syntax = "proto3";

package messaging_pb;

import "mq_schema.proto";

option go_package = "github.com/seaweedfs/seaweedfs/weed/pb/mq_pb";
option java_package = "seaweedfs.mq";
option java_outer_classname = "MessageQueueProto";

//////////////////////////////////////////////////

service SeaweedMessaging {

    // control plane
    rpc FindBrokerLeader (FindBrokerLeaderRequest) returns (FindBrokerLeaderResponse) {
    }

    // control plane for balancer
    rpc PublisherToPubBalancer (stream PublisherToPubBalancerRequest) returns (stream PublisherToPubBalancerResponse) {
    }
    rpc BalanceTopics (BalanceTopicsRequest) returns (BalanceTopicsResponse) {
    }

    // control plane for topic partitions
    rpc ListTopics (ListTopicsRequest) returns (ListTopicsResponse) {
    }
    rpc ConfigureTopic (ConfigureTopicRequest) returns (ConfigureTopicResponse) {
    }
    rpc LookupTopicBrokers (LookupTopicBrokersRequest) returns (LookupTopicBrokersResponse) {
    }

    // invoked by the balancer, running on each broker
    rpc AssignTopicPartitions (AssignTopicPartitionsRequest) returns (AssignTopicPartitionsResponse) {
    }
    rpc ClosePublishers(ClosePublishersRequest) returns (ClosePublishersResponse) {
    }
    rpc CloseSubscribers(CloseSubscribersRequest) returns (CloseSubscribersResponse) {
    }

    // subscriber connects to broker balancer, which coordinates with the subscribers
    rpc SubscriberToSubCoordinator (stream SubscriberToSubCoordinatorRequest) returns (stream SubscriberToSubCoordinatorResponse) {
    }

    // data plane for each topic partition
    rpc PublishMessage (stream PublishMessageRequest) returns (stream PublishMessageResponse) {
    }
    rpc SubscribeMessage (stream SubscribeMessageRequest) returns (stream SubscribeMessageResponse) {
    }
    // The lead broker asks a follower broker to follow itself
    rpc PublishFollowMe (stream PublishFollowMeRequest) returns (stream PublishFollowMeResponse) {
    }
    rpc SubscribeFollowMe (stream SubscribeFollowMeRequest) returns (SubscribeFollowMeResponse) {
    }
}

//////////////////////////////////////////////////

message FindBrokerLeaderRequest {
    string filer_group = 1;
}

message FindBrokerLeaderResponse {
    string broker = 1;
}

//////////////////////////////////////////////////
message BrokerStats {
    int32 cpu_usage_percent = 1;
    map<string, TopicPartitionStats> stats = 2;
}
message TopicPartitionStats {
    schema_pb.Topic topic = 1;
    schema_pb.Partition partition = 2;
    int32 publisher_count = 3;
    int32 subscriber_count = 4;
    string follower = 5;
}


message PublisherToPubBalancerRequest {
    message InitMessage {
        string broker = 1;
    }
    oneof message {
        InitMessage init = 1;
        BrokerStats stats = 2;
    }
}
message PublisherToPubBalancerResponse {
}

message BalanceTopicsRequest {
}
message BalanceTopicsResponse {
}

//////////////////////////////////////////////////
message ConfigureTopicRequest {
    schema_pb.Topic topic = 1;
    int32 partition_count = 2;
    schema_pb.RecordType record_type = 3;
}
message ConfigureTopicResponse {
    repeated BrokerPartitionAssignment broker_partition_assignments = 2;
    schema_pb.RecordType record_type = 3;
}
message ListTopicsRequest {
}
message ListTopicsResponse {
    repeated schema_pb.Topic topics = 1;
}
message LookupTopicBrokersRequest {
    schema_pb.Topic topic = 1;
}
message LookupTopicBrokersResponse {
    schema_pb.Topic topic = 1;
    repeated BrokerPartitionAssignment broker_partition_assignments = 2;
}
message BrokerPartitionAssignment {
    schema_pb.Partition partition = 1;
    string leader_broker = 2;
    string follower_broker = 3;
}

message AssignTopicPartitionsRequest {
    schema_pb.Topic topic = 1;
    repeated BrokerPartitionAssignment broker_partition_assignments = 2;
    bool is_leader = 3;
    bool is_draining = 4;
}
message AssignTopicPartitionsResponse {
}

