From b5d0c9c1a3c543198361c763d16c05cb53107944 Mon Sep 17 00:00:00 2001
From: programmer10110 <programmer10110@yandex.ru>
Date: Fri, 16 Oct 2020 14:00:04 +0300
Subject: [PATCH] get/save an offset for a storage

---
 client/http_server.go | 45 ++++++++++++++++++++++++++++++++-
 cmd/dc4bc_cli/main.go | 59 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+), 1 deletion(-)

diff --git a/client/http_server.go b/client/http_server.go
index 95659e7..4eff00f 100644
--- a/client/http_server.go
+++ b/client/http_server.go
@@ -8,7 +8,6 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
-
 	"time"
 
 	"github.com/depools/dc4bc/client/types"
@@ -80,6 +79,9 @@ func (c *BaseClient) StartHTTPServer(listenAddr string) error {
 	mux.HandleFunc("/startDKG", c.startDKGHandler)
 	mux.HandleFunc("/proposeSignMessage", c.proposeSignDataHandler)
 
+	mux.HandleFunc("/saveOffset", c.saveOffsetHandler)
+	mux.HandleFunc("/getOffset", c.getOffsetHandler)
+
 	c.Logger.Log("Starting HTTP server on address: %s", listenAddr)
 	return http.ListenAndServe(listenAddr, mux)
 }
@@ -100,6 +102,47 @@ func (c *BaseClient) getPubkeyHandler(w http.ResponseWriter, r *http.Request) {
 	successResponse(w, c.GetPubKey())
 }
 
+func (c *BaseClient) getOffsetHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		errorResponse(w, http.StatusBadRequest, "Wrong HTTP method")
+		return
+	}
+	offset, err := c.state.LoadOffset()
+	if err != nil {
+		errorResponse(w, http.StatusInternalServerError, fmt.Sprintf("failed to load offset: %v", err))
+		return
+	}
+	successResponse(w, offset)
+}
+
+func (c *BaseClient) saveOffsetHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		errorResponse(w, http.StatusBadRequest, "Wrong HTTP method")
+		return
+	}
+	reqBytes, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		errorResponse(w, http.StatusBadRequest, fmt.Sprintf("failed to read request body: %v", err))
+		return
+	}
+	defer r.Body.Close()
+
+	var req map[string]uint64
+	if err = json.Unmarshal(reqBytes, &req); err != nil {
+		errorResponse(w, http.StatusInternalServerError, fmt.Sprintf("failed to unmarshal request: %v", err))
+		return
+	}
+	if _, ok := req["offset"]; !ok {
+		errorResponse(w, http.StatusInternalServerError, fmt.Sprintf("offset cannot be null: %v", err))
+		return
+	}
+	if err = c.state.SaveOffset(req["offset"]); err != nil {
+		errorResponse(w, http.StatusInternalServerError, fmt.Sprintf("failed to save offset: %v", err))
+		return
+	}
+	successResponse(w, "ok")
+}
+
 func (c *BaseClient) sendMessageHandler(w http.ResponseWriter, r *http.Request) {
 	if r.Method != http.MethodPost {
 		errorResponse(w, http.StatusBadRequest, "Wrong HTTP method")
diff --git a/cmd/dc4bc_cli/main.go b/cmd/dc4bc_cli/main.go
index 4c98776..3b89256 100644
--- a/cmd/dc4bc_cli/main.go
+++ b/cmd/dc4bc_cli/main.go
@@ -12,6 +12,7 @@ import (
 	"net/http"
 	"path/filepath"
 	"sort"
+	"strconv"
 	"time"
 
 	"github.com/depools/dc4bc/fsm/fsm"
@@ -56,6 +57,8 @@ func main() {
 		getHashOfStartDKGCommand(),
 		getSignaturesCommand(),
 		getSignatureCommand(),
+		saveOffsetCommand(),
+		getOffsetCommand(),
 	)
 	if err := rootCmd.Execute(); err != nil {
 		log.Fatalf("Failed to execute root command: %v", err)
@@ -325,6 +328,62 @@ func getPubKeyCommand() *cobra.Command {
 	}
 }
 
+func saveOffsetCommand() *cobra.Command {
+	return &cobra.Command{
+		Use:   "save_offset [offset]",
+		Short: "saves a new offset for a storage",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			listenAddr, err := cmd.Flags().GetString(flagListenAddr)
+			if err != nil {
+				return fmt.Errorf("failed to read configuration: %v", err)
+			}
+
+			offset, err := strconv.ParseUint(args[0], 10, 64)
+			if err != nil {
+				return fmt.Errorf("failed to parse uint: %w", err)
+			}
+			req := map[string]uint64{"offset": offset}
+			data, err := json.Marshal(req)
+			if err != nil {
+				return fmt.Errorf("failed to create request: %w", err)
+			}
+			resp, err := rawPostRequest(fmt.Sprintf("http://%s/saveOffset", listenAddr), "application/json", data)
+			if err != nil {
+				return fmt.Errorf("failed to save offset: %w", err)
+			}
+			if resp.ErrorMessage != "" {
+				return fmt.Errorf("failed to save offset: %v", resp.ErrorMessage)
+			}
+			fmt.Println(resp.Result.(string))
+			return nil
+		},
+	}
+}
+
+func getOffsetCommand() *cobra.Command {
+	return &cobra.Command{
+		Use:   "get_offset",
+		Short: "returns a current offset for the storage",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			listenAddr, err := cmd.Flags().GetString(flagListenAddr)
+			if err != nil {
+				return fmt.Errorf("failed to read configuration: %v", err)
+			}
+
+			resp, err := rawGetRequest(fmt.Sprintf("http://%s//getOffset", listenAddr))
+			if err != nil {
+				return fmt.Errorf("failed to get offset: %w", err)
+			}
+			if resp.ErrorMessage != "" {
+				return fmt.Errorf("failed to get offset: %v", resp.ErrorMessage)
+			}
+			fmt.Println(uint64(resp.Result.(float64)))
+			return nil
+		},
+	}
+}
+
 func getUsernameCommand() *cobra.Command {
 	return &cobra.Command{
 		Use:   "get_username",