change Msg to be an interface implemented by Backends, remove passthr…

…oughs on Server to go straight to Backend

backend.go

@@ -12,17 +12,39 @@ type BackendConstructorFunc func(*config.Courier) Backend
 
 // Backend represents the part of Courier that deals with looking up and writing channels and results
 type Backend interface {
+	// Start starts the backend and opens any db connections it needs
 	Start() error
+
+	// Stop stops the backend closing any db connections it has open
 	Stop() error
 
+	// GetChannel returns the channel with the passed in type and UUID
 	GetChannel(ChannelType, ChannelUUID) (Channel, error)
-	WriteMsg(*Msg) error
+
+	// NewIncomingMsg creates a new message from the given params
+	NewIncomingMsg(channel Channel, urn URN, text string) Msg
+
+	// NewOutgoingMsg creates a new outgoing message from the given params
+	NewOutgoingMsg(channel Channel, urn URN, text string) Msg
+
+	// WriteMsg writes the passed in message to our backend
+	WriteMsg(Msg) error
+
+	// WriteMsgStatus writes the passed in status update to our backend
 	WriteMsgStatus(*MsgStatusUpdate) error
+
+	// WriteChannelLogs writes the passed in channel logs to our backend
 	WriteChannelLogs([]*ChannelLog) error
 
-	PopNextOutgoingMsg() (*Msg, error)
-	MarkOutgoingMsgComplete(*Msg)
+	// PopNextOutgoingMsg returns the next message that needs to be sent, callers should call MarkOutgoingMsgComplete with the
+	// returned message when they have dealt with the message (regardless of whether it was sent or not)
+	PopNextOutgoingMsg() (Msg, error)
+
+	// MarkOutgoingMsgComplete marks the passed in message as having been processed. Note this should be called even in the case
+	// of errors during sending as it will manage the number of active workers per channel
+	MarkOutgoingMsgComplete(Msg)
 
+	// Health returns a string describing any health problems the backend has, or empty string if all is well
 	Health() string
 }
 

backends/rapidpro/backend.go

@@ -35,8 +35,18 @@ func (b *backend) GetChannel(ct courier.ChannelType, uuid courier.ChannelUUID) (
 	return getChannel(b, ct, uuid)
 }
 
+// NewIncomingMsg creates a new message from the given params
+func (b *backend) NewIncomingMsg(channel courier.Channel, urn courier.URN, text string) courier.Msg {
+	return newMsg(MsgIncoming, channel, urn, text)
+}
+
+// NewOutgoingMsg creates a new outgoing message from the given params
+func (b *backend) NewOutgoingMsg(channel courier.Channel, urn courier.URN, text string) courier.Msg {
+	return newMsg(MsgOutgoing, channel, urn, text)
+}
+
 // PopNextOutgoingMsg pops the next message that needs to be sent
-func (b *backend) PopNextOutgoingMsg() (*courier.Msg, error) {
+func (b *backend) PopNextOutgoingMsg() (courier.Msg, error) {
 	// pop the next message off our queue
 	rc := b.redisPool.Get()
 	defer rc.Close()
@@ -47,37 +57,36 @@ func (b *backend) PopNextOutgoingMsg() (*courier.Msg, error) {
 	}
 
 	if msgJSON != "" {
-		dbMsg := DBMsg{}
-		err = json.Unmarshal([]byte(msgJSON), &dbMsg)
+		dbMsg := &DBMsg{}
+		err = json.Unmarshal([]byte(msgJSON), dbMsg)
 		if err != nil {
 			return nil, err
 		}
 
