syntax = "proto3";

package threads;
option go_package = "./proto;threads";
import "google/protobuf/timestamp.proto";
import "google/protobuf/wrappers.proto";

service Threads {
	// Create a conversation
	rpc CreateConversation(CreateConversationRequest) returns (CreateConversationResponse);
	// Read a conversation using its ID, can filter using group ID if provided
	rpc ReadConversation(ReadConversationRequest) returns (ReadConversationResponse);
	// Update a conversations topic
	rpc UpdateConversation(UpdateConversationRequest) returns (UpdateConversationResponse);
	// Delete a conversation and all the messages within
	rpc DeleteConversation(DeleteConversationRequest) returns (DeleteConversationResponse);
	// List all the conversations for a group
	rpc ListConversations(ListConversationsRequest) returns (ListConversationsResponse);
	// Create a message within a conversation
	rpc CreateMessage(CreateMessageRequest) returns (CreateMessageResponse);
	// List the messages within a conversation in reverse chronological order, using sent_before to
	// offset as older messages need to be loaded
	rpc ListMessages(ListMessagesRequest) returns (ListMessagesResponse);
	// RecentMessages returns the most recent messages in a group of conversations. By default the 
	// most messages retrieved per conversation is 25, however this can be overriden using the 
	// limit_per_conversation option
	rpc RecentMessages(RecentMessagesRequest) returns (RecentMessagesResponse);
}

message Conversation {
	string id = 1;
	string group_id = 2;
	string topic = 3;
	google.protobuf.Timestamp created_at = 4;
}

message Message {
	string id = 1;
	string author_id = 2;
	string conversation_id = 3;
	string text = 4;
	google.protobuf.Timestamp sent_at = 5;
}

message CreateConversationRequest {
	string group_id = 1;
	string topic = 2;
}

message CreateConversationResponse {
	Conversation conversation = 1;
}

message ReadConversationRequest {
	string id = 1;
	google.protobuf.StringValue group_id = 2;
}

message ReadConversationResponse {
	Conversation conversation = 1;
}

message ListConversationsRequest {
	string group_id = 1;
}

message ListConversationsResponse {
	repeated Conversation conversations = 1;
}

message UpdateConversationRequest {
	string id = 1;
	string topic = 2;
}

message UpdateConversationResponse {
	Conversation conversation = 1;
}

message DeleteConversationRequest {
	string id = 1;
}

message DeleteConversationResponse {}

message CreateMessageRequest {
	string id = 1;
	string conversation_id = 2;
	string author_id = 3;
	string text = 4;
}

message CreateMessageResponse {
	Message message = 1;
}

message ListMessagesRequest {
	string conversation_id = 1;
	google.protobuf.Timestamp sent_before = 2;
	google.protobuf.Int32Value limit = 3;
}

message ListMessagesResponse {
	repeated Message messages = 1;
}

message RecentMessagesRequest {
	repeated string conversation_ids = 1;
	google.protobuf.Int32Value limit_per_conversation = 2;
}

message RecentMessagesResponse {
	repeated Message messages = 1;
}