// Package cli implements the sutil command tree.
//
// The tree is built by New rather than assembled in init functions, so
// the package holds no global state and tests can construct it repeatedly
// with captured input and output.
package cli

import (
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

// Params configures New.
type Params struct {
	// Version is the version string embedded at build time. It is shown
	// by `sutil version`, `sutil --version`, and `sutil info`.
	Version string

	// ConfigDir is the directory searched for the optional .sneak
	// configuration file. Empty means the user's home directory; tests set
	// it to a temporary directory so the real home is never consulted.
	ConfigDir string
}

// app carries the state shared by every command: the build parameters,
// the --config flag, and the configuration loaded before any command runs.
type app struct {
	params     Params
	configFile string
	config     *viper.Viper
}

// New builds the root sutil command with every subcommand attached.
func New(p Params) *cobra.Command {
	a := &app{params: p, configFile: "", config: nil}

	root := &cobra.Command{
		Use:   "sutil",
		Short: "sneak's shell utility",
		Long: `sutil is a small collection of shell utilities worth having on every
machine: a fast pseudorandom byte stream and a memorable password generator.

Before any command runs, sutil loads the optional configuration file named
by --config, or else ~/.sneak.yaml (or .json, .toml, ...) if it exists, and
makes environment variables available alongside it.`,
		Version:           p.Version,
		SilenceUsage:      true,
		PersistentPreRunE: a.loadConfig,
	}

	root.PersistentFlags().StringVar(
		&a.configFile, "config", "",
		"config file (default is "+configName+".* in the home directory)",
	)

	root.AddCommand(
		newVersionCommand(p),
		newInfoCommand(a),
		newGenerateCommand(),
	)

	return root
}