package agent_client

import (
	"context"
	"fmt"
	"github.com/seaweedfs/seaweedfs/weed/mq/topic"
	"github.com/seaweedfs/seaweedfs/weed/pb"
	"github.com/seaweedfs/seaweedfs/weed/pb/mq_agent_pb"
	"github.com/seaweedfs/seaweedfs/weed/pb/schema_pb"
	"google.golang.org/grpc"
)

type SubscribeOption struct {
	ConsumerGroup           string
	ConsumerGroupInstanceId string
	Topic                   topic.Topic
	Filter                  string
	MaxSubscribedPartitions int32
	PerPartitionConcurrency int32
}

type SubscribeSession struct {
	Option    *SubscribeOption
	stream    grpc.BidiStreamingClient[mq_agent_pb.SubscribeRecordRequest, mq_agent_pb.SubscribeRecordResponse]
	sessionId int64
}

func NewSubscribeSession(agentAddress string, option *SubscribeOption) (*SubscribeSession, error) {
	// call local agent grpc server to create a new session
	clientConn, err := pb.GrpcDial(context.Background(), agentAddress, true, grpc.WithInsecure())
	if err != nil {
		return nil, fmt.Errorf("dial agent server %s: %v", agentAddress, err)
	}
	agentClient := mq_agent_pb.NewSeaweedMessagingAgentClient(clientConn)

	resp, err := agentClient.StartSubscribeSession(context.Background(), &mq_agent_pb.StartSubscribeSessionRequest{
		ConsumerGroup:           option.ConsumerGroup,
		ConsumerGroupInstanceId: option.ConsumerGroupInstanceId,
		Topic: &schema_pb.Topic{
			Namespace: option.Topic.Namespace,
			Name:      option.Topic.Name,
		},
		MaxSubscribedPartitions: option.MaxSubscribedPartitions,
		Filter:                  option.Filter,
	})
	if err != nil {
		return nil, err
	}
	if resp.Error != "" {
		return nil, fmt.Errorf("start subscribe session: %v", resp.Error)
	}

	stream, err := agentClient.SubscribeRecord(context.Background())
	if err != nil {
		return nil, fmt.Errorf("subscribe record: %v", err)
	}

	return &SubscribeSession{
		Option:    option,
		stream:    stream,
		sessionId: resp.SessionId,
	}, nil
}