From d6b0483feb598a0c69c0d17a754545a9355e500c Mon Sep 17 00:00:00 2001
From: Ben Burwell <ben@benburwell.com>
Date: Thu, 24 May 2018 23:59:09 -0400
Subject: Authenticate to bridge from config

---
 config.go | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++------
 main.go   | 65 +++++++++++++++++++++++++++++++++++++++++++++++----------------
 2 files changed, 101 insertions(+), 22 deletions(-)

diff --git a/config.go b/config.go
index a12a240..1402c17 100644
--- a/config.go
+++ b/config.go
@@ -1,8 +1,10 @@
 package main
 
 import (
+	"errors"
 	"io/ioutil"
 	"log"
+	"strings"
 
 	"github.com/BurntSushi/xdg"
 	"gopkg.in/yaml.v2"
@@ -10,13 +12,15 @@ import (
 
 const XDG_CONFIG_NAME = "phlux"
 
+type BridgeConfig struct {
+	BridgeID string `yaml:"id"`
+	Token    string `yaml:"token"`
+}
+
 type PhluxConfig struct {
-	Latitude  float64 `yaml:"latitude"`
-	Longitude float64 `yaml:"longitude"`
-	Bridges   []struct {
-		BridgeID string `yaml:"id"`
-		Token    string `yaml:"token"`
-	} `yaml:"bridges"`
+	Latitude  float64        `yaml:"latitude"`
+	Longitude float64        `yaml:"longitude"`
+	Bridges   []BridgeConfig `yaml:"bridges"`
 }
 
 func (c *PhluxConfig) Read() {
@@ -37,3 +41,45 @@ func (c *PhluxConfig) Read() {
 		return
 	}
 }
+
+func (c *PhluxConfig) GetBridgeToken(id string) (string, error) {
+	lc := strings.ToLower(id)
+	for _, bridge := range c.Bridges {
+		if strings.ToLower(bridge.BridgeID) == lc {
+			return bridge.Token, nil
+		}
+	}
+	return "", errors.New("No token found for bridge " + id)
+}
+
+func (c *PhluxConfig) SetBridgeToken(id, token string) {
+	for _, bridge := range c.Bridges {
+		if bridge.BridgeID == id {
+			bridge.Token = token
+			return
+		}
+	}
+	c.Bridges = append(c.Bridges, BridgeConfig{
+		BridgeID: id,
+		Token:    token,
+	})
+}
+
+func (c *PhluxConfig) Save() (err error) {
+	out, err := yaml.Marshal(c)
+	if err != nil {
+		log.Printf("Error marshalling config: %s\n", err.Error())
+	}
+	var paths xdg.Paths
+	configFile, err := paths.ConfigFile(XDG_CONFIG_NAME)
+	if err != nil {
+		log.Printf("No config file found: %s\n", err.Error())
+		return
+	}
+	err = ioutil.WriteFile(configFile, out, 0600)
+	if err != nil {
+		log.Printf("Error writing config file %s: %s\n", configFile, err.Error())
+		return
+	}
+	return
+}
diff --git a/main.go b/main.go
index 6253cbb..00850db 100644
--- a/main.go
+++ b/main.go
@@ -1,14 +1,15 @@
 package main
 
 import (
+	"errors"
+	"fmt"
 	"log"
-	"os"
 	"time"
 
 	hue "github.com/benburwell/gohue"
 )
 
-const username = "phlux"
+const USERNAME = "phlux"
 
 func main() {
 	var config PhluxConfig
@@ -23,29 +24,61 @@ func main() {
 	desiredColorTemp := getDesiredColorTemperature(time.Now(), config.Latitude, config.Longitude)
 	for _, bridge := range bridges {
 		log.Printf("Bridge: %s\n", bridge.IPAddress)
-		updateBridge(bridge, desiredColorTemp)
+		updateBridge(&bridge, desiredColorTemp, &config)
 	}
 }
 
-func updateBridge(bridge hue.Bridge, ct ColorTemperature) {
-	//username, err := bridge.CreateUser(username)
-	//if err != nil {
-	//	panic("Could not create user on bridge")
-	//}
-	//fmt.Printf("Made user %s for bridge %s\n", username, bridge.IPAddress)
-	err := bridge.Login(os.Getenv("HUE_LOGIN"))
+// In case we don't know the bridge's serial number for some reason, we won't
+// be able to look up the token, nor will we be able to save it. There is still
+// a chance we will be able to successfully log in though: if the link button
+// has been pressed, we should be able to create ourselves a temporary token.
+func authenticateOnce(bridge *hue.Bridge) error {
+	token, err := bridge.CreateUser(USERNAME)
 	if err != nil {
-		log.Fatalf("Could not log in to bridge: %s\n", err.Error())
+		return errors.New(fmt.Sprintf("Could not create temporary token: %s", err.Error()))
 	}
-	log.Println("Logged in to bridge")
+	log.Printf("Made token %s for bridge %s\n", token, bridge.IPAddress)
+	err = bridge.Login(token)
+	if err != nil {
+		return errors.New(fmt.Sprintf("Failed to log in with temporary token: %s", err.Error()))
+	}
+	log.Printf("Logged in to bridge %s\n", bridge.IPAddress)
+	return nil
+}
+
+func createToken(bridge *hue.Bridge, config *PhluxConfig) error {
+	if err := authenticateOnce(bridge); err != nil {
+		return err
+	}
+	config.SetBridgeToken(bridge.Info.Device.SerialNumber, bridge.Username)
+	config.Save()
+	return nil
+}
 
-	config, err := bridge.GetConfig()
+// Attempt to authenticate to the bridge using a variety of techniques,
+// including looking up a saved token for the bridge's serial number and
+// attempting to generate a new token for the bridge assuming the link button
+// has been pressed.
+func authenticate(bridge *hue.Bridge, config *PhluxConfig) error {
+	// get bridge info, which contains serial number
+	err := bridge.GetInfo()
 	if err != nil {
-		log.Fatalf("Could not get bridge info: %s\n", err.Error())
+		return authenticateOnce(bridge)
 	}
-	log.Printf("Bridge name: %s\n", config.Name)
-	log.Printf("Bridge ID: %s\n", config.BridgeID)
+	token, err := config.GetBridgeToken(bridge.Info.Device.SerialNumber)
+	if err != nil {
+		return createToken(bridge, config)
+	}
+	err = bridge.Login(token)
+	if err != nil {
+		log.Fatalf("Could not log in to bridge: %s\n", err.Error())
+	}
+	log.Println("Logged in to bridge")
+	return nil
+}
 
+func updateBridge(bridge *hue.Bridge, ct ColorTemperature, config *PhluxConfig) {
+	authenticate(bridge, config)
 	lights, err := bridge.GetAllLights()
 	if err != nil {
 		log.Fatalf("Error getting lights: %s\n", err.Error())
-- 
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