[#1310] object: Move target initialization to separate package

* Split the logic of write target initialization to different packages;
* Refactor patch and put services: since both service initialize the target
  themselves.

Signed-off-by: Airat Arifullin <a.arifullin@yadro.com>

pkg/services/object/common/writer/remote.go

@@ -0,0 +1,131 @@
+package writer
+
+import (
+	"context"
+	"crypto/ecdsa"
+	"fmt"
+
+	clientcore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/client"
+	netmapCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/netmap"
+	objectcore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
+	internalclient "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/internal/client"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/util"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
+	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+type remoteWriter struct {
+	privateKey *ecdsa.PrivateKey
+
+	commonPrm *util.CommonPrm
+
+	nodeInfo clientcore.NodeInfo
+
+	clientConstructor ClientConstructor
+}
+
+// RemoteSender represents utility for
+// sending an object to a remote host.
+type RemoteSender struct {
+	keyStorage *util.KeyStorage
+
+	clientConstructor ClientConstructor
+}
+
+// RemotePutPrm groups remote put operation parameters.
+type RemotePutPrm struct {
+	node netmap.NodeInfo
+
+	obj *objectSDK.Object
+}
+
+func (t *remoteWriter) WriteObject(ctx context.Context, obj *objectSDK.Object, _ objectcore.ContentMeta) error {
+	c, err := t.clientConstructor.Get(t.nodeInfo)
+	if err != nil {
+		return fmt.Errorf("(%T) could not create SDK client %s: %w", t, t.nodeInfo, err)
+	}
+
+	var prm internalclient.PutObjectPrm
+
+	prm.SetClient(c)
+	prm.SetPrivateKey(t.privateKey)
+	prm.SetSessionToken(t.commonPrm.SessionToken())
+	prm.SetBearerToken(t.commonPrm.BearerToken())
+	prm.SetXHeaders(t.commonPrm.XHeaders())
+	prm.SetObject(obj)
+
+	err = t.putSingle(ctx, prm)
+	if status.Code(err) != codes.Unimplemented {
+		return err
+	}
+
+	return t.putStream(ctx, prm)
+}
+
+func (t *remoteWriter) putStream(ctx context.Context, prm internalclient.PutObjectPrm) error {
+	_, err := internalclient.PutObject(ctx, prm)
+	if err != nil {
+		return fmt.Errorf("(%T) could not put object to %s: %w", t, t.nodeInfo.AddressGroup(), err)
+	}
+	return nil
+}
+
+func (t *remoteWriter) putSingle(ctx context.Context, prm internalclient.PutObjectPrm) error {
+	_, err := internalclient.PutObjectSingle(ctx, prm)
+	if err != nil {
+		return fmt.Errorf("(%T) could not put single object to %s: %w", t, t.nodeInfo.AddressGroup(), err)
+	}
+	return nil
+}
+
+// NewRemoteSender creates, initializes and returns new RemoteSender instance.
+func NewRemoteSender(keyStorage *util.KeyStorage, cons ClientConstructor) *RemoteSender {
+	return &RemoteSender{
+		keyStorage:        keyStorage,
+		clientConstructor: cons,
+	}
+}
+
+// WithNodeInfo sets information about the remote node.
+func (p *RemotePutPrm) WithNodeInfo(v netmap.NodeInfo) *RemotePutPrm {
+	if p != nil {
+		p.node = v
+	}
+
+	return p
+}
+
+// WithObject sets transferred object.
+func (p *RemotePutPrm) WithObject(v *objectSDK.Object) *RemotePutPrm {
+	if p != nil {
+		p.obj = v
+	}
+
+	return p
+}
+
+// PutObject sends object to remote node.
+func (s *RemoteSender) PutObject(ctx context.Context, p *RemotePutPrm) error {
+	key, err := s.keyStorage.GetKey(nil)
+	if err != nil {
+		return err
+	}
+
+	t := &remoteWriter{
+		privateKey:        key,
+		clientConstructor: s.clientConstructor,
+	}
+
+	err = clientcore.NodeInfoFromRawNetmapElement(&t.nodeInfo, netmapCore.Node(p.node))
+	if err != nil {
+		return fmt.Errorf("parse client node info: %w", err)
+	}
+
+	if err := t.WriteObject(ctx, p.obj, objectcore.ContentMeta{}); err != nil {
+		return fmt.Errorf("(%T) could not send object: %w", s, err)
+	}
+
+	return nil
+}