package redis

import (
	"context"
	"fmt"
	"hash/fnv"
	"net/url"
	"strconv"
	"strings"

	"git.apinb.com/bsm-sdk/core/vars"
	cacheRedis "github.com/redis/go-redis/v9"
)

const (
	Nil = cacheRedis.Nil
)

// RedisClient .
type RedisClient struct {
	DB     int
	Client *cacheRedis.Client
	Ctx    context.Context
	memory map[string]any
}

func New(dsn string, hashRadix string) *RedisClient {
	client, err := NewWithContext(context.Background(), dsn, hashRadix)
	if err != nil {
		panic(err)
	}
	return client
}

func NewWithContext(ctx context.Context, dsn string, hashRadix string) (*RedisClient, error) {
	if ctx == nil {
		ctx = context.Background()
	}

	arg, err := url.Parse(dsn)
	if err != nil {
		return nil, fmt.Errorf("parse redis dsn: %w", err)
	}
	pwd, _ := arg.User.Password()

	//get db number,default:0
	var db int = 0
	arg.Path = strings.ReplaceAll(arg.Path, "/", "")
	if arg.Path == "" {
		db = Hash(hashRadix)
	} else {
		db, err = strconv.Atoi(arg.Path)
		if err != nil {
			return nil, fmt.Errorf("parse redis db index: %w", err)
		}
	}

	//connect redis server
	client := cacheRedis.NewClient(&cacheRedis.Options{
		Addr:     arg.Host,
		Password: pwd, // no password set
		DB:       db,  // use default DB
		Protocol: 3,
	})
	_, err = client.Ping(ctx).Result()
	if err != nil {
		_ = client.Close()
		return nil, fmt.Errorf("ping redis: %w", err)
	}

	return &RedisClient{
		DB:     db,
		Client: client,
		Ctx:    ctx,
		memory: make(map[string]any),
	}, nil
}

func Hash(s string) int {
	if vars.RedisShardings <= 0 {
		return 0
	}

	h := fnv.New32a()
	_, _ = h.Write([]byte(strings.ToLower(s)))
	return int(h.Sum32()) % vars.RedisShardings
}