// Copyright (c) 2025 Nikolai Papin
// 
// This file is part of Easywish
// 
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
// the GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package utils

import (
	"crypto/rand"
	"fmt"
	"io"
)

func GenerateSecure6DigitNumber() (string, error) {
	maxNumber := 1000000
	b := make([]byte, 4)

	if _, err := io.ReadFull(rand.Reader, b); err != nil {
		return "", fmt.Errorf("failed to read random bytes: %w", err)
	}

	num := int(uint32(b[0])<<24 | uint32(b[1])<<16 | uint32(b[2])<<8 | uint32(b[3])) % maxNumber

	return fmt.Sprintf("%06d", num), nil
}