-		// create courier msg from our db msg
-		channel, err := b.GetChannel(courier.AnyChannelType, dbMsg.ChannelUUID)
+		// populate the channel on our db msg
+		channel, err := b.GetChannel(courier.AnyChannelType, dbMsg.ChannelUUID_)
 		if err != nil {
 			return nil, err
 		}
-
-		// TODO: what other attributes are needed here?
-		msg := courier.NewOutgoingMsg(channel, dbMsg.URN, dbMsg.Text).WithID(dbMsg.ID).WithExternalID(dbMsg.ExternalID)
-		msg.WorkerToken = token
-
-		return msg, nil
+		dbMsg.Channel_ = channel
+		dbMsg.WorkerToken_ = token
+		return dbMsg, nil
 	}
 
 	return nil, nil
 }
 
 // MarkOutgoingMsgComplete marks the passed in message as having completed processing, freeing up a worker for that channel
-func (b *backend) MarkOutgoingMsgComplete(msg *courier.Msg) {
+func (b *backend) MarkOutgoingMsgComplete(msg courier.Msg) {
 	rc := b.redisPool.Get()
 	defer rc.Close()
-	queue.MarkComplete(rc, msgQueueName, msg.WorkerToken)
+
+	dbMsg := msg.(*DBMsg)
+	queue.MarkComplete(rc, msgQueueName, dbMsg.WorkerToken_)
 }
 
 // WriteMsg writes the passed in message to our store
-func (b *backend) WriteMsg(m *courier.Msg) error {
+func (b *backend) WriteMsg(m courier.Msg) error {
 	return writeMsg(b, m)
 }
 

backends/rapidpro/backend_test.go

@@ -45,6 +45,11 @@ func (ts *MsgTestSuite) SetupSuite() {
 		panic(fmt.Errorf("Unable to read testdata.sql: %s", err))
 	}
 	ts.b.db.MustExec(string(sql))
+
+	// clear redis
+	r := ts.b.redisPool.Get()
+	defer r.Close()
+	r.Do("FLUSHDB")
 }
 
 func (ts *MsgTestSuite) TearDownSuite() {
@@ -145,17 +150,17 @@ func (ts *MsgTestSuite) TestStatus() {
 	ts.NoError(err)
 	m, err := readMsgFromDB(ts.b, courier.NewMsgID(10001))
 	ts.NoError(err)
-	ts.Equal(m.Status, courier.MsgSent)
-	ts.True(m.ModifiedOn.After(now))
+	ts.Equal(m.Status_, courier.MsgSent)
+	ts.True(m.ModifiedOn_.After(now))
 
 	// update by external id
 	status = courier.NewStatusUpdateForExternalID(channel, "ext1", courier.MsgFailed)
 	err = ts.b.WriteMsgStatus(status)
 	ts.NoError(err)
 	m, err = readMsgFromDB(ts.b, courier.NewMsgID(10000))
 	ts.NoError(err)
-	ts.Equal(m.Status, courier.MsgFailed)
-	ts.True(m.ModifiedOn.After(now))
+	ts.Equal(m.Status_, courier.MsgFailed)
+	ts.True(m.ModifiedOn_.After(now))
 
 	// no such external id
 	status = courier.NewStatusUpdateForExternalID(channel, "ext2", courier.MsgSent)
@@ -174,7 +179,7 @@ func (ts *MsgTestSuite) TestOutgoingQueue() {
 	defer r.Close()
 
 	dbMsg, err := readMsgFromDB(ts.b, courier.NewMsgID(10000))
-	dbMsg.ChannelUUID, _ = courier.NewChannelUUID("dbc126ed-66bc-4e28-b67b-81dc3327c95d")
+	dbMsg.ChannelUUID_, _ = courier.NewChannelUUID("dbc126ed-66bc-4e28-b67b-81dc3327c95d")
 	ts.NoError(err)
 	ts.NotNil(dbMsg)
 
@@ -191,10 +196,10 @@ func (ts *MsgTestSuite) TestOutgoingQueue() {
 	ts.NotNil(msg)
 
 	// make sure it is the message we just added
-	ts.Equal(dbMsg.ID, msg.ID)
+	ts.Equal(dbMsg.ID(), msg.ID())
 
 	// and that it has the appropriate text
-	ts.Equal(msg.Text, "test message")
+	ts.Equal(msg.Text(), "test message")
 
