package main

import (
	"flag"
	"os"
	"path/filepath"
	"runtime"
	"text/template"
)

type UsageArgs struct {
	Version        string
	BuildDate      string
	OS             string
	Arch           string
	DefaultDataDir string
}

var usageTmpl = `usage: grumble [options]

 grumble {{.Version}} ({{.BuildDate}})
 target: {{.OS}}, {{.Arch}}

 --help
     Shows this help listing.

 --datadir <data-dir> (default: {{.DefaultDataDir}})
     Directory to use for server storage.

 --log <log-path> (default: $DATADIR/grumble.log)
     Log file path.

 --regen-keys
     Force grumble to regenerate its global RSA
     keypair (and certificate).

     The global keypair lives in the root of the
     grumble data directory.

 --import-murmurdb <murmur-sqlite-path>
     Import a Murmur SQLite database into grumble.

     Use the --cleanup argument to force grumble to
     clean up its data directory when doing the
     import. This is *DESTRUCTIVE*! Use with care.
`

type args struct {
	ShowHelp  bool
	DataDir   string
	LogPath   string
	RegenKeys bool
	SQLiteDB  string
	CleanUp   bool
}

func defaultDataDir() string {
	homedir := os.Getenv("HOME")
	dirname := ".grumble"
	if runtime.GOOS == "windows" {
		homedir = os.Getenv("USERPROFILE")
	}
	return filepath.Join(homedir, dirname)
}

func defaultLogPath() string {
	return filepath.Join(defaultDataDir(), "grumble.log")
}

func Usage() {
	t, err := template.New("usage").Parse(usageTmpl)
	if err != nil {
		panic("unable to parse usage template")
	}

	err = t.Execute(os.Stdout, UsageArgs{
		Version:        version,
		BuildDate:      buildDate,
		OS:             runtime.GOOS,
		Arch:           runtime.GOARCH,
		DefaultDataDir: defaultDataDir(),
	})
	if err != nil {
		panic("unable to execute usage template")
	}
}

var Args args

func init() {
	flag.Usage = Usage

	flag.BoolVar(&Args.ShowHelp, "help", false, "")
	flag.StringVar(&Args.DataDir, "datadir", defaultDataDir(), "")
	flag.StringVar(&Args.LogPath, "log", defaultLogPath(), "")
	flag.BoolVar(&Args.RegenKeys, "regen-keys", false, "")

	flag.StringVar(&Args.SQLiteDB, "import-murmurdb", "", "")
	flag.BoolVar(&Args.CleanUp, "cleanup", false, "")
}