From 555f322f2b853774d97fce57d46c6bae402a28d5 Mon Sep 17 00:00:00 2001
From: David Florness <david@florness.com>
Date: Tue, 25 Aug 2020 19:29:04 -0400
Subject: [PATCH] Fetch election from master when not available via elections
 file

---
 main.go | 89 ++++++++++++++++++++++++++++++---------------------------
 1 file changed, 47 insertions(+), 42 deletions(-)

diff --git a/main.go b/main.go
index 522b174..b325725 100644
--- a/main.go
+++ b/main.go
@@ -69,7 +69,7 @@ func (localVoter *LocalVoter) Bootstrap() {
 	wg.Wait()
 }
 
-func (election *Election) setupMaster() {
+func (election *Election) SetupMaster() {
 	fmt.Println("share this with peers:")
 	fmt.Printf("%s\n", election.electionKey)
 
@@ -87,8 +87,7 @@ func (election *Election) setupMaster() {
 	})
 
 	fmt.Println("press ENTER to solidify group of voters and start voting")
-	stdReader := bufio.NewReader(os.Stdin)
-	_, err := stdReader.ReadString('\n')
+	_, err := bufio.NewReader(os.Stdin).ReadString('\n')
 	if err != nil {
 		panic(err)
 	}
@@ -113,46 +112,51 @@ func (election *Election) setupMaster() {
 	election.RUnlock()
 }
 
-func (election *Election) setupSlave() {
-	logger.Info("attempting to open stream with master peer...")
+func (election *Election) SetupSlave() {
 	localVoter := election.localVoter
-	stream, err := localVoter.NewStream(localVoter.ctx, election.masterID, protocolID)
-	rw := bufio.NewReadWriter(bufio.NewReader(stream), bufio.NewWriter(stream))
-	if err != nil {
-		panic(err)
-	}
-	logger.Info("opened stream with master peer")
 
-	logger.Info("fetching election info from master")
-	_, err = rw.WriteString("info")
-	if err != nil {
-		panic(err)
-	}
-	rw.Flush()
-	stream.Close() // only stops writing
-	// first field is the rendezvous string, which is used for peer
-	// discovery
-	str, err := rw.ReadString('\n')
-	if err != nil && err != io.EOF {
-		panic(err)
-	}
-	str = stripNewline(str)
-	election.rendezvousNonce = Nonce(str)
-	// remaining fields are the candidates
-	for {
+	// have candidates and nonce been loaded from elections file?
+	// if not, fetch them from master
+	if len(election.Candidates) == 0 || election.rendezvousNonce == "" {
+		logger.Info("attempting to open stream with master peer...")
+		stream, err := localVoter.NewStream(localVoter.ctx, election.masterID, protocolID)
+		rw := bufio.NewReadWriter(bufio.NewReader(stream), bufio.NewWriter(stream))
+		if err != nil {
+			panic(err)
+		}
+		logger.Info("opened stream with master peer")
+
+		logger.Info("fetching election info from master")
+		_, err = rw.WriteString("info")
+		if err != nil {
+			panic(err)
+		}
+		rw.Flush()
+		stream.Close() // only stops writing
+		// first field is the rendezvous string, which is used for peer
+		// discovery
 		str, err := rw.ReadString('\n')
 		if err != nil && err != io.EOF {
 			panic(err)
 		}
 		str = stripNewline(str)
-		if str != "" {
-			election.Candidates = append(election.Candidates, Candidate(str))
-		}
-		if err == io.EOF {
-			break
+		election.rendezvousNonce = Nonce(str)
+		// remaining fields are the candidates
+		for {
+			str, err := rw.ReadString('\n')
+			if err != nil && err != io.EOF {
+				panic(err)
+			}
+			str = stripNewline(str)
+			if str != "" {
+				election.Candidates = append(election.Candidates, Candidate(str))
+			}
+			if err == io.EOF {
+				break
+			}
 		}
+		logger.Info("done fetching election info")
 	}
-	logger.Info("done fetching election info")
 
 	logger.Info("checking authenticity of election info...")
 	verifyElectionInfo(election, election.merkleRoot)
@@ -164,6 +168,7 @@ func (election *Election) setupSlave() {
 	localVoter.SetStreamHandler(protocolID, func(stream network.Stream) {
 		streamHandler(stream, election)
 	})
+
 	findPeers(ch, election)
 }
 
@@ -196,8 +201,7 @@ func main() {
 		// TODO: ensure at least 2 candidates
 		election = NewElectionWithCandidates(candidates)
 	} else if electionKey := flag.Arg(0); electionKey != "" {
-		// we are a slave slave the and election key was given via CLI
-		// args
+		// we are a slave the and election key was given via CLI args
 		election = NewElectionWithElectionKey(electionKey)
 	} else {
 		// create/join election via TUI
@@ -208,16 +212,17 @@ func main() {
 		}
 	}
 
+	// saves identity
+	if err := election.saveInfo(); err != nil {
+		panic(err)
+	}
+
 	election.localVoter.Bootstrap()
 
 	if election.masterID == election.localVoter.ID() {
-		election.setupMaster()
+		election.SetupMaster()
 	} else {
-		election.setupSlave()
-	}
-
-	if err := election.saveInfo(); err != nil {
-		panic(err)
+		election.SetupSlave()
 	}
 
 	startVoting(election)
-- 
2.38.4