From 3302cc28b671892e3d94f6ce7b299ffdfa366ed2 Mon Sep 17 00:00:00 2001
From: Rowan Seymour <rowanseymour@gmail.com>
Date: Tue, 13 Mar 2018 13:14:19 -0500
Subject: [PATCH 1/3] Don't add duplicate URNs to contacts

---
 flows/actions/add_contact_urn.go  |  6 ++++--
 flows/contact.go                  | 20 +++++++++++++++++---
 flows/events/contact_urn_added.go |  3 +--
 3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/flows/actions/add_contact_urn.go b/flows/actions/add_contact_urn.go
index 78253eea6..e33128a0d 100644
--- a/flows/actions/add_contact_urn.go
+++ b/flows/actions/add_contact_urn.go
@@ -63,8 +63,10 @@ func (a *AddContactURNAction) Execute(run flows.FlowRun, step flows.Step, log fl
 		log.Add(events.NewErrorEvent(fmt.Errorf("unable to add URN '%s:%s': %s", a.Scheme, evaluatedPath, err.Error())))
 		return nil
 	}
-	urn = urn.Normalize("")
 
-	log.Add(events.NewURNAddedEvent(urn))
+	if !run.Contact().HasURN(urn) {
+		log.Add(events.NewURNAddedEvent(urn))
+	}
+
 	return nil
 }
diff --git a/flows/contact.go b/flows/contact.go
index 2fa72a350..43d3fc1e9 100644
--- a/flows/contact.go
+++ b/flows/contact.go
@@ -76,10 +76,24 @@ func (c *Contact) Name() string { return c.name }
 func (c *Contact) URNs() URNList { return c.urns }
 
 // AddURN adds a new URN to this contact
-func (c *Contact) AddURN(urn urns.URN) {
-	// TODO normalize and check we're not adding duplicates
+func (c *Contact) AddURN(urn urns.URN) error {
+	if c.HasURN(urn) {
+		return fmt.Errorf("contact already has the URN %s", urn)
+	}
+	c.urns = append(c.urns, &ContactURN{URN: urn.Normalize("")})
+	return nil
+}
 
-	c.urns = append(c.urns, &ContactURN{URN: urn})
+// HasURN checks whether the contact has the given URN
+func (c *Contact) HasURN(urn urns.URN) bool {
+	urn = urn.Normalize("")
+
+	for u := range c.urns {
+		if c.urns[u].URN == urn {
+			return true
+		}
+	}
+	return false
 }
 
 // Groups returns the groups that this contact belongs to
diff --git a/flows/events/contact_urn_added.go b/flows/events/contact_urn_added.go
index b89eddd58..1fc8b16d2 100644
--- a/flows/events/contact_urn_added.go
+++ b/flows/events/contact_urn_added.go
@@ -47,6 +47,5 @@ func (e *ContactURNAddedEvent) Apply(run flows.FlowRun) error {
 		return fmt.Errorf("can't apply event in session without a contact")
 	}
 
-	run.Contact().AddURN(e.URN)
-	return nil
+	return run.Contact().AddURN(e.URN)
 }

From 6aa54c263154b97f3529a2bc3c1d9e461049b79a Mon Sep 17 00:00:00 2001
From: Rowan Seymour <rowanseymour@gmail.com>
Date: Tue, 13 Mar 2018 13:17:55 -0500
Subject: [PATCH 2/3] Adding a duplicate URN should be consistent with adding a
 duplicate group

---
 flows/contact.go                  | 6 +++---
 flows/events/contact_urn_added.go | 3 ++-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/flows/contact.go b/flows/contact.go
index 43d3fc1e9..c6594011d 100644
--- a/flows/contact.go
+++ b/flows/contact.go
@@ -76,12 +76,12 @@ func (c *Contact) Name() string { return c.name }
 func (c *Contact) URNs() URNList { return c.urns }
 
 // AddURN adds a new URN to this contact
-func (c *Contact) AddURN(urn urns.URN) error {
+func (c *Contact) AddURN(urn urns.URN) bool {
 	if c.HasURN(urn) {
-		return fmt.Errorf("contact already has the URN %s", urn)
+		return false
 	}
 	c.urns = append(c.urns, &ContactURN{URN: urn.Normalize("")})
-	return nil
+	return true
 }
 
 // HasURN checks whether the contact has the given URN
diff --git a/flows/events/contact_urn_added.go b/flows/events/contact_urn_added.go
index 1fc8b16d2..b89eddd58 100644
--- a/flows/events/contact_urn_added.go
+++ b/flows/events/contact_urn_added.go
@@ -47,5 +47,6 @@ func (e *ContactURNAddedEvent) Apply(run flows.FlowRun) error {
 		return fmt.Errorf("can't apply event in session without a contact")
 	}
 
-	return run.Contact().AddURN(e.URN)
+	run.Contact().AddURN(e.URN)
+	return nil
 }

From 323437e28fd802eebdb8ec2dda000decc692440b Mon Sep 17 00:00:00 2001
From: Rowan Seymour <rowanseymour@gmail.com>
Date: Tue, 13 Mar 2018 13:47:08 -0500
Subject: [PATCH 3/3] Fix for style

---
 flows/contact.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/flows/contact.go b/flows/contact.go
index c6594011d..1371bb7e2 100644
--- a/flows/contact.go
+++ b/flows/contact.go
@@ -88,8 +88,8 @@ func (c *Contact) AddURN(urn urns.URN) bool {
 func (c *Contact) HasURN(urn urns.URN) bool {
 	urn = urn.Normalize("")
 
-	for u := range c.urns {
-		if c.urns[u].URN == urn {
+	for _, u := range c.urns {
+		if u.URN == urn {
 			return true
 		}
 	}