package svc

import (
	"fmt"
	"net"
	"strconv"
	"sync"
	"time"

	"lone-services/pkg/discovery"
	"lone-services/pkg/utils"
	"lone-services/services/order/internal/config"

	"github.com/zeromicro/go-zero/core/logx"
	"github.com/zeromicro/go-zero/zrpc"
	"gorm.io/gorm"
)

// 缓存条目
type rpcClientCacheEntry struct {
	cli      zrpc.Client
	target   string
	expireAt time.Time
}

const rpcClientCacheTTL = 30 * time.Second //缓存过期时间

var (
	rpcCacheLock sync.Mutex
	rpcCache     = make(map[string]*rpcClientCacheEntry)
)

func GetRpcClient(serviceName string) (zrpc.Client, error) {
	if serviceName == utils.StringEmpty {
		err := fmt.Errorf("rpc serviceName is empty")
		logx.Error(err)
		return nil, err
	}

	cacheKey := serviceName

	rpcCacheLock.Lock()
	entry, ok := rpcCache[cacheKey]
	if ok && time.Now().Before(entry.expireAt) {
		rpcCacheLock.Unlock()
		return entry.cli, nil
	}
	delete(rpcCache, cacheKey)
	rpcCacheLock.Unlock()

	inst, err := discovery.Pick(serviceName)
	if err != nil {
		err = fmt.Errorf("discovery pick %s failed: %w", serviceName, err)
		logx.Error(err)
		return nil, err
	}

	target := net.JoinHostPort(inst.IP, strconv.FormatUint(inst.Port, utils.NumberTen))

	cli := zrpc.MustNewClient(zrpc.RpcClientConf{
		Target:  target,
		Timeout: utils.RpcTimeOut, //rpc调用超时5s
	})

	rpcCacheLock.Lock()
	rpcCache[cacheKey] = &rpcClientCacheEntry{
		cli:      cli,
		target:   target,
		expireAt: time.Now().Add(rpcClientCacheTTL),
	}
	rpcCacheLock.Unlock()

	return cli, nil
}

type ServiceContext struct {
	Config config.Config
	DB     *gorm.DB
	Prefix string

	ProductSvcName string //服务名
}

func NewServiceContext(c config.Config, db *gorm.DB) *ServiceContext {
	//启动仅读取配置，不建立rpc连接 多个服务就多个
	productSvc := utils.GetConfigString("services.product")

	if productSvc == utils.StringEmpty {
		logx.Error("config services.product empty")
	}

	svcCtx := &ServiceContext{
		Config:         c,
		DB:             db,
		Prefix:         utils.GetConfigString("mysql.prefix"),
		ProductSvcName: productSvc,
	}

	return svcCtx
}