Prepare list-buckets handler

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

api/handler/list-buckets.go

@@ -0,0 +1,73 @@
+package handler
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/nspcc-dev/neofs-s3-gate/api"
+	"github.com/nspcc-dev/neofs-s3-gate/auth"
+	"go.uber.org/zap"
+)
+
+func (h *handler) ListBucketsHandler(w http.ResponseWriter, r *http.Request) {
+	var (
+		res *ListBucketsResponse
+		rid = api.GetRequestID(r.Context())
+	)
+
+	tkn, err := auth.GetBearerToken(r.Context())
+	if err != nil {
+		h.log.Error("something went wrong",
+			zap.String("request_id", rid),
+			zap.Error(err))
+
+		api.WriteErrorResponse(r.Context(), w, api.Error{
+			Code:           api.GetAPIError(api.ErrInternalError).Code,
+			Description:    err.Error(),
+			HTTPStatusCode: http.StatusInternalServerError,
+		}, r.URL)
+
+		return
+	}
+
+	list, err := h.obj.ListBuckets(r.Context())
+	if err != nil {
+		h.log.Error("something went wrong",
+			zap.String("request_id", rid),
+			zap.Error(err))
+
+		api.WriteErrorResponse(r.Context(), w, api.Error{
+			Code:           api.GetAPIError(api.ErrInternalError).Code,
+			Description:    err.Error(),
+			HTTPStatusCode: http.StatusInternalServerError,
+		}, r.URL)
+
+		return
+	}
+
+	res = &ListBucketsResponse{
+		Owner: Owner{
+			ID:          tkn.OwnerID.String(),
+			DisplayName: tkn.OwnerID.String(),
+		},
+	}
+
+	for _, item := range list {
+		res.Buckets.Buckets = append(res.Buckets.Buckets, Bucket{
+			Name:         item.Name,
+			CreationDate: item.Created.Format(time.RFC3339),
+		})
+	}
+
+	if err = api.EncodeToResponse(w, res); err != nil {
+		h.log.Error("something went wrong",
+			zap.String("request_id", rid),
+			zap.Error(err))
+
+		api.WriteErrorResponse(r.Context(), w, api.Error{
+			Code:           api.GetAPIError(api.ErrInternalError).Code,
+			Description:    err.Error(),
+			HTTPStatusCode: http.StatusInternalServerError,
+		}, r.URL)
+	}
+}