package grpc_client

import (
	"context"
	"fmt"
	"git.hlsq.asia/mmorpg/service-common/log"
	"google.golang.org/grpc"
	"google.golang.org/protobuf/proto"
	"sync"
)

type GatewayFun int

const (
	FunToClient GatewayFun = iota
)

var gatewayServer sync.Map // map[string]*gatewayStream

type gatewayStream struct {
	mu     sync.Mutex
	stream grpc.ClientStream
}

func findGatewayBySID(sid int64, fun GatewayFun) (*gatewayStream, error) {
	key := gatewayKey(sid, fun)

	if v, ok := gatewayServer.Load(key); ok {
		return v.(*gatewayStream), nil
	}

	client, err := GatewayNewClient(sid)
	if err != nil {
		log.Errorf("findGatewayBySID cannot find client: %v", err)
		return nil, err
	}
	var stream grpc.ClientStream
	switch fun {
	case FunToClient:
		stream, err = client.ToClient(context.Background())
	}
	if err != nil {
		log.Errorf("findGatewayBySID %v err: %v, sid: %v", fun, err, sid)
		return nil, err
	}

	ss := &gatewayStream{stream: stream}
	if actual, loaded := gatewayServer.LoadOrStore(key, ss); loaded {
		go func() { _ = stream.CloseSend() }()
		return actual.(*gatewayStream), nil
	}

	return ss, nil
}

func SendMessageToGateway(sid int64, fun GatewayFun, msg proto.Message, re ...bool) error {
	ss, err := findGatewayBySID(sid, fun)
	if err != nil {
		return err
	}

	ss.mu.Lock()
	err = ss.stream.SendMsg(msg)
	ss.mu.Unlock()

	if err != nil {
		key := gatewayKey(sid, fun)
		if v, ok := gatewayServer.Load(key); ok && v == ss {
			gatewayServer.Delete(key)
			_ = ss.stream.CloseSend()
		}
		// 如果没有标识本次是重试的，就重试一次（默认重试）
		if re == nil || !re[0] {
			return SendMessageToGateway(sid, fun, msg, true)
		}
		return err
	}
	return nil
}

func gatewayKey(sid int64, fun GatewayFun) string {
	return fmt.Sprintf("%v-%v", sid, fun)
}