package mixrepoimpl

import (
	"context"
	"github.com/bwmarrin/snowflake"
	"hash/fnv"
	"math"
	"os"
	"voucher/internal/biz/mixrepos"
	"voucher/internal/data"
)

type GenerateRepoImpl struct {
	rdb *data.Rdb

	node *snowflake.Node
}

func NewGenerateMixRepoImpl(rdb *data.Rdb) (mixrepos.GenerateMixRepo, error) {

	g := &GenerateRepoImpl{rdb: rdb}

	name, err := os.Hostname()
	if err != nil {
		return nil, err
	}

	serverId := g.hashMod(name)

	node, err := snowflake.NewNode(int64(serverId))
	if err != nil {
		return nil, err
	}

	g.node = node

	return g, nil
}

// hashMod hash mod
func (s *GenerateRepoImpl) hashMod(hashStr string) int {
	hash := fnv.New32a()
	_, _ = hash.Write([]byte(hashStr))

	hashValue := hash.Sum32()
	return int(math.Mod(float64(hashValue), 32))
}

// GeneratorString 生成字符串
func (s *GenerateRepoImpl) GeneratorString(_ context.Context) string {
	return s.node.Generate().String()
}

// GeneratorNumber 生成 int64
func (s *GenerateRepoImpl) GeneratorNumber(_ context.Context) int64 {
	return s.node.Generate().Int64()
}