package handler

import (
	"crypto/rand"
	"crypto/sha256"
	"encoding/hex"
	"fmt"
	"io"
	"time"
)

const charset = "abcdefghijklmnopqrstuvwxyz0123456789"

func generateId() (string, error) {
	bytes := make([]byte, 10)
	if _, err := io.ReadFull(rand.Reader, bytes); err != nil {
		return "", err
	}

	for i := range bytes {
		bytes[i] = charset[bytes[i]%byte(len(charset))]
	}
	return string(bytes), nil
}

func TimeAgo(t time.Time) string {
	ago := time.Since(t)
	seconds := int(ago.Seconds())

	switch {
	case seconds < 60:
		return fmt.Sprintf("%ds ago", seconds)
	case seconds < 3600:
		return fmt.Sprintf("%dm ago", seconds/60)
	case seconds < 86400:
		return fmt.Sprintf("%dh ago", seconds/3600)
	default:
		return fmt.Sprintf("%dd ago", seconds/86400)
	}
}

func hash(content string) string {
	h := sha256.New()
	h.Write([]byte(content))
	return hex.EncodeToString(h.Sum(nil))
}