From 79cdeaaf8ba788e4ab6fd5a56ef84e614675e099 Mon Sep 17 00:00:00 2001
From: Jamie Holdstock <jholdstock@decred.org>
Date: Sun, 25 Apr 2021 14:22:13 +0100
Subject: [PATCH] Add parser for blockconnected notification (#238)

---
 background/background.go |  3 +--
 go.sum                   |  1 -
 rpc/dcrd.go              | 25 +++++++++++++++++++++++++
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/background/background.go b/background/background.go
index e6161bf..1b4bc69 100644
--- a/background/background.go
+++ b/background/background.go
@@ -12,7 +12,6 @@ import (
 	"sync"
 	"time"
 
-	"decred.org/dcrwallet/rpc/client/dcrd"
 	"github.com/decred/dcrd/chaincfg/v3"
 	"github.com/decred/vspd/database"
 	"github.com/decred/vspd/rpc"
@@ -46,7 +45,7 @@ func (n *NotificationHandler) Notify(method string, params json.RawMessage) erro
 		return nil
 	}
 
-	header, _, err := dcrd.BlockConnected(params)
+	header, err := rpc.ParseBlockConnectedNotification(params)
 	if err != nil {
 		log.Errorf("Failed to parse dcrd block notification: %v", err)
 		return nil
diff --git a/go.sum b/go.sum
index fc840c9..295f43c 100644
--- a/go.sum
+++ b/go.sum
@@ -171,7 +171,6 @@ golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208 h1:qwRHBd0NqMbJxfbotnDhm2ByMI1Shq4Y6oRJo21SGJA=
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
diff --git a/rpc/dcrd.go b/rpc/dcrd.go
index 71b0cff..e95a046 100644
--- a/rpc/dcrd.go
+++ b/rpc/dcrd.go
@@ -5,8 +5,10 @@
 package rpc
 
 import (
+	"bytes"
 	"context"
 	"encoding/hex"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"strings"
@@ -221,3 +223,26 @@ func (c *DcrdRPC) CanTicketVote(rawTx *dcrdtypes.TxRawResult, ticketHash string,
 
 	return live, nil
 }
+
+// ParseBlockConnectedNotification extracts the block header from a
+// blockconnected JSON-RPC notification.
+func ParseBlockConnectedNotification(params json.RawMessage) (*wire.BlockHeader, error) {
+	var notif []string
+	err := json.Unmarshal(params, &notif)
+	if err != nil {
+		return nil, fmt.Errorf("json unmarshal error: %w", err)
+	}
+
+	if len(notif) == 0 {
+		return nil, errors.New("notification is empty")
+	}
+
+	rawHeader := notif[0]
+	var header wire.BlockHeader
+	err = header.Deserialize(hex.NewDecoder(bytes.NewReader([]byte(rawHeader))))
+	if err != nil {
+		return nil, fmt.Errorf("error creating block header from bytes: %w", err)
+	}
+
+	return &header, nil
+}