package util

import (
	"encoding/hex"
	"math/rand"
	"time"

	"github.com/bwmarrin/snowflake"
)

// var passwordChars = []rune("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=_+!@#$%^&*()[]{}|;:,.<>/?")
var passwordChars = []rune("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=_+!@#$%^&*?")
func GeneratePassword(length int) string {
    rand.Seed(time.Now().UnixNano())

    b := make([]rune, length)
    for i := range b {
        b[i] = passwordChars[rand.Intn(len(passwordChars))]
    }

    code := string(b)
    return code
}

func GenerateToken() string {
    rand.Seed(time.Now().UnixNano())
    b := make([]byte, 32)
    if _, err := rand.Read(b); err != nil {
        return ""
    }
    return hex.EncodeToString(b)
}

var snowflakeNodeIndex int64 = 0
func GenerateID() string {
	node, err := snowflake.NewNode(snowflakeNodeIndex)
	if err != nil {
		panic(err)
	}
    return node.Generate().String()
}

func GetEnd(token string) string {
    if len(token) < 8 {
        return ""
    }
    return token[len(token)-8:]
}