package warren

import (
	"flag"
	"os"
	"text/template"
)

type ICommand interface {
	GetName() string
	GetSummary() string
}

var commands map[string]ICommand = make(map[string]ICommand)

// shamelessly snagged from the go tool
// each command gets its own set of args,
// defines its own entry point, and provides its own help
type Command struct {
	Run  func(cmd *Command, args ...string)
	Flag flag.FlagSet

	Name    string
	Usage   string // multiline doc about using cmd
	Summary string // one line info about cmd
}

func (c *Command) GetName() string {
	return c.Name
}

func (c *Command) GetSummary() string {
	return c.Summary
}

func (c *Command) Exec(args []string) {
	c.Flag.Usage = func() {
		// helpFunc(c, c.Name)
	}
	c.Flag.Parse(args)
	c.Run(c, c.Flag.Args()...)
}

func RegisterCommand(c ICommand) {
	commands[c.GetName()] = c
}

func GetCommand(name string) ICommand {
	return commands[name]
}

var usageTmpl = template.Must(template.New("usage").Parse(`
Commands:{{range $k, $v := .}}
     {{$v.GetName| printf "%-10s"}} {{$v.GetSummary}}{{end}}
`))

func PrintCommandUsage() {
	usageTmpl.Execute(os.Stdout, commands)
}