util.go

package main

import (
	"bufio"
	"bytes"
	"errors"
	"flag"
	"fmt"
	"io/ioutil"
	"strings"

	"github.com/kballard/go-shellquote"
	"github.com/whyrusleeping/hellabot"
)

type FlagString struct {
	HasValue bool
	Value    string
}

func (fs FlagString) String() string {
	return fs.Value
}

func (fs *FlagString) Set(s string) error {
	fs.Value = s
	fs.HasValue = true
	return nil
}

func Usage(fset *flag.FlagSet) string {
	var usage bytes.Buffer
	fset.SetOutput(&usage)
	fset.Usage()
	return usage.String()
}

func ParseFlags(msg *hbot.Message, fset *flag.FlagSet) error {
	args, err := shellquote.Split(msg.Content)
	if err != nil {
		return err
	}
	if len(args) == 0 {
		args = []string{""}
	}
	fset.SetOutput(ioutil.Discard)
	if err = fset.Parse(args[1:]); err == nil {
		return nil
	}
	if err == flag.ErrHelp {
		return errors.New(Usage(fset))
	}
	return err
}

func ErrorReply(bot *hbot.Bot, msg *hbot.Message, err error) {
	MultiLineReply(bot, msg, err.Error())
}

func MultiLineReply(bot *hbot.Bot, msg *hbot.Message, s string) {
	s = strings.Replace(s, "\t", "  ", -1)
	r := strings.NewReader(s)
	ss := bufio.NewScanner(r)
	for ss.Scan() {
		bot.Reply(msg, ss.Text())
	}
}

func HasPrefix(prefix string) func(*hbot.Bot, *hbot.Message) bool {
	return func(bot *hbot.Bot, msg *hbot.Message) bool {
		return strings.HasPrefix(msg.Content, prefix)
	}
}

func HasCommand(command string) func(*hbot.Bot, *hbot.Message) bool {
	return func(bot *hbot.Bot, msg *hbot.Message) bool {
		words, err := shellquote.Split(msg.Content)
		if err != nil || len(words) == 0 {
			return false
		}
		return strings.TrimSpace(words[0]) == command
	}
}

func ReplyTo(bot *hbot.Bot, msg *hbot.Message, s string) {
	bot.Reply(msg, fmt.Sprintf("%s: %s", msg.From, s))
}