syntax = "proto3";

package event;

option go_package = "./proto;event";
import "google/protobuf/struct.proto";

service Event {
	rpc Publish(PublishRequest) returns (PublishResponse) {}
	rpc Consume(ConsumeRequest) returns (stream ConsumeResponse) {}
	rpc Read(ReadRequest) returns (ReadResponse) {}
}

message Ev {
	// event id
	string id = 1;
	// event timestamp
	string timestamp = 2;
	// event message
	google.protobuf.Struct message = 3;
}

// Publish a event to the event stream.
message PublishRequest {
	// The topic to publish to
	string topic = 1;
	// The json message to publish
	google.protobuf.Struct message = 4;
}

message PublishResponse {}

// Consume events from a given topic.
message ConsumeRequest {
	// The topic to subscribe to
	string topic = 1;
	// Optional group for the subscription
	string group = 2;
	// Optional offset to read from e.g "2006-01-02T15:04:05.999Z07:00"
	string offset = 3;
}

// A blocking event will be returned in response.
message ConsumeResponse {
	// The topic subscribed to
	string topic = 1;
	// Unique message id
	string id = 2;
	// Timestamp of publishing
	string timestamp = 3;
	// The next json message on the topic
	google.protobuf.Struct message = 4;
}

// Read stored events
message ReadRequest {
	// topic to read from
	string topic = 1;
	// number of events to read; default 25
	int32 limit = 2;
	// offset for the events; default 0
	int32 offset = 3;
}

message ReadResponse {
	// the events
	repeated Ev events = 1;
}