feat: Config files and verbosity flags

This commit enables loading configuration from files, either explicity
with the -c or --config flag, the working directory PWD or the home
directory $HOME.

Only the $HOME configuration will be generated automatically.

Ref: #1

src/root.go

@@ -3,9 +3,19 @@ package src
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 
 	"github.com/caffeine-addictt/video-manager/src/utils"
+	"github.com/mitchellh/go-homedir"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+// Global variables
+var (
+	cfgFile string
+	verbose bool
+	debug   bool
 )
 
 // Root command
@@ -18,6 +28,58 @@ var rootCommand = &cobra.Command{
 	),
 }
 
+// Configuration
+func init() {
+	cobra.OnInitialize(initConfig)
+	rootCommand.PersistentFlags().StringVarP(&cfgFile, "config", "c", "", "config file (default is $HOME/.video-manager)")
+
+	// Verbosity
+	rootCommand.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "Verbose output")
+	rootCommand.PersistentFlags().BoolVarP(&debug, "debug", "d", false, "Debug output")
+}
+
+func initConfig() {
+	home, err := homedir.Dir()
+	if err != nil {
+		fmt.Println("Failed to get home directory")
+		Debug(err.Error())
+		os.Exit(1)
+	}
+
+	if cfgFile != "" {
+		// Reading provided configuration file
+		viper.SetConfigFile(cfgFile)
+		Debug("-c supplied at " + cfgFile)
+	} else {
+		// Reading configuration file from either pwd or $HOME
+		viper.AddConfigPath(".")
+		viper.AddConfigPath(home)
+		viper.SetConfigName(".video-manager")
+		viper.SetConfigType("yaml")
+		Debug("-c not supplied, looking for configuration file in " + home + " or pwd")
+	}
+
+	// Read file
+	if err := viper.ReadInConfig(); err != nil {
+		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
+			fmt.Println("Configuration file not found")
+
+			// Create configuration at $HOME if it does not exist
+			if cfgFile != "" {
+				os.Exit(1)
+			}
+
+			viper.SafeWriteConfigAs(filepath.Join(home, ".video-manager"))
+			fmt.Println("Created default configuration file at " + home + "/.video-manager")
+		} else {
+			fmt.Println("Failed to read configuration file")
+			Debug(err.Error())
+			os.Exit(1)
+		}
+	}
+	Info("Loaded configuration from " + viper.ConfigFileUsed())
+}
+
 func Execute() {
 	if err := rootCommand.Execute(); err != nil {
 		fmt.Println(err)