package saltyim

import (
	"bytes"
	"fmt"
	"hash/fnv"
	"os"

	"github.com/logrusorgru/aurora"
	"github.com/posener/formatter"
	log "github.com/sirupsen/logrus"
	"go.yarn.social/lextwt"
)

const (
	DateTimeFormat = "2006-01-02 15:04:05"
)

func boundedInt(value, low, high uint8) uint8 {
	diff := high - low
	return (((value - low) % diff) + low)
}

func GetUserColor(user string, lower, upper uint8) uint8 {
	h := fnv.New32()
	h.Sum([]byte(user))
	return boundedInt(uint8(h.Sum32()), lower, upper)
}

// FormatMessage formats the msg for display on the terminal
func FormatMessage(msg string) string {
	s, err := lextwt.ParseSalty(msg)
	if err != nil {
		fmt.Fprintf(os.Stderr, "error parsing message %q: %s", msg, err)
		return ""
	}

	st, ok := s.(*lextwt.SaltyText)
	if !ok {
		log.Errorf("unexpected error, expected type lextwt.SaltyText got #%v", st)
		return ""
	}

	userColor := GetUserColor(st.User.String(), 16, 231)

	buf := &bytes.Buffer{}

	f := formatter.Formatter{
		Writer: buf,
		Indent: []byte(">  "),
		Width:  80,
	}

	if _, err := f.Write([]byte(st.LiteralText())); err != nil {
		fmt.Fprintf(os.Stderr, "error formatting message: %s", err)
		return ""
	}

	return fmt.Sprintf(
		"%s\t%s\n%s\n",
		aurora.Sprintf(aurora.Blue(st.Timestamp.DateTime().Local().Format(DateTimeFormat))),
		aurora.Sprintf(aurora.Index(userColor, st.User.String())),
		buf.String(),
	)
}