[#137] Add index page support

Signed-off-by: Nikita Zinkevich <n.zinkevich@yadro.com>

internal/handler/handler.go

@@ -30,6 +30,8 @@ type Config interface {
 	DefaultTimestamp() bool
 	ZipCompression() bool
 	ClientCut() bool
+	IndexPageEnabled() bool
+	IndexPageTemplate() string
 	BufferMaxSizeForPut() uint64
 	NamespaceHeader() string
 }
@@ -208,41 +210,50 @@ func (h *Handler) byAddress(c *fasthttp.RequestCtx, f func(context.Context, requ
 
 // byObjectName is a wrapper for function (e.g. request.headObject, request.receiveFile) that
 // prepares request and object address to it.
-func (h *Handler) byObjectName(req *fasthttp.RequestCtx, f func(context.Context, request, oid.Address)) {
+func (h *Handler) byObjectName(c *fasthttp.RequestCtx, f func(context.Context, request, oid.Address)) {
 	var (
-		bucketname = req.UserValue("cid").(string)
-		key        = req.UserValue("oid").(string)
+		bucketname = c.UserValue("cid").(string)
+		key        = c.UserValue("oid").(string)
 		log        = h.log.With(zap.String("bucketname", bucketname), zap.String("key", key))
+		download   = c.QueryArgs().GetBool("download")
 	)
 
 	unescapedKey, err := url.QueryUnescape(key)
 	if err != nil {
-		logAndSendBucketError(req, log, err)
+		logAndSendBucketError(c, log, err)
 		return
 	}
 
-	ctx := utils.GetContextFromRequest(req)
+	ctx := utils.GetContextFromRequest(c)
 
 	bktInfo, err := h.getBucketInfo(ctx, bucketname, log)
 	if err != nil {
-		logAndSendBucketError(req, log, err)
+		logAndSendBucketError(c, log, err)
 		return
 	}
 
 	foundOid, err := h.tree.GetLatestVersion(ctx, &bktInfo.CID, unescapedKey)
+	if h.config.IndexPageEnabled() && !download && string(c.Method()) != fasthttp.MethodHead {
+		if isDir(unescapedKey) || isContainerRoot(unescapedKey) {
+			if code := checkErrorType(err); code == fasthttp.StatusNotFound || code == fasthttp.StatusOK {
+				c.SetStatusCode(code)
+				h.browseObjects(c, bktInfo, unescapedKey)
+				return
+			}
+		}
+	}
 	if err != nil {
 		if errors.Is(err, tree.ErrNodeAccessDenied) {
-			response.Error(req, "Access Denied", fasthttp.StatusForbidden)
-			return
+			response.Error(c, "Access Denied", fasthttp.StatusForbidden)
+		} else {
+			response.Error(c, "object wasn't found", fasthttp.StatusNotFound)
+			log.Error(logs.GetLatestObjectVersion, zap.Error(err))
 		}
-		log.Error(logs.GetLatestObjectVersion, zap.Error(err))
-
-		response.Error(req, "object wasn't found", fasthttp.StatusNotFound)
 		return
 	}
 	if foundOid.DeleteMarker {
 		log.Error(logs.ObjectWasDeleted)
-		response.Error(req, "object deleted", fasthttp.StatusNotFound)
+		response.Error(c, "object deleted", fasthttp.StatusNotFound)
 		return
 	}
 
@@ -250,7 +261,7 @@ func (h *Handler) byObjectName(req *fasthttp.RequestCtx, f func(context.Context,
 	addr.SetContainer(bktInfo.CID)
 	addr.SetObject(foundOid.OID)
 
-	f(ctx, *h.newRequest(req, log), addr)
+	f(ctx, *h.newRequest(c, log), addr)
 }
 
 // byAttribute is a wrapper similar to byAddress.
@@ -379,3 +390,25 @@ func (h *Handler) readContainer(ctx context.Context, cnrID cid.ID) (*data.Bucket
 
 	return bktInfo, err
 }
+
+func (h *Handler) listObjects(ctx context.Context, bucketInfo *data.BucketInfo, prefix string) ([]map[string]string, error) {
+	nodes, _, err := h.tree.GetSubTreeByPrefix(ctx, bucketInfo, prefix, true)
+	if err != nil {
+		return nil, err
+	}
+
+	var objects = make([]map[string]string, 0, len(nodes))
+	for _, node := range nodes {
+		meta := node.GetMeta()
+		if meta == nil {
+			continue
+		}
+		var obj = make(map[string]string, len(meta))
+		for _, m := range meta {
+			obj[m.GetKey()] = string(m.GetValue())
+		}
+		objects = append(objects, obj)
+	}
+
+	return objects, nil
+}