[#13] Rename go module name according to NSPCC standards

- refactoring s3 gate structure
- cleanup unused code
- rename go module to `github.com/nspcc-dev/neofs-s3-gate`

closes #13

Signed-off-by: Evgeniy Kulikov <kim@nspcc.ru>

api/layer/container.go

@@ -0,0 +1,130 @@
+package layer
+
+import (
+	"context"
+	"time"
+
+	"github.com/nspcc-dev/neofs-api-go/container"
+	"github.com/nspcc-dev/neofs-api-go/refs"
+	"github.com/nspcc-dev/neofs-api-go/service"
+	"github.com/nspcc-dev/neofs-s3-gate/auth"
+	"go.uber.org/zap"
+)
+
+type (
+	BucketInfo struct {
+		Name    string
+		CID     refs.CID
+		Created time.Time
+	}
+
+	ListObjectsParams struct {
+		Bucket    string
+		Prefix    string
+		Token     string
+		Delimiter string
+		MaxKeys   int
+	}
+)
+
+func (n *layer) containerInfo(ctx context.Context, cid refs.CID) (*BucketInfo, error) {
+	bearer, err := auth.GetBearerToken(ctx)
+	if err != nil {
+		n.log.Error("could not receive bearer token",
+			zap.Error(err))
+		return nil, err
+	}
+
+	req := new(container.GetRequest)
+	req.SetCID(cid)
+	req.SetTTL(service.SingleForwardingTTL)
+	// req.SetBearer(bearer)
+
+	_ = bearer
+
+	if err = service.SignRequestData(n.key, req); err != nil {
+		n.log.Error("could not prepare request",
+			zap.Error(err))
+		return nil, err
+	}
+
+	conn, err := n.cli.GetConnection(ctx)
+	if err != nil {
+		n.log.Error("could not prepare client",
+			zap.Error(err))
+		return nil, err
+	}
+
+	// todo: think about timeout
+	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+	defer cancel()
+
+	res, err := container.NewServiceClient(conn).Get(ctx, req)
+	if err != nil {
+		n.log.Error("could not list buckets",
+			zap.Error(err))
+		return nil, err
+	}
+
+	_ = res
+
+	return &BucketInfo{
+		CID:     cid,
+		Name:    cid.String(), // should be fetched from container.GetResponse
+		Created: time.Time{},  // should be fetched from container.GetResponse
+	}, nil
+}
+
+func (n *layer) containerList(ctx context.Context) ([]BucketInfo, error) {
+	bearer, err := auth.GetBearerToken(ctx)
+	if err != nil {
+		n.log.Error("could not receive bearer token",
+			zap.Error(err))
+		return nil, err
+	}
+
+	req := new(container.ListRequest)
+	req.OwnerID = n.uid
+	req.SetTTL(service.SingleForwardingTTL)
+	// req.SetBearer(bearer)
+
+	_ = bearer
+
+	if err := service.SignRequestData(n.key, req); err != nil {
+		n.log.Error("could not prepare request",
+			zap.Error(err))
+		return nil, err
+	}
+
+	conn, err := n.cli.GetConnection(ctx)
+	if err != nil {
+		n.log.Error("could not prepare client",
+			zap.Error(err))
+		return nil, err
+	}
+
+	// todo: think about timeout
+	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+	defer cancel()
+
+	res, err := container.NewServiceClient(conn).List(ctx, req)
+	if err != nil {
+		n.log.Error("could not list buckets",
+			zap.Error(err))
+		return nil, err
+	}
+
+	list := make([]BucketInfo, 0, len(res.CID))
+	for _, cid := range res.CID {
+		info, err := n.containerInfo(ctx, cid)
+		if err != nil {
+			n.log.Error("could not fetch container info",
+				zap.Error(err))
+			continue
+		}
+
+		list = append(list, *info)
+	}
+
+	return list, nil
+}