[gui] Add configuration package

gui/config/config.go

+// Package config handles basic configuration store for the GUI only.
+// DFSS configuration is stored in the HOME/.dfss/config.json file
+package config
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os"
+	"os/user"
+	"path/filepath"
+)
+
+// CAFile is the filename for the root certificate
+const CAFile = "ca.pem"
+
+// CertFile is the filename for the user certificate
+const CertFile = "cert.pem"
+
+// KeyFile is the filename for the private user key
+const KeyFile = "key.pem"
+
+// ConfigFile is the filename for the DFSS configuration file
+const ConfigFile = "config.json"
+
+// Config is the structure that will be persisted in the configuration file
+type Config struct {
+	Platform string
+
+	// Virtual-only fields
+	Registered    bool `json:"-"`
+	Authenticated bool `json:"-"`
+}
+
+// Load loads the configuration file into memory.
+// If the file does not exist, the configuration will holds default values.
+func Load() (conf Config) {
+	data, err := ioutil.ReadFile(getConfigFilename())
+	if err != nil {
+		return
+	}
+
+	_ = json.Unmarshal(data, &conf)
+
+	// Fill virtual-only fields
+	path := GetHomeDir()
+	conf.Registered = isFileValid(filepath.Join(path, KeyFile))
+	conf.Authenticated = isFileValid(filepath.Join(path, CertFile))
+	return
+}
+
+// Save stores the current configuration object from memory.
+func Save(c Config) {
+	data, err := json.MarshalIndent(c, "", "  ")
+	if err != nil {
+		return
+	}
+
+	_ = ioutil.WriteFile(getConfigFilename(), data, 0600)
+}
+
+// GetHomeDir is a helper to get the .dfss store directory
+func GetHomeDir() string {
+	u, err := user.Current()
+	if err != nil {
+		return ""
+	}
+
+	dfssPath := filepath.Join(u.HomeDir, ".dfss")
+	if err := os.MkdirAll(dfssPath, os.ModeDir|0700); err != nil {
+		return ""
+	}
+
+	return dfssPath + string(filepath.Separator)
+}
+
+func getConfigFilename() string {
+	return filepath.Join(GetHomeDir(), ConfigFile)
+}
+
+func isFileValid(file string) bool {
+	_, err := os.Stat(file)
+	return err == nil
+}

gui/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"dfss"
+	"dfss/gui/config"
 	"dfss/gui/userform"
 	"github.com/visualfc/goqt/ui"
 )
@@ -10,8 +11,13 @@ const WIDTH = 650
 const HEIGHT = 350
 
 func main() {
+
+	// Load configuration
+	conf := config.Load()
+
+	// Start first window
 	ui.Run(func() {
-		form := userform.NewWidget()
+		form := userform.NewWidget(&conf)
 
 		layout := ui.NewVBoxLayout()
 		layout.AddWidget(form.W)

gui/userform/userform.go

@@ -2,11 +2,9 @@ package userform
 
 import (
 	"io/ioutil"
-	"os"
-	osuser "os/user"
-	"path/filepath"
 
 	"dfss/dfssc/user"
+	"dfss/gui/config"
 	"github.com/visualfc/goqt/ui"
 )
 
@@ -14,7 +12,7 @@ type Widget struct {
 	W *ui.QWidget
 }
 
-func NewWidget() *Widget {
+func NewWidget(conf *config.Config) *Widget {
 	file := ui.NewFileWithName(":/userform/userform.ui")
 	loader := ui.NewUiLoader()
 	form := loader.Load(file)
@@ -27,7 +25,7 @@ func NewWidget() *Widget {
 	feedbackLabel := ui.NewLabelFromDriver(form.FindChild("feedbackLabel"))
 	registerButton := ui.NewPushButtonFromDriver(form.FindChild("registerButton"))
 
-	home := getHomeDir()
+	home := config.GetHomeDir()
 	fileDialog := ui.NewFileDialogWithParentCaptionDirectoryFilter(nil, "Select the CA file for the platform", home, "Root Certificates (*.pem);;Any (*.*)")
 
 	// Events
@@ -40,13 +38,13 @@ func NewWidget() *Widget {
 
 	fileDialog.OnFileSelected(func(ca string) {
 		fileDialog.Hide()
-		caDest := home + "ca.pem"
+		caDest := home + config.CAFile
 		_ = copyCA(ca, caDest)
 
 		err := user.Register(
-			home+"ca.pem",
-			home+"cert.pem",
-			home+"key.pem",
+			caDest,
+			home+config.CertFile,
+			home+config.KeyFile,
 			hostField.Text(),
 			passwordField.Text(),
 			"", "", "", emailField.Text(), 2048,
@@ -54,7 +52,8 @@ func NewWidget() *Widget {
 		if err != nil {
 			feedbackLabel.SetText(err.Error())
 		} else {
-			feedbackLabel.SetText("Registration done! Please check your mails.")
+			conf.Platform = hostField.Text()
+			config.Save(*conf)
 		}
 		form.SetDisabled(false)
 	})
@@ -67,20 +66,6 @@ func NewWidget() *Widget {
 	return &Widget{W: form}
 }
 
-func getHomeDir() string {
-	u, err := osuser.Current()
-	if err != nil {
-		return ""
-	}
-
-	dfssPath := filepath.Join(u.HomeDir, ".dfss")
-	if err := os.MkdirAll(dfssPath, os.ModeDir|0700); err != nil {
-		return ""
-	}
-
-	return dfssPath + string(filepath.Separator)
-}
-
 func copyCA(from string, to string) error {
 	if from == to {
 		return nil