package gfetcd

import (
	"context"
	"fmt"
	"globalfintech/golib/tlog"
	"os"
	"strings"
	"time"

	"github.com/coreos/etcd/clientv3"
	"google.golang.org/grpc"
	"google.golang.org/grpc/grpclog"
	"google.golang.org/grpc/keepalive"
)

// 客户端配置
type ResolverConfig struct {
	BasicConfig
	WatchServers []string `toml:"watch_servers"` // 依赖的服务名称
}

type Resolver struct {
	userCfg    *ResolverConfig
	etcdCli    *clientv3.Client
	rpcServers map[string]*grpc.ClientConn
}

func NewResolver(cfg *ResolverConfig) (resolver *Resolver, err error) {

	if cfg.Debug {
		clientv3.SetLogger(grpclog.NewLoggerV2WithVerbosity(os.Stderr, os.Stderr, os.Stderr, 4))
	}

	cli, err := etcdDial(&cfg.BasicConfig)
	if err != nil {
		return nil, err
	}

	resolver = &Resolver{
		userCfg:    cfg,
		etcdCli:    cli,
		rpcServers: make(map[string]*grpc.ClientConn),
	}

	for _, serviceName := range cfg.WatchServers {

		service := ServiceKey(cfg.Prefix, serviceName)
		tlog.Debugf("ETCD RESOLVER||service: %s", service)

		//r := &etcdnaming.GRPCResolver{Client: cli} // todo: 全部更新为新版后，改为这种方式
		r := &GFgrpcResolver{Client: cli}
		b := grpc.RoundRobin(r)

		resolver.rpcServers[service], err = grpc.Dial(service, grpc.WithInsecure(),
			grpc.WithTimeout(time.Second*5),
			grpc.WithKeepaliveParams(keepalive.ClientParameters{Time: time.Duration(2) * time.Second}),
			grpc.WithBalancer(b),
			grpc.WithBlock())
		if err != nil {
			tlog.Errorf("ETCD RESOLVER||service: %s ||grpc dial err:%s", service, err)
			return nil, fmt.Errorf("grpc dial err")
		}
	}

	return resolver, nil
}

func (self *Resolver) Call(ctx context.Context, method string, args, reply interface{}, opts ...grpc.CallOption) error {
	// method format: /<serviceName>/<methodName>
	// eg. "/case_expire.CaseExpire/ExpireCase"

	t := strings.Split(method, "/")
	if len(t) < 3 {
		tlog.Errorf("ETCD RESOLVER||method name: %s incorrect format", method)
		return fmt.Errorf("invalid method format")
	}

	serviceKey := ServiceKey(self.userCfg.Prefix, t[1], "")

	tlog.Debugf("ETCD RESOLVER||Call(serviceKey: %s, method: %s)",
		serviceKey, method)

	conn, ok := self.rpcServers[serviceKey]
	if !ok {
		tlog.Errorf("ETCD RESOLVER||method: %s||no grpc client available", method)
		return fmt.Errorf("no grpc client available")
	}

	return grpc.Invoke(ctx, method, args, reply, conn, opts...)
}