From b2d6c165c52537a9865aa526b25e574f20c08029 Mon Sep 17 00:00:00 2001
From: Felipe Martinez <pipernene@gmail.com>
Date: Sun, 29 Nov 2020 15:58:26 +0100
Subject: [PATCH] Add discovery interface

---
 broker/broker.go       |  1 -
 client/client.go       |  2 ++
 discovery/discovery.go |  7 +++++++
 options/options.go     | 16 ++--------------
 service.go             | 29 ++++++++++++++++++++++++-----
 5 files changed, 35 insertions(+), 20 deletions(-)
 create mode 100644 discovery/discovery.go

diff --git a/broker/broker.go b/broker/broker.go
index 6fdd921..dcdf4c9 100644
--- a/broker/broker.go
+++ b/broker/broker.go
@@ -3,7 +3,6 @@ package broker
 import "context"
 
 type Broker interface {
-	Connect(ctx context.Context) error
 	Close() error
 	Publish(ctx context.Context, topic string, data *Message) error
 	Subscribe(ctx context.Context, topic string, callback func(*Message)) error
diff --git a/client/client.go b/client/client.go
index 1f4afaa..6daaff0 100644
--- a/client/client.go
+++ b/client/client.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/MouseHatGames/mice/broker"
 	"github.com/MouseHatGames/mice/codec"
+	"github.com/MouseHatGames/mice/discovery"
 	"github.com/MouseHatGames/mice/logger"
 	"github.com/MouseHatGames/mice/options"
 	"github.com/MouseHatGames/mice/transport"
@@ -27,6 +28,7 @@ type client struct {
 	trans  transport.Transport
 	broker broker.Broker
 	log    logger.Logger
+	disc   discovery.Discovery
 }
 
 type CallError struct {
diff --git a/discovery/discovery.go b/discovery/discovery.go
new file mode 100644
index 0000000..31e860f
--- /dev/null
+++ b/discovery/discovery.go
@@ -0,0 +1,7 @@
+package discovery
+
+import "net"
+
+type Discovery interface {
+	Find(svc string) (net.IP, error)
+}
diff --git a/options/options.go b/options/options.go
index 44cfda5..5060fe1 100644
--- a/options/options.go
+++ b/options/options.go
@@ -4,6 +4,7 @@ import (
 	"github.com/MouseHatGames/mice/broker"
 	"github.com/MouseHatGames/mice/codec"
 	"github.com/MouseHatGames/mice/config"
+	"github.com/MouseHatGames/mice/discovery"
 	"github.com/MouseHatGames/mice/logger"
 	"github.com/MouseHatGames/mice/router"
 	"github.com/MouseHatGames/mice/transport"
@@ -20,6 +21,7 @@ type Options struct {
 	Router    router.Router
 	Broker    broker.Broker
 	Config    config.Config
+	Discovery discovery.Discovery
 }
 
 // Option represents a function that can be used to mutate an Options object
@@ -45,17 +47,3 @@ func Logger(l logger.Logger) Option {
 		o.Logger = l
 	}
 }
-
-// Codec sets the codec that will transform the messages
-func Codec(c codec.Codec) Option {
-	return func(o *Options) {
-		o.Codec = c
-	}
-}
-
-// Transport sets the transport that will deliver and receive messages to and from other services
-func Transport(t transport.Transport) Option {
-	return func(o *Options) {
-		o.Transport = t
-	}
-}
diff --git a/service.go b/service.go
index 77330f3..d51120e 100644
--- a/service.go
+++ b/service.go
@@ -1,7 +1,6 @@
 package mice
 
 import (
-	"context"
 	"errors"
 	"fmt"
 
@@ -26,6 +25,10 @@ type Service interface {
 	Start() error
 }
 
+type starter interface {
+	Start() error
+}
+
 type service struct {
 	options options.Options
 	server  server.Server
@@ -75,15 +78,31 @@ func (s *service) Start() error {
 		return errors.New("missing service name")
 	}
 
-	if s.options.Broker != nil {
-		if err := s.options.Broker.Connect(context.Background()); err != nil {
-			return fmt.Errorf("broker connect: %w", err)
-		}
+	if err := tryStart(map[string]interface{}{
+		"broker":    s.options.Broker,
+		"codec":     s.options.Codec,
+		"config":    s.options.Config,
+		"discovery": s.options.Discovery,
+		"logger":    s.options.Logger,
+		"transport": s.options.Transport,
+	}); err != nil {
+		return err
 	}
 
 	return s.server.Start()
 }
 
+func tryStart(objs map[string]interface{}) error {
+	for k, v := range objs {
+		if s, ok := v.(starter); ok {
+			if err := s.Start(); err != nil {
+				return fmt.Errorf("start %s: %w", k, err)
+			}
+		}
+	}
+	return nil
+}
+
 func (s *service) Server() server.Server {
 	return s.server
 }