 	// mark this message as dealt with
 	ts.b.MarkOutgoingMsgComplete(msg)
@@ -237,7 +242,7 @@ func (ts *MsgTestSuite) TestWriteMsg() {
 
 	// create a new courier msg
 	urn := courier.NewTelURNForChannel("12065551212", knChannel)
-	msg := courier.NewIncomingMsg(knChannel, urn, "test123").WithExternalID("ext123").WithReceivedOn(now).WithContactName("test contact")
+	msg := newMsg(MsgIncoming, knChannel, urn, "test123").WithExternalID("ext123").WithReceivedOn(now).WithContactName("test contact")
 
 	// try to write it to our db
 	err := ts.b.WriteMsg(msg)
@@ -247,36 +252,36 @@ func (ts *MsgTestSuite) TestWriteMsg() {
 	ts.NotZero(msg.ID)
 
 	// load it back from the id
-	m, err := readMsgFromDB(ts.b, msg.ID)
+	m, err := readMsgFromDB(ts.b, msg.ID())
 	ts.NoError(err)
 
 	// load our URN
-	contactURN, err := contactURNForURN(ts.b.db, m.OrgID, m.ChannelID, m.ContactID, urn)
+	contactURN, err := contactURNForURN(ts.b.db, m.OrgID_, m.ChannelID_, m.ContactID_, urn)
 	ts.NoError(err)
 
 	// make sure our values are set appropriately
-	ts.Equal(knChannel.ID_, m.ChannelID)
-	ts.Equal(knChannel.OrgID_, m.OrgID)
-	ts.Equal(contactURN.ContactID, m.ContactID)
-	ts.Equal(contactURN.ID, m.ContactURNID)
-	ts.Equal(MsgIncoming, m.Direction)
-	ts.Equal(courier.MsgPending, m.Status)
-	ts.Equal(DefaultPriority, m.Priority)
-	ts.Equal("ext123", m.ExternalID)
-	ts.Equal("test123", m.Text)
-	ts.Equal([]string(nil), m.Attachments)
-	ts.Equal(1, m.MessageCount)
-	ts.Equal(0, m.ErrorCount)
-	ts.Equal(now, m.SentOn.In(time.UTC))
-	ts.NotNil(m.NextAttempt)
-	ts.NotNil(m.CreatedOn)
-	ts.NotNil(m.ModifiedOn)
-	ts.NotNil(m.QueuedOn)
-
-	contact, err := contactForURN(ts.b.db, m.OrgID, m.ChannelID, urn, "")
+	ts.Equal(knChannel.ID_, m.ChannelID_)
+	ts.Equal(knChannel.OrgID_, m.OrgID_)
+	ts.Equal(contactURN.ContactID, m.ContactID_)
+	ts.Equal(contactURN.ID, m.ContactURNID_)
+	ts.Equal(MsgIncoming, m.Direction_)
+	ts.Equal(courier.MsgPending, m.Status_)
+	ts.Equal(DefaultPriority, m.Priority_)
+	ts.Equal("ext123", m.ExternalID_)
+	ts.Equal("test123", m.Text_)
+	ts.Equal([]string(nil), m.Attachments_)
+	ts.Equal(1, m.MessageCount_)
+	ts.Equal(0, m.ErrorCount_)
+	ts.Equal(now, m.SentOn_.In(time.UTC))
+	ts.NotNil(m.NextAttempt_)
+	ts.NotNil(m.CreatedOn_)
+	ts.NotNil(m.ModifiedOn_)
+	ts.NotNil(m.QueuedOn_)
+
+	contact, err := contactForURN(ts.b.db, m.OrgID_, m.ChannelID_, urn, "")
 	ts.Equal("test contact", contact.Name)
-	ts.Equal(m.OrgID, contact.OrgID)
-	ts.Equal(m.ContactID, contact.ID)
+	ts.Equal(m.OrgID_, contact.OrgID)
+	ts.Equal(m.ContactID_, contact.ID)
 	ts.NotNil(contact.UUID)
 	ts.NotNil(contact.ID)
 }