message SubscriberToSubCoordinatorRequest {
    message InitMessage {
        string consumer_group = 1;
        string consumer_group_instance_id = 2;
        schema_pb.Topic topic = 3;
        // The consumer group instance will be assigned at most max_partition_count partitions.
        // If the number of partitions is less than the sum of max_partition_count,
        // the consumer group instance may be assigned partitions less than max_partition_count.
        // Default is 1.
        int32 max_partition_count = 4;
        // If consumer group instance changes, wait for rebalance_seconds before reassigning partitions
        // Exception: if adding a new consumer group instance and sum of max_partition_count equals the number of partitions,
        // the rebalance will happen immediately.
        // Default is 10 seconds.
        int32 rebalance_seconds = 5;
    }
    message AckUnAssignmentMessage {
        schema_pb.Partition partition = 1;
    }
    message AckAssignmentMessage {
        schema_pb.Partition partition = 1;
    }
    oneof message {
        InitMessage init = 1;
        AckAssignmentMessage ack_assignment = 2;
        AckUnAssignmentMessage ack_un_assignment = 3;
    }
}
message SubscriberToSubCoordinatorResponse {
    message Assignment {
        BrokerPartitionAssignment partition_assignment = 1;
    }
    message UnAssignment {
        schema_pb.Partition partition = 1;
    }
    oneof message {
        Assignment assignment = 1;
        UnAssignment un_assignment = 2;
    }
}

//////////////////////////////////////////////////
message ControlMessage {
    bool is_close = 1;
    string publisher_name = 2;
}
message DataMessage {
    bytes key = 1;
    bytes value = 2;
    int64 ts_ns = 3;
    ControlMessage ctrl = 4;
}
message PublishMessageRequest {
    message InitMessage {
        schema_pb.Topic topic = 1;
        schema_pb.Partition partition = 2;
        int32 ack_interval = 3;
        string follower_broker = 4;
        string publisher_name = 5; // for debugging
    }
    oneof message {
        InitMessage init = 1;
        DataMessage data = 2;
    }
}
message PublishMessageResponse {
    int64 ack_sequence = 1;
    string error = 2;
    bool should_close = 3;
}
message PublishFollowMeRequest {
    message InitMessage {
        schema_pb.Topic topic = 1;
        schema_pb.Partition partition = 2;
    }
    message FlushMessage {
        int64 ts_ns = 1;
    }
    message CloseMessage {
    }
    oneof message {
        InitMessage init = 1;
        DataMessage data = 2;
        FlushMessage flush = 3;
        CloseMessage close = 4;
    }
}
message PublishFollowMeResponse {
    int64 ack_ts_ns = 1;
}
message SubscribeMessageRequest {
    message InitMessage {
        string consumer_group = 1;
        string consumer_id = 2;
        string client_id = 3;
        schema_pb.Topic topic = 4;
        schema_pb.PartitionOffset partition_offset = 5;
        string filter = 6;
        string follower_broker = 7;
        int32 sliding_window_size = 8;
    }
    message AckMessage {
        int64 sequence = 1;
        bytes key = 2;
    }
    oneof message {
        InitMessage init = 1;
        AckMessage ack = 2;
    }
}
message SubscribeMessageResponse {
    message SubscribeCtrlMessage {
        string error = 1;
        bool is_end_of_stream = 2;
        bool is_end_of_topic = 3;
    }
    oneof message {
        SubscribeCtrlMessage ctrl = 1;
        DataMessage data = 2;
    }
}
message SubscribeFollowMeRequest {
    message InitMessage {
        schema_pb.Topic topic = 1;
        schema_pb.Partition partition = 2;
        string consumer_group = 3;
    }
    message AckMessage {
        int64 ts_ns = 1;
    }
    message CloseMessage {
    }
    oneof message {
        InitMessage init = 1;
        AckMessage ack = 2;
        CloseMessage close = 3;
    }
}
message SubscribeFollowMeResponse {
    int64 ack_ts_ns = 1;
}
message ClosePublishersRequest {
    schema_pb.Topic topic = 1;
    int64 unix_time_ns = 2;
}
message ClosePublishersResponse {
}
message CloseSubscribersRequest {
    schema_pb.Topic topic = 1;
    int64 unix_time_ns = 2;
}
message CloseSubscribersResponse {
}