From 9ab0571d2935bd7b88707024fae8bf2b7d7bda94 Mon Sep 17 00:00:00 2001
From: Evgeniy Kulikov <kim@nspcc.ru>
Date: Thu, 20 Aug 2020 02:35:51 +0300
Subject: [PATCH] Implement CopyObject handler

Signed-off-by: Evgeniy Kulikov <kim@nspcc.ru>
---
 api/handler/copy.go     | 96 +++++++++++++++++++++++++++++++++++++++++
 api/handler/response.go |  7 +++
 2 files changed, 103 insertions(+)
 create mode 100644 api/handler/copy.go

diff --git a/api/handler/copy.go b/api/handler/copy.go
new file mode 100644
index 00000000..92235ccd
--- /dev/null
+++ b/api/handler/copy.go
@@ -0,0 +1,96 @@
+package handler
+
+import (
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"github.com/gorilla/mux"
+	"github.com/nspcc-dev/neofs-s3-gate/api"
+	"github.com/nspcc-dev/neofs-s3-gate/api/layer"
+	"go.uber.org/zap"
+)
+
+// path2BucketObject returns bucket and object.
+func path2BucketObject(path string) (bucket, prefix string) {
+	path = strings.TrimPrefix(path, api.SlashSeparator)
+	m := strings.Index(path, api.SlashSeparator)
+	if m < 0 {
+		return path, ""
+	}
+	return path[:m], path[m+len(api.SlashSeparator):]
+}
+
+func (h *handler) CopyObjectHandler(w http.ResponseWriter, r *http.Request) {
+	var (
+		err error
+		inf *layer.ObjectInfo
+
+		req = mux.Vars(r)
+		bkt = req["bucket"]
+		obj = req["object"]
+		rid = api.GetRequestID(r.Context())
+	)
+
+	src := r.Header.Get("X-Amz-Copy-Source")
+	// Check https://docs.aws.amazon.com/AmazonS3/latest/dev/ObjectVersioning.html
+	// Regardless of whether you have enabled versioning, each object in your bucket
+	// has a version ID. If you have not enabled versioning, Amazon S3 sets the value
+	// of the version ID to null. If you have enabled versioning, Amazon S3 assigns a
+	// unique version ID value for the object.
+	if u, err := url.Parse(src); err == nil {
+		// Check if versionId query param was added, if yes then check if
+		// its non "null" value, we should error out since we do not support
+		// any versions other than "null".
+		if vid := u.Query().Get("versionId"); vid != "" && vid != "null" {
+			api.WriteErrorResponse(r.Context(), w, api.Error{
+				Code:           api.GetAPIError(api.ErrNoSuchVersion).Code,
+				Description:    "",
+				HTTPStatusCode: http.StatusBadRequest,
+			}, r.URL)
+			return
+		}
+
+		src = u.Path
+	}
+
+	srcBucket, srcObject := path2BucketObject(src)
+
+	params := &layer.CopyObjectParams{
+		SrcBucket: srcBucket,
+		DstBucket: bkt,
+		SrcObject: srcObject,
+		DstObject: obj,
+	}
+
+	if inf, err = h.obj.CopyObject(r.Context(), params); err != nil {
+		h.log.Error("could not copy object",
+			zap.String("request_id", rid),
+			zap.String("dst_bucket_name", bkt),
+			zap.String("dst_object_name", obj),
+			zap.String("src_bucket_name", srcBucket),
+			zap.String("src_object_name", srcObject),
+			zap.Error(err))
+
+		api.WriteErrorResponse(r.Context(), w, api.Error{
+			Code:           api.GetAPIError(api.ErrInternalError).Code,
+			Description:    err.Error(),
+			HTTPStatusCode: http.StatusInternalServerError,
+		}, r.URL)
+	} else if err = api.EncodeToResponse(w, &CopyObjectResponse{LastModified: inf.Created.Format(time.RFC3339)}); err != nil {
+		h.log.Error("something went wrong",
+			zap.String("request_id", rid),
+			zap.String("dst_bucket_name", bkt),
+			zap.String("dst_object_name", obj),
+			zap.String("src_bucket_name", srcBucket),
+			zap.String("src_object_name", srcObject),
+			zap.Error(err))
+
+		api.WriteErrorResponse(r.Context(), w, api.Error{
+			Code:           api.GetAPIError(api.ErrInternalError).Code,
+			Description:    err.Error(),
+			HTTPStatusCode: http.StatusInternalServerError,
+		}, r.URL)
+	}
+}
diff --git a/api/handler/response.go b/api/handler/response.go
index 84d61cf4..d29d263f 100644
--- a/api/handler/response.go
+++ b/api/handler/response.go
@@ -87,6 +87,13 @@ type LocationResponse struct {
 	Location string   `xml:",chardata"`
 }
 
+// CopyObjectResponse container returns ETag and LastModified of the successfully copied object
+type CopyObjectResponse struct {
+	XMLName      xml.Name `xml:"http://s3.amazonaws.com/doc/2006-03-01/ CopyObjectResult" json:"-"`
+	LastModified string   // time string of format "2006-01-02T15:04:05.000Z"
+	ETag         string   // md5sum of the copied object.
+}
+
 // MarshalXML - StringMap marshals into XML.
 func (s StringMap) MarshalXML(e *xml.Encoder, start xml.StartElement) error {