From 3e85db8d95925b70b18e1c813d73d070e31e1345 Mon Sep 17 00:00:00 2001
From: migwi <migwindungu0@gmail.com>
Date: Tue, 1 Jan 2019 02:44:21 +0300
Subject: [PATCH] Add stack trace implementation to track the current Hub

---
 analytics/chains.go | 60 +++++++++++++++++++++++++++------------------
 1 file changed, 36 insertions(+), 24 deletions(-)

diff --git a/analytics/chains.go b/analytics/chains.go
index f426d5d..afd55e6 100644
--- a/analytics/chains.go
+++ b/analytics/chains.go
@@ -54,10 +54,11 @@ func ChainDiscovery(client *rpcclient.Client, txHash string) ([]*Hub, error) {
 	// back in time when the source for each path can be identified.
 	var hubsChain []*Hub
 
-	var depth = 3
+	var depth = 2
 
-	for _, val := range tx.Outpoints {
-		var setCount, hubCount, newDepth int
+	for _, val := range tx.Outpoints[3:] {
+		var setCount, hubCount int
+		var stackTrace []*Hub
 		count := 1
 
 		entry := &Hub{
@@ -67,9 +68,9 @@ func ChainDiscovery(client *rpcclient.Client, txHash string) ([]*Hub, error) {
 		}
 
 		hubCopy := entry
-		origHub := entry
+		// origHub := entry
 
-		err = handleDepths(entry, hubCopy, origHub, client, count, depth, setCount, newDepth, hubCount)
+		err = handleDepths(entry, hubCopy, stackTrace, client, count, depth, setCount, hubCount)
 		if err != nil {
 			return nil, err
 		}
@@ -82,32 +83,43 @@ func ChainDiscovery(client *rpcclient.Client, txHash string) ([]*Hub, error) {
 	return hubsChain, nil
 }
 
-func handleDepths(prevHub, curHub, origHub *Hub, client *rpcclient.Client, count, depth, setCount, newDepth, hubCount int) error {
-	err := curHub.getDepth(client)
-	if err != nil || count == depth {
-		return err
-	}
+func handleDepths(curHub, prevHub *Hub, stack []*Hub, client *rpcclient.Client, count, depth, setCount, hubCount int) error {
+	// Adds items to the stack.
+	stack = append(stack, curHub)
 
-	if hubCount == len(prevHub.Matched[setCount].Inputs) {
-		hubCount = 0
-		count++
+	if count == depth || curHub.TxHash == "" {
+		// backtrack till we find an unvisited Hub.
+		for {
+			if len(stack) == 0 {
+				return nil
+			}
 
-		if setCount+1 < len(prevHub.Matched) {
-			setCount++
-		} else {
-			setCount = 0
-			prevHub = origHub.Matched[setCount].Inputs[hubCount]
-		}
+			curHub = stack[len(stack)-1]
 
-	}
+			if hubCount+1 < len(prevHub.Matched[setCount].Inputs) {
+				hubCount++
+				count--
+				break
+			} else if setCount+1 < len(prevHub.Matched) && hubCount == len(prevHub.Matched[setCount].Inputs) {
+				setCount++
+				count--
+				hubCount = 0
+				break
+			}
 
-	curHub = prevHub.Matched[setCount].Inputs[hubCount]
+			stack = stack[len(stack)-1:]
+		}
+	}
 
-	if len(prevHub.Matched) > 0 && hubCount < len(prevHub.Matched[setCount].Inputs) {
-		hubCount++
+	err := curHub.getDepth(client)
+	if err != nil {
+		return err
 	}
 
-	return handleDepths(prevHub, curHub, origHub, client, count, depth, setCount, newDepth, hubCount)
+	fmt.Printf(" >>>>>> setCount %v, len %v >>>>> hubCount %v, len %v \n", setCount, len(curHub.Matched), hubCount, len(curHub.Matched[setCount].Inputs))
+	curHub = curHub.Matched[setCount].Inputs[hubCount]
+
+	return handleDepths(curHub, prevHub, stack, client, count+1, depth, setCount, hubCount)
 }
 
 // getDepth appends all the sets linked to a given output after a given amount