add root command

define flags --host, --port, --loglevel

viper reads values from env vars

cmd/root.go

@@ -0,0 +1,78 @@
+/*
+Copyright © 2026 NAME HERE <EMAIL ADDRESS>
+*/
+package cmd
+
+import (
+	"os"
+	"strings"
+
+	"github.com/charmbracelet/log"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+
+	"github.com/onyx-and-iris/xair-cli/internal/xair"
+)
+
+// rootCmd represents the base command when called without any subcommands
+var rootCmd = &cobra.Command{
+	Use:   "xair-cli",
+	Short: "A command-line utility to interact with Behringer X Air mixers via OSC",
+	Long: `xair-cli is a command-line tool that allows users to send OSC messages
+to Behringer X Air mixers for remote control and configuration. It supports
+various commands to manage mixer settings directly from the terminal.`,
+	PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
+		level, err := log.ParseLevel(viper.GetString("loglevel"))
+		if err != nil {
+			return err
+		}
+		log.SetLevel(level)
+
+		client, err := xair.NewClient(viper.GetString("host"), viper.GetInt("port"))
+		if err != nil {
+			return err
+		}
+		cmd.SetContext(WithContext(cmd.Context(), client))
+
+		client.StartListening()
+		err, resp := client.RequestInfo()
+		if err != nil {
+			return err
+		}
+
+		log.Infof("Received mixer info: %+v", resp)
+
+		return nil
+	},
+	PersistentPostRunE: func(cmd *cobra.Command, args []string) error {
+		client := ClientFromContext(cmd.Context())
+		if client != nil {
+			client.Stop()
+		}
+		return nil
+	},
+	Run: func(cmd *cobra.Command, args []string) {
+		cmd.Help()
+	},
+}
+
+func Execute() {
+	err := rootCmd.Execute()
+	if err != nil {
+		os.Exit(1)
+	}
+}
+
+func init() {
+	rootCmd.PersistentFlags().StringP("host", "H", "mixer.local", "host address of the X Air mixer")
+	rootCmd.PersistentFlags().IntP("port", "p", 10024, "Port number of the X Air mixer")
+	rootCmd.PersistentFlags().
+		StringP("loglevel", "l", "warn", "Log level (debug, info, warn, error, fatal, panic)")
+
+	viper.SetEnvKeyReplacer(strings.NewReplacer("-", "_"))
+	viper.SetEnvPrefix("XAIR_CLI")
+	viper.AutomaticEnv()
+	viper.BindPFlag("host", rootCmd.PersistentFlags().Lookup("host"))
+	viper.BindPFlag("port", rootCmd.PersistentFlags().Lookup("port"))
+	viper.BindPFlag("loglevel", rootCmd.PersistentFlags().Lookup("loglevel"))
+}