package hashids

import (
	"fmt"
	"os"

	"github.com/speps/go-hashids"
)

var hids *hashids.HashID

func GetHashids() *hashids.HashID {
	if hids != nil {
		return hids
	}

	hidsData := hashids.NewData()
	hidsData.Alphabet = "abcdefghijklmnopqrstuvwxyz1234567890"
	hidsData.Salt = os.Getenv("HASH_SALT")

	hidsData.MinLength = 6
	h, _ := hashids.NewWithData(hidsData)

	return h
}

func GenerateCode(id int64) string {
	numbers := make([]int, 1)
	numbers[0] = int(id)
	encoded, _ := GetHashids().Encode(numbers)
	return encoded
}

func DecodeCode(code string) (int, error) {
	decoded, err := GetHashids().DecodeWithError(code)

	if err != nil {
		return 0, err
	}
	if len(decoded) < 1 {
		return 0, fmt.Errorf("invalid code")
	}

	return decoded[0], nil
}