);
+                        return ServerResponse.noContent().build();
+                    } catch (S3Exception e) {
+                        return ServerResponse.badRequest().build();
+                    }
+                })
+                .get();
+    }
+
+    public ServerResponse listBuckets(ServerRequest request) {
+        return ServerResponse.ok().body(service.listBuckets());
+    }
 }