// Package cli implements the galahad2lcd command-line interface.
package cli

import (
	"context"
	"fmt"
	"log/slog"
	"os"

	"github.com/spf13/cobra"
)

// Execute runs the CLI and returns the first error encountered. The version
// is injected by the caller (typically main via -ldflags).
func Execute(version string) error {
	root := newRootCmd(version)
	return root.Execute()
}

func newRootCmd(version string) *cobra.Command {
	var verbose bool

	root := &cobra.Command{
		Use:   "galahad2lcd",
		Short: "Driver for the Lian Li Galahad II LCD",
		Long: `galahad2lcd streams H.264 video to the Lian Li Galahad II LCD
display over USB.`,
		SilenceUsage:  true,
		SilenceErrors: true,
		PersistentPreRun: func(cmd *cobra.Command, _ []string) {
			level := slog.LevelInfo
			if verbose {
				level = slog.LevelDebug
			}
			slog.SetDefault(slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{Level: level})))
		},
	}

	root.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "enable debug logging")

	root.AddCommand(
		newDaemonCmd(),
		newSetCmd(),
		newListCmd(),
		newVersionCmd(version),
	)
	return root
}

func newVersionCmd(version string) *cobra.Command {
	return &cobra.Command{
		Use:   "version",
		Short: "Print the version and exit",
		Args:  cobra.NoArgs,
		RunE: func(cmd *cobra.Command, _ []string) error {
			fmt.Fprintln(cmd.OutOrStdout(), version)
			return nil
		},
	}
}

// signalContext returns a context cancelled on SIGINT and SIGTERM so that
// systemctl stop and Ctrl-C both trigger a clean shutdown.
func signalContext() (context.Context, context.CancelFunc) {
	return newSignalContext()
}